Hypoadiponectinemia, Type 2 Diabetes, Ethnicity, and Exercise Training: A Meta-Analysis of Iranian Randomized Controlled Clinical Trials

Abstract

Background and objectives: Considering racial/ethnic differences is necessary when recommending lifestyle modifications for patients with diabetes. Racial/ethnic diversity may affect hypoadiponectinemia responses to exercise training among individuals with type 2 diabetes. This systematic review and meta-analysis is the first to investigate effects of exercise training on circulating adiponectin concentrations in Iranians with type 2 diabetes. Methods: Literature searches of the Cochrane Central Register of Controlled Trials were carried out using the following search strategy: [exercise OR training OR physical activity OR Training] AND diabetes AND adiponectin. Next, RCTs were included and compared with each type of supervised exercise (aerobic training, resistance training, or combined training). Pooled intervention effects were evaluated and reported as standardized mean difference (MD) and 95% confidence intervals using a random effects model. Subgroup and sensitivity analysis was performed for study heterogeneity and following primary screening full text of the articles was evaluated. Results: Fourteen studies with 444 individuals (236 men and 128 women) were included in the analysis. The age of the participants ranged between 18 and 60 years. The number of exercise sessions per week ranged between 3 and 5. The duration of interventions ranged between 6 and 12 weeks. The meta-analysis showed that adiponectin levels increased significantly in diabetic subjects after physical activity (MD: 0.72 ng/dl, p <0.001,), but the heterogeneity of the study remained significant (I 2 = 89%). Conclusion: Overall, physical exercise, particularly aerobic exercise, increases adiponectin levels in Iranians with diabetes. However, this effect of exercise may be influenced by race/ethnic differences, type of training, frequency, type of adiponectin measurement, and complex and heterogeneous exercise responses of individual with diabetes.