The Effect of a Six- Month Aerobic Exercise on Levels of GH, IGF-1 and GH/IGF-1 Ratio Serum in Sedentary Middle-aged Women

Abstract

Introduction: In recent years, a number of researches have been carried out regarding the relationship between atherosclerosis and serum levels of GH and IGF-1 and different results were obtained. This study aimed to determine the effect of a six-month aerobic exercise on levels of GH, IGF-1 and GH/IGF-1 ratio serum in sedentary middle-aged women Methods: Nineteen healthy females, who were selected by convenience sampling method, were divided into two [active (n=11) and non-active (n=8)] groups. The exercise protocol included aerobic exercise training lasted for 6 months and 3 sessions per week. Every session lasted for 60 minutes with intensity of 55-65 percent of heart rate reserve. Blood samples were taken and Serum IGF-1 and GH were measured before and after six months of aerobic training. To make intra and intergroup comparisons as well as to investigate the interactive effect, repeated measure analysis of variance were used. For all statistical comparisons, the level of significance was set at p < 0.05. Results: This study demonstrated that the level of serum IGF-1 in middle-aged women decreased significantly (P=0.016). However, the levels of GH didn't change significantly during this period. Moreover, GH to IGF-1 ratio increased significantly (P=0.007). Conclusion: The study results indicated that six-month aerobic exercise led to a decrease on the levels of IGF-1 and did not make a change in GH serum in sedentary middle-aged women. In other words, doing aerobic exercises reduced IGF-1 levels that have a significant relationship with severity of a coronary disease and thus can prevent the atherosclerosis disease