GH, IGFBP-1, and IGFBP-3 response to oral glucose tolerance test in perimenopausal women: no influence of body mass index

Objectives: an increasing interest is being focused on the role of the soma totropic axis in the modulation of body weight and fat distribution, partic ularly in climacteric women. The influence of the glycometabolic state on t he somatotropic axis in postmenopausal and in obese subjects has not been i nvestigated. The aim of the present study is to evaluate whether menopause and body mass index (BMI) affect the response of growth hormone (GH), insul in-like growth factor-binding protein-1 (IGFBP-1) and -3 (IGFBP-3) to the o ral glucose tolerance test (OGTT). Methods: the study included 24 women, aged 45-55 years, categorized into 4 groups, premenopausal pre-obese (BMI = 28.5 +/- 0.8 Kg/m(2)) and normal bod y weight (BMI = 22.2 +/- 1.1 Kg/m(2)), and postmenopausal pre-obese and nor mal body weight. All women underwent: (1) it biophysical evaluation with de termination of waist/hip ratio; (2) an assessment of fat and lean tissue ma ss and body fat distribution by total body DEXA; and to (3) an OGTT. Results: in response to OGTT plasma GH levels significantly decreased in al l groups, but the relative decrease was more prominent in the lean subjects . A significant decrease of IGFBP-1 levels in response to OGTT was observed in all women, regardless of menopausal age and BMI, while IGFBP-3 levels d id not significantly change in either group. Conclusions: in conclusion, the impact of both BMI and menopausal condition on GH, IGFBP-1, and -3 response to OGTT is limited to a blunted GH respons e in overweight women compared with normally-weighing ones. These findings appear to rule out the hypothesis that a common glycometabolic derangement may affect both the modifications of body weight and of the somatotropic ax is observed in perimenopausal women. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.