Exercise-induced changes in systemic inflammatory biomarkers in overweight and obese populations: a bibliometric analysis and umbrella review of meta-analyses.

BACKGROUND

Systemic chronic low-grade inflammation contributes to obesity-related comorbidities. Exercise is widely recommended as a non-pharmacological strategy, but evidence regarding its biomarker-specific anti-inflammatory effects remains fragmented. This study integrated bibliometric analysis with an umbrella review to map global trends and evaluate the certainty of evidence regarding exercise-induced immunomodulation in overweight and obese populations.

METHODS

Bibliometric data from 2005 to 2025 were retrieved from the Web of Science Core Collection to map publication trends, knowledge structure, and emerging research topics. Concurrently, a comprehensive search across five databases through December 1, 2025 identified pairwise meta-analyses of randomized controlled trials (RCTs). Methodological quality and primary-study overlap were evaluated using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2), Risk of Bias in Systematic Reviews (ROBIS), and the corrected covered area (CCA). Pooled standardized mean differences (SMDs) were re-estimated using random-effects models, and evidence certainty was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

The bibliometric analysis of 12,101 records revealed a shift in research emphasis toward mechanism-oriented topics, including cellular immune crosstalk and inflammatory pathway regulation. The umbrella review included 25 meta-analyses encompassing 342 RCTs (>30,000 participants). Class II evidence supported exercise-related reductions in C-reactive protein (CRP) (SMD = -0.29, 95% confidence interval [CI]: -0.35 to -0.23), interleukin-1β (IL-1β) (SMD = -0.43, 95% CI: -0.70 to -0.17), and interleukin-8 (IL-8) (SMD = -0.32, 95% CI: -0.50 to -0.14). The IL-1β estimate demonstrated improved consistency following sensitivity analysis. Tumor necrosis factor-α (TNF-α) showed Class III evidence, whereas interleukin-6 (IL-6), leptin, adiponectin, and interleukin-18 (IL-18) were supported by Class IV evidence, mainly because of substantial heterogeneity, publication bias, limited information size, or high review overlap. Interleukin-10 (IL-10) showed no significant systemic response (SMD = 0.18, 95% CI: -0.10 to 0.45; Class V).

CONCLUSIONS

Exercise is associated with favorable changes in several systemic inflammatory biomarkers in overweight and obese populations, with the most consistent evidence for CRP, IL-1β, and IL-8. Nevertheless, evidence maturity remains uneven across biomarkers, underscoring the need for better-standardized and adequately powered randomized trials to support precision exercise prescription.

SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/, identifier CRD420251246180.