Effects of exercise on C-reactive protein, inflammatory cytokine and adipokine in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

Objective C-reactive protein (CRP), inflammatory cytokines, and adipokines contribute to atherosclerosis, insulin resistance, and development of late-onset complication in patients with type 2 diabetes. We performed a systematic review to assess effects of exercise interventions on inflammatory markers/cytokines and adipokines. Materials/Methods We searched electronic databases (MEDLINE, EMBASE, and Cochrane Controlled Trials Registry) and reference lists in relevant papers for articles published in 1966-2013. We selected studies that evaluated the effects of exercise intervention on inflammatory markers/cytokines and adipokines in adult patients with type 2 diabetes. Weighted mean differences of exercise on outcomes were derived using fixed or random effect models; factors influencing heterogeneity were identified using meta-regression analysis. Results Fourteen randomized controlled trials (824 patients) were included in our meta-analysis. Exercise was associated with a significant in CRP = - 0.66 mg/l (95% CI, - 1.09 to - 0.23 mg/l; - 14% from baseline) and interleukin-6 (IL-6) = - 0.88 pg/ml (95% CI, - 1.44 to - 0.32 pg/ml; - 18% from baseline) but did not alter adiponectin or resistin levels; aerobic exercise program was associated with a significant change in leptin = - 3.72 ng/ml (95% CI, - 6.26 to - 1.18 ng/ml; - 24% from baseline). For IL-6, exercise was more effective in those with a longer duration in the program and larger number of sessions during study (p = 0.001). Conclusions Exercise decreases inflammatory cytokine (CRP and IL-6) in patients with type 2 diabetes. Exercise could be a therapeutic option for improving abnormalities in inflammation levels in patients with diabetes.