Periodontitis is associated with cognitive impairment among older adults: analysis of NHANES-III

Abstract

Background: Periodontitis is ubiquitous and associated with serological evidence of exposure to periodontal organisms, systemic inflammation, and vascular disease. Dementia is a major public health problem likely related to a complex interaction between genetics and diseases associated with systemic inflammation, including diabetes, smoking, and stroke.

Methods: To assess relationships between systemic exposure to periodontal pathogens and cognitive test outcomes, we analyzed data from the Third National Health and Nutrition Examination Survey (NHANES-III), a nationally representative cross-sectional observational study among older adults. We included 2355 participants ≥ 60 years who completed measures of cognition and Poryphyromonas gingivalis IgG. Using SUDAAN, logistic regression models examined the association of P.gingivalis IgG with cognitive test performance.

Results: Poor immediate verbal memory (<5/9 points) was prevalent in 5.7% and 6.5% overall had impaired delayed recall (<4/9); 22.1% had difficulty with serial subtractions (<5/5 trials correct). Individuals with the highest P.gingivalis IgG (>119 Elisa Units, EU) were more likely to have poor delayed verbal recall (OR=2.89, 95% CI: 1.14-7.29) and impaired subtraction (OR=1.95, 95%CI: 1.22-3.11) than those with the lowest (≤57EU), with dose-response relationships for both (p-trend, delayed memory=0.045, subtraction= 0.04). After adjusting for socioeconomic and vascular variables these relationships remained robust for the highest P. gingivalis IgG group (delayed verbal memory: OR= 3.01 [95% CI: 1.06-8.53]; subtraction: OR= 2.00 [95% CI: 1.19-3.36]). In contrast, immediate verbal memory was not significantly associated with P. gingivalis.

Conclusion: A serological marker of periodontitis is associated with impaired delayed memory and calculation. Further exploration of relationships between oral health and cognition is warranted.