Background: The management of type 2 diabetes mellitus is complicated by the presence of risk factors related to overweight and obesity, particularly visceral adiposity. However, weight loss and weight maintenance are difficult for patients with diabetes, and the benefits of dietary modifications are typically modest. Sibutramine is a serotonin- and norepinephrine-reuptake inhibitor that reduces food intake by inducing early satiety and attenuates the decrease in basal energy expenditure associated with weight loss. Previous trials of sibutramine in overweight and obese patients with type 2 diabetes have shown significant weight loss accompanied by better glycemic control.
Objective: The goal of this study was to assess the effect on body weight and glycemic control of sibutramine in combination with glibenclamide in obese Hispanic patients with type 2 diabetes.
Methods: This was a 12-month, randomized, double-blind, placebo-controlled clinical trial conducted at the Endocrinology Service, General Hospital of Mexico, Mexico City. Included were overweight or obese (body mass index [BMI] >27 kg/M2) patients with type 2 diabetes between the ages of 24 and 65 years who had been receiving glibenclamide monotherapy for at least 2 weeks and whose glucose concentrations were stable. Patients were randomized to receive sibutramine 10 mg or placebo once daily. The primary efficacy measures were change in body weight, waist circumference, and glycosylated hemoglobin (HbA1c). Anthropometrics and fasting glucose concentrations were measured monthly. HbA1c was determined at baseline and at 6 and 12 months. Laboratory parameters were measured at baseline and at the end of the study.
Results: Forty-four patients were randomized to receive sibutramine (28 women, 16 men; mean [SD] age, 47.6 [9.0] years), and 42 were randomized to receive placebo (31 women, 11 men; mean age, 45.8 [8.1] years). Twenty-four patients in the sibutramine group and 23 in the placebo group completed the trial. In the sibutramine group, body weight was reduced from a mean (SD) of 73.9 (10.3) kg at baseline to 69.8 (10.6) kg at month 12; BMI decreased from 29.9 (2.6) to 28.2 (2.9) kg/M2; waist circumference was reduced from 94.9 (8.4) to 90.8 (8.4) cm; the plasma fasting glucose concentration decreased from 140.4 (29.4) to 114.2 (32.0) mg/dL; and the HbA1c value was reduced from 8.9% (1.2) to 8.3% (1.2) (all, P < 0.001). In the placebo group, the corresponding changes were from 74.5 (10.3) kg at baseline to 73.1 (11.2) kg at month 12; from 30.1 (2.5) to 29.5 (2.9) kg/M2; from 94.4 (7.3) to 93.1 (8.3) cm (P < 0.05); from 140.7 (25.2) to 123.9 (38.3) mg/dL (P < 0.05); and from 9.0% (1.2) to 9.1% (1.3). In the sibutramine group, weight loss continued for up to 12 months.
Conclusion: In this population of obese Hispanic patients with type 2 diabetes, sibutramine combined with glibenclamide therapy achieved weight loss for up to 12 months and was associated with better glycemic control than placebo.