Change search
Refine search result
1 - 40 of 40
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Bahl, Aileen
    et al.
    Pöllänen, Eija
    Ismail, Khadeeja
    Sipilä, Sarianna
    Mikkola, Tuija M
    Berglund, Eva C
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Lindqvist, Carl Mårten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Syvänen, Ann-Christine
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Rantanen, Taina
    Kaprio, Jaakko
    Kovanen, Vuokko
    Ollikainen, Miina
    Hormone Replacement Therapy Associated White Blood Cell DNA Methylation and Gene Expression are Associated With Within-Pair Differences of Body Adiposity and Bone Mass2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 6, p. 647-661Article in journal (Refereed)
    Abstract [en]

    The loss of estrogen during menopause causes changes in the female body, with wide-ranging effects on health. Estrogen-containing hormone replacement therapy (HRT) leads to a relief of typical menopausal symptoms, benefits bone and muscle health, and is associated with tissue-specific gene expression profiles. As gene expression is controlled by epigenetic factors (including DNA methylation), many of which are environmentally sensitive, it is plausible that at least part of the HRT-associated gene expression is due to changes in DNA methylation profile. We investigated genome-wide DNA methylation and gene expression patterns of white blood cells (WBCs) and their associations with body composition, including muscle and bone measures of monozygotic (MZ) female twin pairs discordant for HRT. We identified 7,855 nominally significant differentially methylated regions (DMRs) associated with 4,044 genes. Of the genes with DMRs, five (ACBA1, CCL5, FASLG, PPP2R2B, and UHRF1) were also differentially expressed. All have been previously associated with HRT or estrogenic regulation, but not with HRT-associated DNA methylation. All five genes were associated with bone mineral content (BMC), and ABCA1, FASLG, and UHRF1 were also associated with body adiposity. Our study is the first to show that HRT associates with genome-wide DNA methylation alterations in WBCs. Moreover, we show that five differentially expressed genes with DMRs associate with clinical measures, including body fat percentage, lean body mass, bone mass, and blood lipids. Our results indicate that at least part of the known beneficial HRT effects on body composition and bone mass may be regulated by DNA methylation associated alterations in gene expression in circulating WBCs.

  • 2.
    Baker, Laura
    et al.
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Tuvblad, Catherine
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Wang, Pan
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Gomez, Karina
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Bezdjian, Serena
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Niv, Sharon
    Department of Psychology (SGM 501), University of Southern California, Los Angeles, United States.
    Raine, Adrian
    Departments of Criminology and Psychiatry, University of Pennsylvania, Philadelphia PA, United States .
    The southern california twin register at the University of Southern California: III2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 1, p. 336-343Article in journal (Refereed)
  • 3.
    Bladh, Marie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Carstensen, John
    Linköping University, Department of Medical and Health Sciences, Health and Society. Linköping University, Faculty of Health Sciences.
    Josefsson, Ann
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Finnström, Orvar
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center of Paediatrics and Gynaecology and Obstetrics, Department of Paediatrics in Linköping.
    Sydsjö, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Obstetrics and gynecology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Hospitalization in Adolescence and Young Adulthood Among Twins and Singletons: A Swedish Cohort Study of Subjects Born Between 1973 and 19832013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 3, p. 707-715Article in journal (Refereed)
    Abstract [en]

    Children born with non-optimal birth characteristics — that is, are small for gestational age and/or preterm — have an increased risk for several long-term effects such as neurological sequelae and chronic disease. The purpose of this study was to examine whether twins exhibited a different outcome, compared with singletons, in terms of hospitalization during adolescence and early adulthood, and to what extent differences remain when considering the divergence in birth characteristics between singletons and twins. Persons born between 1973 and 1983 in Sweden and surviving until age 13 were included and followed until the end of 2006. Data on birth characteristics, parental socio-demographic factors, and hospitalizations were collected from national registers. Adjusting for parental socio-demographic factors, twins had a higher risk of being hospitalized than singletons (odds ratio, OR = 1.17, 95% confidence interval, CI = 1.10–1.25) and more often due to ‘Congenital anomalies’ (OR = 1.18, 95% CI = 1.06–1.28), ‘Infections’ (OR = 1.14; 95% CI = 1.08–1.20), ‘External causes of illness’ (OR = 1.10, 95% CI = 1.06–1.15), and ‘Diseases of the nervous system’ (OR = 1.18, 95% CI = 1.10–1.26). Stratifying for birth characteristics, this difference diminishes, and for some diagnoses non-optimal twins seem to do slightly better than non-optimal singletons. Thus, twins with non-optimal birth characteristics had a lower risk of hospitalization than non-optimal singletons on, for example, ‘Congenital anomalies’ and ‘Diseases of the nervous system’ (OR = 0.86, 95% CI = 0.77–0.96; OR = 0.88, 95% CI = 0.81–0.97, respectively) and Total (any) hospitalization (OR = 0.87, 95% CI = 0.83–0.92). Among those with optimal birth characteristics, twins had an increased hospitalization due to ‘External causes of illness’ (OR = 1.07, 95% CI = 1.02–1.13) compared with optimal singletons. Twins have higher hospitalization rates than singletons. In stratifying for birth characteristics, this difference diminishes, and for some diagnoses, non-optimal twins seem to do less poorly than non-optimal singletons.

  • 4.
    Bladh, Marie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Josefsson, Ann
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Carstensen, John
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Medicine and Health Sciences.
    Finnström, Orvar
    Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Paediatrics in Linköping. Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Sydsjö, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Intergenerational cohort study of preterm and small-for-gestational-age birth in twins and singletons2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 5, p. 581-590Article in journal (Refereed)
    Abstract [en]

    To date several studies have investigated the intergenerational effect of preterm and small-for-gestational-age births. However, most studies excluded both twin mothers and twin offspring from the analyses. Thus, the objective of this study was to investigate the intergenerational effect of preterm birth and small for gestational age (SGA) among twins and singletons.

    A prospective population based register study of mother-first-born offspring pairs recorded in the Swedish Medical Birth Register was performed. The study included 4073 twins and 264,794 singletons born in 1973-1983 and their firstborns born in 1986-2009. Preterm birth was defined as birth <37 weeks of gestation and SGA as < 2 standard deviations of the Swedish standard. Logistic regressions were performed to estimate the intergenerational effect of each birth characteristic. Adjustments were made for maternal grandmothers and mother’s socio-demographic factors in addition to maternal birth- characteristics.

    Among mothers born as singletons, being born preterm was associated with an increased risk for delivering a preterm child (adjusted OR 1.39, 95% CI 1.29-1.50) while being born SGA increased the likelihood of a SGA child (adjusted OR 3.04, 95% CI 2.80-3.30) as well as a preterm child (adjusted OR 1.30, 95% CI 1.20-1.40). In twin mothers, the corresponding ORs tended to be lower and the only statistically significant association was between a SGA mother and a SGA child (adjusted OR 2.15, 95% CI 1.40-3.31). A statistically significant interaction between twinning and mother’s size for gestational was identified in a multivariate linear regression analysis indicating that singleton mothers born SGA were associated with a lower birth weight compared to mothers not born SGA.

    Preterm birth and SGA appear to be transferred from one generation to the next, although not always reaching statistical significance. These effects seem to be less evident in mothers born as twins compared with those born as singletons.

  • 5.
    Catalano, Ralph A.
    et al.
    Univ Calif Berkeley, Sch Publ Hlth, 50 Univ Hall, Berkeley, CA 94720 USA..
    Saxton, Katherine B.
    Santa Clara Univ, Dept Biol, Santa Clara, CA USA..
    Gemmill, Alison
    Univ Calif Berkeley, Dept Demog, Berkeley, CA 94720 USA..
    Hartig, Terry
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Institute for Housing and Urban Research.
    Twinning in Norway Following the Oslo Massacre: Evidence of a "Bruce Effect' in Humans2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 5, p. 485-491Article in journal (Refereed)
    Abstract [en]

    Emerging theory and empirical work suggest that the Bruce Effect', or the increase in spontaneous abortion observed in non-human species when environments become threatening to offspring survival, may also appear in humans. We argue that, if it does, the effect would appear in the odds of twins among male and female live births. We test the hypothesis, implied by our argument, that the odds of a twin among male infants in Norway fell below, while those among females rose above, expected levels among birth cohorts in gestation in July 2011 when a deranged man murdered 77 Norwegians, including many youths. Results support the hypothesis and imply that the Bruce Effect operates in women to autonomically raise the standard of fetal fitness necessary to extend the gestation of twins. This circumstance has implications for using twins to estimate the relative contributions of genes and environment to human responses to exogenous stimuli.

  • 6.
    Davis, Deborah W
    et al.
    Department of Pediatrics,University of Louisville School of Medicine,Louisville, KY,USA..
    Turkheimer, Eric
    Department of Psychology,University of Virginia,Charlottesville, VA,USA..
    Finkel, Deborah
    Department of Psychology, School of Social Sciences,Indiana University Southeast,New Albany, IN,USA..
    Beam, Christopher
    Department of Psychology, Dornsife College,University of Southern California,Los Angeles, CA,USA..
    Ryan, Lesa
    Department of Pediatrics,University of Louisville School of Medicine,Louisville, KY,USA..
    The Louisville Twin Study: Past, Present and Future.2019In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, p. 1-6Article in journal (Refereed)
    Abstract [en]

    The Louisville Twin Study (LTS) is nationally recognized as one of the largest and most comprehensive studies of child development related to multiple birth status. The LTS is unique because of the extensive longitudinal face-to-face assessments, the frequency of data collection, the inclusion of data on additional family members (i.e., parents, siblings, grandparents; and later, twins' own spouses and children), and the variety of data collection methods used. Data preservation efforts began in 2008 and are largely complete, although efforts are ongoing to obtain funding to convert the electronic data to a newer format. A pilot study was completed in the summer of 2018 to bring the twins, who are now middle-aged, back for testing. A grant is currently under review to extend the pilot study to include all former participants who are now ≥40 years of age. Opportunities for collaboration are welcome.

  • 7.
    Dominicus, Annica
    et al.
    Stockholm University, Faculty of Science, Department of Mathematics.
    Palmgren, Juni
    Stockholm University, Faculty of Science, Department of Mathematics.
    Pedersen, Nancy L.
    Bias in variance components due to nonresponse in twin studies2006In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 9, no 2, p. 185-193Article in journal (Refereed)
    Abstract [en]

    Incomplete data on trait values may bias estimates of genetic and environmental variance components obtained from twin analyses. If the nonresponse mechanism is 'ignorable' then methods such as full information maximum likelihood estimation will produce consistent variance component estimates. If, however, nonresponse is 'nonignorable', then the situation is more complicated. We demonstrate that a within-pair correlation of nonresponse, possibly different for monozygotic (MZ) and dizygotic (DZ) twins, may well be compatible with 'ignorability'. By means of Monte Carlo simulation, we assess the potential bias in variance component estimates for different types of nonresponse mechanisms. The simulation results guide the interpretation of analyses of data on perceptual speed from the Swedish Adoption/Twin Study of Aging. The results suggest that the dramatic decrease in genetic influences on perceptual speed observed after 13 years of follow-up is not attributable solely to dropout from the study, and thus support the hypothesis that genetic influences on some cognitive abilities decrease with age in late life.

