The effects of circuit resistance training on plasma progranulin level, insulin resistance and body composition in obese men.
Background Progranulin (PGRN) is implicated in obesity and insulin resistance (IR). The aim of this study was to evaluate the effects of 8 weeks of circuit resistance training (CRT) on plasma PGRN, IR and body composition in obese men. Materials and methods Twenty-eight healthy obese men [age: 36 ± 7.7 years, body weight (BW): 96.4 ± 15.6 kg, body mass index (BMI): 32.4 ± 4.5 kg/m2] completed the study. Subjects were randomly assigned to two groups of control and training. Subjects in the training group underwent training for 8 weeks, 3 times a week. Blood samples and anthropometric characteristics were taken before the commencement of the exercise protocol and 72 h after the last training session. The homeostatic model assessment of insulin resistance (HOMA-IR) was used to measure IR. Results BW, BF%, BMI, waist-hip ratio (WHR), HOMA-IR and plasma PGRN levels except lean body mass (LBM) were significantly reduced in the training group (p < 0.05). Additionally, except for LBM, subjects in the training group had significantly decreased BW, BF%, BMI, WHR, HOMA-IR and plasma PGRN levels compared to changes in those in the control group (p < 0.05). Significant correlations were found between the changes in plasma PGRN and the changes in insulin, HOMA-IR and BMI (p < 0.05). Conclusions The findings showed that 8 weeks of CRT improved body composition and IR which were accompanied by reduced plasma PGRN levels. This study suggests that CRT has the potential for obese individuals to counteract obesity-associated health impairments.