Effects of resistance training on C-reactive protein in menopausal and postmenopausal women: a systematic review and meta-analysis of randomized controlled trials.

IMPORTANCE: Menopause is a biological stage associated with increased cardiovascular morbidity and mortality due to changes in sex hormone levels.

OBJECTIVE: This systematic review aimed to investigate the benefits and harms of RT in menopausal and postmenopausal women.

EVIDENCE REVIEW: We searched PubMed, Embase, CENTRAL, Scopus, and Web of Science from inception to 2021, and clinical trial registries. Randomized controlled trials (RCT) in menopausal and postmenopausal women that compared women undergoing RT programs with a control group were included. The primary outcomes were C-reactive protein level and adverse events; and, the secondary outcomes were lipid profile and waist circumference. Two reviewers independently selected the studies, extracted data, and assessed the completeness of RT programs, risk of bias, and quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach (GRADE). A random-effects model was used. Statistical significance was set at P < 0.05.

FINDINGS: Twelve RCTs published from 2012 to 2020 met the inclusion criteria (n = 482). Four follow-up periods were assessed. RT caused reductions in C-reactive protein levels compared to those in the control group in postmenopausal women in the short- to long-term follow-up (mean difference, -0.47 mg/dL; 95% confidence interval, -0.66 to -0.29; P < 0.00001). Furthermore, RT may reduce C-reactive protein levels even at moderate and moderate-to-high intensity (P < 0.0001 and P = 0.0005, respectively). Similar findings were found for lipid profiles in the short- to long-term follow-up (P < 0.05). RT may have had little to no effect on waist circumference. The certainty of the body of evidence was assessed as very low and downgraded owing to serious study limitations, inconsistency, imprecision, and publication bias.

CONCLUSIONS AND RELEVANCE: There was very low-quality evidence supporting the benefits of RT compared with control for C-reactive protein levels and lipid profile. No benefits were found for the outcome of waist circumference in postmenopausal women with different comorbidities or risk factors. Safety data were scarce. We have little confidence in the results, and the true effect is likely to be substantially different. Further well-conducted and well-reported RCTs are warranted to strengthen the evidence.

PROTOCOL REGISTRATION: PROSPERO CRD42020213125.