Prevalence and influencing factors of sarcopenia among patients with knee osteoarthritis: a systematic review and meta-analysis protocol

Introduction Epidemiological literature indicates that sarcopenia (SA) is increasingly prevalent among patients with knee osteoarthritis (KOA). This study aims to provide the pooled prevalence of SA and identify determinant factors associated with SA among patients with KOA.Methods and analysis This systematic review follows Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) auxiliary writing checklist. A thorough literature review and systematic search will be performed using the electronic databases of PubMed, Web of Science, Embase, CNKI and WanFang, covering the period from the earliest records until 11 September 2024. Reference lists of the eligible studies will also be carried out. The search strategy will be based on two main concepts, namely 'knee osteoarthritis' and 'sarcopenia', taking the form of a combination of MeSH terms and entry terms to find literature. Two reviewers will independently evaluate each title and abstract. All observational studies documenting the prevalence of SA and/or associated factors in KOA will be included. The prevalence of SA will be subjected to a single-group meta-analysis using Stata 18.0 software. Pooled prevalence with a 95% CI will be calculated using random effects and quality-effects models. The pooled relative hazards will be calculated using a random-effects Meta-analysis. The main analysis results will include differences in the prevalence of SA in KOA patients by diagnostic criteria, course of KOA, disease status (eg, knee pain, disease duration), physical activity, diagnostic criteria and different geographical contexts. Secondary results may analyse subgroups such as gender and age, and further, a meta-regression analysis will be used to synthesise the factors influencing SA. Sensitivity analyses and heterogeneity between studies and evidence of publication bias will also be assessed.Ethics and dissemination This review will summarise the prevalence and influencing factors of SA in patients with KOA based on existing evidence. It is expected that the results will identify gaps in knowledge and areas for further research. The review will be submitted for publication in topic specific journals and disseminated to professional networks. Individual patient data are not included, so ethical approval is not required.PROSPERO registration number CRD42023490539.