Effects of weight loss on epicardial adipose tissue thickness and its relationship between serum soluble CD40 ligand levels in obese men

Background Epicardial adipose tissue (EAT) induces activated inflammatory cells secreting cytokines, including soluble CD40 ligand (sCD40L). In turn, the serum sCD40L can trigger inflammatory responses. We examined the reduction of EAT in response to weight loss (WL) and its relationship with alterations in sCD40L in obese men. Methods We prospectively provided dietary education and exercise intervention for 3 months for 32 non-diabetic obese men with metabolic syndrome. Twenty-five age-matched healthy men served as controls. Circulating sCD40L was measured, and EAT thickness (EATt) was determined by magnetic resonance imaging before and after WL. Results EATt was increased in the obese individuals, but there were no significant differences in baseline serum sCD40L levels between the 2 groups. Serum concentrations of sCD40L were higher in individuals with high right atrioventricular groove (RAVG)–EATt. EATt was reduced significantly in individuals who completed the weight-loss program. In addition, a positive correlation was shown between changes in sCD40L and RAVG–EATt. Multiple linear regression analysis showed the change in sCD40L to be independently associated with the change in RAVG–EATt. Conclusion WL can significantly reduce epicardial fat thickness, and the reduced EATt after WL may provide a beneficial reduction in circulating levels of sCD40L in obese males.