The Impact of Resistance Training on IL-6, TNF-a, and CRP Levels in the Elderly: A Systematic Review and Meta-Analysis Study

Abstract

Background: Inflammatory markers have been linked to an increased risk of cardiovascular diseases including atherosclerosis, coronary artery disease, and heart failure in the elderly individuals. Resistance exercises are one effective method to manage inflammation in this population. Objectives: This meta-analysis aimed to explore the impact of resistance training on inflammatory markers in the elderly. Methods: All randomized controlled clinical trials (from 2004 to 2023) that examined the effect of resistance training on tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), and C-reactive protein (CRP) in individuals over 50 years old were selected through a systematic search of PubMed, Google Scholar, Web of Science and SID databases, that out of 600 studies identified, 31 met the inclusion criteria for our analysis. Random and fixed effects models, along with the I2 heterogeneity test, Egger test, and funnel plot, were used to determine publication bias using CMA2 software. The effect size (ES) was reported in terms of the standard mean difference (SMD) and a 95% confidence interval (CI). Results: The meta-analysis results indicated that resistance training significantly reduced CRP (ES = -0.49, 95% CI = -0.34 to -0.64, P = 0.001) and IL-6 (ES = -0.27, 95% CI = -0.41 to -0.13, P = 0.001) levels. However, it did not have a significant effect on TNF-α levels (ES = -0.22, 95% CI = 0.02 to -0.47, P = 0.075). Subgroup analyses revealed that resistance training for more than 16 weeks and a training frequency of three times a week led to a greater decrease in CRP and IL-6 levels in the elderly. <b>Conclusions:</b> The findings of this meta-analysis suggest a significant decrease in CRP and IL-6 levels in the elderly due to resistance training. Furthermore, the subgroup analysis indicated that higher training volumes (training duration and frequency) result in a greater reduction in these markers' levels. Based on these findings, it is advisable for elderly individuals to consider incorporating resistance training into their regular exercise routines.