The effect of weight reduction on plasma concentrations of ghrelin and insulin-like growth factor 1 in obese women

Abstract

Introduction: The aim of the present study was to examine how weight loss treatment modulates plasma concentrations of ghrelin and insulin-like growth factor 1 (IGF-1) in obese women and to determine whether there is any association with possible changes in plasma concentrations of these hormones after weight loss.
Material and methods: The study group consisted of 22 obese women without additional disease (age 40.6 ± 12.9 years; BMI 37.2 ± 4.6 kg/m²). All subjects participated in a 3-month weight reduction program. The measurements were performed at baseline and after weight loss. Plasma concentration of ghrelin and IGF-1 were measured by enzyme – linked immunosorbent assay (ELISA) kit. Serum concentrations of insulin were measured by radioimmunoassay (RIA). Body composition was determined by bioelectrical impedance analysis using a Bodystat analyser.
Results: The mean weight loss was 9.3 ± 4.1 kg (9.7 ± 4.3%). Following weight loss, plasma ghrelin and IGF-1 concentrations increased significantly (63.5 ± 13.0 vs. 72.8 ± 15.1 pg/ml; p < 0.01; 126.9 ± 67.0 vs. 170.5 ± 83.3 ng/ml p < 0.01, respectively) and serum insulin concentrations decreased significantly (17.5 ± 8.5 vs. 14.8 ± 10.4 mIU/ml p< 0.05). We observed a significant positive correlation between the increase of ghrelin and decrease of body fat percentage after weight loss (r = 0.44, p = 0.03). There are no correlations between change of ghrelin and IGF-1concentrations and between changes of insulin and IGF 1 concentrations.
Conclusion: Plasma concentrations of ghrelin and IGF-1 increased after weight loss. However, it seems there is no association between serum concentrations of ghrelin and IGF-1 in obese women.