ObjectivesBoth sleep disorders and pain decrease quality of life in patients with Parkinson's disease (PD). However, little is known about the relationship between objective sleep disturbances and pain in patients with PD. This study aimed to (1) examine the clinical characteristics of pain in PD patients and (2) explore the correlation between pain and sleep disturbances in PD patients. MethodsParkinson's disease patients (N = 144) underwent extensive clinical evaluations of motor and nonmotor symptoms and characteristics of pain. Overnight video-polysomnography was also conducted. Clinical characteristics and sleep parameters were compared between PD patients with or without pain. ResultsPain was reported by 75 patients (52.1%), with 49 (65.3%) reporting pain of at least moderate severity. PD patients with pain were older and had longer disease duration, more severe PD symptoms as assessed by Hoehn and Yahr stage and the Unified Parkinson's Disease Rating Scale, and higher L-dopa equivalent daily dose compared with PD patients without pain. PD patients with pain also showed significantly decreased sleep efficiency (57.06% 15.84% vs. 73.80% +/- 12.00%, P < 0.001), increased nonrapid eye movement stage 1 (N1) sleep (33.38% +/- 19.32% vs. 17.84% +/- 8.48%, P < 0.001), and decreased rapid eye movement sleep (12.76% +/- 8.24% vs. 16.06% +/- 6.53%, P = 0.009). Binary logistic regression analysis revealed that poorer activities of daily living, depressed mood, higher percentage of N1 sleep, and lower sleep efficiency were independent predictors of pain in patients with PD. ConclusionsMusculoskeletal pain is the most common type of pain in patients with PD. Disrupted sleep continuity, altered sleep architecture, depressed mood, and compromised activities of daily living may be associated with pain in patients with PD.