Continuous positive airway pressure deepens sleep in patients with Alzheimer's disease and obstructive sleep apnea

Objective: Patients with Alzheimer's disease (AD) and obstructive sleep apnea (OSA) experience disrupted sleep. This study examined the effect of continuous positive airway pressure (CPAP) on sleep parameters in AD patients with OSA. Methods: A randomized placebo-controlled trial of 3 weeks of therapeutic CPAP (tCPAP) vs. 3 weeks placebo CPAP (pCPAP) followed by 3 weeks tCPAP in patients with AD and OSA. Polysomnography data from screening after one night and after 3 weeks of treatment were analyzed. Records were scored for percent of each sleep stage, total sleep time (TST), sleep efficiency (SE), sleep period (SP), time in bed (TIB), sleep onset (SO), wake time after sleep onset (WASO), and arousals. A randomized design comparing one night of pCPAP to tCPAP and a paired analysis combining 3 weeks of tCPAP were performed. Results: Fifty-two participants (mean age = 77.8 years, SID = 7.3) with AD and OSA were included. After one treatment night, the tCPAP group had significantly less % Stage 1 (p = 0.04) and more % Stage 2 sleep (p = 0.02) when compared to the pCPAP group. In the paired analysis, 3 weeks of tCPAP resulted in significant decreases in WASO (p = 0.005), % Stage I (p = 0.001), arousals (p = 0.005), and an increase in % Stage 3 (p = 0.006). Conclusion: In mild to moderate AD patients with OSA, the use of tCPAP resulted in deeper sleep after just one night, with improvements maintained for 3 weeks. (C) 2009 Elsevier B.V. All rights reserved.