Protocol for a systematic review of the associations between inflammatory markers and lung function, muscle force and exercise capacity in people with COPD

INTRODUCTION: The prevalence of chronic obstructive pulmonary disease (COPD) has been on the rise, with acute exacerbation of COPD associated with the highest burden and multiple pulmonary and systemic consequences. People with COPD have been found to have an abnormal response of systemic inflammation. To date, although limited, there are studies that suggest negative associations between inflammatory markers and important clinical outcomes such as exercise capacity and muscle force. This protocol aims to systematically review the evidence for (i) the associations between inflammatory markers and lung function, muscle force and exercise capacity and (ii) the influence of other factors (eg, hospitalisation, exercise programme) on the level of inflammatory markers in people with COPD.

METHODS AND ANALYSIS: Scopus, PubMed, Cochrane, Web of Science and ProQuest will be searched from database inception to February 2023 using PEO search strategy (Population: adults with COPD; Exposure: inflammatory markers; Outcomes: lung function, muscle force and exercise capacity). Four reviewers working in pairs will independently screen articles for eligibility and extract data that fulfilled the inclusion criteria. Depending on the design of the included studies, either Cochrane risk-of-bias version 2 or the Newcastle-Ottawa Scale tools will be used to rate the methodological quality of the included studies. Effect sizes reported in each individual study will be standardised to Cohen's d and a random effects model will be used to calculate the pooled effect size for the association.

ETHICS AND DISSEMINATION: Ethical approval is unnecessary as this study will only use publicly available data. The findings will be disseminated through publication in peer-reviewed journals and conferences.

PROSPERO REGISTRATION NUMBER: CRD42022284446.