Effect of exercise on abdominal obesity and inflammatory response in the older adults: a systematic review and meta-analysis of randomized controlled trials

Background Abdominal obesity and chronic inflammation are key indicators of aging, associated with various age-related diseases. While exercise is thought to mitigate these issues, its specific effects on abdominal obesity, adiponectin, and inflammatory markers in older adults need further exploration. Objective This systematic review and meta-analysis aimed to evaluate the effects of exercise on abdominal obesity, adiponectin, and inflammation markers in older adults. Methods A search was conducted up to February 20, 2025, using six electronic databases (Medline, Web of Science, Embase, CINHAL, Scopus, and Cochrane). The inclusion criteria focused on randomized controlled trials assessing exercise interventions in healthy older adults or those with obesity, diabetes, or metabolic syndrome (MetS). Relevant citations were analyzed using Rayyan software, while the quality of studies was assessed with the Cochrane risk of bias tool, and data were meta-analyzed using Review Manager (RevMan) 5.4 software. Results From 7,622 citations, 128 articles were screened for full text, resulting in 19 RCTs with 1,130 participants included. The meta-analysis indicated that exercise (aerobic, resistance, or combined training) significantly reduced abdominal obesity, demonstrated by a decrease in waist circumference (WC) with a mean difference (MD) of −2.03 cm (95% confidence interval [CI]: −4.06 to −0.01, p = 0.05) and body mass index (BMI) with an MD of −0.49 kg/m 2 (95% CI: −0.70 to −0.27, p < 0.0001). Furthermore, exercise lowered levels of C-reactive protein (CRP, MD = −0.07 mg/L, 95% CI: −0.13 to −0.02, p = 0.006), tumor necrosis factor-α (TNF-α, MD = −0.66 pg/mL, 95% CI: −1.07 to −0.25, p = 0.002), and interleukin-6 (IL-6, MD = −0.33 pg/mL, 95% CI: −0.60 to −0.05, p = 0.02). Key subgroup findings included: (1) Obese older adults and those with MetS experienced 2–3 times greater WC reduction than healthy peers; (2) Vigorous physical activity (VPA) was more effective than moderate-to-vigorous physical activity (MVPA) in lowering TNF-α; (3) Short-term interventions (