• orlistat;
  • type 2 diabetes;
  • glycaemic control;
  • obesity;
  • haemoglobin A1C

Aim: To assess the long-term effects of orlistat on body weight, glycaemic control and cardiovascular risk factors in overweight patients with type 2 diabetes.

Methods: This was a multicentre, randomized, placebo-controlled study with a 4-week placebo plus diet lead-in period and a 48-week, double-blind treatment period. Overweight or obese adults [body mass index (BMI) ≥ 28 kg/m2] with HbA1c of 6.5–11% and clinical type 2 diabetes were randomized to orlistat (120 mg t.i.d. n = 189) or placebo (n = 180) in conjunction with a low-calorie diet. Patients had either received sulphonylurea therapy for at least 2 months before the study or were not receiving any antidiabetic medication (the majority of which were drug-naïve).

Results: After 1 year, patients in the orlistat group lost significantly more weight than patients in the placebo group (−5.4% vs. −3.6%; p = 0.006). Moreover, significantly more patients achieved weight loss of ≥ 5% with orlistat compared with placebo (51.3% vs. 31.6%; p = 0.0001). Patients treated with orlistat also had significantly greater improvements than placebo-treated patients in HbA1c (−0.9% vs. –0.4%; p < 0.001), fasting glucose (−1.6 vs.–0.7 mmol/l; p = 0.004) and post-prandial glucose (−1.8 vs. –0.5 mmol/l; p = 0.003). In addition, orlistat-treated patients had a significantly greater reduction in LDL cholesterol compared with placebo. Overall, orlistat had a similar safety profile to placebo, with the exception of a higher incidence of generally mild and transient gastrointestinal events known to be associated with the mode of action of orlistat.

Conclusions: Treatment with orlistat plus diet resulted in significant weight loss, improved glycaemic control and cardiovascular risk factor profile in overweight patients with type 2 diabetes.