  • 8.
    Gustafsson, Per A
    et al.
    Department of Clinical and Experimental Medicine, Child and Adolescent Psychiatry, Linköping University, Linköping, Sweden.
    Gustafsson, Per E
    Department of Public Health and Clinical Medicine, Family Medicine, Umeå University, Umeå, Sweden.
    Anckarsäter, Henrik
    Department of Neuroscience and Physiology, Forensic Psychiatry, Gothenburg University, Gothenburg, Sweden.
    Lichtenstein, Paul
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Ljung, Therese
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Nelson, Nina
    Department of Clinical and Experimental Medicine, Department of Pediatrics, Linköping University, Linköping, Sweden.
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Heritability of cortisol regulation in children2011In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 14, no 6, p. 553-561Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The normal development of cortisol regulation during childhood is thought to be influenced by a complex interplay between environmental and genetic factors.

    METHOD: The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in a sample of 151 twin pairs aged 9-16 years. Salivary cortisol was collected on two consecutive days when the children attended school--immediately after awakening, 30 min post-awakening and at bedtime.

    RESULTS: Heritability was highest (60%) for cortisol levels about 30 min after awakening. For samples taken immediately at awakening heritability was less pronounced (28%) and in the evening low (8%).

    CONCLUSION: The limited genetic influence on evening levels, moderate on cortisol at awakening and high on awakening response, might imply two genetic regulation patterns, one specifically for awakening response and one for the circadian rhythm proper. These findings could explain divergent results in previous studies and highlight the importance of taking the circadian rhythm into account in studies of cortisol levels in children.

  • 9. Gustafsson, Per A.
    et al.
    Gustafsson, Per E
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Anckarsäter, Henrik
    Lichtenstein, Paul
    Ljung, Therese
    Nelson, Nina
    Larsson, Henrik
    Heritability of the cortisol regulation in children2011In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 14, no 6, p. 553-561Article in journal (Refereed)
    Abstract [en]

    Background: The normal development of cortisol regulation during childhood is thought to be influenced by a complex interplay between environmental and genetic factors. Method: The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in a sample of 151 twin pairs aged 9-16 years. Salivary cortisol was collected on two consecutive days when the children attended school immediately after awakening, 30 min post-awakening and at bedtime. Results: Heritability was highest (60%) for cortisol levels about 30 min after awakening. For samples taken immediately at awakening heritability was less pronounced (28%) and in the evening low (8%). Conclusion: The limited genetic influence on evening levels, moderate on cortisol at awakening and high on awakening response, might imply two genetic regulation patterns, one specifically for awakening response and one for the circadian rhythm proper. These findings could explain divergent results in previous studies and highlight the importance of taking the circadian rhythm into account in studies of cortisol levels in children.

  • 10.
    Gustafsson, Per
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Child and Adolescent Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Child and Adolescent Psychiatry.
    Gustafsson, Per E
    Umeå University.
    Anckarsater, Henrik
    Gothenburg University.
    Lichtenstein, Paul
    Karolinska Institute.
    Ljung, Therese
    Karolinska Institute.
    Nelson, Nina
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Larsson, Henrik
    Karolinska Institute.
    Heritability of Cortisol Regulation in Children2011In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 14, no 6, p. 553-561Article in journal (Refereed)
    Abstract [en]

    Background: The normal development of cortisol regulation during childhood is thought to be influenced by a complex interplay between environmental and genetic factors. Method: The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in a sample of 151 twin pairs aged 9-16 years. Salivary cortisol was collected on two consecutive days when the children attended school immediately after awakening, 30 min post-awakening and at bedtime. Results: Heritability was highest (60%) for cortisol levels about 30 min after awakening. For samples taken immediately at awakening heritability was less pronounced (28%) and in the evening low (8%). Conclusion: The limited genetic influence on evening levels, moderate on cortisol at awakening and high on awakening response, might imply two genetic regulation patterns, one specifically for awakening response and one for the circadian rhythm proper. These findings could explain divergent results in previous studies and highlight the importance of taking the circadian rhythm into account in studies of cortisol levels in children.

  • 11.
    Hur, Yoon-Mi
    et al.
    Department of Education, Mokpo National University, Jeonnam, South Korea.
    Bogl, Leonie H.
    Department of Public Health, University of Helsinki, Helsinki, Finland.
    Ordoñana, Juan R.
    Department of Human Anatomy and Psychobiology and Murcia Institute for Biomedical Research (IMIB-ARRIXACA), University of Murcia, Murcia, Spain.
    Taylor, Jeanette
    Department of Psychology, Florida State University, Tallahassee, FL, USA.
    Hart, Sara A.
    Department of Psychology, Florida State University, Tallahassee, FL, USA.
    Tuvblad, Catherine
    Örebro University, School of Law, Psychology and Social Work.
    Ystrom, Eivind
    PROMENTA Research Center, Department of Psychology, University of Oslo, Oslo, Norway; Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway.
    Dalgård, Christine
    Department of Public Health, Environmental Medicine, and Danish Twin Registry, University of Southern Denmark, Odense, Denmark.
    Skytthe, Axel
    Department of Public Health, and Danish Twin Registry, University of Southern Denmark, Odense, Denmark.
    Willemsen, Gonneke
    Department of Biological Psychology, Vrije Universiteit, Amsterdam, the Netherlands.
    Twin Family Registries Worldwide: An Important Resource for Scientific Research2019In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 22, no 6, p. 427-437Article in journal (Refereed)
    Abstract [en]

    Much progress has been made in twin research since our last special issue on twin registries (Hur, Y.-M., & Craig, J. M. (2013). Twin Research and Human Genetics, 16, 1-12.). This special issue provides an update on the state of twin family registries around the world. This issue includes 61 papers on twin family registries from 25 countries, of which 3 describe consortia based on collaborations of several twin family registries. The articles included in this issue discuss the establishment and maintenance of twin registries, recruitment strategies, methods of zygosity assessment, research aims and major findings from twin family cohorts, as well as other important topics related to twin studies. The papers amount to approximately 1.3 million monozygotic, dizygotic twins and higher order multiples and their family members who participate in twin studies around the world. Nine new twin family registries have been established across the world since our last issue, which demonstrates that twin registers are increasingly important in studies of the determinants and correlates of complex traits from disease susceptibility to healthy development.

  • 12.
    Jelenkovic, Aline
    et al.
    Department of Social Research, University of Helsinki, Helsinki, Finland; Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country UPV/EHU, Leioa, Spain.
    Tuvblad, Catherine
    Örebro University, School of Law, Psychology and Social Work. Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Silventoinen, Karri
    Department of Social Research, University of Helsinki, Helsinki, Finland; University Graduate School of Medicine, Osaka University, Osaka, Japan.
    Zygosity differences in height and body mass index of twins from infancy to old age: a study of the CODATwins project2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 5, p. 557-570Article in journal (Refereed)
    Abstract [en]

    A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m(2) in childhood and adolescence and up to 0.2 kg/m(2) in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.

