Effect of endurance training on serum Apelin levels, C-reactive protein and insulin resistance index in middle-aged sedentary men

Apelin is a novel adipokine that is closely related with insulin resistance. The aim of this study was to assess the effects of endurance training on Apelin, C-reactive protein (CRP) and insulin resistance index in middle-aged sedentary men.
In this quasi-experimental study, 30 men aged between 48 to 60 years with body mass index (BMI) of ≥30 kg/m2, were randomly allocated to the endurance training (n=15), and control groups (n=15). The training program consisted of 12 weeks of endurance training (treadmill running) with 50-75% maximum heart rate. Before and 48 hours after the 12 weeks exercise, measurement of Apelin, CRP and insulin resistance index were performed. Paired t-test and Independent t-test were used for statistical analysis using SPSS software.
Results revealed that after 12 weeks endurance training, significant reductions were observed in the levels of CRP (p=0.001), BMI (p=0.001), fat percent (p=0.001), Apelin levels (p=0.027) and insulin resistance index (p=0.002) of experimental group compared to control group.
Generally, it seems that significant reductions in Apelin and CRP levels as a result of reduced body fat mass following 12 weeks of endurance training have been effective in reducing insulin resistance.