Effects of different types of exercise on systemic metabolic health in overweight/obese patients with type 2 diabetes mellitus: a network meta-analysis

BACKGROUND: With the acceleration of global urbanization and lifestyle changes, overweight/obese patients with type 2 diabetes mellitus have become major public health challenges, and these two conditions often coexist. Exercise is recognized as a key non-pharmacological intervention in the comprehensive management of the two diseases. However, whether different exercise interventions have their respective advantages in improving blood glucose, blood lipids, body composition and cardiopulmonary function remains to be fully elucidated. METHODS: A systematic search was conducted in the PubMed, Embase, Cochrane Library, and Web of Science databases to identify randomized controlled trials involving overweight/obese patients with type 2 diabetes mellitus. After screening the literature, extracting data, and assessing the risk of bias of the included studies, a network meta-analysis was performed using Stata 16.0 software. The certainty of evidence was evaluated using the CINeMA framework. RESULTS: A total of 16 randomized controlled trials (RCTs) were included: aerobic exercise (AE), resistance training (RT), combined training (CT), and high-intensity interval exercise (HIIE). Nine studies reported glycated hemoglobin A1c (HbA1c), twelve studies assessed body mass index (BMI), and six studies measured the percentage body fat (PBF). The network meta‑analysis results showed that aerobic exercise (AE) (MD, - 0.91; 95% CI, - 1.32 to - 0.50), resistance training (RT) (MD, - 0.97; 95% CI, - 1.51 to - 0.43), combined training (CT) (MD, - 0.76; 95% CI, - 1.19 to - 0.33), and high‑intensity interval exercise (HIIE) (MD, - 1.24; 95% CI, - 1.72 to - 0.76) all demonstrated significantly lower HbA1c levels compared with the control group (CON). According to the surface under the cumulative ranking curve (SUCRA), high-intensity interval exercise ranked relatively high in reducing HbA1c in overweight/obese patients with type 2 diabetes mellitus (SUCRA = 90.2%). AE reduced BMI (MD, - 0.61; 95% CI, - 0.94 to - 0.28) and PBF (MD, - 0.66; 95% CI, - 1.29 to - 0.02) compared with CON, while no statistically significant differences were observed in the other comparisons. AE ranked relatively better for reducing both BMI (SUCRA = 92.0%) and PBF (SUCRA = 81.5%) in overweight/obese patients with type 2 diabetes mellitus. According to SUCRA values, different exercise interventions had their respective advantages across different outcome indicators. CONCLUSIONS: Different exercise modalities demonstrate distinct advantages in improving metabolic parameters. HIIE shows positive effects in improving HbA1c, FBG, lipid profiles (TC, TG, and HDL), and in reducing WC and systolic blood pressure (SBP). AE can improve body composition indicators (BMI, PBF, and BW) and enhance VO₂max. RT improves HbA1c, FBG, TC, and TG. CT improves HbA1c and FBG. In clinical practice, individualized exercise prescriptions should be formulated based on patients' specific metabolic needs.