Research in Medicine

Abstract Background: According to the importance of GH/IGF-I axis and reported effects of physical activity on this axis among healthy children, this study was conducted to determine the effect of a prolonged physical activity program on growth mediators in children with idiopathic short stature (ISS). Materials and methods: fourteen pre-pubertal short stature children were randomly allocated to physical activity or control group (7 children in each group). Children in physical activity group performed 8 week physical activity program. Simultaneously, children in control group participated in a drawing course. IGF-I and IGFBP-3 levels in blood were determined after 5 and 8 weeks. Repeated-measure analyses of variance were performed statistical analysis. P<0.05 was considered statistically significant. Results: A significant decrease was observed in IGF-I levels of physical activity group but not in control group after 8 weeks. IGFBP-3 fluctuations were not significant in both groups. Conclusion: Brief endurance-type physical activity program seemed to have resulted in catabolic rather than anabolic responses of the growth axis despite the fact that physical activity led to improved cardiorespiratory responses to physical activity. It is suggested that prolonged physical activity program (>8 weeks) may result in anabolic responses of the GH/IGF-I axis.