The Impact of Exercise on Interleukin-6 to Counteract Immunosenescence: Methodological Quality and Overview of Systematic Reviews

Abstract

Objective: This study evaluated the methodological quality of published systematic reviews on randomized and non-randomized clinical trials to synthesize evidence on the association between IL-6, immunosenescence, and aerobic and/or resistance exercise. Method: The Preferred Reporting Items for Overviews of Systematic Reviews (PRIO-harms) guideline was used, with registration number CRD42022346142-PROSPERO. Relevant databases such as Cochrane Library, PubMed, Web of Science, Scopus, and Google Scholar were searched using English Medical Subject Headings terms. Inclusion criteria were systematic reviews analyzing aerobic exercise, resistance exercise, or a combination of both and assessing IL-6 as a biomarker of cellular immunosenescence in humans. The Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) was employed. Results: Out of 742 identified articles, 18 were eligible, and 13 were selected for analysis. Sample sizes ranged from 249 to 1421 participants, mostly female, with ages ranging from 17 to 95 years. Aerobic exercise was the most studied type (46.15%), followed by combined exercise (38.46%) and resistance exercise (15.38%). Aerobic exercise showed a statistically significant reduction in IL-6, C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) levels. Among the 13 reviews analyzed using AMSTAR-2, 8 were rated as critically low quality, and 5 were classified as low quality. Conclusion: Aerobic exercise has anti-inflammatory properties and the potential to modulate IL-6, CRP, and TNF-α levels in immunosenescence. However, the limited methodological quality of the analyzed systematic reviews highlights the urgent need for robust, high-quality studies to improve access to information and facilitate evidence-based decision-making in healthcare.