DIVERGENT EFFECTS OF SHORT-TERM, VERY-LOW-CALORIE DIET ON INSULIN-LIKE GROWTH-FACTOR-I AND INSULIN-LIKE-GROWTH-FACTOR BINDING PROTEIN-3 SERUM CONCENTRATIONS IN PREMENOPAUSAL WOMEN WITH OBESITY

Objective: Insulin-like growth factor-I (IGF-I) and insulinlike growth factor binding protein-3 (IGFBP-3) serum concentrations provide a goo d measure of the biological effects of growth hormone. The aims of the present study were to: (1) investigate the associations of IGF-I and IGFBP3 with body fat mass and distribution, and (2) evaluate the effec ts of 3 weeks of very-low-calorie diet (VLCD) (318 kcal/day, with 40 g protein, 35 g carbohydrate, and 2 g fat) on IGF-I and IGFBP-3 serum c oncentrations. Research Methods and Procedures: The study was performe d in 21 nondiabetic premenopausal women with obesity (body mass index >27.0 kg/m(2); age: ranging from 18 to 48 years). Body fat mass and di stribution were measured by computed tomography. Results: Before dieta ry treatment, IGF-I and IGFBP-3 serum concentrations were inversely as sociated with visceral adipose tissue (VAT) area (p<0.005 and p<0.05, respec tively), but not with either total body fat or subcutaneous adi pose tissue area. VLCD produced a significant decrease of body mass in dex (p<0.001), total body fat (p<0.001), VAT (p<0.005), subcutaneous a dipose tissue (p<0.001), IGF-I concentrations (p<0.05), and an increas e of IGFBP-3 serum levels (p<0.001). The association of VAT with eithe r IGF-I or IGFBP-3 serum concentrations was not maintained following V LCD. Discussion: Our study suggests that visceral adipose tissue, rath er than adiposity per se, accounts for IGF-I and IGFBP-3 serum concent rations, and that rapid weight loss, possibly due to nutritional chang es, results in lower IGF-I concentrations, higher IGFBP-3 concentratio ns, and abrogation of the inverse associations of VAT with IGF-I and I GFBP-3.