Exercise training-induced changes in exerkine concentrations may be relevant to the metabolic control of type 2 diabetes mellitus patients:A systematic review and meta-analysis of randomized controlled trials

Background:This study investigates the effects of exercise training on exerkines in patients with type 2 diabetes mellitus to determine the opti-mal exercise prescription.Methods:A systematic search for relevant studies was performed in 3 databases.Randomized controlled trials investigating the effects of exer-cise training on at least one of the following exerkines were included:adiponectin,apelin,brain-derived neurotrophic factor,fetuin-A,fibroblast growth factor-21,follistatin,ghrelin,interleukin(IL)-6,IL-8,IL-10,IL-15,IL-18,leptin,myostatin,omentin,resistin,retinol-binding protein 4,tumor necrosis factor-α,and visfatin.Results:Forty randomized controlled trials were selected for data extraction(n=2160).Exercise training induces changes in adiponectin,fetuin-A,fibroblast growth factor-21,IL-6,IL-10,leptin,resistin,and tumor necrosis factor-α levels but has no significant effects on apelin,IL-18,and ghrelin compared to controls.Physical exercise training favored large and positive changes in pooled exerkines(i.e.,an overall effect size calculated from several exerkines)(Hedge's g=1.02,95％confidence interval(95％CI):0.76-1.28),which in turn were related to changes in glycated hemoglobin(mean difference(MD)=-0.81％,95％CI:-0.95％to-0.67％),fasting glucose(MD=-23.43 mg/dL,95％CI:-30.07 mg/dL to-16.80 mg/dL),waist circumference(MD=-3.04 cm,95％CI:-4.02 cm to-2.07 cm),and body mass(MD=-1.93 kg,95％CI:-2.00 kg to-1.86 kg).Slightly stronger effects were observed with aerobic,resistance,or high-intensity interval protocols at moderate-to vigorous-intensity and with programs longer than 24 weeks that comprise at least 3 sessions per week and more than 60 min per session.Conclusion:Exercise training represents an anti-inflammatory therapy and metabolism-improving strategy with minimal side effects for patients with type 2 diabetes mellitus.