BMI, physical activity and risk of gallstone disease in Chinese women

Abstract

Gallstone disease is known to be more common among obese individuals, particularly women. The effect of weight change and physical activity (PA) on gallstone risk, however, has seldom been examined. We evaluated the association of gallstone disease with weight, weight change, and PA among Chinese women in Shanghai. We conducted a case–control study nested in the Shanghai Women's Health Study, including 8485 women with self-reported, physician-diagnosed, prevalent gallstone disease and 16,970 frequency-matched controls by birth year and age at gallstone diagnosis (4-year intervals). Information on height, weight history, PA, and other exposures was obtained by in-person interviews between 1997 and 2000. Exposures after gallstone diagnosis were truncated. Occupational PA (OPA) levels were derived from indices of sitting time and energy expenditure based on job history. Housework PA (HPA) was measured using daily hours spent on housework. Odds ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analyses. Odds ratios for gallstone increased significantly with usual body mass index (BMI) and BMI at age 50, but not BMI at age 20. After adjusting for usual BMI, weight gain between ages 20 and 50 further increased the risk (OR = 1.9, CI = 1.6, 2.3 for subjects in the upper tertile of BMI increase). The effects of both overweight and weight gain were more prominent for postmenopausal women. Gallstone prevalence was inversely associated with HPA, with 30% reduction in risk for women with highest level of HPA (OR = 0.70, CI = 0.58, 0.84). Gallstone prevalence also was positively associated with increasing sitting time at work, although overall no significant association was found for OPA. HPA did not significantly modify weight-related gallstone associations. Overweight and weight gain increase the risk of gallstone in women, and regular PA may reduce risk. The effects of overweight, weight gain, and PA on gallstone prevalence appear to be independent of each other.