A PROSPECTIVE-STUDY OF SYMPTOMATIC GALLSTONES IN WOMEN - RELATION WITH ORAL-CONTRACEPTIVES AND OTHER RISK-FACTORS

Objective: To examine the relation between oral contraceptives (OCs), body mass index (BMI), weight change, alcohol use, parity, smoking, an d symptomatic gallstones in women less than 45 years of age. Methods: In this prospective study, associations between the various self-repor ted exposures and symptomatic gallstones were assessed in 96,211 femal e United States nurses with 425 cases of gallstones, using multiple lo gistic regression. Results: We found little relation between ever-use of OCs and symptomatic gallstones (relative risk [RR] 1.2, 95% confide nce interval [CI] 0.9-1.6), although there was a modest elevation in r isk for long-term use (RR 1.5, 95% CI 1.0-2.2 for 10-14 years; RR 1.6, 95% CI 1.0-2.4 for 15 or more years). There was also an increased ris k in current users of OCs (RR 1.6, 95% CI 1.1-2.4). The risk of sympto matic gallstones increased with increasing BMI and weight gain since a ge 18. Women with four or more births had an elevated risk of symptoma tic gallstones (RR 2.0, 95% CI 1.3-3.2), and current cigarette smokers had a slightly higher risk than never-smokers (RR 1.3, 95% CI 1.0-1.7 ). The risk decreased with increasing alcohol intake. Conclusion: We f ound no substantial increase in the risk of symptomatic gallstones amo ng ever-OC users, although current and long-term users had somewhat el evated risks. Body mass index remains the strongest predictor of sympt omatic gallstones among young women.