Day-to-day variation of urinary NGAL and rational for creatinine correction
2013 (English)In: Clinical Biochemistry, ISSN 0009-9120, E-ISSN 1873-2933, Vol. 46, no 1-2, 70-72 p.Article in journal (Refereed) Published
Clinical studies evaluating the new tubular biomarker urinary neutrophil gelatinase-associated lipocalin (U-NGAL) in urine increase and there is no consensus whether absolute U-NGAL concentrations or urinary NGAL/creatinine (U-NGAL/Cr) ratios should be used when chronic tubular dysfunction is studied. The aim was to study the biological variation of U-NGAL in healthy subjects and the rational for urinary Creatinine (U-Cr) correction in two different study samples.
DESIGN AND METHODS:
To study biological variation of U-NGAL and U-NGAL/Cr ratio and the association between U-NGAL and U-Cr in healthy subjects 13 young males and females (median age 29years) collected morning urine in 10 consecutive days. Additionally, a random subsample of 400 males from a population-based cohort (aged 78years) collecting 24-hour urine during one day was studied.
The calculated biological variation for absolute U-NGAL was 27% and for U-NGAL/Cr ratio 101%. Absolute U-NGAL increased linearly with U-Cr concentration (the theoretical basis for creatinine adjustment) in the older males (R=0.19, P<0.001) and with borderline significance in the young adults (R=0.16, P=0.08). The U-NGAL/Cr ratio was, however, negatively associated with creatinine in the older males (R=-0.14, P<0.01) and in the young adults (R=-0.16, P=0.07) indicating a slight "overadjustment".
The study provide some support for the use of U-NGAL/Cr ratio but the rather large biological variation and risk of possible overadjustment need to be considered. Both absolute U-NGAL and U-NGAL/Cr ratios should be reported for the estimation of chronic tubular dysfunction.
Place, publisher, year, edition, pages
2013. Vol. 46, no 1-2, 70-72 p.
Urology and Nephrology
IdentifiersURN: urn:nbn:se:uu:diva-182320DOI: 10.1016/j.clinbiochem.2012.09.022ISI: 000313406800015PubMedID: 23041245OAI: oai:DiVA.org:uu-182320DiVA: diva2:559452