  • 13.
    Jelenkovic, Aline
    et al.
    Univ Helsinki, Dept Social Res, FIN-00014 Helsinki, Finland.;Univ Basque Country UPV EHU, Dept Genet Phys Anthropol & Anim Physiol, Leioa, Spain..
    Yokoyama, Yoshie
    Osaka City Univ, Dept Publ Hlth Nursing, Osaka 558, Japan..
    Sund, Reijo
    Univ Helsinki, Dept Social Res, FIN-00014 Helsinki, Finland..
    Honda, Chika
    Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan..
    Bogl, Leonie H.
    Univ Helsinki, Dept Publ Hlth, FIN-00014 Helsinki, Finland..
    Aaltonen, Sari
    Univ Helsinki, Dept Social Res, FIN-00014 Helsinki, Finland.;Univ Helsinki, Dept Publ Hlth, FIN-00014 Helsinki, Finland..
    Ji, Fuling
    Qingdao Ctr Dis Control & Prevent, Dept Noncommunicable Dis Prevent, Qingdao, Peoples R China..
    Ning, Feng
    Qingdao Ctr Dis Control & Prevent, Dept Noncommunicable Dis Prevent, Qingdao, Peoples R China..
    Pang, Zengchang
    Qingdao Ctr Dis Control & Prevent, Dept Noncommunicable Dis Prevent, Qingdao, Peoples R China..
    Ordonana, Juan R.
    Univ Murcia, Dept Human Anat & Psychobiol, Murcia, Spain.;IMIB Arrixaca, Murcia, Spain..
    Sanchez-Romera, Juan F.
    IMIB Arrixaca, Murcia, Spain.;Univ Murcia, Dept Dev & Educ Psychol, Murcia, Spain..
    Colodro-Conde, Lucia
    Univ Murcia, Dept Human Anat & Psychobiol, Murcia, Spain.;QIMR Berghofer Med Res Inst, Brisbane, Qld, Australia..
    Burt, S. Alexandra
    Michigan State Univ, E Lansing, MI 48824 USA..
    Klump, Kelly L.
    Michigan State Univ, E Lansing, MI 48824 USA..
    Medland, Sarah E.
    QIMR Berghofer Med Res Inst, Brisbane, Qld, Australia..
    Montgomery, Grant W.
    QIMR Berghofer Med Res Inst, Brisbane, Qld, Australia..
    Kandler, Christian
    Univ Bielefeld, Dept Psychol, D-33615 Bielefeld, Germany..
    McAdams, Tom A.
    Kings Coll London, Inst Psychiat Psychol & Neurosci, MRC Social Genet & Dev Psychiat Ctr, London WC2R 2LS, England..
    Eley, Thalia C.
    Kings Coll London, Inst Psychiat Psychol & Neurosci, MRC Social Genet & Dev Psychiat Ctr, London WC2R 2LS, England..
    Gregory, Alice M.
    Univ London, Dept Psychol, London, England..
    Saudino, Kimberly J.
    Boston Univ, Dept Psychol & Brain Sci, Boston, MA 02215 USA..
    Dubois, Lise
    Univ Ottawa, Sch Epidemiol Publ Hlth & Prevent Med, Ottawa, ON, Canada..
    Boivin, Michel
    Univ Laval, Ecole Psychol, Quebec City, PQ, Canada.;Tomsk State Univ, Inst of Genet Neurobiol & Social Fdn Child Dev, Tomsk 634050, Russia..
    Tarnoki, Adam D.
    Semmelweis Univ, Dept Radiol & Oncotherapy, H-1085 Budapest, Hungary..
    Tarnoki, David L.
    Semmelweis Univ, Dept Radiol & Oncotherapy, H-1085 Budapest, Hungary..
    Haworth, Claire M. A.
    Univ Bristol, MRC Integrat Epidemiol Unit, Bristol, Avon, England..
    Plomin, Robert
    Kings Coll London, Inst Psychiat Psychol & Neurosci, MRC Social Genet & Dev Psychiat Ctr, London WC2R 2LS, England..
    Oncel, Sevgi Y.
    Kirikkale Univ, Fac Arts & Sci, Dept Stat, Kirikkale, Turkey..
    Aliev, Fazil
    Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Dept Psychiat, Richmond, VA USA.;Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Dept Psychol, Richmond, VA USA.;Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Dept Human & Mol Genet, Richmond, VA USA.;Karabuk Univ, Dept Actuaria & Risk Management, Karabuk, Turkey..
    Stazi, Maria A.
    Natl Ctr Epidemiol Surveillance & Hlth Promot, Ist Super Sanita, Rome, Italy..
    Fagnani, Corrado
    Natl Ctr Epidemiol Surveillance & Hlth Promot, Ist Super Sanita, Rome, Italy..
    D'Ippolito, Cristina
    Natl Ctr Epidemiol Surveillance & Hlth Promot, Ist Super Sanita, Rome, Italy..
    Craig, Jeffrey M.
    Royal Childrens Hosp, Murdoch Childerens Res Inst, Melbourne, Vic, Australia.;Univ Melbourne, Dept Paediat, Melbourne, Vic, Australia..
    Saffery, Richard
    Royal Childrens Hosp, Murdoch Childerens Res Inst, Melbourne, Vic, Australia.;Univ Melbourne, Dept Paediat, Melbourne, Vic, Australia..
    Siribaddana, Sisira H.
    Inst Res & Dev, Battaramulla, Sri Lanka.;Rajarata Univ Sri Lanka, Fac Med & Allied Sci, Saliyapura, Sri Lanka..
    Hotopf, Matthew
    South London & Maudsley NHS Fdn Trust, NIHR Mental Hlth Biomed Res Ctr, London, England.;Kings Coll London, Inst Psychiat Psychol & Neurosci, London WC2R 2LS, England..
    Sumathipala, Athula
    Inst Res & Dev, Battaramulla, Sri Lanka.;Keele Univ, Fac Hlth, Sch Primary Care Res, Res Inst Primary Care & Hlth Sci, Keele, Staffs, England..
    Rijsdijk, Fruhling
    Kings Coll London, Inst Psychiat Psychol & Neurosci, MRC Social Genet & Dev Psychiat Ctr, London WC2R 2LS, England..
    Spector, Timothy
    Kings Coll London, Dept Twin Res & Genet Epidemiol, London WC2R 2LS, England..
    Mangino, Massimo
    Kings Coll London, Dept Twin Res & Genet Epidemiol, London WC2R 2LS, England..
    Lachance, Genevieve
    Kings Coll London, Dept Twin Res & Genet Epidemiol, London WC2R 2LS, England..
    Gatz, Margaret
    Univ So Calif, Dept Psychol, Los Angeles, CA 90089 USA.;Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden..
    Butler, David A.
    Natl Acad Sci, Inst Med, Washington, DC 20418 USA..
    Bayasgalan, Gombojav
    Hlth Twin Assoc Mongolia, Ulaanbaatar, Mongol Peo Rep..
    Narandalai, Danshiitsoodol
    Hlth Twin Assoc Mongolia, Ulaanbaatar, Mongol Peo Rep.;Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Hiroshima, Japan..
    Freitas, Duarte L.
    Univ Madeira, Dept Phys Educ & Sport, Funchal, Portugal..
    Maia, Jose Antonio
    Univ Porto, Fac Sport, CIFI2D, P-4100 Oporto, Portugal..
    Harden, K. Paige
    Univ Texas Austin, Dept Psychol, Austin, TX 78712 USA..
    Tucker-Drob, Elliot M.
    Univ Texas Austin, Dept Psychol, Austin, TX 78712 USA..
    Kim, Bia
    Pusan Natl Univ, Dept Psychol, Busan, South Korea..
    Chong, Youngsook
    Hong, Changhee
    Pusan Natl Univ, Dept Psychol, Busan, South Korea..
    Shin, Hyun Jung
    Pusan Natl Univ, Dept Psychol, Busan, South Korea..
    Christensen, Kaare
    Univ Southern Denmark, Inst Publ Hlth Epidemiol Biostat & Biodemog, Danish Twin Registry, Odense, Denmark.;Odense Univ Hosp, Dept Biochem & Clin Pharmacol, DK-5000 Odense, Denmark.;Odense Univ Hosp, Dept Clin Genet, DK-5000 Odense, Denmark..
    Skytthe, Axel
    Univ Southern Denmark, Inst Publ Hlth Epidemiol Biostat & Biodemog, Danish Twin Registry, Odense, Denmark..
    Kyvik, Kirsten O.
    Univ Southern Denmark, Dept Clin Res, Odense, Denmark.;Odense Univ Hosp, Odense Patient Data Explorat Network OPEN, DK-5000 Odense, Denmark..
    Derom, Catherine A.
    Univ Hosp Leuven, Ctr Human Genet, Leuven, Belgium..
    Vlietinck, Robert F.
    Univ Hosp Leuven, Ctr Human Genet, Leuven, Belgium..
    Loos, Ruth J. F.
    Icahn Sch Med Mt Sinai, Mindich Child Hlth & Dev Inst, Charles Bronfman Inst Personalized Med, New York, NY 10029 USA..
    Cozen, Wendy
    Univ So Calif, Keck Sch Med, Dept Prevent Med, Los Angeles, CA 90033 USA.;Univ So Calif, Kenneth Norris Jr Comprehens Canc Ctr, Los Angeles, CA 90033 USA..
    Hwang, Amie E.
    Univ So Calif, Keck Sch Med, Dept Prevent Med, Los Angeles, CA 90033 USA..
    Mack, Thomas M.
    Univ So Calif, Keck Sch Med, Dept Prevent Med, Los Angeles, CA 90033 USA.;Univ So Calif, Kenneth Norris Jr Comprehens Canc Ctr, Los Angeles, CA 90033 USA..
    He, Mingguang
    Sun Yat Sen Univ, State Key Lab Ophthalmol, Zhongshan Ophthalm Ctr, Guangzhou 510275, Guangdong, Peoples R China.;Univ Melbourne, Ctr Eye Res Australia, Melbourne, Vic, Australia..
    Ding, Xiaohu
    Sun Yat Sen Univ, State Key Lab Ophthalmol, Zhongshan Ophthalm Ctr, Guangzhou 510275, Guangdong, Peoples R China..
    Chang, Billy
    Sun Yat Sen Univ, State Key Lab Ophthalmol, Zhongshan Ophthalm Ctr, Guangzhou 510275, Guangdong, Peoples R China..
    Silberg, Judy L.
    Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Dept Human & Mol Genet, Richmond, VA USA..
    Eaves, Lindon J.
    Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Dept Human & Mol Genet, Richmond, VA USA..
    Maes, Hermine H.
    Virginia Commonwealth Univ, Psychiat & Massey Canc Ctr, Dept Human & Mol Genet, Richmond, VA USA..
    Cutler, Tessa L.
    Univ Melbourne, Ctr Biostat & Epidemiol, Australian Twin Registry, Melbourne, Vic, Australia..
    Hopper, John L.
    Univ Melbourne, Ctr Biostat & Epidemiol, Australian Twin Registry, Melbourne, Vic, Australia.;Seoul Natl Univ, Sch Publ Hlth, Dept Epidemiol, Seoul, South Korea..
    Aujard, Kelly
    Univ Melbourne, Ctr Biostat & Epidemiol, Melbourne, Vic, Australia..
    Magnusson, Patrik K. E.
    Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden..
    Pedersen, Nancy L.
    Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden..
    Aslan, Anna K. Dahl
    Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology. Jönköping University, School of Health and Welfare, HHJ. Ageing - living conditions and health.
    Song, Yun-Mi
    Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Family Med, Seoul, South Korea..
    Yang, Sarah
    Seoul Natl Univ, Sch Publ Hlth, Dept Epidemiol, Seoul, South Korea.;Seoul Natl Univ, Inst Hlth & Environm, Seoul, South Korea..
    Lee, Kayoung
    Inje Univ, Coll Med, Busan Paik Hosp, Dept Family Med, Busan, South Korea..
    Baker, Laura A.
    Univ So Calif, Dept Psychol, Los Angeles, CA 90089 USA..
    Tuvblad, Catherine
    Univ So Calif, Dept Psychol, Los Angeles, CA 90089 USA.;Univ Orebro, Sch Law Psychol & Social Work, SE-70182 Orebro, Sweden..
    Bjerregaard-Andersen, Morten
    INDEPTH Network, Bandim Hlth Project, Bissau, Guinea Bissau.;Statens Serum Inst, Res Ctr Vitamines & Vaccines, DK-2300 Copenhagen, Denmark.;Odense Univ Hosp, Dept Endocrinol, DK-5000 Odense, Denmark..
    Beck-Nielsen, Henning
    Odense Univ Hosp, Dept Endocrinol, DK-5000 Odense, Denmark..
    Sodemann, Morten
    Odense Univ Hosp, Dept Infect Dis, DK-5000 Odense, Denmark..
    Heikkila, Kauko
    Univ Helsinki, Dept Publ Hlth, FIN-00014 Helsinki, Finland..
    Tan, Qihua
    Univ Southern Denmark, Inst Publ Hlth, Epidemiol Biostat & Biodemog, Odense, Denmark..
    Zhang, Dongfeng
    Qingdao Univ, Coll Med, Dept Publ Hlth, Qingdao 266071, Peoples R China..
    Swan, Gary E.
    Stanford Univ, Dept Med, Sch Med, Stanford Prevent Res Ctr, Stanford, CA 94305 USA..
    Krasnow, Ruth
    SRI Int, Ctr Hlth Sci, Menlo Pk, CA 94025 USA..
    Jang, Kerry L.
    Univ British Columbia, Dept Psychiat, Vancouver, BC, Canada..
    Knafo-Noam, Ariel
    Hebrew Univ Jerusalem, Jerusalem, Israel..
    Mankuta, David
    Hebrew Univ Jerusalem, Sch Med, Hadassah Hosp, Dept Obstet & Gynecol, IL-91010 Jerusalem, Israel..
    Abramson, Lior
    Hebrew Univ Jerusalem, Jerusalem, Israel..
    Lichtenstein, Paul
    Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden..
    Krueger, Robert F.
    Univ Minnesota, Dept Psychol, Minneapolis, MN 55455 USA..
    McGue, Matt
    Univ Minnesota, Dept Psychol, Minneapolis, MN 55455 USA..
    Pahlen, Shandell
    Univ Minnesota, Dept Psychol, Minneapolis, MN 55455 USA..
    Tynelius, Per
    Karolinska Inst, Dept Publ Hlth Sci, Stockholm, Sweden..
    Duncan, Glen E.
    Univ Washington, Ctr Clin & Epidemiol Res, Seattle, WA 98195 USA..
    Buchwald, Dedra
    Univ Washington, Ctr Clin & Epidemiol Res, Seattle, WA 98195 USA..
    Corley, Robin P.
    Univ Colorado, Inst Behav Genet, Boulder, CO 80309 USA..
    Huibregtse, Brooke M.
    Univ Colorado, Inst Behav Genet, Boulder, CO 80309 USA..
    Nelson, Tracy L.
    Colorado State Univ, Dept Hlth & Exercise Sci, Ft Collins, CO 80523 USA.;Colorado State Univ, Colorado Sch Publ Hlth, Ft Collins, CO 80523 USA..
    Whitfield, Keith E.
    Duke Univ, Psychol & Neurosci, Durham, NC USA..
    Franz, Carol E.
    Univ Calif San Diego, Dept Psychiat, San Diego, CA 92103 USA..
    Kremen, William S.
    Univ Calif San Diego, Dept Psychiat, San Diego, CA 92103 USA.;VA San Diego Ctr Excellence Stress & Mental Hlth, La Jolla, CA USA..
    Lyons, Michael J.
    Boston Univ, Dept Psychol, Boston, MA 02215 USA..
    Ooki, Syuichi
    Ishikawa Prefectural Nursing Univ, Dept Hlth Sci, Kahoku, Ishikawa, Japan..
    Brandt, Ingunn
    Norwegian Inst Publ Hlth, Div Epidemiol, Dept Genes & Environm, Oslo, Norway..
    Nilsen, Thomas Sevenius
    Norwegian Inst Publ Hlth, Div Epidemiol, Dept Genes & Environm, Oslo, Norway..
    Inui, Fujio
    Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan.;Kio Univ, Fac Hlth Sci, Nara, Japan..
    Watanabe, Mikio
    Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan..
    Bartels, Meike
    Vrije Univ Amsterdam, Dept Biol Psychol, Amsterdam, Netherlands..
    van Beijsterveldt, Toos C. E. M.
    Vrije Univ Amsterdam, Dept Biol Psychol, Amsterdam, Netherlands..
    Wardle, Jane
    UCL, Inst Epidemiol & Hlth Care, Hlth Behav Res Ctr, Dept Epidemiol & Publ Hlth, London, England..
    Llewellyn, Clare H.
    UCL, Inst Epidemiol & Hlth Care, Hlth Behav Res Ctr, Dept Epidemiol & Publ Hlth, London, England..
    Fisher, Abigail
    UCL, Inst Epidemiol & Hlth Care, Hlth Behav Res Ctr, Dept Epidemiol & Publ Hlth, London, England..
    Rebato, Esther
    Univ Basque Country UPV EHU, Dept Genet Phys Anthropol & Anim Physiol, Leioa, Spain..
    Martin, Nicholas G.
    QIMR Berghofer Med Res Inst, Brisbane, Qld, Australia..
    Iwatani, Yoshinori
    Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan..
    Hayakawa, Kazuo
    Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan..
    Sung, Joohon
    Seoul Natl Univ, Sch Publ Hlth, Dept Epidemiol, Seoul, South Korea.;Seoul Natl Univ, Inst Hlth & Environm, Seoul, South Korea..
    Harris, Jennifer R.
    Norwegian Inst Publ Hlth, Div Epidemiol, Dept Genes & Environm, Oslo, Norway..
    Willemsen, Gonneke
    Vrije Univ Amsterdam, Dept Biol Psychol, Amsterdam, Netherlands..
    Busjahn, Andreas
    HealthTwist GmbH, Berlin, Germany..
    Goldberg, Jack H.
    Univ Washington, Sch Publ Hlth, Dept Epidemiol, Seattle, WA 98195 USA..
    Rasmussen, Finn
    Karolinska Inst, Dept Publ Hlth Sci, Stockholm, Sweden..
    Hur, Yoon-Mi
    Mokpo Natl Univ, Dept Educ, Jeonnam, South Korea..
    Boomsma, Dorret I.
    Vrije Univ Amsterdam, Dept Biol Psychol, Amsterdam, Netherlands..
    Sorensen, Thorkild I. A.
    Univ Bristol, MRC Integrat Epidemiol Unit, Bristol, Avon, England.;Univ Copenhagen, Fac Med & Hlth Sci, Novo Nordisk Fdn, Ctr Basic Metab Res,Sect Metab Genet, Copenhagen, Denmark.;Bispebjerg and Frederiksberg Hosp, Inst Prevent Med, Copenhagen, Denmark..
    Kaprio, Jaakko
    Univ Helsinki, Dept Publ Hlth, FIN-00014 Helsinki, Finland.;Natl Inst Hlth & Welfare, Helsinki, Finland.;FIMM, Inst Mol Med, Helsinki, Finland..
    Silventoinen, Karri
    Univ Helsinki, Dept Social Res, FIN-00014 Helsinki, Finland.;Osaka Univ, Osaka Univ Grad Sch Med, Osaka, Japan..
    Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 5, p. 557-570Article in journal (Refereed)
    Abstract [en]

