GROWTH-HORMONE TREATMENT OF ABDOMINALLY OBESE MEN REDUCES ABDOMINAL FAT MASS, IMPROVES GLUCOSE AND LIPOPROTEIN METABOLISM, AND REDUCES DIASTOLIC BLOOD-PRESSURE

The most central findings in both GH deficiency in adults and the meta bolic syndrome are abdominal/visceral obesity and insulin resistance. Abdominal obesity is associated with blunted GH secretion and low seru m insulin-like growth factor-I concentrations. GH treatment in GH-defi cient adults has demonstrated favorable effects on most of the feature s of GH deficiency in adults, but it is not known whether GH can impro ve some of the metabolic aberrations observed in abdominal/visceral ob esity. Thirty men, 48-66 yr old, with abdominal/visceral obesity were treated with recombinant human GH (rhGH) in a 9-month randomized, doub le-blind, placebo-controlled trial. The daily dose of rhGH was 9.5 mu g/kg. Body fat was assessed from total body potassium, and abdominal s c and visceral adipose tissue was measured using computed tomography. The glucose disposal rate (GDR) was measured during an euglycemic, hyp erinsulinemic glucose clamp. In response to the rhGH treatment, total body fat and abdominal sc and visceral adipose tissue decreased by 9.2 +/- 2.4%, 6.1 +/- 3.2%, and 18.1 +/- 7.6%, respectively. After an ini tial decrease in the GDR at 6 weeks, the GDR increased in the rhGH-tre ated group as compared with the placebo-treated one (P < 0.05). The me an serum concentrations of total cholesterol (P < 0.01) and triglyceri de (P < 0.05) decreased, whereas blood glucose and serum insulin conce ntrations were unaffected by the rhGH treatment. Furthermore, diastoli c blood pressure decreased and systolic blood pressure was unchanged i n response to rhGH treatment. This trial has demonstrated that GH can favorably affect some of the multiple perturbations associated with ab dominal/visceral obesity. This includes a reduction in abdominal/visce ral obesity, an improved insulin sensitivity, and favorable effects on lipoprotein metabolism and diastolic blood pressure.