Resistance training enhances metabolic and muscular health and reduces systemic inflammation in middle-aged and older adults with type 2 diabetes: a meta-analysis

This meta-analysis evaluated the effects of resistance training on insulin resistance, muscle function, and systemic inflammation in middle-aged and older adults (aged 50 years and older) with type 2 diabetes mellitus (T2DM). PubMed, Web of Science, Scopus, and Cochrane CENTRAL were systematically searched from their inception to May 20, 2025. Forty-three randomized controlled trials (n = 2012 (55.8 % women); mean age 57.8 ± 8.4 years; mean BMI 30.9 ± 3.8 kg/m(2)) were included. Resistance training was associated with improvements in markers of insulin resistance, including insulin (mean difference: MD -1.35 μIU/mL), HOMA-IR (MD -1.15), fasting glucose (MD -6.99 mg/dL), and HbA1c (MD -0.55 %), as well as a modest reduction in BMI (MD -0.37 kg/m(2)). Furthermore, resistance training increased muscle mass (MD 0.89 kg) and both upper-body (standardized mean difference: SMD 2.28) and lower-body strength (SMD 2.02). A significant reduction in C-reactive protein (CRP; SMD -0.80) was observed, though no significant changes were found for tumor necrosis factor-α (TNF-α) or interleukin-6 (IL-6). Overall, resistance training provides consistent benefits for insulin sensitivity, muscle function, and systemic inflammation in middle-aged and older adults with T2DM, supporting its role as an important adjunct to lifestyle-based diabetes management strategies aimed at promoting healthier aging.