Impact of periodic leg movements on prognosis in patients with sleep-disordered breathing and cardiovascular disease, treating with positive airway pressure devices

Abstract

Background: Periodic leg movements (PLMs) are a disorder characterized by regularly recurring movements of the legs during sleep. It is unclear that PLMs contributes to poor prognosis in patients with cardiovascular disease (CVD) and sleep-disordered breathing (SDB). The aim of this observational study is to determine whether the presence of PLMs affect the long-term outcomes in the patients with CVD and SDB, treating with positive airway pressure (PAP) devices. Methods and results: We studied 181 SDB (apnea-hypopnea index [AHI] ≥15) patients with a history of hospitalization due to CVD, who diagnosed by overnight polysomnography and then treated with PAP devices for secondary prevention. The frequency of PLMs per hour of sleep was quantified as the PLM index (PLMI). Eighty five patients who could continue with PAP therapy were enrolled. They were classified into 2 groups; PLMs group (PLMI ≥30/h) and non-PLMs group (PLMI <30/h). The main outcome measures were cardiovascular death and hospitalization due to CVD during 24 months follow-up. A figure illustrates Kaplan-Meier curves. The hazard ratio was calculated using the Cox proportional hazard model. The univariate predictors of the main outcome were hemoglobin, estimated glomerular filtration rate, brain natriuretic peptide (BNP), left ventricular ejection fraction and PLMI ≥30/h. The multivariate analysis revealed that PLMI ≥30/h (HR, 3.19; 95% CI, 1.07-9.48; p=0.037) and BNP (HR, 1.002; 95% CI, 1.00-1.04; p=0.01) were significantly independent variables for cardiovascular events. ![Figure][1] Kaplan-Meier event free survival curves Conclusion: The PLMs affects long-term cardiovascular outcomes in patients with CVD and SDB, treating with PAP devices. [1]: pending:yes