The reduction in visceral fat mass in response to growth hormone is more marked in men than in oestrogen-deficient women

Context: Women with severe growth hormone (GH) deficiency have a less marked response to GH replacement than men. This has mostly been attributed to the attenuating effects of oestrogen replacement therapy. Objective: Fifteen men and 15 age- and BMI-matched women with abdominal obesity (mean age: 58 range 51-64 years were treated for one year with similar does (0.47 vs. 0.51 mg/day) of GH. All women were postmenopausal not receiving oestrogen treatment. Insulin sensitivity was assessed using a hyperrinsulinemic euglycemic clamp and body composition by computed tomography (CT) scans and from total body potassium, K(40). Results: Men and women were comparable at baseline in terms of waist circumference. IGF-I and lipid levels. After one year of GH treatment, there was a 18% reduction in visceral adipose tissue (VAT) in men and a 5% reduction in women (P = 0.0001 men vs. women). Although the magnitude of the difference was small, men increased more in thigh muscle mass (P < 0.0001 vs. women). A reduction in thigh intermuscular adipose tissue (IMAT) and diastolic blood pressure was seen only in men (both p < 0.05 vs. baseline). A decrease in LDL cholesterol, and an increase in serum insulin, was observed only in women (both p < 0.05 vs. baseline). Conclusion: Low dose GH treatment reduced VAT more markedly in men as compared with women. As all women were postmenopausal and oestrogen-deficient, this gender difference in responsiveness was not due to an antagonistic effect of oestrogen on peripheral GH action. (C) 2008 Elsevier Ltd. All rights reserved.