    A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m(2) in childhood and adolescence and up to 0.2 kg/m(2) in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.

  • 14. Karasek, Deborah
    et al.
    Goodman, Julia
    Gemmill, Alison
    Falconi, April
    Hartig, Terry
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Institute for Housing and Urban Research.
    Magganas, Aristotle
    Catalano, Ralph
    Twins Less Frequent Than Expected Among Male Births in Risk Averse Populations2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 3, p. 314-320Article in journal (Refereed)
    Abstract [en]

    Male twin gestations exhibit higher incidence of fetal morbidity and mortality than singleton gestations. From an evolutionary perspective, the relatively high rates of infant and child mortality among male twins born into threatening environments reduce the fitness of these gestations, making them more vulnerable to fetal loss. Women do not perceive choosing to spontaneously abort gestations although the outcome may result from estimates, made without awareness, of the risks of continuing a pregnancy. Here, we examine whether the non-conscious decisional biology of gestation can be linked to conscious risk aversion. We test this speculation by measuring the association between household surveys in Sweden that gauge financial risk aversion in the population and the frequency of twins among live male births. We used time-series regression methods to estimate our suspected associations and Box-Jenkins modeling to ensure that autocorrelation did not confound the estimation or reduce its efficiency. We found, consistent with theory, that financial risk aversion in the population correlates inversely with the odds of a twin among Swedish males born two months later. The odds of a twin among males fell by approximately 3.5% two months after unexpectedly great risk aversion in the population. This work implies that shocks that affect population risk aversion carry implications for fetal loss in vulnerable twin pregnancies.

  • 15.
    Lichtenstein, Paul
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden.
    Tuvblad, Catherine
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden.
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden.
    Carlström, Eva
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden.
    The Swedish Twin study of CHild and Adolescent Development: the TCHAD-study2007In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 10, no 1, p. 67-73Article in journal (Refereed)
    Abstract [en]

    The Swedish Twin study of CHild and Adolescent Development (TCHAD) is a longitudinal study of how genes and environments contribute to development of health and behavioral problems from childhood to adulthood. The study includes 1480 twin pairs followed since 1994, when the twins were 8 to 9 years old. The last data collection was in 2005 when the twins were 19 to 20 years old. Both parents and twins have provided data. In this article we describe the sample, data collections, and measures used. In addition, we provide some key findings from the study, focusing on antisocial behavior, criminality, and psychopathic personality.

  • 16.
    Liu, Jianghong
    et al.
    School of Nursing, University of Pennsylvania, Philadelphia PA, USA.
    Tuvblad, Catherine
    Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Li, Linda
    School of Nursing, University of Pennsylvania, Philadelphia PA, USA.
    Raine, Adrian
    Departments of Criminology, Psychiatry, and Psychology, University of Pennsylvania, Philadelphia PA, USA.
    Baker, Laura A.
    Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Medical record validation of maternal recall of pregnancy and birth events from a twin cohort2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 4, p. 845-860Article in journal (Refereed)
    Abstract [en]

    This study aims to assess the validity of maternal recall for several perinatal variables 8-10 years after pregnancy in a twin sample. Retrospective information was collected 8-10 years after the delivery event in a cohort of mothers from the University of Southern California Twin Study (N = 611) and compared with medical records for validity analysis. Recall of most variables showed substantial to perfect agreement (κ = 0.60-1.00), with notable exceptions for specific medical problems during pregnancy (κ ≤ 0.40) and substance use when mothers provided continuous data (e.g., number of cigarettes per day; r ≤ 0.24). With the exception of delivery method, neonatal intensive care unit admission, birth weight, neonatal information, and post-delivery complications were also recalled with low accuracy. For mothers of twins, maternal recall is generally a valid measure for perinatal variables 10 years after pregnancy. However, caution should be taken regarding variables such as substance use, medical problems, birth length, and post-delivery complications.

  • 17. Magnusson, Patrik K E
    et al.
    Almqvist, Catarina
    Rahman, Iffat
    Ganna, Andrea
    Viktorin, Alexander
    Walum, Hasse
    Halldner, Linda
    Lundström, Sebastian
    Ullén, Fredrik
    Långström, Niklas
    Larsson, Henrik
    Nyman, Anastasia
    Gumpert, Clara Hellner
    Råstam, Maria
    Anckarsäter, Henrik
    Cnattingius, Sven
    Johannesson, Magnus
    Ingelsson, Erik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.
    Klareskog, Lars
    de Faire, Ulf
    Pedersen, Nancy L
    Lichtenstein, Paul
    The Swedish Twin Registry: establishment of a biobank and other recent developments2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 1, p. 317-329Article in journal (Refereed)
    Abstract [en]

    The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.

  • 18.
    Magnusson, Patrik K. E.
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Almqvist, Catarina
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Women's and Children's Health and Astrid Lindgren Children's Hospital, Stockholm, Sweden.
    Rahman, Iffat
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Ganna, Andrea
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Viktorin, Alexander
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Walum, Hasse
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Halldner, Linda
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Center of Neurodevelopmental Disorders (KIND), Karolinska Institutet, Stockholm, Sweden.
    Lundström, Sebastian
    CELAM (Center for Ethics, Law and Mental Health), University of Gothenburg, Gothenburg, Sweden; R&D Unit, Swedish Prison and Probation Service, Norrköping, Sweden; Gillberg Neuropsychiatry Centre, Institution of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
    Ullén, Fredrik
    Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Långström, Niklas
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; R&D Unit, Swedish Prison and Probation Service, Norrköping, Sweden.
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Nyman, Anastasia
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Gumpert, Clara Hellner
    Centre for Psychiatry Research & Education, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Råstam, Maria
    Department of Clinical Sciences, Lund University, Lund, Sweden.
    Anckarsäter, Henrik
    CELAM (Center for Ethics, Law and Mental Health), University of Gothenburg, Gothenburg, Sweden.
    Cnattingius, Sven
    Unit of Clinical Epidemiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
    Johannesson, Magnus
    Department of Economics, Stockholm School of Economics, Stockholm, Sweden.
    Ingelsson, Erik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Klareskog, Lars
    Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden.
    de Faire, Ulf
    Division of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Pedersen, Nancy L.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Lichtenstein, Paul
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    The Swedish Twin Registry: establishment of a biobank and other recent developments2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 1, p. 317-329Article in journal (Refereed)
    Abstract [en]

    The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.

