This page is alzhub.org's plain-English summary of a published study, not the paper itself. It is generated from the record we hold for this study, sourced and linked below — check the original for the full text and methods.

55/100

✓ Peer-reviewed alzhub usefulness score 55 out of 100. Biomarkers

Topic: Amyloid, tau and blood-test diagnosis

Plain-language summary

Importance Disrupted sleep commonly occurs with progressing neurodegenerative disease. Large, well-characterized neuroimaging studies of cognitively unimpaired adults are warranted to clarify the magnitude and onset of the association between sleep and emerging β-amyloid (Aβ) pathology. Objective To evaluate the associations between daytime and nighttime sleep duration with regional Aβ pathology in older cognitively unimpaired adults. Design, setting, and participants In this cross-sectional study, screening data were collected between April 1, 2014, and December 31, 2017, from healthy, cognitively unimpaired adults 65 to 85 years of age who underwent florbetapir F 18 positron emission tomography (PET), had APOE genotype information, scored between 25 and 30 on the Mini-Mental State Examination, and had a Clinical Dementia Rating of 0 for the Anti-Amyloid Treatment in Asymptomatic Alzheimer Disease (A4) Study. Data analysis was performed from December 1, 2019, to May 10, 2021. Exposures Self-reported daytime and nighttime sleep duration. Main outcomes and measures Regional Aβ pathology, measured by florbetapir PET standardized uptake value ratio. Results Amyloid PET and sleep duration information was acquired on 4425 cognitively unimpaired participants (mean [SD] age, 71.3 [4.7] years; 2628 [59.4%] female; 1509 [34.1%] tested Aβ positive). Each additional hour of nighttime sleep was associated with a 0.005 reduction of global Aβ standardized uptake value ratio (F1, 4419 = 5.0; P = .03), a 0.009 reduction of medial orbitofrontal Aβ (F1, 4419 = 17.4; P Conclusions and relevance In this cross-sectional study, the increased risk of Aβ deposition with reduced nighttime sleep duration occurred early, before cognitive impairment or significant Aβ deposition. Daytime sleep may be associated with an increase in risk for early Aβ accumulation and did not appear to be corrective for loss of nighttime sleep, demonstrating a circadian rhythm dependence of sleep in preventing Aβ accumulation. Treatments that improve sleep may reduce early Aβ accumulation and aid in delaying the onset of cognitive dysfunction associated with early Alzheimer disease.

What this study adds

Evidence grade: Low

This is a cross-sectional study. In cognitively unimpaired older adults, each additional hour of nighttime sleep was associated with a small reduction in global amyloid PET signal. Reported effect size: 59.4%; 34.1%.

Taken from this record’s own fields, not from reading the paper. The grade is assigned from the abstract’s wording; what that means.

Cite this study APA, Vancouver, BibTeX · download .bib or .ris

APA 7th

Insel, P. S., Mohlenhoff, B. S., Neylan, T. C., Krystal, A. D., & Mackin, R. S. (2021). Association of Sleep and β-Amyloid Pathology Among Older Cognitively Unimpaired Adults. JAMA network open. https://doi.org/10.1001/jamanetworkopen.2021.17573

Vancouver

Insel PS, Mohlenhoff BS, Neylan TC, Krystal AD, Mackin RS. Association of Sleep and β-Amyloid Pathology Among Older Cognitively Unimpaired Adults. JAMA network open. 2021. doi:10.1001/jamanetworkopen.2021.17573. PMID: 34297074.

BibTeX

@article{insel2021-34297074,
  author  = {Insel, P. S. and Mohlenhoff, B. S. and Neylan, T. C. and Krystal, A. D. and Mackin, R. S.},
  title   = {{Association of Sleep and β-Amyloid Pathology Among Older Cognitively Unimpaired Adults}},
  journal = {JAMA network open},
  year    = {2021},
  doi     = {10.1001/jamanetworkopen.2021.17573},
  pmid    = {34297074},
  url     = {https://doi.org/10.1001/jamanetworkopen.2021.17573}
}

Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.

How to read this study

Design: this is a cross-sectional study. Everyone is measured once, so it cannot show which came first. Read it as a snapshot of how two things go together at one moment.
Size: the record gives no participant count. Look for one in the original before trusting a pattern.
Effect: the record reports “59.4%; 34.1%”. A statistically significant result can still be small in daily life.

