Lipase inhibition by orlistat: effects on gall-bladder kinetics and cholecystokinin release in obesity.

Author: Mathus-Vliegen EM, Van Ierland-Van Leeuwen ML, Terpstra A

Author affiliation: Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. e.mathus-vliegen@amc.uva.nl

Publication date & source: 2004.03.01, Aliment Pharmacol Ther., 19(5):601-11.

Publication type: Clinical Trial; Randomized Controlled Trial

BACKGROUND: Obese subjects are at risk of developing gallstones as a result of the obese state and during weight reduction. AIM: To study whether orlistat, by lipase inhibition, impairs gall-bladder emptying, thus further predisposing weight-losing obese subjects to gallstone formation. METHODS: Patients entering a randomized clinical trial of 1 month of diet, followed by treatment with placebo, 3 x 60 mg orlistat or 3 x 120 mg orlistat, underwent gall-bladder emptying studies measured by ultrasound. Meal-induced cholecystokinin release and gall-bladder emptying were investigated at the start, at randomization and after 1 and 12 months. RESULTS: One month of dieting did not change gall-bladder emptying and cholecystokinin release. After 1 month, placebo treatment resulted in a decreased fasting volume of 11%, compared with increases of 26% and 47% with 60 and 120 mg orlistat, respectively. Gall-bladder emptying increased by 9% with placebo and decreased by 15% and 53% with 60 and 120 mg orlistat, respectively. Fasting cholecystokinin values and cholecystokinin release decreased significantly in the orlistat group. After 1 year, a persistent but attenuated effect of orlistat on gall-bladder emptying and cholecystokinin release remained. Three of 40 patients developed gallstones, two on placebo with major weight loss and one on 60 mg orlistat. CONCLUSIONS: One month of lipase inhibition by orlistat significantly impaired gall-bladder motility, which persisted to some extent after 1 year. Obese subjects with diabetes or hyperlipidaemia, who are more at risk of gallstones, should be followed carefully.