Background: The prevalence of type 2 diabetes mellitus (T2DM) presents a challenge for health organizations because of its high likelihood of morbidity and mortality. There is an increasing body of evidence exploring the efficacy of resistance training (RT) alone on glycemic control. Objective: To update the effectiveness of RT on glycosylated hemoglobin (HbA1c) and fasting glucose in adults diagnosed with T2DM. Methods: CINAHL (EBSDCO), PubMed, MEDLINE (Ovid), and EMBASE (Ovid) databases were searched from inception to 30 January 2024. Published randomized controlled trials (RCTs) of adult humans with T2DM assessing the impact of RT on HbA1c and fasting glucose compared with control condition were included. Data were pooled by the inverse-variance method and reported as mean differences (MDs) with 95% confidence intervals (CIs). Results: Forty-six RCTs totaling 2130 participants met the inclusion criteria. Meta-analysis demonstrated RT significantly reduced HbA1c (MD -0.50% [95% CI, -0.67, -0.34 %], p < .00,001) and fasting glucose (MD -12.03 mg/dl [95% CI, -19.36, -4.69 mg/dl], p = .001). Subgroup analyses found that exercise training durations, gender, and risk of bias had statistically significant effects on HbA1c levels and fasting glucose concentrations after resistance training. However, meta-regression analyses revealed that variables including year of publication, number of sessions per week, mean sample age, sample size, and study quality scores did not significantly affect the change in either HbA1c or glucose. Conclusion: Our meta-analysis with meta-regression delivers further evidence that RT programs are effective approach in attenuation of HbA1c and fasting glucose in individuals with T2DM.
Keywords: fasting blood sugar; glycosylated hemoglobin; meta-analysis; resistance exercise; type 2 diabetes.