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

Abstract

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 (β = 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.