Bound to supine sleep: Parkinson's disease and the impact of nocturnal immobility

Background: Impaired nocturnal mobility is a well-known problem in Parkinson's disease (PD), and clinical experience suggests a predominance of supine body position during sleep. However, this assumption - and potential consequences still awaits objective validation by a polysomnography-based and adequately controlled study. Methods: Clinical and polysomnographical analysis of 80 consecutive PD patients and 80 control subjects carefully matched for age, sex, body mass index and apnea-hypopnea index. Results: PD patients slept twice as much in supine position than control subjects (62.2 +/- 32.9% vs. 34.2 +/- 28.5%, p < 0.001). In PD, but not in control subjects, more supine sleep correlated with fewer changes in body position (rho = -0.434, p < 0.001). Longer PD disease duration was an independent predictor of more supine sleep in multiple linear regression analysis (beta = 0.389, p < 0.001); conversely, more supine sleep was associated with higher apnea-hypopnea index and daytime sleepiness. Conclusions: We confirmed that supine sleep is common in PD, and increases with longer disease duration. Our findings indicate that supine sleep may contribute to the overall disease burden by deteriorating sleep-disordered breathing and daytime vigilance. (C) 2015 Elsevier Ltd. All rights reserved.