XENical in the prevention of diabetes in obese subjects (XENDOS) study: a randomized study of orlistat as an adjunct to lifestyle changes for the prevention of type 2 diabetes in obese patients.

OBJECTIVE: It is well established that the risk of developing type 2 diabetes is closely linked to the presence and duration of overweight and obesity. A reduction in the incidence of type 2 diabetes with lifestyle changes has previously been demonstrated. We hypothesized that adding a weight-reducing agent to lifestyle changes may lead to an even greater decrease in body weight, and thus the incidence of type 2 diabetes, in obese patients. RESEARCH DESIGN AND METHODS: In a 4-year, double-blind, prospective study, we randomized 3,305 patients to lifestyle changes plus either orlistat 120 mg or placebo, three times daily. Participants had a BMI >/=30 kg/m2 and normal (79%) or impaired (21%) glucose tolerance (IGT). Primary endpoints were time to onset of type 2 diabetes and change in body weight. Analyses were by intention to treat. RESULTS: Of orlistat-treated patients, 52% completed treatment compared with 34% of placebo recipients (P < 0.0001). After 4 years' treatment, the cumulative incidence of diabetes was 9.0% with placebo and 6.2% with orlistat, corresponding to a risk reduction of 37.3% (P = 0.0032). Exploratory analyses indicated that the preventive effect was explained by the difference in subjects with IGT. Mean weight loss after 4 years was significantly greater with orlistat (5.8 vs. 3.0 kg with placebo; P < 0.001) and similar between orlistat recipients with impaired (5.7 kg) or normal glucose tolerance (NGT) (5.8 kg) at baseline. A second analysis in which the baseline weights of subjects who dropped out of the study was carried forward also demonstrated greater weight loss in the orlistat group (3.6 vs. 1.4 kg; P < 0.001). CONCLUSIONS: Compared with lifestyle changes alone, orlistat plus lifestyle changes resulted in a greater reduction in the incidence of type 2 diabetes over 4 years and produced greater weight loss in a clinically representative obese population. Difference in diabetes incidence was detectable only in the IGT subgroup; weight loss was similar in subjects with IGT or NGT [correction].

Effect of orlistat added to diet (30% of calories from fat) on plasma lipids, glucose, and insulin in obese patients with hypercholesterolemia.

The objective of this study was to quantify the effectiveness of orlistat plus a reduced calorie diet on decreasing cardiovascular disease risk in obese individuals with elevated low-density lipoprotein (LDL) cholesterol concentrations, and to compare the beneficial effects in patients with hypercholesterolemia only (type IIA) with those in subjects with combined dyslipidemia (type IIB). Hypercholesterolemic patients treated with orlistat lost more weight (mean +/- SEM 9.9 +/- 0.4 vs 6.1 +/- 0.5 kg, p = 0.0001) and had greater decreases in plasma cholesterol (p = 0.0001), LDL cholesterol (p = 0.0001), triglycerides (p = 0.06), glucose (p = 0.07), and insulin (p = 0.02) concentrations compared with the diet-only treated patients. The greater degree of weight loss in orlistat-treated subjects was similar irrespective of the form of dyslipidemia, and plasma total and LDL cholesterol and insulin levels decreased to a significantly greater degree (p <0.05) in those patients who received orlistat and who had either type IIA and IIB dyslipidemia. However, triglyceride and insulin concentrations decreased and high-density lipoprotein (HDL) cholesterol increased to a significantly greater degree following orlistat-assisted weight loss in patients with type IIB compared with type IIA subjects, which was associated with a significantly greater decrease in the ratio of LDL/HDL cholesterol. Thus, weight loss in response to a reduced calorie diet in obese hypercholesterolemic patients was associated with a significant decrease in plasma LDL cholesterol levels. The beneficial metabolic effects of weight loss were accentuated in response to orlistat administration, and the improvement was greatest in patients with combined dyslipidemia (type IIB).