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Change in body mass index and risk of incident Alzheimer disease
Buchman AS, Wilson RS, Bienias JL, Shah RC, Evans DA, Bennett DA.. Neurology, 2005-09-01
Topic: Amyloid, tau and blood-test diagnosis
Objective To examine the association of change in body mass index (BMI) with risk of Alzheimer disease (AD). Methods Nine hundred eighteen older Catholic clergy participating in the Religious Orders Study without dementia at baseline were studied. Outcome measures were the clinical diagnosis of AD and change in cognitive function. Results During a mean follow-up of 5.5 years, 151 persons developed AD. BMI averaged 27.4 at baseline and declined in about half the participants. In a proportional hazards model adjusted for age, sex, and education, each 1-unit less of BMI at baseline was associated with about a 5% increase in the risk of AD (hazard ratio = 0.944; 95% CI = 0.908 to 0.981), and each 1-unit annual decline in BMI (about the 10th percentile) was associated with about a 35% increase in the risk of AD compared with a person experiencing no change in BMI (about the 50th percentile) (hazard ratio = 0.730; 95% CI = 0.625 to 0.852). The results were similar after controlling for chronic diseases and excluding persons who developed AD during the first 4 years of observation. Random effects models showed that the rate of cognitive decline increased by about 8% for each 1-unit less of BMI at baseline and declined an additional 40%/year in persons losing 1 unit of BMI/year compared with those with no change in BMI. Conclusion Declining body mass index (BMI) is associated with increased risk of incident Alzheimer disease (AD). Loss of BMI may reflect pathologic processes that contribute to the subsequent development of AD.
Key findings
- Results During a mean follow-up of 5.5 years, 151 persons developed AD.
- In a proportional hazards model adjusted for age, sex, and education, each 1-unit less of BMI at baseline was associated with about a 5% increase in the risk of AD (hazard ratio = 0.944; 95% CI = 0.908 to 0.981), and each 1-unit annual decline in BMI (about the 10th percentile) was associated with about a 35% increase in the risk of AD compared with a person experiencing no change in BMI (about the 50th percentile) (hazard ratio = 0.730; 95% CI = 0.625 to 0.852).
- The results were similar after controlling for chronic diseases and excluding persons who developed AD during the first 4 years of observation.
- Random effects models showed that the rate of cognitive decline increased by about 8% for each 1-unit less of BMI at baseline and declined an additional 40%/year in persons losing 1 unit of BMI/year compared with those with no change in BMI.
- Conclusion Declining body mass index (BMI) is associated with increased risk of incident Alzheimer disease (AD).
Why it matters
Among 918 older Catholic clergy without dementia, followed for an average of 5.5 years (151 developed Alzheimer's), people whose body mass index fell by about 1 unit a year had roughly a 35% higher risk of Alzheimer's than people whose weight held steady, and those with a lower BMI at the start also had somewhat higher risk; results were similar after excluding people diagnosed in the first 4 years. The authors suggest that weight loss "may reflect pathologic processes that contribute to the subsequent development of AD," meaning it may be an early sign rather than a cause. This is an observational study and does not show that gaining or keeping weight would prevent Alzheimer's.
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Study details
- Participants151
- Evidence strengthLow
How this study scored 55/100
Published in a leading specialty journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| 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 | 1 / 5 | 2005 — older than 20 years, still counted |
| Sample size | 2 / 4 | 151 participants |
| 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 (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 401 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 17.4 citations a year over 23 year(s) since 2005 |
| Impact for its field and year | 4 / 6 | Cited 11.4× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 37 other studies in this library |
| Still being cited | 2 / 4 | Cited 26 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author David Alan Bennett: h-index 197 (OpenAlex, whole career) |
| Institution's track record | 0 / 3 | Rush University Medical Center: institution h-index 670 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 16186530) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 55 / 100 | — |
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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.
APA 7th
Buchman, A. S., Wilson, R. S., Bienias, J. L., Shah, R. C., Evans, D. A., & Bennett, D. A. (2005). Change in body mass index and risk of incident Alzheimer disease. Neurology. https://doi.org/10.1212/01.wnl.0000176061.33817.90
Vancouver
Buchman AS, Wilson RS, Bienias JL, Shah RC, Evans DA, Bennett DA. Change in body mass index and risk of incident Alzheimer disease. Neurology. 2005. doi:10.1212/01.wnl.0000176061.33817.90. PMID: 16186530.
BibTeX
@article{buchman2005-16186530,
author = {Buchman, A. S. and Wilson, R. S. and Bienias, J. L. and Shah, R. C. and Evans, D. A. and Bennett, D. A.},
title = {{Change in body mass index and risk of incident Alzheimer disease}},
journal = {Neurology},
year = {2005},
doi = {10.1212/01.wnl.0000176061.33817.90},
pmid = {16186530},
url = {https://doi.org/10.1212/01.wnl.0000176061.33817.90}
}
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