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Cognitive effects of treating obstructive sleep apnea in Alzheimer's disease: a randomized controlled study
Ancoli-Israel S, Palmer BW, Cooke JR, Corey-Bloom J, Fiorentino L, Natarajan L, Liu L, Ayalon L et al.. Journal of the American Geriatrics Society, 2008-09-15
Topic: Amyloid, tau and blood-test diagnosis
Objectives 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. Design 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. Setting General clinical research center. Participants Fifty-two men and women with mild to moderate AD and OSA. Intervention CPAP. Measurements 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. Conclusion 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.
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APA 7th
Ancoli-Israel, S., Palmer, B. W., Cooke, JR., Corey-Bloom, J., Fiorentino, L., Natarajan, L., et al. (2008). Cognitive effects of treating obstructive sleep apnea in Alzheimer's disease: a randomized controlled study. Journal of the American Geriatrics Society. https://doi.org/10.1111/j.1532-5415.2008.01934.x
Vancouver
Ancoli-Israel S, Palmer BW, Cooke JR, Corey-Bloom J, Fiorentino L, Natarajan L, et al. Cognitive effects of treating obstructive sleep apnea in Alzheimer's disease: a randomized controlled study. Journal of the American Geriatrics Society. 2008. doi:10.1111/j.1532-5415.2008.01934.x. PMID: 18795985.
BibTeX
@article{ancoliisrael2008-18795985,
author = {Ancoli-Israel, S. and Palmer, B. W. and Cooke, JR. and Corey-Bloom, J. and Fiorentino, L. and Natarajan, L. and Liu, L. and Ayalon, L. and others},
title = {{Cognitive effects of treating obstructive sleep apnea in Alzheimer's disease: a randomized controlled study}},
journal = {Journal of the American Geriatrics Society},
year = {2008},
doi = {10.1111/j.1532-5415.2008.01934.x},
pmid = {18795985},
url = {https://doi.org/10.1111/j.1532-5415.2008.01934.x}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
Key findings
- Objectives 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.
- 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.
Why it matters
In this randomized trial of 52 people with mild to moderate Alzheimer's disease and obstructive sleep apnea, comparing 3 weeks of therapeutic versus placebo CPAP showed no significant improvements in cognition, though pre- and post-treatment scores after 3 weeks of therapeutic CPAP in both groups did improve. The study was underpowered to make definitive statements, and it does not show that treating sleep apnea cures or prevents Alzheimer's disease.
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Study details
- Evidence strengthHigh
How this study scored 67/100
Published in a peer-reviewed journal, and it is a randomized controlled trial. Scored zero for sample size and effect reported because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of the American Geriatrics Society) |
| Journal's citation record | 3 / 4 | Journal of the American Geriatrics Society: journal h-index 344 (OpenAlex, 2026-10-29) |
| Study design | 11 / 12 | A randomized controlled trial (from PubMed type “Randomized Controlled Trial”) |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2008 — within 20 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (pubmed indexes it as a clinical or observational study) |
| Randomized / blinded | 2 / 2 | Randomized and blinded or placebo-controlled (as stated in the record) |
| Times cited | 6 / 7 | Cited 378 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 18.9 citations a year over 20 year(s) since 2008 |
| Impact for its field and year | 4 / 6 | Cited 9.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 13 other studies in this library |
| Still being cited | 2 / 4 | Cited 36 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author José S. Loredo: h-index 49 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of California San Diego: institution h-index 1,852 (OpenAlex) |
| Multicenter collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 18795985) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 67 / 100 | — |
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Read the original
- DOI: 10.1111/j.1532-5415.2008.01934.x
- PubMed: 18795985
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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