Insulin-Like Growth Factor-1, Leptin, Body Composition, and Clinical Status Interactions in Children with Cystic Fibrosis.

Background/Aims: Children with cystic fibrosis (CF) are of increased risk of reduced fat body mass (FBM) and lean body mass (LBM). Serum concentrations of insulin-like growth factor-1 (IGF-1)and leptin could be markers of LBM and/or FBM depletion. To evaluate the relationships between disease activity, body composition, IGF-1and leptin concentrations in CF children. Methods: A cross-sectional study with 26 CF children aged 5.0–15.5 years and 33 healthy controls, mean age 9.4 years. Body composition was evaluated by dual-energy X-ray absorptiometry. Fasting blood samples were analyzed for leptin, IGF-1and IGFBP-3. Results: FBM standard deviation score (SDS; CF boys –0.02 ± 0.88 vs. 0.78 ± 0.65, p < 0.01; CF girls –0.37 ± 1.15 vs. 0.70 ± 0.97, p < 0.05), leptin concentration (CF boys 2.07 ± 0.79 vs. 3.07 ± 1.28 ng/ml, p < 0.05; CF girls 2.71 ± 0.86 vs. 5.00 ± 2.95 ng/ml, p < 0.05) and IGF-1SDS (CF boys –1.43 ± 1.50 vs. –0.32 ± 0.88, p < 0.05; CF girls –0.66 ± 1.66 vs. 0.64 ± 0.57, p < 0.01) were lower in CF children compared to controls. Shwachman score was the strongest predictor of lean body mass (R = 0.63). Leptin levels explain 60% of the variability in FBM. Conclusion: Serum concentrations of IGF-1 and leptin are decreased in children with CF and are associated with clinical conditions and body composition. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]