Effects Of Aerobic Exercise On Endothelial Function And Serum Adropin Level In Obese Adolescents

BackgroundObesity is a mild inflammatory disease, which is an important independently risk factor for cardiovascular disease.In recent years, the prevalence of obesity in both adults and children is increasing rapidly, having already become extremely common in developing and developed nations.How to detect and intervene for cardiovascular risk factors early in obese adolescents has become a hot topic at home and abroad.Vascular endothelial dysfunction is a manifestation of cardiovascular disease early, early detection and improved endothelial dysfunction is an effective strategy to reduce long-term risk of cardiovascular disease. Studies have shown that obese adolescents already exists endothelial dysfunction, and exercise intervention can significantly improve endothelial dysfunction in obese adolescents' state.Adropin is a newly discovered secreted protein, studies have reported that serum adropin level may be capable of response obese state of the human body, besides, adropin can regulate vascular endothelial function by regulating endothelial nitric oxide(NO)synthesis and release.ObjectiveTo observe the difference of endothelial function and serum adropin levels in normal weight adolescents and obese adolescents.To discuss the effect of aerobic exercise on circulating adropin levels and endothelial function in obeses adolescents.In addition, to investigate the inherent correlation of serum adropin and endothelial function.Methods45 obese adolescents were enrolled, including 36 boys and 9 girls, aged 16-19 years old.The normal-weight adolescent participants were matched for age and sex.The obese adolescents participated in a 12-week aerobic exercise training. We recorded their characteristics such as age, sex, height, weight and body composition.We also measured blood biochemical indices such as liver function, renal function,lipids, fasting blood glucose and fasting serum insulin. Additionally, we measured serum adropin level by enzyme linked immunosorbent assay(ELISA). We also performed Endo-PAT2000 measured vascular reactive hyperemia index(RHI).Result1. Obese adolescents serum adropin levels [(2.64 ± 0.93) ng / ml vs.(3.23 ± 0.87)ng / ml, p = 0.018] and vascular reactive hyperemia index(RHI) [(1.70 ± 0.37) vs.(2.03 ± 0.43), p = 0.002] were significantly lower than normal weight adolescents.2. After weight loss programme, obese adolescents total cholesterol, low-density lipoprotein cholesterol, fasting glucose, fasting insulin and insulin resistance index were significantly decreased, besides, high-density lipoprotein cholesterol levels were significantly increased. In addition, Serum adropin levels [(2.64 ± 0.93) ng vs. 3.57 ±0.95 ng, p <0.01] and vascular reactive hyperemia index [(1.70 ± 0.37) vs.(1.84 ±0.29), p <0.01] were significantly increased after weight loss programme but were independent of changes of body weitht.3. In all 65 subject, pearson correlation analysis displayed that serum adropin was related to high density lipoprotein(r=0.389, p<0.01), vascular reactive hyperemia index(r = 0.32, p<0.01),diastolic blood pressure(r=-0.272, p<0.05), body weight(r=-0.35, p<0.01), BMI(r=-0.248, p<0.05), waist-hip ratio(r=-0.335, p<0.01), alanine aminotransferase(r=-0.313, p<0.05), uric acid(r=-0.424, p<0.01), triglycerides(r=-0.316, p=0.01), fasting plasma glucose(r =-0.266, p<0.05), insulin(r=-0.41,p<0.01) and insulin resistance index(r =-0.44, p<0.01). Multiple linear stepwise regression analysis revealed that insulin resistance index(t=-3.301, p<0.01) and HDL-C were independently correlated with adropin.4. In the obese adolescents, training-induced changes in RHI were positively correlated with training-induced change in systolic blood pressure(r =0.317, p <0.05),training-induced change in creatinine(r=0.322, p<0.05), and training-induced change in serum adropin concentration(r=0.445,p<0.01). Futhermore, multiple linear stepwise regression analysis showed that training-induced change in serum adropinlevels was independent factor of training-induced changes in RHI(t=3.261, P <0.01).Conclusion1. Obese adolescents' serum adropin levels and RHI were significantly lower than normal body weight.Furthermore, a program of 12-wk aerobic exercise training in obese adolescents increased the levels of serum adropin and RHI, and these improvements were independent of changes in body weight.2. Serum adropin was significantly correlated with HDL-C, TG, glucose and insulin.Thus adropin may play an important role in regulating glucose and lipid metabolism.3. We observed positive correlation between the training-induced changes in serum adropin level and RHI. Therefore the increased in serum adropin level in response to aerobic exercise training may be related to the increase RHI in obese adolescents.