Abstract / Summary
Abstract Background Metabolic syndrome (MetS) is a major risk factor for type 2 diabetes mellitus and cardiovascular disease. This systematic review and network meta-analysis compared the effects of different exercise regimens on metabolic outcomes in adults with MetS. Methods Randomized controlled trials (RCTs) examining exercise interventions in adults aged ≥ 18 years with MetS were included. PubMed, Web of Science, the Cochrane Library, Embase, CNKI, VIP, CBM, and the Wanfang Database were searched. Risk of bias was assessed using the Cochrane risk-of-bias tool, and confidence in the network estimates was evaluated using CINeMA. Treatment effects were expressed as mean differences (MDs) with 95% confidence intervals (CIs). Results Forty-five publications derived from 42 unique RCTs involving 3,998 participants evaluated seven exercise modalities: moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), resistance training (RT), MICT combined with RT (MICT + RT), HIIT combined with RT (HIIT + RT), whole-body electromyostimulation (WB-EMS), and stretching-toning-balance training (STBT). Based on the SUCRA rankings, HIIT + RT ranked highest for reducing waist circumference (MD, -7.09 cm; 95% CI, -13.41 to -0.77). MICT + RT ranked highest for reducing systolic blood pressure (MD, -14.22 mmHg; 95% CI, -21.90 to -6.54), diastolic blood pressure (MD, -6.96 mmHg; 95% CI, -11.60 to -2.33), HOMA-IR (MD, -1.87; 95% CI, -3.06 to -0.67), and MetS-Z (MD, -3.74; 95% CI, -5.63 to -1.85). STBT ranked highest for reducing triglycerides (MD, -0.39 mmol/L; 95% CI, -0.51 to -0.26) and increasing HDL-C (MD, 0.10 mmol/L; 95% CI, 0.04 to 0.16). Most network estimates were supported by low- or very low-certainty evidence. Conclusion Exercise may improve metabolic outcomes in adults with MetS, with different modalities showing potentially different effects across outcomes. However, because most estimates were supported by low- or very low-certainty evidence and approximately half of the included reports were judged to be at high risk of bias, the SUCRA rankings should be regarded as exploratory rather than definitive evidence of superiority. Further large, well-designed RCTs are required. Trial registration PROSPERO (ID: CRD420261358745 https://www.crd.york.ac.uk/PROSPERO/view/CRD420261358745 ).