What the evidence grade means here

This page is graded low. alzhub.org assigns the grade automatically from keywords in the abstract, not from reading the paper. Low means the abstract matched neither pattern. It is the default label, and it does not mean the work is poor; many sound lab and imaging papers land here. It can add at most 5 of the 100 points in the study score, and it is a label about design, not a verdict on whether the findings are true.

New to reading papers? Six questions to ask of any Alzheimer’s study · how we score.

Key findings

Results Amyloid PET and sleep duration information was acquired on 4425 cognitively unimpaired participants (mean [SD] age, 71.3 [4.7] years; 2628 [59.4%] female; 1509 [34.1%] tested Aβ positive).
Each additional hour of nighttime sleep was associated with a 0.005 reduction of global Aβ standardized uptake value ratio (F1, 4419 = 5.0; P = .03), a 0.009 reduction of medial orbitofrontal Aβ (F1, 4419 = 17.4; P < .001), and a 0.011 reduction of anterior cingulate Aβ (F1, 4419 = 15.9; P < .001).
Daytime sleep may be associated with an increase in risk for early Aβ accumulation and did not appear to be corrective for loss of nighttime sleep, demonstrating a circadian rhythm dependence of sleep in preventing Aβ accumulation.
Treatments that improve sleep may reduce early Aβ accumulation and aid in delaying the onset of cognitive dysfunction associated with early Alzheimer disease.

Why it matters

In cognitively unimpaired older adults, each additional hour of nighttime sleep was associated with a small reduction in global amyloid PET signal. This is a cross-sectional association and does not show that changing sleep treats, cures, or prevents Alzheimer disease.

New to this subject? Start with our plain-English guide: Blood tests & biomarkers →

Study details

Study designcross-sectional
Effect size59.4%; 34.1%
Evidence strengthLow

How this study scored 55/100

Published in a leading specialty journal, and it is a snapshot of people at one point in time. Scored zero for sample size, studied in people and randomized / blinded because the record does not state it.

Component	Points	Why
Journal tier	9 / 10	Tier 2 — leading specialty journal (JAMA network open)
Journal's citation record	2 / 4	JAMA Network Open: journal h-index 235 (OpenAlex, 2026-10-29)
Study design	4 / 12	A snapshot of people at one point in time
Strength of evidence	1 / 5	Rated “low” in our summary
Peer-review validation	10 / 10	Peer-reviewed. Published as an article in a named peer-reviewed journal.
How recent	3 / 5	2021 — within 6 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	2 / 3	Effect reported as a number, without an interval or test
Studied in people	0 / 3	Not stated whether this was studied in people — scores zero (not stated in the record — scored 0)
Randomized / blinded	0 / 2	No randomization or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	4 / 7	Cited 98 times (OpenAlex, 2026-10-10)
Citations per year	3 / 5	14.0 citations a year over 7 year(s) since 2021
Impact for its field and year	3 / 6	Cited 7.8× the average for papers of its field and year (OpenAlex FWCI)
Cited by studies here	2 / 6	Cited by 9 other studies in this library
Still being cited	3 / 4	Cited 73 times in 2024–2026 (2026 still in progress; OpenAlex)
Senior author's track record	2 / 4	Last-listed author R. Scott Mackin: h-index 36 (OpenAlex, whole career)
Institution's track record	2 / 3	University of California, San Francisco: institution h-index 1,915 (OpenAlex)
Multicenter collaboration	1 / 3	OpenAlex lists 3 institution(s) in 2 countries
Indexed in PubMed	2 / 2	Indexed in PubMed (PMID 34297074)
Free to read	2 / 2	Free to read
Total	55 / 100	—

What each of these 20 components measures, and what this score is not →

Read the original

Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).

Studies in the library that share something with this one. The line above each title says what.

Studies this one cites

Referenced by this study and also in the alzhub library, so you can read them here.

Later studies that cite this one

9 studies in the alzhub library list this one in their references. Showing the 8 highest-scoring.

Related studies in Biomarkers from nearby years

Also tagged “precursor”

1,337 studies in the library carry the topic tag “precursor”; these are this study's neighbours in a fixed, alphabetical-by-hash tour of them, not the closest in content. All 1,337 tagged studies.

Studies sharing this one's topic tags

Similar studies

More on Biomarkers

See all studies in Biomarkers →