Prevalence and Predictors of Restless Legs Syndrome in Patients Having Chronic Obstructive Pulmonary Diseases: A Systematic Review and Meta-analysis

Limited studies have examined the prevalence of restless legs syndrome (RLS) among patients with chronic obstructive pulmonary disease (COPD) including its correlates and impact, with varying results suggesting a need for systematic review and meta-analysis to address this important issue. Despite a careful search by authors, a systematic review and/ or meta-analysis was not found and hence, present study was planned.

To address the research question, a systematic literature search was carried out with the keywords “RLS” OR “restless legs syndrome” AND “COPD” OR “chronic obstructive pulmonary disease” OR “COAD” OR “chronic obstructive airway disease” in three databases: Pubmed, Scopus and Google Scholar between 8th June 2021 to 20th July 2021. A total of 69,298 articles were found across these databases. Studies were included if they had assessed proportion of RLS with or without control group in human subjects suffering from stable COPD as the primary end-point, assessment of RLS was done through clinical diagnosis or a screening tool, sample size was greater than 30 and studies published in English language.

Total eight studies were included in the meta-analysis with a total of 10,749 participants in cross sectional studies. Meta-analysis suggested that patients with COPD have higher prevalence of RLS compared to control population or prevalence in general adult population (Cumulative log OR = 4.86; 95% CI 1.70–13.92; t = 3.55; P < 0.009). A significant effect of geographic area was observed on the occurrence of RLS. Subgroup analysis by geographic area depicted that while odds ratio was greater for studies from Brazil, India and Turkey than the overall odd ratio, for other areas e.g., Iran, Italy, and Sweden it was lower than cumulative odds ratio. It appears that non-validated methods of diagnosis of RLS were likely to provide greater prevalence compared to validated method. Studies included in the meta-analysis had clinical, methodological as well as statistical heterogeneity.

Present study showed that prevalence of RLS is higher among patients having COPD. However, factors which increase the risk for RLS remain to be examined in future studies.