PROPHYLAXIS AGAINST GALLSTONE FORMATION WITH URSODEOXYCHOLIC ACID IN PATIENTS PARTICIPATING IN A VERY-LOW-CALORIE DIET PROGRAM

Objective: To determine whether prophylactic treatment with ursodeoxyc holic acid can prevent gallstone formation in persons participating in a very-low-calorie weight reduction diet program. Design: Multicenter , double-blind, placebo-controlled, multidose clinical trial. Patients were treated with placebo or with 300 mg/d, 600 mg/d, or 1200 mg/d of ursodeoxycholic acid. Setting: 31 Health Management Resources weight management centers. Patients: 1004 patients were initially enrolled in a 16-week, 520-kcal/d, Health Management Resources liquid protein die t program. All patients had a body mass index of 38 kg/m(2) or more an d a normal gallbladder ultrasonogram before study entry. Bile analysis was done in 32 patients. Measurements: Body weight and body mass inde x were measured before the diet was started and at 2-week intervals fo r 16 weeks. Gallbladder ultrasonography was done before enrollment and after 8 and 16 weeks of dieting. Bile was obtained by endoscopy and a nalyzed for cholesterol crystals and lipid levels. Results: Mean body weight for all patients at the start of dieting was 128.2 kg +/- 23.2 kg; mean initial body mass index was 44.2 kg/m(2) +/- 6.0 kg/m(2). Gal lstones developed in 28% (95% CI, 22% to 35%) of patients receiving pl acebo, in 8% (CI, 5% to 13%) of patients treated with 300 mg/d of urso deoxycholic acid, in 3% (CI, 1% to 7%) of patients treated with 600 mg /d of ursodeoxycholic acid, and in 2% (CI, 0.5% to 5%) of patients tre ated with 1200 mg/d of ursodeoxycholic acid. The differences between p atients receiving placebo and patients receiving ursodeoxycholic acid were statistically significant. The percentage of ursodeoxycholic acid in bile increased stepwise with increasing doses of ursodeoxycholic a cid. Conclusions: Ursodeoxycholic acid, 600 mg/d, is highly effective in preventing gallstone formation in patients having dietary-induced w eight reduction.