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

Abstract

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 To study gender related differences in the response to GH treatment in men and postmenopausal women. Methods 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 doses (0.47 vs. 0.51 mg/day) of GH. All women were postmenopausal not receiving oestrogen treatment. Insulin sensitivity was assessed using a hyperinsulinemic 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-1 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.