Glucose metabolism and visceral fat in GH deficient adults: 1 year of GH replacement Luciana Diniz Carneiro Spina * ,D ebora Vieira Soares, Rosane R.L.O. Brasil, Eliana M.C. da Silva, Priscila M. Lobo, Fl avia Lucia Conceic ß~ ao, M ario Vaisman Endocrine Service of Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro – UFRJ, Rio de Janeiro, RJ, Brazil Received 19 May 2003 Abstract 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 ¼ 0:029) with lower fasting glucose levels (P ¼ 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 ¼ 0:024) and in 2-h-OGTT insulin levels at 3, 6 and 12 months (P ¼ 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 ¼ 0:049) and a reduction in the ISI-composite (P ¼ 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 ¼ 0:0001 and 0.023, respectively). In conclusion, 12 months of GH replacement seem to impair glucose homeostasis, despite favorable alterations in body com- position. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: Glucose metabolism; Visceral fat; GH deficiency in adults; GH replacement 1. Introduction The benefits of recombinant human growth hor- mone (GH) replacement in GH-deficient adults (GHDA) are well documented, but a possible GH-in- duced impairment of insulin sensitivity is still a matter of concern. Several studies have shown that GH replacement in adults improves well being, body composition, bone mineral density, muscle strength and exercise perfor- mance. GH replacement induces an increase in lean body mass and a concomitant reduction in fat mass, with a particular reduction in central obesity [1–8]. Insulin resistance may be more prevalent in adults with untreated GH deficiency [9–11], however the im- pact of GH replacement on this feature is controver- sial. There is evidence to suggest that long-term beneficial effects on body composition and physical fitness may balance GH insulin antagonistic effects, but some studies reported impaired insulin sensitivity de- spite favorable changes in body composition. Indeed, increases in both insulin sensitivity and insulin resis- tance have been described in the literature [1,2,5–8, 10,11]. The present study was undertaken to evaluate the effects of 12-month GH replacement on glucose me- tabolism and visceral fat in Brazilian adults with GH deficiency. www.elsevier.com/locate/ghir Growth Hormone & IGF Research 14 (2004) 45–51 * Corresponding author. Present address: Rua Jos e Linhares, 244/ 205, Leblon Cep 22430-220, Rio de Janeiro, RJ, Brazil. Tel.: +55-21- 2562-2748; fax: +55-21-2274-8359. E-mail address: luspina@openlink.com.br (L.D.C. Spina). 1096-6374/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.ghir.2003.08.002