. Improvement of serum adiponectin and leptin concentrations: effects of a low-calorie or isocaloric diet combined with metformin or orlistat - a prospective randomized open-label trial

OBJECTIVE: We compared the effects of three weight loss interventions on serum concentrations of adiponectin and leptin in obese premenopausal women. PATIENTS AND METHODS: 114 obese Caucasian women were randomized into three groups receiving a low-calorie diet (LC; n = 39), an isocaloric diet with 500 mg of metformin twice a day (IM; n = 38), and an isocaloric diet with 120 mg of orlistat three times a day (IO; n = 37), for three months. Serum concentrations of adiponectin and leptin were evaluated, along with anthropometric and body composition parameters, at baseline and after the study. RESULTS: Both IO and LC, but not IM, caused an increase in serum adiponectin concentration (p < 0.01, p < 0.05 respectively). A decrease in serum leptin level was documented in the LC (p < 0.001), IM (p < 0.01), and IO group (p < 0.01). Beneficial changes in anthropometric and body composition values were observed following all interventions with the greatest advantage seen in the IO group. The strongest correlations, of Delta adiponectin with Delta body weight (r = -0.54), Delta BMI (r = -0.49), Delta FAT [%] (r = -0.48), Delta FAT [kg] (r = -0.48), and Delta lean [%] (r = 0.48); and of Delta leptin with Delta body weight, Delta BMI, Delta waist, Delta fat, and Delta lean, were documented in the IO group. CONCLUSIONS: Beneficial effects were observed on serum leptin concentration, weight loss, and body composition for all interventions and in all examined groups, with the greatest advantage being associated with the orlistat treatment. Improvements in serum adiponectin con-centrations resulted from the low-calorie and isocaloric diets with orlistat, but not from the isocaloric diet with metformin. We find these strategies more promising for the treatment of obesity and its related complications in obese premenopausal women.