Thiazide use and the risk of cholecystectomy in women

As part of a case-control study of gallstone disease conducted among the female members of Group Health Cooperative of Puget Sound, the authors investigated the possible etiologic role of prior use of thiazide diuretics. One hundred fifty-three women who underwent gallstone surgery between January 1979 and September 1980, and 156 controls selected from membership files, were interviewed about their past use of certain medications, their reproductive history, and physical and demographic characteristics. The risk of gallstone disease which required surgery among women who had used thiazides relative to those who had not used this drug, after controlling for age, race, pregnancy, and body mass index, was 1.9 (95% confidence interval (CI) = 1.0-3.7). However, this association was present only among women who were not overweight, i.e., those with body mass index less than or equal to 36, for whom the relative risk was 5.0 (95% CI = 1.8-13.5). Among overweight women, the relative risk was 1.0 (95% CI = 0.5-2.2). Among women who were not overweight, there was no further increase in risk with increasing duration or recency of thiazide use. These data fail to agree with data from earlier studies which show a possible thiazide-gallstone disease association. The results of the present study suggest that if thiazide use has any influence on the occurrence of gallstone disease in women, that influence exists primarily in those who are not overweight.