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 alte rations of hypothalamo-pituitary-adrenal (HPA) axis. It has been hypothesiz ed that treatment with metformin (MET) and dexfenfluramine (DEX) could coun teract those endocrine-metabolic alterations. Thus, we studied the effects of 3-month treatment with MET or DEX on anthropometric (BMI, WHR, FM and FF M), metabolic (basal and OGTT-induced glucose) and hormonal variables (IGF- I, DHEA-S, androstendione, testosterone, fT3, fT4, TSH, basal and OGTT-indu ced 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 p atients were on balanced hypocaloric diet (1400 Kcal/day). Patients were ra ndomly assigned to treatment with MET (no.=10, 500 mg twice daily po) or DE X (no.=10, 15 mg thrice daily po) or placebo (no.=8). Before treatment all groups had similar anthropometric, metabolic and hormonal values. After 3-m onth treatment with MET, DEX or placebo, weight, BMI and WHR reductions wer e 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 in sulin response, glucose/insulin ratio showed a similar trend toward improve ment in all groups, white IGF-I, 24 h urinary cortisol, DHEA-S, androstendi one, testosterone, thyroid hormone and TSH levels did not show any variatio n. Significant (p<0.02) and similar reductions of DBP, but not of SEP, leve rs were found in all groups. In conclusion, our findings demonstrate that, at least after 3-month treatment, metformin and dexfenfluramine do not modi fy 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.