  • 19.
    Magnusson, Patrik K. E.
    et al.
    Karolinska Inst, Dept Med Epidemiol & Biostat, Box 281, S-17177 Stockholm, Sweden..
    Lee, Donghwan
    Ewha Womans Univ, Dept Stat, Seoul, South Korea..
    Chen, Xu
    Karolinska Inst, Dept Med Epidemiol & Biostat, Box 281, S-17177 Stockholm, Sweden..
    Szatkiewicz, Jin
    Univ N Carolina, Dept Genet, Chapel Hill, NC USA..
    Pramana, Setia
    Inst Stat, Jakarta, Indonesia..
    Teo, Shumei
    Karolinska Inst, Dept Med Epidemiol & Biostat, Box 281, S-17177 Stockholm, Sweden..
    Sullivan, Patrick F.
    Karolinska Inst, Dept Med Epidemiol & Biostat, Box 281, S-17177 Stockholm, Sweden.;Univ N Carolina, Dept Genet, Chapel Hill, NC USA..
    Feuk, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medicinsk genetik och genomik. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Pawitan, Yudi
    Karolinska Inst, Dept Med Epidemiol & Biostat, Box 281, S-17177 Stockholm, Sweden..
    One CNV Discordance in NRXN1 Observed Upon Genome-wide Screening in 38 Pairs of Adult Healthy Monozygotic Twins2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 2, p. 97-103Article in journal (Refereed)
    Abstract [en]

    Monozygotic (MZ) twins stem from the same single fertilized egg and therefore share all their inherited genetic variation. This is one of the unequivocal facts on which genetic epidemiology and twin studies are based. To what extent this also implies that MZ twins share genotypes in adult tissues is not precisely established, but a common pragmatic assumption is that MZ twins are 100% genetically identical also in adult tissues. During the past decade, this view has been challenged by several reports, with observations of differences in post-zygotic copy number variations (CNVs) between members of the same MZ pair. In this study, we performed a systematic search for differences of CNVs within 38 adult MZ pairs who had been misclassified as dizygotic (DZ) twins by questionnaire-based assessment. Initial scoring by PennCNV suggested a total of 967 CNV discor dances. The within-pair correlation in number of CNVs detected was strongly dependent on confidence score filtering and reached a plateau of r = 0.8 when restricting to CNVs detected with confidence score larger than 50. The top-ranked discordances were subsequently selected for validation by quantitative polymerase chain reaction (qPCR), from which one single similar to 120kb deletion in NRXN1 on chromosome 2 (bp 51017111-51136802) was validated. Despite involving an exon, no sign of cognitive/mental consequences was apparent in the affected twin pair, potentially reflecting limited or lack of expression of the transcripts containing this exon in nerve/brain.

  • 20. Mather, Lisa
    et al.
    Blom, Victoria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Sport Psychology research group.
    Bergström, Gunnar
    Svedberg, Pia
    An Underlying Common Factor, Influenced by Genetics and Unique Environment, Explains the Covariation Between Major Depressive Disorder, Generalized Anxiety Disorder, and Burnout: A Swedish Twin Study.2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 6, p. 619-627Article in journal (Refereed)
    Abstract [en]

    Depression and anxiety are highly comorbid due to shared genetic risk factors, but less is known about whether burnout shares these risk factors. We aimed to examine whether the covariation between major depressive disorder (MDD), generalized anxiety disorder (GAD), and burnout is explained by common genetic and/or environmental factors. This cross-sectional study included 25,378 Swedish twins responding to a survey in 2005-2006. Structural equation models were used to analyze whether the trait variances and covariances were due to additive genetics, non-additive genetics, shared environment, and unique environment. Univariate analyses tested sex limitation models and multivariate analysis tested Cholesky, independent pathway, and common pathway models. The phenotypic correlations were 0.71 (0.69-0.74) between MDD and GAD, 0.58 (0.56-0.60) between MDD and burnout, and 0.53 (0.50-0.56) between GAD and burnout. Heritabilities were 45% for MDD, 49% for GAD, and 38% for burnout; no statistically significant sex differences were found. A common pathway model was chosen as the final model. The common factor was influenced by genetics (58%) and unique environment (42%), and explained 77% of the variation in MDD, 69% in GAD, and 44% in burnout. GAD and burnout had additive genetic factors unique to the phenotypes (11% each), while MDD did not. Unique environment explained 23% of the variability in MDD, 20% in GAD, and 45% in burnout. In conclusion, the covariation was explained by an underlying common factor, largely influenced by genetics. Burnout was to a large degree influenced by unique environmental factors not shared with MDD and GAD.

  • 21. Mather, Lisa
    et al.
    Blom, Victoria
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Work and organizational psychology. The Swedish School of Sport and Health Sciences, Sweden; Karolinska Institutet, Sweden.
    Bergström, Gunnar
    Svedberg, Pia
    An Underlying Common Factor, Influenced by Genetics and Unique Environment, Explains the Covariation Between Major Depressive Disorder, Generalized Anxiety Disorder, and Burnout: A Swedish Twin Study2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 6, p. 619-627Article in journal (Refereed)
    Abstract [en]

    Depression and anxiety are highly comorbid due to shared genetic risk factors, but less is known about whether burnout shares these risk factors. We aimed to examine whether the covariation between major depressive disorder (MDD), generalized anxiety disorder (GAD), and burnout is explained by common genetic and/or environmental factors. This cross-sectional study included 25,378 Swedish twins responding to a survey in 2005-2006. Structural equation models were used to analyze whether the trait variances and covariances were due to additive genetics, non-additive genetics, shared environment, and unique environment. Univariate analyses tested sex limitation models and multivariate analysis tested Cholesky, independent pathway, and common pathway models. The phenotypic correlations were 0.71 (0.69-0.74) between MDD and GAD, 0.58 (0.56-0.60) between MDD and burnout, and 0.53 (0.50-0.56) between GAD and burnout. Heritabilities were 45% for MDD, 49% for GAD, and 38% for burnout; no statistically significant sex differences were found. A common pathway model was chosen as the final model. The common factor was influenced by genetics (58%) and unique environment (42%), and explained 77% of the variation in MDD, 69% in GAD, and 44% in burnout. GAD and burnout had additive genetic factors unique to the phenotypes (11% each), while MDD did not. Unique environment explained 23% of the variability in MDD, 20% in GAD, and 45% in burnout. In conclusion, the covariation was explained by an underlying common factor, largely influenced by genetics. Burnout was to a large degree influenced by unique environmental factors not shared with MDD and GAD.

  • 22.
    Mather, Lisa
    et al.
    Karolinska Insitutet.
    Gunnar, Bergström
    Karolinska Insitutet.
    Blom, Victoria
    Karolinska Insitutet.
    Pia, Svedberg
    Karolinska Institutet.
    The covariation between burnout and sick leave due to mental disorders is explained by a shared genetic liability: A prospective Swedish twin study with a five year follow-up.2014In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 17, no 6, p. 535-544Article in journal (Refereed)
    Abstract [en]

    Background: This study aims to assess whether the associations between burnout and sick leave due to stress-related mental disorders, other mental disorders, and somatic conditions are influenced by familial (genetic and shared environmental) factors. Methods: In this prospective cohort study, 23,611 Swedish twins born between 1959 and 1985, who answered a web-based questionnaire, including the Pines Burnout Measure 2004–2006, were included. Registry data on sick leave spells from the response date until December 31, 2010 were obtained from the Swedish Social Insurance Agency. Logistic regression analysis was performed to assess odds ratios with 95% confidence intervals for the association between burnout and sick leave for the whole sample, while conditional logistic regression of the same-sex discordant twin pairs was used to estimate the association between burnout and sick leave, adjusting for familial confounding. The Bivariate Cholesky models were used to assess whether the covariation between burnout and sick leave was explained by common genetic and/or shared environmental factors. Results: Burnout was a risk factor for sick leave due to stress-related and other mental disorders, and these associations were explained by familial factors. The phenotypic correlation between burnout and sick leave due to somatic conditions was 0.07 and the association was not influenced by familial factors. The phenotypic correlations between burnout and sick leave due to stress-related (0.26) and other mental disorders (0.30) were completely explained by common genetic factors. Conclusions: The association between burnout and sick leave due to stress-related and other mental disorders seems to be a reflection of a shared genetic liability.

  • 23.
    Oskarsson, Sven
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Government.
    Dawes, Christopher
    Johannesson, Magnus
    Magnusson, Patrik K. E.
    The Genetic Origins of the Relationship between Psychological Traits and Social Trust2012In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 15, no 1, p. 21-33Article in journal (Refereed)
    Abstract [en]

    Recent studies have shown that trusting attitudes and behavior are biologically influenced. Focusing on the classic trust game, it has been demonstrated that oxytocin increases trust and that humans are endowed with genetic variation that influences their behavior in the game. Moreover, several studies have shown that a large share of the variation in survey responses to trust items is accounted for by an additive genetic component. Against this backdrop, this article makes two important contributions. First, utilizing a unique sample of more than 2,000 complete Swedish twin pairs, we provide further evidence of the heritability of social trust. Our estimates of the additive genetic component in social trust were consistent across the sexes - .33 for males and .39 for females - and are similar to the results reported in earlier studies. Secondly, we show that social trust is phenotypically related to three psychological traits - extraversion, personal control, and intelligence - and that genetic factors account for most of these correlations. Jointly, these psychological factors share around 30% of the genetic influence on social trust both for males and females. Future studies should further explore the possible causal pathways between genes and trust using panel data on both psychological traits and social trust.

  • 24. Ousdal, Olga Therese
    et al.
    Anand Brown, Andrew
    Jensen, Jimmy
    Oslo University Hospital, Oslo, Norway & University of Oslo, Oslo, Norway & Charité Universitätsmedizin, Berlin, Germany.
    Nakstad, Per H
    Melle, Ingrid
    Agartz, Ingrid
    Djurovic, Srdjan
    Bogdan, Ryan
    Hariri, Ahmad R
    Andreassen, Ole A
    Associations between variants near a monoaminergic pathways gene (PHOX2B) and amygdala reactivity: a genome-wide functional imaging study.2012In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 15, no 3, p. 273-285Article in journal (Refereed)
    Abstract [en]

    As the amygdala is part of the phylogenetic old brain, and its anatomical and functional properties are conserved across species, it is reasonable to assume genetic influence on its activity. A large corpus of candidate gene studies indicate that individual differences in amygdala activity may be caused by genetic variants within monoaminergic signaling pathways such as dopamine, serotonin, and norepinephrine. However, to our knowledge, the use of genome-wide data to discover genetic variants underlying individual differences in adult amygdala activity is novel. In the present study, the combination of genome-wide data and functional imaging phenotypes from an emotional faces task yielded a significant association between rs10014254 and the amygdala using a region of interest approach. This single nucleotide polymorphism is located in a regulatory region upstream of the Paired-like homeobox 2b (PHOX2B) gene; therefore it could affect the expression of this gene. PHOX2B regulates the expression of enzymes necessary for the synthesis of several monoamines and is essential for the development of the autonomic nervous system. However, an attempt to replicate the finding in an independent sample from North America did not succeed. The synthesis of functional magnetic resonance imaging (fMRI) and genome-wide data takes a hypothesis-free approach as to which genetic variants are of interest. Therefore, we believe that an undirected finding within such a plausible region is of interest, and that our results add further support to the hypothesis that monoaminergic signaling pathways play a central role in regulating amygdala activity.

