Periodic limb movements during sleep may reduce excessive daytime sleepiness in men with obstructive sleep apnea

Purpose The impact of periodic limb movements during sleep (PLMS) on excessive daytime sleepiness (EDS) is controversial. We investigated the relationship between PLMS and EDS in men with obstructive sleep apnea (OSA). Methods This was a cross-sectional study of men with OSA. PLMS parameters were a PLM index (PLMI) > 15 per hour of sleep and a PLM-arousal index (PLMAI) > 5 per hour of sleep. The Epworth Sleepiness Scale (ESS) and the Beck Depression Inventory were used. EDS was defined as an ESS score >= 11. Multivariate logistic regression analysis was performed with adjustments for several covariates. Results Of 1111 men with OSA, 14.0% (n = 156) had a PLMI > 15/h, and 3.7% (n = 41) had a PLMAI > 5/h. EDS was noted in 39.5% (n = 439) of men. Men with a PLMI > 15/h were less likely to have EDS (odd ratio [OR], 0.598; 95% confidence interval [CI], 0.414-0.864; p = 0.006). This association remained significant after controlling for age, body mass index, depressive symptoms, total sleep time, and severity of OSA (OR, 0.675; 95% CI, 0.456-0.999; p = 0.049). Men with a PLMAI > 5/h were less likely to have EDS, but this result did not reach statistical significance (OR, 0.550; 95% CI, 0.273-1.109; p = 0.095). Conclusions PLMS defined as PLMI > 15/h are significantly and inversely associated with EDS in men with OSA, even after controlling for several confounding variables.