Background: The associations between physical exercise, physical and psychosocial work demands, and risk of musculoskeletal pain are well documented. However, studies investigating these independent associations related to the risk of fibromyalgia (FM) are limited. Further, the protective effect of physical exercise on the risk of FM among subjects with physical and psychosocial work demands has never been assessed. Hence, the purpose of the present study was to examine the independent effect of leisure time physical exercise, physical work demands, and psychosocial work demands, on the future risk of FM. A second objective was to assess the combined effect of physical exercise and respectively, physical and psychosocial work demands, on the risk of FM to investigate if physical exercise could compensate for the possible adverse effects of high work demands.
Methods: A population-based health survey (HUNT 1) was conducted from 1984 to 1986 in Nord-Trøndelag County, Norway, with follow-up during 1995-97 (HUNT 2). With baseline measurements of physical exercise (frequency, duration and intensity), and physical and psychosocial work demands, the risk of FM among 16,785 women aged ≥20 years without FM or physical impairments at baseline was examined. Risk of FM was assessed by calculations of odds ratio (OR), with adjustments for possible confounders.
Results: At follow-up, 366 cases of incident FM were reported. A moderate inverse dose-response association was found between physical exercise and risk of FM (P for trend, 0.02), where women who reported ≥2.0 hours of exercise per week had a 35% lower risk of FM compared to inactive women (OR 0.65, 95% CI 0.42-1.00). Furthermore, a positive dose-response association was observed between physical and psychosocial work demands and risk of FM (P for trend, <0.001 for both types of demands), with an OR of 2.08 (95% CI 1.26-3.43) and 2.25 (95% CI 1.32-3.82) among women who reported the highest level of physical and psychosocial work demands, respectively. The combined analysis showed an increased risk of FM among inactive women who reported high physical and psychosocial work demands; ORs were respectively 1.86 (95% CI 1.29-2.68) and 2.18 (95% CI 1.48-3.21).
Conclusion: In this prospective longitudinal study of female workers, we found that being physical inactive during leisure time and having high physical and psychosocial work demands were associated with an increased risk of FM, whereas physical exercise seemed to reduce the risk of FM among women with high work demands. Thus, emphasizing the importance of leisure time physical exercise in relation with high physical and psychosocial work demands is important when recommending strategies for the prevention of FM.
2011. , 27 p.