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/m(2)] 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.