Effects of Exercise Training on Circulating Retinol-Binding Protein 4 and Cardiovascular Disease Risk Factors in Obese Men

Abstract

Introduction: The purpose of this study was to investigate the effects of 12-week exercise training on circulating retinol-binding protein 4 (RBP4) concentration and cardiovascular disease (CVD) risk factors in obese men. Methods: 29 obese men (age 48 ± 2 years; BMI 29.6 ± 0.7 kg/m²) participated in a 12-week exercise program (50–70% maximal heart rates; 3 times/week) without calorie restriction. Anthropometric parameters, CVD risk factors (total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol, triglycerides (TG), and quantitative insulin sensitivity check index), and circulating RBP4 and adipokine (adiponectin, leptin, and interleukin-6 (IL-6)) concentrations were measured. Results: Exercise training significantly improved in absolute peak oxygen consumption (p < 0.05), and CVD risk factors (p < 0.05), with the exception of HDLC. There was a significant decrease in circulating RBP4, leptin, and IL-6 concentrations (p < 0.05). Stepwise regression analysis revealed that changes in RBP4 concentration were independently related to the changes in TG concentration (β = 0.46, p < 0.05). Conclusion: These results demonstrate that exercise training without calorie restriction improves several CVD risk factors and circulating RBP4 and adipokine concentrations. Moreover, the change in circulating RBP4 may be more associated with the improvements in TG concentration in obese men.