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Periodontitis and incident cognitive decline and dementia: A 15-year prospective cohort study of older men residing in Northern Ireland
Dominic N. Farsi, Rena Abadalkareem, Gerard James Linden, Gareth J. McKay, Claire T. McEvoy, Michael McAlinden, Lewis Winning, Michael J. Hurley et al.. Journal of Alzheimer s Disease, 2025-12-12
Topic: Risk, prevention and care in population studies
Plain-language summary
BackgroundPeriodontitis is a chronic bacterial infection that elicits systemic inflammation. While retrospective studies have linked periodontal pathogens with Alzheimer's disease (AD) and dementia, few have combined cognitive assessments, pathogen exposure, and inflammatory markers.ObjectiveTo investigate the longitudinal risk between periodontitis, cognitive impairment and dementia.MethodsWe examined the relationship between periodontitis and onset of mild cognitive impairment (MCI) and dementia over 15.6 years (SD 1.6) in older men from Northern Ireland enrolled in the PRIME-COG cohort, using logistic regression. We also assessed associations between exposure to periodontal pathogens and blood inflammatory markers.ResultsAmong 642 men, baseline periodontitis was not significantly associated with later onset of dementia and/or MCI (severe versus mild/none, OR 0.83, 95% CI 0.45-1.50, p = 0.923). However, having more teeth predicted lower risk (OR 0.95, 95% CI 0.91-0.99, p = 0.023). Dementia and/or MCI was associated with higher serum IL-6, IL-8, and IFN-γ at baseline, and IL-8 and TGF-β at follow-up. IgG levels to periodontal pathogens remained stable in men who developed dementia and/or MCI but declined in cognitively normal men. A positive correlation between IgG to periodontal pathogens and proinflammatory cytokines was observed in men who developed dementia and/or MCI.ConclusionsClinical periodontitis was not associated with dementia or MCI onset, but tooth retention was protective. Elevated inflammatory markers in affected men suggest systemic inflammation may contribute to cognitive decline. Larger, more diverse cohort studies are needed to clarify the role of periodontal disease in dementia and AD risk.
What this study adds
Evidence grade: Moderate
This is a follow-up (cohort) study. In 642 older men followed for about 15 years, baseline periodontitis was not significantly associated with later dementia or mild cognitive impairment, though having more teeth predicted lower risk. Reported effect size: OR 0.83; OR 0.95.
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
Farsi, D. N., Abadalkareem, R., Linden, G. J., McKay, G. J., McEvoy, C. T., McAlinden, M., et al. (2025). Periodontitis and incident cognitive decline and dementia: A 15-year prospective cohort study of older men residing in Northern Ireland. Journal of Alzheimer s Disease. https://doi.org/10.1177/13872877251401563
Vancouver
Farsi DN, Abadalkareem R, Linden GJ, McKay GJ, McEvoy CT, McAlinden M, et al. Periodontitis and incident cognitive decline and dementia: A 15-year prospective cohort study of older men residing in Northern Ireland. Journal of Alzheimer s Disease. 2025. doi:10.1177/13872877251401563. PMID: 41384827.
BibTeX
@article{farsi2025-41384827,
author = {Farsi, Dominic N. and Abadalkareem, Rena and Linden, Gerard James and McKay, Gareth J. and McEvoy, Claire T. and McAlinden, Michael and Winning, Lewis and Hurley, Michael J. and others},
title = {{Periodontitis and incident cognitive decline and dementia: A 15-year prospective cohort study of older men residing in Northern Ireland}},
journal = {Journal of Alzheimer s Disease},
year = {2025},
doi = {10.1177/13872877251401563},
pmid = {41384827},
url = {https://doi.org/10.1177/13872877251401563}
}
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
- We also assessed associations between exposure to periodontal pathogens and blood inflammatory markers.ResultsAmong 642 men, baseline periodontitis was not significantly associated with later onset of dementia and/or MCI (severe versus mild/none, OR 0.83, 95% CI 0.45-1.50, p = 0.923).
- However, having more teeth predicted lower risk (OR 0.95, 95% CI 0.91-0.99, p = 0.023).
- Dementia and/or MCI was associated with higher serum IL-6, IL-8, and IFN-γ at baseline, and IL-8 and TGF-β at follow-up.
- A positive correlation between IgG to periodontal pathogens and proinflammatory cytokines was observed in men who developed dementia and/or MCI.ConclusionsClinical periodontitis was not associated with dementia or MCI onset, but tooth retention was protective.
Why it matters
In 642 older men followed for about 15 years, baseline periodontitis was not significantly associated with later dementia or mild cognitive impairment, though having more teeth predicted lower risk. Higher inflammatory markers were associated with dementia or mild cognitive impairment, but the study does not show that treating periodontitis prevents dementia.
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Study details
- Study designcohort study
- Effect sizeOR 0.83; OR 0.95
- Evidence strengthModerate
How this study scored 52/100
Published in a peer-reviewed journal, and it is a cohort study following people over time. Scored zero for sample size, studied in people and randomized / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of Alzheimer s Disease) |
| Journal's citation record | 2 / 4 | Journal of Alzheimer s Disease: journal h-index 218 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 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 | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| 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 | 1 / 7 | Cited 4 times (OpenAlex, 2026-10-10) |
| Citations per year | 1 / 5 | 1.3 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 3 / 6 | Cited 3.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 1 / 4 | Cited 4 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Bernadette McGuinness: h-index 59 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | King's College London: institution h-index 1,348 (OpenAlex) |
| Multicenter collaboration | 2 / 3 | OpenAlex lists 6 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 41384827) |
| Free to read | 2 / 2 | Free to read |
| Total | 52 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1177/13872877251401563
- PubMed: 41384827
- Original source →
- Free full text: Journal of Alzheimer s Disease →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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