Restless legs syndrome: A new comorbidity in idiopathic pulmonary fibrosis

Objective: Sleep disorders have a high prevalence among patients with idiopathic pulmonary fibrosis (IPF). The prevalence of restless legs syndrome (RLS) is not known in these patients, neither is its clinical impact as a comorbidity. We investigated the association of RLS with IPF and characterized the clinical features of RLS in a cohort of IPF patients. Methods: Fifty patients with diagnosis of IPF were prospectively enrolled. RLS was diagnosed using the validated 5-item RLS criteria. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index. The prevalence of RLS in the IPF group was compared to that observed in a group of 293 patients referred for suspect of sleep disorders. The relationships between RLS and clinical parameters were determined using multivariate logistic regression. Results: Prevalence of RLS in the IPF group was significantly higher than in the control population of patients referred for sleep disorders (IPF: 24%, controls 10%: χ2 6.49, p = 0.011). Higher PSQI score confirmed to be associated with RLS after adjusting for demographics and clinical parameters of disease severity (OR = 1.38, 95%CI 1.08–1.76; p = 0.01). Conclusions: RLS is highly prevalent in IPF and significantly worsen sleep quality in these patients. The benefit/risk ratio of a specific therapeutic intervention for RLS in IPF should be assessed in further prospective research.