Endocrine Abstracts

Aim: Sibutramine, orlistat and metformin appear beneficial for the treatment of adult with obesity. Several investigators have suggested that larger weight losses might be achieved by combining weight loss agents. The aim of this study was to compare the effectiveness of sibutramine monotherapy versus sibutramine plus metformin combination therapy in obese women with normal glucose tolerance.

Material-method: This is a 6 month, prospective and randomized study. Forty obese women (age: 44.1±8.6 years) with a body mass index (BMI) ≥ 30 kg/m² were consecutively enrolled in the study and were randomly assigned to receive either 10 mg/day sibutramine (group 1; n: 20) or 1700 mg/day metformin in addition to 10 mg/day sibutramine (group 2; n: 20). Dietary counselling was offered to each patient. Body mass index (BMI), waist circumference and insulin resistance by homeostasis model assessment model (HOMA) were measured at baseline, third month and sixth month. OGTT with insulin response was repeated at the end of the study.

Results: Baseline characteristics were similar in both treatment groups. Three patients in group 2 were dropped out of the study in the first month because of gastrointestinal discomfort. BMI values decreased significantly in both groups at the end of the study compared with baseline (group 1, 39.6±5.7 vs. 35.5±6.6 kg/m², P<0.001 and group 2, 40.1±4.8 vs. 37.3±4.5 kg/m², P<0.001) but there was not a statistically significant difference between treatment groups according to BMI at the end of the study. Waist circumference and HOMA values of both groups were significantly decreased at 6th month, but there was not a significant difference initially and at the end between groups either.

Conclusion: The combination of sibutramine with metformin or sibutramine alone treatment protocols are effective in maintaining weight loss, reduction in waist circumference and insulin resistance parameters. But still combination treatment of sibutramine and metformin does not seem to be superior to sibutramine alone.