  • 25.
    Pedersen, Nancy L.
    et al.
    Karolinska Institutet.
    Christensen, Kaare
    The Danish Twin Registry, University of Southern Denmark, Institute of Public Health, Epidemiology, Denmark .
    Dahl, Anna
    Jönköping University, School of Health and Welfare, HHJ. Ageing - living conditions and health. Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology.
    Finkel, Deborah
    Department of Psychology, Indiana University Southeast, New Albany, IN, USA .
    Franz, Carol E.
    Department of Psychiatry, University of California – San Diego, La Jolla, CA, USA .
    Gatz, Margaret
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Horwitz, Briana N.
    Department of Psychology, Penn State University, University Park, PA, USA.
    Johansson, Boo
    Department of Psychology, University of Gothenburg, Gothenburg, Sweden.
    Johnson, Wendy
    Department of Psychology and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK .
    Kremen, William S.
    Department of Psychiatry, University of California – San Diego, La Jolla, CA, USA.
    Lyons, Michael J.
    Department of Psychology, Boston University, Boston, MA, USA.
    Malmberg, Bo
    Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology. Jönköping University, School of Health and Welfare, HHJ. Ageing - living conditions and health.
    McGue, Matt
    Department of Psychology, University of Minnesota, Minneapolis, MN, USA.
    Neiderhiser, Jenae
    Department of Psychology, Penn State University, University Park, PA, USA .
    Petersen, Inge
    The Danish Twin Registry, University of Southern Denmark, Institute of Public Health, Epidemiology, Odense C, Denmark.
    Reynolds, Chandra A.
    Department of Psychology, University of California – Riverside, Riverside, CA, USA.
    IGEMS: The Consortium on Interplay of Genes and Environment Across Multiple Studies2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 1, p. 481-489Article in journal (Refereed)
    Abstract [en]

    The Interplay of Genes and Environment across Multiple Studies (IGEMS) group is a consortium of eight longitudinal twin studies established to explore the nature of social context effects and gene-environment interplay in late-life functioning. The resulting analysis of the combined data from over 17,500 participants aged 25–102 at baseline (including nearly 2,600 monogygotic and 4,300 dizygotic twin pairs and over 1,700 family members) aims to understand why early life adversity, and social factors such as isolation and loneliness, are associated with diverse outcomes including mortality, physical functioning (health, functional ability), and psychological functioning (well-being, cognition), particularly in later life.

  • 26.
    Pedersen, Nancy L.
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Gatz, Margaret
    Center for Economic and Social Research, University of Southern California, Los Angeles, CA, United States.
    Finch, Brian K
    Center for Economic and Social Research, University of Southern California, Los Angeles, CA, United States.
    Finkel, Deborah
    Department of Psychology, Indiana University Southeast, New Albany, IN, United States.
    Butler, David A.
    Office of Military and Veterans Health, Health and Medicine Division, National Academies of Sciences, Engineering, and Medicine, Washington, DC, United States.
    Dahl Aslan, Anna K.
    Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology. Jönköping University, School of Health and Welfare, HHJ. ARN-J (Aging Research Network - Jönköping).
    Franz, Carol E.
    Department of Psychiatry, University of California San Diego, San diego, CA, United States.
    Kaprio, Jaakko
    Department of Public Health,Faculty of Medicine, Institute for Molecular Medicine FIMM, HiLIFE, University of Helsinki, Helsinki, Finland.
    Lapham, Susan
    Research and Evaluation, American Institutes for Research, Washington, DC, United States.
    McGue, Matt
    Department of Psychology, University of Minnesota, Minneapolis, MN, United States.
    Mosing, Miriam A.
    Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Neiderhiser, Jenae
    Department of Psychology, Penn State University, University Park, PA, United States.
    Nygaard, Marianne
    Danish Twin Registry, University of Southern Denmark, Odense C, Denmark.
    Panizzon, Matthew
    Department of Psychiatry, University of California San Diego, San diego, CA, United States.
    Prescott, Carol A.
    Department of Psychology, University of Southern California, Los Angeles, CA, United States.
    Reynolds, Chandra A.
    Department of Psychology, University of California-Riverside, Riverside, CA, United States.
    Sachdev, Perminder
    Centre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, NSW, Australia.
    Whitfield, Keith E.
    Department of Psychology, Wayne State University, Detroit, MI, United States.
    IGEMS: The Consortium on Interplay of Genes and Environment Across Multiple Studies - An Update2019In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 22, no 6, p. 809-816Article in journal (Refereed)
    Abstract [en]

    The Interplay of Genes and Environment across Multiple Studies (IGEMS) is a consortium of 18 twin studies from 5 different countries (Sweden, Denmark, Finland, United States, and Australia) established to explore the nature of gene-environment (GE) interplay in functioning across the adult lifespan. Fifteen of the studies are longitudinal, with follow-up as long as 59 years after baseline. The combined data from over 76,000 participants aged 14-103 at intake (including over 10,000 monozygotic and over 17,000 dizygotic twin pairs) support two primary research emphases: (1) investigation of models of GE interplay of early life adversity, and social factors at micro and macro environmental levels and with diverse outcomes, including mortality, physical functioning and psychological functioning; and (2) improved understanding of risk and protective factors for dementia by incorporating unmeasured and measured genetic factors with a wide range of exposures measured in young adulthood, midlife and later life.

  • 27. Reynolds, Chandra A
    et al.
    Gatz, Margret
    Berg, Stig
    Jönköping University, School of Health Science, HHJ, Institute of Gerontology. Jönköping University, School of Health Science, HHJ. Ageing - living conditions and health.
    Pedersen, Nancy L
    Genotype-environment interactions: Cognitive aging and social factors2007In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 10, no 2, p. 241-254Article in journal (Refereed)
  • 28.
    Scheers Andersson, Elina
    et al.
    Karolinska Institutet.
    Silventoinen, Karri
    Department of Social Research, Helsinki, Finland.
    Tynelius, Per
    Karolinska Institutet.
    Nohr, Ellen A
    University of Southern Denmark, Odense, Denmark.
    Sørensen, Thorkild I A
    University of Copenhagen, Copenhagen, Denmark / Bispebjerg and Frederiksberg Hospital, Copenhagen, The Capital Region, Denmark / Bristol University, Bristol, UK.
    Rasmussen, Finn
    Karolinska Institutet.
    Heritability of gestational weight gain--a Swedish register-based twin study2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 4, p. 410-8Article in journal (Refereed)
    Abstract [en]

    Gestational weight gain (GWG) is a complex trait involving intrauterine environmental, maternal environmental, and genetic factors. However, the extent to which these factors contribute to the total variation in GWG is unclear. We therefore examined the genetic and environmental influences on the variation in GWG in the first and second pregnancy in monozygotic (MZ) and dizygotic (DZ) twin mother-pairs. Further, we explored if any co-variance existed between factors influencing the variation in GWG of the mothers’ first and second pregnancies. By using Swedish nationwide record-linkage data, we identified 694 twin mother-pairs with complete data on their first pregnancy and 465 twin mother-pairs with complete data on their second pregnancy during 1982–2010. For a subanalysis, 143 twin mother-pairs had complete data on two consecutive pregnancies during the study period. We used structural equation modeling (SEM) to assess the contribution of genetic, shared, and unique environmental factors to the variation in GWG. A bivariate Cholesky decomposition model was used for the subanalysis. We found that genetic factors explained 43% (95% CI: 36–51%) of the variation in GWG in the first pregnancy and 26% (95% CI: 16–36%) in the second pregnancy. The remaining variance was explained by unique environmental factors. Both overlapping and distinct genetic and unique environmental factors influenced GWG in the first and the second pregnancy. This study showed that GWG has a moderate heritability, suggesting that a large part of the variation in the trait can be explained by unique environmental factors.

  • 29.
    Scheers Andersson, Elina
    et al.
    Karolinska Institutet.
    Silventoinen, Karri
    University of Helsinki, Helsinki, Finland.
    Tynelius, Per
    Karolinska Institutet / Stockholm County Council.
    Nohr, Ellen A
    University of Southern Denmark, Odense, Denmark.
    Sørensen, Thorkild I A
    University of Copenhagen, Copenhagen, Denmark / Bispebjerg and Frederiksberg Hospital, Copenhagen, The Capital Region, Denmark / Bristol University, Bristol, UK.
    Rasmussen, Finn
    Karolinska Institutet / Stockholm County Council.
    Total and Trimester-Specific Gestational Weight Gain and Offspring Birth and Early Childhood Weight: A Prospective Cohort Study on Monozygotic Twin Mothers and Their Offspring2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 4, p. 367-76Article in journal (Refereed)
    Abstract [en]

    Gestational weight gain (GWG) has in numerous studies been associated with offspring birth weight (BW) and childhood weight. However, these associations might be explained by genetic confounding as offspring inherit their mother's genetic potential to gain weight. Furthermore, little is known about whether particular periods of pregnancy could influence offspring body weight differently. We therefore aimed to explore total and trimester-specific effects of GWG in monozygotic (MZ) twin mother-pairs on their offspring's BW, weight at 1 year and body mass index (BMI) at 5 and 10 years. MZ twin mothers born 1962-1975 were identified in national Swedish registers, and data on exposure and outcome variables was collected from medical records. We analyzed associations within and between twin pairs. We had complete data on the mothers' GWG and offspring BW for 82 pairs. The results indicated that total, and possibly also second and third trimester GWG were associated with offspring BW within the twin pairs in the fully adjusted model (β = 0.08 z-score units, 95% CI: 0.001, 0.17; β = 1.32 z-score units, 95% CI: -0.29, 2.95; and β = 1.02 z-score units, 95% CI: -0.50, 2.54, respectively). Our findings, although statistically weak, suggested no associations between GWG and offspring weight or BMI during infancy or childhood. Our study suggests that total, and possibly also second and third trimester, GWG are associated with offspring BW when taking shared genetic and environmental factors within twin pairs into account. Larger family-based studies with long follow-up are needed to confirm our findings.

