Effects of pulmonary rehabilitation on systemic inflammation in chronic obstructive pulmonary disease: a meta-analysis

Chronic obstructive pulmonary disease (COPD) is marked by both lung-related and systemic symptoms, notably chronic inflammation. Despite pulmonary rehabilitation (PR) being a critical treatment for COPD, its influence on systemic inflammation remains unclear. This meta-analysis was conducted to assess PR's effect on circulating inflammatory markers in COPD patients. We systematically reviewed databases like PubMed, EMBASE, and Web of Science to select randomized controlled trials and observational studies that investigated the impact of PR on systemic inflammation. We calculated the mean differences (MD) in inflammatory markers before and after PR using a random-effects model and assessed the risk of bias with established tools. Our study included six investigations (four RCTs, two observational) with 147 COPD patients. Our findings show notable increases in IL-6 (MD 0.44, 95% CI 0.17-0.70, P = 0.001), CRP (MD 0.56, 95% CI 0.31-0.81, P<0.00001), and TNF-alpha (MD 0.41, 95% CI 0.12-0.70, P = 0.005) following PR. However, sensitivity analysis pinpointed the study by El-Kader et al. as a key influence on these results. Excluding this study led to nonsignificant changes. Thus, our meta-analysis uncovers an unanticipated rise in inflammatory markers post-PR in COPD patients, questioning the assumed anti-inflammatory benefits of PR.