Which cytokine is the most related to weight loss-induced decrease in arterial stiffness in overweight and obese men?

Obesity and increased arterial stiffness are risk factors for cardiovascular disease. A well-known characteristic of obesity is the chronic low-grade inflammatory state, and it causes elevation of arterial stiffness. Weight-loss reduces arterial stiffness and inflammatory level in obese individuals. However, it is unclear which inflammatory factor is most related to weight loss-induce decreases in arterial stiffness in overweight and obese men. Thus, the aim of this study was to determine which circulating cytokine level has the most effect on decreasing arterial stiffness after lifestyle modification. Twenty overweight and obese men completed a 12-week period of lifestyle modifications (combination of aerobic exercise training and dietary modification). We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness, and circulating cytokine levels using comprehensive analysis. After the 12-week lifestyle modifications, body mass was markedly decreased. Also, baPWV and the levels of several circulating cytokines significantly decreased after the lifestyle modifications. We observed a positive correlation between changes in baPWV and circulating interleukin-6 (IL-6) levels. Furthermore, multiple liner regression analysis revealed that change in baPWV was significantly associated with that in IL-6 levels after consideration of changes in systolic blood pressure and body mass index. These results suggest that for overweight and obese men, a 12-week period of lifestyle modifications-induced a decrease in circulating cytokine levels (especially IL-6 levels), leads to decreased baPWV.