  • 30.
    Sillanpää, Elina
    et al.
    Gerontology Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
    Niskala, Paula
    Gerontology Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
    Laakkonen, Eija K.
    Gerontology Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
    Ponsot, Elodie
    Örebro University, School of Health Sciences.
    Alén, Markku
    Department of Medical Rehabilitation, Oulu University Hospital, Oulu, Finland.
    Kaprio, Jaakko
    Department of Public Health, University of Helsinki, Helsinki, Finland.
    Kadi, Fawzi
    Örebro University, School of Health Sciences.
    Kovanen, Vuokko
    Gerontology Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
    Sipilä, Sarianna
    Gerontology Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
    Leukocyte and Skeletal Muscle Telomere Length and Body Composition in Monozygotic Twin Pairs Discordant for Long-term Hormone Replacement Therapy2017In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 20, no 2, p. 119-131Article in journal (Refereed)
    Abstract [en]

    Estrogen-based hormone replacement therapy (HRT) may be associated with deceleration of cellular aging. We investigated whether long-term HRT has effects on leukocyte (LTL) or mean and minimum skeletal muscle telomere length (SMTL) in a design that controls for genotype and childhood environment. Associations between telomeres, body composition, and physical performance were also examined. Eleven monozygotic twin pairs (age 57.6 ± 1.8 years) discordant for HRT were studied. Mean duration of HRT use was 7.3 ± 3.7 years in the user sister, while their co-twins had never used HRT. LTL was measured by qPCR and SMTLs by southern blot. Body and muscle composition were estimated by bioimpedance and computed tomography, respectively. Physical performance was measured by jumping height and grip strength. HRT users and non-users did not differ in LTL or mean or minimum SMTL. Within-pair correlations were high in LTL (r = 0.69, p = .020) and in mean (r = 0.74, p = .014) and minimum SMTL (r = 0.88, p = .001). Body composition and performance were better in users than non-users. In analyses of individuals, LTL was associated with BMI (r 2 = 0.30, p = .030), percentage total body (r 2 = 0.43, p = .014), and thigh (r 2 = 0.55, p = .004) fat, while minimum SMTL was associated with fat-free mass (r 2 = 0.27, p = .020) and thigh muscle area (r 2 = 0.42, p = .016). We found no associations between HRT use and telomere length. Longer LTLs were associated with lower total and regional fat, while longer minimum SMTLs were associated with higher fat-free mass and greater thigh muscle area. This suggests that telomeres measured from different tissues may have different associations with measures of body composition.

  • 31. Silventoinen, K.
    et al.
    Jelenkovic, A.
    Yokoyama, Y.
    Sund, R.
    Sugawara, M.
    Tanaka, M.
    Matsumoto, S.
    Bogl, L. H.
    Freitas, D. L.
    Maia, J. A.
    Hjelmborg, J. V. B.
    Aaltonen, S.
    Piirtola, M.
    Latvala, A.
    Calais-Ferreira, L.
    Oliveira, V. C.
    Ferreira, P. H.
    Ji, F.
    Ning, F.
    Pang, Z.
    Ordoñana, J. R.
    Sánchez-Romera, J. F.
    Colodro-Conde, L.
    Burt, S. A.
    Klump, K. L.
    Martin, N. G.
    Medland, S. E.
    Montgomery, G. W.
    Kandler, C.
    McAdams, T. A.
    Eley, T. C.
    Gregory, A. M.
    Saudino, K. J.
    Dubois, L.
    Boivin, M.
    Brendgen, M.
    Dionne, G.
    Vitaro, F.
    Tarnoki, A. D.
    Tarnoki, D. L.
    Haworth, C. M. A.
    Plomin, R.
    Öncel, S.Y.
    Aliev, F.
    Medda, E.
    Nisticò, L.
    Toccaceli, V.
    Craig, J. M.
    Saffery, R.
    Siribaddana, S. H.
    Hotopf, M.
    Sumathipala, A.
    Rijsdijk, F.
    Jeong, H. -U
    Spector, T.
    Mangino, M.
    Lachance, G.
    Gatz, M.
    Butler, D. A.
    Gao, W.
    Yu, C.
    Li, L.
    Bayasgalan, G.
    Narandalai, D.
    Harden, K. P.
    Tucker-Drob, E. M.
    Christensen, K.
    Skytthe, A.
    Kyvik, K. O.
    Derom, C. A.
    Vlietinck, R. F.
    Loos, R. J. F.
    Cozen, W.
    Hwang, A. E.
    Mack, T. M.
    He, M.
    Ding, X.
    Silberg, J. L.
    Maes, H. H.
    Cutler, T. L.
    Hopper, J. L.
    Magnusson, P. K. E.
    Pedersen, N. L.
    Dahl Aslan, Anna K.
    Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology. Jönköping University, School of Health and Welfare, HHJ. ARN-J (Aging Research Network - Jönköping).
    Baker, L. A.
    Tuvblad, C.
    Bjerregaard-Andersen, M.
    Beck-Nielsen, H.
    Sodemann, M.
    Ullemar, V.
    Almqvist, C.
    Tan, Q.
    Zhang, D.
    Swan, G. E.
    Krasnow, R.
    Jang, K. L.
    Knafo-Noam, A.
    Mankuta, D.
    Abramson, L.
    Lichtenstein, P.
    Krueger, R. F.
    McGue, M.
    Pahlen, S.
    Tynelius, P.
    Rasmussen, F.
    Duncan, G. E.
    Buchwald, D.
    Corley, R. P.
    Huibregtse, B. M.
    Nelson, T. L.
    Whitfield, K. E.
    Franz, C. E.
    Kremen, W. S.
    Lyons, M. J.
    Ooki, S.
    Brandt, I.
    Nilsen, T. S.
    Harris, J. R.
    Sung, J.
    Park, H. A.
    Lee, J.
    Lee, S. J.
    Willemsen, G.
    Bartels, M.
    Van Beijsterveldt, C. E. M.
    Llewellyn, C. H.
    Fisher, A.
    Rebato, E.
    Busjahn, A.
    Tomizawa, R.
    Inui, F.
    Watanabe, M.
    Honda, C.
    Sakai, N.
    Hur, Y. -M
    Sorensen, T. I. A.
    Boomsma, D. I.
    Kaprio, J.
    The CODATwins Project: The current status and recent findings of COllaborative Project of Development of Anthropometrical Measures in Twins2019In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 22, no 6, p. 800-808Article in journal (Refereed)
    Abstract [en]

    The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural-geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status. 

  • 32.
    Silventoinen, K.
    et al.
    Department of Social Research, Department University of Helsinki, Helsinki, Finland; Center for Twin Research, Osaka University Graduate School of Medicine, Osaka, Japan.
    Tuvblad, Catherine
    Örebro University, School of Law, Psychology and Social Work. Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Kaprio, J.
    Department of Public Health, University of Helsinki, Helsinki, Finland; Institute for Molecular Medicine Finland FIMM, Helsinki, Finland.
    The CODATwins Project: The Current Status and Recent Findings of COllaborative Project of Development of Anthropometrical Measures in Twins2019In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 22, no 6, p. 800-808, article id PII S1832427419000355Article in journal (Refereed)
    Abstract [en]

    The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m(2)) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural-geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.

  • 33. Silventoinen, Karri
    et al.
    Jelenkovic, Aline
    Latvala, Antti
    Sund, Reijo
    Yokoyama, Yoshie
    Ullemar, Vilhelmina
    Almqvist, Catarina
    Derom, Catherine A.
    Vlietinck, Robert F.
    Loos, Ruth J. F.
    Kandler, Christian
    Honda, Chika
    Inui, Fujio
    Iwatani, Yoshinori
    Watanabe, Mikio
    Rebato, Esther
    Stazi, Maria A.
    Fagnani, Corrado
    Brescianini, Sonia
    Hur, Yoon-Mi
    Jeong, Hoe-Uk
    Cutler, Tessa L.
    Hopper, John L.
    Busjahn, Andreas
    Saudino, Kimberly J.
    Ji, Fuling
    Ning, Feng
    Pang, Zengchang
    Rose, Richard J.
    Koskenvuo, Markku
    Heikkilae, Kauko
    Cozen, Wendy
    Hwang, Amie E.
    Mack, Thomas M.
    Siribaddana, Sisira H.
    Hotopf, Matthew
    Sumathipala, Athula
    Rijsdijk, Fruhling
    Sung, Joohon
    Kim, Jina
    Lee, Jooyeon
    Lee, Sooji
    Nelson, Tracy L.
    Whitfield, Keith E.
    Tan, Qihua
    Zhang, Dongfeng
    Llewellyn, Clare H.
    Fisher, Abigail
    Burt, S. Alexandra
    Klump, Kelly L.
    Knafo-Noam, Ariel
    Mankuta, David
    Abramson, Lior
    Medland, Sarah E.
    Martin, Nicholas G.
    Montgomery, Grant W.
    Magnusson, Patrik K. E.
    Pedersen, Nancy L.
    Dahl Aslan, Anna K.
    Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology. Jönköping University, School of Health and Welfare, HHJ. ARN-J (Aging Research Network - Jönköping).
    Corley, Robin P.
    Huibregtse, Brooke M.
    OEncel, Sevgi Y.
    Aliev, Fazil
    Krueger, Robert F.
    Mcgue, Matt
    Pahlen, Shandell
    Willemsen, Gonneke
    Bartels, Meike
    Van Beijsterveldt, Catharina E. M.
    Silberg, Judy L.
    Eaves, Lindon J.
    Maes, Hermine H.
    Harris, Jennifer R.
    Brandt, Ingunn
    Nilsen, Thomas S.
    Rasmussen, Finn
    Tynelius, Per
    Baker, Laura A.
    Tuvblad, Catherine
    Ordonana, Juan R.
    Sanchez-Romera, Juan F.
    Colodro-Conde, Lucia
    Gatz, Margaret
    Butler, David A.
    Lichtenstein, Paul
    Goldberg, Jack H.
    Harden, K. Paige
    Tucker-Drob, Elliot M.
    Duncan, Glen E.
    Buchwald, Dedra
    Tarnoki, Adam D.
    Tarnoki, David L.
    Franz, Carol E.
    Kremen, William S.
    Lyons, Michael J.
    Maia, Jose A.
    Freitas, Duarte L.
    Turkheimer, Eric
    Sorensen, Thorkild I. A.
    Boomsma, Dorret I.
    Kaprio, Jaakko
    Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts2017In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 20, no 5, p. 395-405Article in journal (Refereed)
    Abstract [en]

    Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990-1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

