Longitudinal relationship of severe periodontitis with cognitive decline in older Japanese

Epidemiologic data examining the longitudinal relationship between periodontitis and cognitive status are very limited, especially in Asian populations. The present study examined the longitudinal relationship of periodontitis with cognitive decline in 85 Japanese community-dwelling individuals (average age: 79.3 years) for whom data were available from comprehensive health examinations conducted in 2010 and 2013.

Based on a baseline full-mouth periodontal examination, severe periodontitis was defined using a Centers for Disease Control and Prevention/American Academy of Periodontology definition. Cognitive decline during the 3-year study period was defined using the results of the Mini-Mental State Examination (MMSE). Information on age, gender, education, depression, body mass index, smoking status, alcohol use, exercise, hypertension, diabetes, history of cardiovascular disease and stroke, and baseline MMSE scores were obtained and tested as potential confounders in the statistical models.

Among 85 study participants, 21 (24.7%) were defined as having severe periodontitis. Multivariable Poisson regression analyses revealed that severe periodontitis was significantly associated with an increased risk of cognitive decline [adjusted relative risk = 2.2; 95% confidence interval (95% CI): 1.1-4.5]. Furthermore, multivariable linear regression analyses revealed that participants with severe periodontitis had a 1.8-point greater decrease (95% CI: -3.3 to -0.2) in MMSE score than those without severe periodontitis.

Within the limitations related to its small sample size, the findings of the present study suggest that severe periodontitis is significantly associated with future decline in cognitive function among community-dwelling older Japanese subjects.