Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2023 Feb 1;52(2):afad015.
doi: 10.1093/ageing/afad015.

The impact of study factors in the association of periodontal disease and cognitive disorders: systematic review and meta-analysis

Harriet Larvin  1 , Chenyi Gao  1 , Jing Kang  2 , Vishal R Aggarwal  1 , Susan Pavitt  1 , Jianhua Wu  1   3
Affiliations
Meta-Analysis

The impact of study factors in the association of periodontal disease and cognitive disorders: systematic review and meta-analysis

Harriet Larvin et al. Age Ageing. .

Abstract

Aim: The aim was to assess study factors that impact the association of cognitive disorders in people with periodontal disease (PD).

Method: Medline, EMBASE and Cochrane databases were searched until February 2022 using keywords and MeSH: (periodon* OR tooth loss OR missing teeth) AND (dementia OR Alzheimer's Disease OR cognitive*). Observational studies reporting prevalence or risk of cognitive decline, dementia or Alzheimer's disease (AD) in people with PD compared with healthy controls were included. Meta-analysis quantified the prevalence and risk (relative risk[RR]) of cognitive decline, dementia/AD, respectively. Meta-regression/subgroup analysis explored the impact of study factors including PD severity and classification type, and gender.

Results: Overall, 39 studies were eligible for meta-analysis: 13 cross-sectional and 26 longitudinal studies. PD demonstrated increased risks of cognitive disorders (cognitive decline-RR = 1.33, 95% CI = 1.13-1.55; dementia/AD-RR = 1.22, 95% CI = 1.14-1.31). Risk of cognitive decline increased with PD severity (moderate-[RR] = 1.14, 95% confidence interval [CI] = 1.07-1.22; severe-RR = 1.25, 95% CI = 1.18-1.32). For every 10% population increase in females, the risk of cognitive decline increased by 34% (RR = 1.34, 95% CI = 1.16-1.55). Self-reported PD showed a lower risk of cognitive disorders compared with clinical classification (cognitive decline-RR = 0.77, 95% CI = 0.65-0.91; dementia/AD-RR = 0.86, 95% CI = 0.77-0.96).

Conclusion: The prevalence and risk estimates of cognitive disorders in association with PD can be influenced by gender, the disease classification of PD and its severity. Further homologous evidence taking these study factors into consideration is needed to form robust conclusions.

Keywords: Periodontitis; cognitive decline; cohort studies; dementia; older people; systematic review.

PubMed Disclaimer

Conflict of interest statement

None.

Figures

Figure 1
Figure 1
Forest plot showing results from random effect meta-analysis for the prevalence of cognitive disorders. Key: Alzheimer’s disease, AD; degrees of freedom, df; periodontal disease, PD; prevalence risk ratio, PRR.
Figure 2
Figure 2
Forest plot showing results from random effect meta-analysis for the incident risk of cognitive disorders. Key: Alzheimer’s disease, AD; degrees of freedom, df; case numbers not reported, NR; periodontal disease, PD; relative risk, RR.
See this image and copyright information in PMC

References

    1. Jin LJ, Lamster IB, Greenspan JS, Pitts NB, Scully C, Warnakulasuriya S. Global burden of oral diseases: emerging concepts, management and interplay with systemic health. Oral Dis 2016; 22: 609–19. 10.1111/odi.12428. - DOI - PubMed
    1. Nichols E, Szoeke CEI, Vollset SE et al. Global, regional, and national burden of Alzheimer’s disease and other dementias, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol 2019; 18: 88–106. - PMC - PubMed
    1. Li J, Xu H, Pan W, Wu B. Association between tooth loss and cognitive decline: a 13-year longitudinal study of Chinese older adults. PLoS One 2017; 12: e0171404–4. - PMC - PubMed
    1. Okamoto N, Morikawa M, Tomioka K, Yanagi M, Amano N, Kurumatani N. Association between tooth loss and the development of mild memory impairment in the elderly: the Fujiwara-Kyo study. J Alzheimers Dis 2015; 44: 777–86. - PubMed
    1. Kato H, Takahashi Y, Iseki C et al. Tooth loss-associated cognitive impairment in the elderly: a community-based study in Japan. Internal medicine (Tokyo, Japan) 2019; 58: 1411–6. - PMC - PubMed

Publication types

MeSH terms