  • 34. Silventoinen, Karri
    et al.
    Jelenkovic, Aline
    Sund, Reijo
    Honda, Chika
    Aaltonen, Sari
    Yokoyama, Yoshie
    Tarnoki, Adam D
    Tarnoki, David L
    Ning, Feng
    Ji, Fuling
    Pang, Zengchang
    Ordoñana, Juan R
    Sánchez-Romera, Juan F
    Colodro-Conde, Lucia
    Burt, S Alexandra
    Klump, Kelly L
    Medland, Sarah E
    Montgomery, Grant W
    Kandler, Christian
    McAdams, Tom A
    Eley, Thalia C
    Gregory, Alice M
    Saudino, Kimberly J
    Dubois, Lise
    Boivin, Michel
    Haworth, Claire M A
    Plomin, Robert
    Öncel, Sevgi Y
    Aliev, Fazil
    Stazi, Maria A
    Fagnani, Corrado
    D'Ippolito, Cristina
    Craig, Jeffrey M
    Saffery, Richard
    Siribaddana, Sisira H
    Hotopf, Matthew
    Sumathipala, Athula
    Spector, Timothy
    Mangino, Massimo
    Lachance, Genevieve
    Gatz, Margaret
    Butler, David A
    Bayasgalan, Gombojav
    Narandalai, Danshiitsoodol
    Freitas, Duarte L
    Maia, José Antonio
    Harden, K Paige
    Tucker-Drob, Elliot M
    Christensen, Kaare
    Skytthe, Axel
    Kyvik, Kirsten O
    Hong, Changhee
    Chong, Youngsook
    Derom, Catherine A
    Vlietinck, Robert F
    Loos, Ruth J F
    Cozen, Wendy
    Hwang, Amie E
    Mack, Thomas M
    He, Mingguang
    Ding, Xiaohu
    Chang, Billy
    Silberg, Judy L
    Eaves, Lindon J
    Maes, Hermine H
    Cutler, Tessa L
    Hopper, John L
    Aujard, Kelly
    Magnusson, Patrik K E
    Pedersen, Nancy L
    Dahl Aslan, Anna K
    Jönköping University, School of Health and Welfare, HHJ. Ageing - living conditions and health. Jönköping University, School of Health and Welfare, HHJ, Institute of Gerontology.
    Song, Yun-Mi
    Yang, Sarah
    Lee, Kayoung
    Baker, Laura A
    Tuvblad, Catherine
    Bjerregaard-Andersen, Morten
    Beck-Nielsen, Henning
    Sodemann, Morten
    Heikkilä, Kauko
    Tan, Qihua
    Zhang, Dongfeng
    Swan, Gary E
    Krasnow, Ruth
    Jang, Kerry L
    Knafo-Noam, Ariel
    Mankuta, David
    Abramson, Lior
    Lichtenstein, Paul
    Krueger, Robert F
    McGue, Matt
    Pahlen, Shandell
    Tynelius, Per
    Duncan, Glen E
    Buchwald, Dedra
    Corley, Robin P
    Huibregtse, Brooke M
    Nelson, Tracy L
    Whitfield, Keith E
    Franz, Carol E
    Kremen, William S
    Lyons, Michael J
    Ooki, Syuichi
    Brandt, Ingunn
    Nilsen, Thomas Sevenius
    Inui, Fujio
    Watanabe, Mikio
    Bartels, Meike
    van Beijsterveldt, Toos C E M
    Wardle, Jane
    Llewellyn, Clare H
    Fisher, Abigail
    Rebato, Esther
    Martin, Nicholas G
    Iwatani, Yoshinori
    Hayakawa, Kazuo
    Rasmussen, Finn
    Sung, Joohon
    Harris, Jennifer R
    Willemsen, Gonneke
    Busjahn, Andreas
    Goldberg, Jack H
    Boomsma, Dorret I
    Hur, Yoon-Mi
    Sørensen, Thorkild I A
    Kaprio, Jaakko
    The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 4Article in journal (Refereed)
    Abstract [en]

    For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.

  • 35.
    Silventoinen, Karri
    et al.
    Department of Social Research, University of Helsinki, Helsinki, Finland; Osaka University Graduate School of Medicine, Osaka University, Osaka, Japan.
    Tuvblad, Catherine
    Örebro University, School of Law, Psychology and Social Work. Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Kaprio, Jaakko
    Institute for Molecular Medicine FIMM, Helsinki, Finland; Department of Public Health, University of Helsinki, Helsinki, Finland.
    Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts2017In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 20, no 5, p. 395-405Article in journal (Refereed)
    Abstract [en]

    Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990-1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

  • 36.
    Silventoinen, Karri
    et al.
    Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finland; Graduate School of Medicine, Osaka University, Osaka, Japan.
    Tuvblad, Catherine
    Örebro University, School of Law, Psychology and Social Work. Department of Psychology, University of Southern California, Los Angeles CA, USA.
    Kaprio, Jaako
    Department of Public Health, University of Helsinki, Helsinki, Helsinki, Finland; National Institute for Health and Welfare, Helsinki, Finland; Institute for Molecular Medicine FIMM, Helsinki, Finland.
    The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits2015In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 18, no 4, p. 348-360Article in journal (Refereed)
    Abstract [en]

    For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m(2)) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.

  • 37. Surakka, Ida
    et al.
    Whitfield, John B
    Perola, Markus
    Visscher, Peter M
    Montgomery, Grant W
    Falchi, Mario
    Willemsen, Gonneke
    de Geus, Eco J C
    Magnusson, Patrik K E
    Christensen, Kaare
    Sørensen, Thorkild I A
    Pietiläinen, Kirsi H
    Rantanen, Taina
    Silander, Kaisa
    Widén, Elisabeth
    Muilu, Juha
    Rahman, Iffat
    Liljedahl, Ulrika
    Syvänen, Ann-Christine
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine.
    Palotie, Aarno
    Kaprio, Jaakko
    Kyvik, Kirsten O
    Pedersen, Nancy L
    Boomsma, Dorret I
    Spector, Tim
    Martin, Nicholas G
    Ripatti, Samuli
    Peltonen, Leena
    A Genome-Wide Association Study of Monozygotic Twin-Pairs Suggests a Locus Related to Variability of Serum High-Density Lipoprotein Cholesterol2012In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 15, no 6, p. 691-699Article in journal (Refereed)
    Abstract [en]

    Genome-wide association analysis on monozygotic twin-pairs offers a route to discovery of gene-environment interactions through testing for variability loci associated with sensitivity to individual environment/lifestyle. We present a genome-wide scan of loci associated with intra-pair differences in serum lipid and apolipoprotein levels. We report data for 1,720 monozygotic female twin-pairs from GenomEUtwin project with 2.5 million SNPs, imputed or genotyped, and measured serum lipid fractions for both twins. We found one locus associated with intra-pair differences in high-density lipoprotein cholesterol, rs2483058 in an intron of SRGAP2, where twins carrying the C allele are more sensitive to environmental factors (P = 3.98 × 10-8). We followed up the association in further genotyped monozygotic twins (N = 1,261), which showed a moderate association for the variant (P = 0.200, same direction of an effect). In addition, we report a new association on the level of apolipoprotein A-II (P = 4.03 × 10-8).

  • 38. Svedberg, Pia
    et al.
    Johansson, Saga
    Wallander, Mari-Ann
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Family Medicine and Clinical Epidemiology.
    Pedersen, Nancy L.
    No evidence of sex differences in heritability of irritable bowel syndrome in Swedish twins.2008In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 11, no 2, p. 197-203Article in journal (Refereed)
    Abstract [en]

    Studies have shown that familial aggregation is of importance for abdominal symptoms including irritable bowel syndrome and there are a few reports of a moderate heritability for irritable bowel syndrome. Sex differences in prevalence and incidence of irritable bowel syndrome have been demonstrated however less is known about sex differences in heritability. The objective was to investigate whether there were sex differences in heritability of irritable bowel syndrome while accounting for different prevalences among women and men in different age groups. A sample of 45,750 Swedish twins, whereof 16,961 were complete twin pairs, participated in a telephone interview. The sample was divided into three age groups (40-54, 55-64 and 65 years and older) and the diagnosis of irritable bowel syndrome was operationally defined with a number of disorder specific symptoms. Standard biometrical model fitting analyses were conducted using raw ordinal data from same-sex and opposite-sex twins. The prevalence of irritable bowel syndrome was greater among women than men and more prevalent at younger ages (e.g., women 10.3%, men 6.3% at ages 40-54 years vs. women 6.1%, men 4% at ages over 65 years). The heritability of the disorder was approximately 25% in all age groups. We found no evidence for sex differences in heritability in any of the age groups, however, models allowing prevalences of irritable bowel syndrome to differ between sexes and age groups fitted best.

  • 39. Verweij, Karin J. H.
    et al.
    Mosing, Miriam A.
    Ullén, Fredrik
    Madison, Guy
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Individual differences in personality masculinity-femininity: examining the effects of genes, environment, and prenatal hormone transfer2016In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 19, no 2, p. 87-96Article in journal (Refereed)
    Abstract [en]

    Males and females score differently on some personality traits, but the underlying etiology of these differences is not well understood. This study examined genetic, environmental, and prenatal hormonal influences on individual differences in personality masculinity-femininity (M-F). We used Big-Five personality inventory data of 9,520 Swedish twins (aged 27 to 54) to create a bipolar M-F personality scale. Using biometrical twin modeling, we estimated the influence of genetic and environmental factors on individual differences in a M-F personality score. Furthermore, we tested whether prenatal hormone transfer may influence individuals' M-F scores by comparing the scores of twins with a same-sex versus those with an opposite-sex co-twin. On average, males scored 1.09 standard deviations higher than females on the created M-F scale. Around a third of the variation in M-F personality score was attributable to genetic factors, while family environmental factors had no influence. Males and females from opposite-sex pairs scored significantly more masculine (both approximately 0.1 SD) than those from same-sex pairs. In conclusion, genetic influences explain part of the individual differences in personality M-F, and hormone transfer from the male to the female twin during pregnancy may increase the level of masculinization in females. Additional well-powered studies are needed to clarify this association and determine the underlying mechanisms in both sexes.

  • 40.
    Walum, Hasse
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Westberg, Lars
    Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Lichtenstein, Paul
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Magnusson, Patrik K. E.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Sex differences in jealousy: a population-based twin study in Sweden2013In: Twin Research and Human Genetics, ISSN 1832-4274, E-ISSN 1839-2628, Vol. 16, no 5, p. 941-946Article in journal (Refereed)
    Abstract [en]

    According to the theory of evolved sex differences in jealousy, the challenge for women to ensure paternal investment increased their jealousy response to emotional infidelity, whereas paternal uncertainty exerted selective pressures that shaped men to become more distressed by sexual infidelity. Several studies have investigated whether the effect of these sexually dimorphic selection pressures can be detected in contemporary human populations, with conflicting results. To date, no genetically informed studies of sex differences in jealousy have been conducted. We used data from the Screening Across the Lifespan of Twins Younger (SALTY) sample, containing information concerning self-rated jealousy from 3,197 complete twin pairs collected by the Swedish Twin Registry. Intra-class correlations and structural equation models were used to assess the genetic influence on jealousy and to investigate sex differences at genetic level. We saw a highly significant sex effect on the relationship between infidelity types, indicating that men, relative to women, reported greater jealousy in response to sexual infidelity than in response to emotional infidelity. The twin models revealed significant heritabilities for both sexual (32%) and emotional (26%) jealousy. The heritabilities were of a similar magnitude in both sexes, and no qualitative sex differences could be detected. We show for the first time that variance in jealousy is to some extent explained by genetic factors. Even though our results from the mean value analyses are in line with the theory of evolved sex differences in jealousy, we could not identify any sex differences on a genetic level.

1 - 40 of 40
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf