Effects of aerobic exercise on components of the metabolic syndrome in older adults with type 2 diabetes mellitus: systematic review and meta-analysis.

Abstract

To determine the effects of aerobic exercise on the components of the metabolic syndrome in older adult diabetic patients by means of a systematic review with meta-analysis. We used the PubMed/Medline, Scopus, Cochrane library, Web of Science databases and the Google Scholar search engine. Randomized controlled trials (RCTs) were selected according to the inclusion criteria. Two reviewers independently determined whether studies met the inclusion criteria, extracted data, and used the Cochrane risk of bias tool (RoB 2). Quantitative analyses were performed in R v 4.0.5, using random effects. We identified 8697 studies, of which 7 RCTs were included in the qualitative synthesis. Most studies were assessed as having a high or low RoB in at least three domains. Meta-analysis showed that aerobic exercise was effective in improving glucose levels (standardized mean difference [SMD]: -1.04; 95% confidence interval [95% CI] -1.27, -0.81), systolic blood pressure (SMD: -0.79; 95% CI: -1.02, -0.56), diastolic blood pressure (SMD: -0.75; 95% CI: -0.98, -0.52), glycosylated hemoglobin (SMD: -0.57, 95% CI: -0.77, -0.37), HDL (SMD: 0.35, 95% CI: 0.15, 0.55), triglycerides (SMD: -0.26, 95% CI: -0.47, -0.06). No significant adverse effects were reported. The level of certainty of the results was low for fasting glucose, moderate for systolic and diastolic blood pressure, and very low for the other outcomes, in addition to few adverse effects. However, these results should be interpreted with caution due to the use of surrogate markers. Aerobic exercise was shown to have a significant improvement in the components of the metabolic syndrome in older diabetic adults, and no major adverse effects were reported. However, we recommend more RCTs with longer intervention time to establish the impact on symptoms and complications.