Cognitive effects of treating obstructive sleep apnea in Alzheimer's disease: a randomized controlled study.
OBJECTIVE
To examine whether treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) in patients with Alzheimer's disease (AD) results in better cognitive function.


METHODS
Randomized double-blind placebo-controlled trial. Participants were randomized to therapeutic CPAP for 6 weeks or placebo CPAP for 3 weeks followed by therapeutic CPAP for 3 weeks.


METHODS
General clinical research center.


METHODS
Fifty-two men and women with mild to moderate AD and OSA.


METHODS
CPAP.


METHODS
A complete neuropsychological test battery was administered before treatment and at 3 and at 6 weeks.


RESULTS
A comparison of subjects randomized to 3 weeks of therapeutic versus placebo CPAP suggested no significant improvements in cognition. A comparison of pre- and posttreatment neuropsychological test scores after 3 weeks of therapeutic CPAP in both groups showed a significant improvement in cognition. The study was underpowered to make definitive statements about improvements within specific cognitive constructs, although exploratory post hoc examination of change scores for individual tests suggested improvements in episodic verbal learning and memory and some aspects of executive functioning such as cognitive flexibility and mental processing speed.


CONCLUSIONS
OSA may aggravate cognitive dysfunction in dementia and thus may be a reversible cause of cognitive loss in patients with AD. OSA treatment seems to improve some cognitive functioning. Clinicians who care for patients with AD should consider implementing CPAP treatment when OSA is present.
Ancoli-Israel
Sonia
S
Departments of Psychiatry, University of California, San Diego, La Jolla, California, USA. sancoliisrael@ucsd.edu
Palmer
Barton W
BW
Cooke
Jana R
JR
Corey-Bloom
Jody
J
Fiorentino
Lavinia
L
Natarajan
Loki
L
Liu
Lianqi
L
Ayalon
Liat
L
He
Feng
F
Loredo
Jose S
JS
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D045422:Continuous Positive Airway Pressure; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010349:Patient Compliance; D020181:Sleep Apnea, Obstructive / Q000523:psychology* / Q000628:therapy*; D016896:Treatment Outcome
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