Obesity and cholecystectomy among women: implications for prevention.

Almost all studies of the association of body mass with the risk of gallbladder disease have found that risk increases with obesity. Some studies report a nonlinear relationship of body mass to gallbladder disease risk, and some report that the association of excess body mass with increased risk of gallbladder disease is confined to younger women. We examined the association of body mass with the risk of cholecystectomy based on data from 14 years of follow-up of 16,638 women. The cholecystectomy rate was much greater in the highest quintile of Quetelet's body mass index than in other quintiles. The striking association of high rates of cholecystectomy with the highest quintile of Quetelet's body mass index was observed in each age group studied. The low incidence of cholecystectomy in young, thin women made the relative risk of cholecystectomy in women in the fifth quintile of body mass highest in women under 25 years of age. The observation that cholecystectomy rates are not linearly associated with obesity suggests that women in the highest quintiles of body mass could be considered a reasonable group in which strategies for prevention of gallbladder disease might be tested.