Effect of Diet and Exercise-induced Weight Reduction on Complement Regulatory Proteins CD55 and CD59 Levels in Overweight Chinese Adolescents

Recent studies have suggested that complement plays an important role in adipose tissue homeostasis and insulin resistance, but the involvement of complement regulatory (CReg) proteins in obesity has not been elucidated. In this study, we examined whether weight reduction induced changes in the levels of the CReg proteins CD55 (decay accelerating factor) and CD59 (membrane attack complex inhibitory factor) on blood cells, before and after a 4-week diet and physical exercise intervention. Fourteen overweight Chinese adolescents with a body mass index > 25 kg·(m2)−1 were enrolled, 12 of whom completed the study. CD55 and CD59 levels on cell surfaces were assessed by flow cytometry. It was observed that anthropometric parameters, serum lipid levels, and glycemic-related factors improved significantly post-intervention. On all cells, the CD59 level was significantly increased post-intervention, while the CD55 level on lymphocytes and neutrophils was significantly decreased post-intervention. The pre-intervention CD55 level on lymphocytes positively correlated with the pre-intervention percent body fat (r = 0.737, p < 0.01). This correlation remained significant (r = 0.737, p < 0.01) post-intervention. In conclusion, these observations show that a 4-week diet and exercise program in overweight Chinese adolescents improved physical characteristics, anthropometric parameters, serum lipid levels, and glycemic-related factors. The CD55 level on lymphocytes correlates with percent body fat. Therefore, adipose-derived factors may constitute possible targets for ameliorating overweight and obesity and its adverse metabolic consequences.