Glucose metabolism and visceral fat in GH deficient adults:: 1 year of GH replacement

The aim of the current study is to evaluate the effects of 12-month growth hormone (GH) replacement on glucose metabolism and visceral fat in 24 adults with GH deficiency (11 men, 13 women, age 41 +/- 1.9 year, BMI 27 +/- 1.2 kg/m(2)). Glucose metabolism was measured in the fasting state by the homeostatic model assessment (HOMA) insulin resistance index and during a standard oral glucose tolerance test (OGTT). Data were analyzed by HOMA and the insulin sensitivity index (ISI)-composite derived from the OGTT. Visceral fat was evaluated by CT scan. GH-deficient adults had increased visceral fat (P = 0.029) with lower fasting glucose levels (P = 0.004) than the control group on baseline evaluation. GH replacement induced deterioration in glucose metabolism, with progressive increment in fasting insulin levels at 6 and 12 months (P = 0.024) and in 2-h-OGTT insulin levels at 3, 6 and 12 months (P = 0.001). Plasma glucose levels did not change during the study. There was a deterioration in insulin sensitivity index observed by an increase in HOMA-IR (P = 0.049) and a reduction in the ISI-composite (P = 0.028), both at 12 months of replacement. Visceral fat and waist-to-hip-ratio (WHR) reduced not only at month 6 but also at month 12 (P = 0.0001 and 0.023, respectively). In conclusion, 12 months of GH replacement seem to impair glucose homeostasis, despite favorable alterations in body composition. (C) 2003 Elsevier Ltd. All rights reserved.