Three-month treatment with metformin or dexfenfluramine does not modify the effects of diet on anthropometric and endocrine-metabolic parameters in abdominal obesity

Abdominal obesity is connoted by hyperinsulinism and insulin insensitivity, a trend toward glucose intolerance, hypoactivity of GH/IGF-I axis and alterations of hypothalamo-pituitary-adrenal (HPA) axis. It has been hypothesized that treatment with metformin (MET) and dexfenfluramine (DEX) could counteract those endocrine-metabolic alterations. Thus, we studied the effects of 3-month treatment with MET or DEX on anthropometric (BMI, WHR, FM and FFM), metabolic (basal and OGTT-induced glucose) and hormonal variables (IGF-I, DHEA-S, androstendione, testosterone, fT3, fT4, TSH, basal and OGTT-induced insulin) as well as on blood pressure in 28 normotensive patients with abdominal obesity (OB, 3 M, 25 F; 47.5+/-1.5 yr [mean+/-SE], BMI 35.4+/-1.1 kg/m(2), WHR 0.98+/-0.04 and 0.86+/-0.07, in M and F, respectively). All patients were on balanced hypocaloric diet (1400 Kcal/day). Patients were randomly assigned to treatment with MET (no.=10, 500 mg twice daily po) or DEX (no.=10, 15 mg thrice daily po) or placebo (no.=8). Before treatment all groups had similar anthropometric, metabolic and hormonal values. After 3-month treatment with MET, DEX or placebo, weight, BMI and WHR reductions were similar in all groups (p<0.05 vs baseline in either group). In each group FFM/FM ratio showed non significant trend toward increase. No significant variations in metabolic and endocrine variables were recorded in each group after 1 and 3-month treatment. However, glucose tolerance, OGTT-induced insulin response, glucose/insulin ratio showed a similar trend toward improvement in all groups, white IGF-I, 24 h urinary cortisol, DHEA-S, androstendione, testosterone, thyroid hormone and TSH levels did not show any variation. Significant (p<0.02) and similar reductions of DBP, but not of SEP, levers were found in all groups. In conclusion, our findings demonstrate that, at least after 3-month treatment, metformin and dexfenfluramine do not modify the effects of diet on anthropometric, metabolic and hormonal parameters as well as on blood pressure in patients with abdominal obesity. (C) 1999, Editrice Kurtis.