Snoring is Associated with an Impaired Motor Function, Disease Severity and the Quality of Life but not with Excessive Daytime Sleepiness in Patients with Parkinson's Disease

Abstract

There are conflicting results regarding the frequency and clinical significance of sleep related breathing disorders in patients with Parkinson's disease (PD). The aim of this study was to investigate the relationship between snoring and its clinical correlates in patients with PD. A total of 93 PD patients and 93 controls were analyzed from a previously conducted cross-sectional study. Snoring was defined as a snoring frequency of ≥ 2 days/week (a score of 2 or higher on the PD Sleep Scale-2 subitem 15). Excessive daytime sleepiness (EDS) was defined as an Epworth Sleepiness Scale score of ≥ 10. Snoring was more prevalent in the patients with PD than in the controls (14.0% vs. 1.1%). The PD patients who snored exhibited greater disease severity, worse scores on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) and the Parkinson fatigue scale and more impaired scores in several domains of the Parkinson's Disease Questionnaire, including the domains of mobility, activities of daily living, emotional well-being, communication and bodily discomfort, when compared to those who did not snore. No between-group differences were found in EDS. A higher proportion of the UPDRS motor scores for bradykinesia was seen in the PD patients who snored compared to that observed in the PD patients who did not snore. We found that snoring was more frequent in PD patients than in controls. Furthermore, snoring in PD patients was associated with disease severity, an impaired motor function and a decreased quality of life, although it was not associated with EDS.