Periodontal Disease and Incident Dementia: The Atherosclerosis Risk in Communities Study (ARIC)

Objective: To test the hypothesis that periodontal disease would be associated with increased risk for dementia and mild cognitive impairment (MCI) we prospectively assessed dementia/MCI outcomes following a baseline periodontal examination.

Methods: Participants enrolled in the Atherosclerosis Risk in Communities Study with a clinical periodontal examination (or edentulous participants) at visit 4 (1996-1998; mean±SD age=63±6, 55% female, 21% black) and adjudicated dementia outcomes through 2016 were included (n=8,275). A subgroup of 4,559 participants had adjudicated dementia and MCI assessments at visit 5 (2011-2013). Participants received a full-mouth periodontal exam and were classified into periodontal profile classes (PPCs) based on the severity and extent of gingival inflammation and attachment loss. MCI and dementia were determined via neurocognitive testing, neurological exam and history, informant interviews, and brain MRI in a subset. Cox proportional hazards models regressed incident dementia on PPCs. Relative risk regression models were utilized for the composite of MCI/dementia.

Results: The cumulative incidence and incidence density of dementia during follow-up (average=18.4 years) were 19% (n=1569) and 11.8 cases per 1,000 person-years. Multivariable adjusted hazard ratios (HRs) [95% CI] for incident dementia among participants with severe-PPC or edentulism (vs. periodontal healthy) were 1.22[1.01-1.47] and 1.21[0.99-1.48], respectively. For the combined dementia/MCI outcome adjusted risk ratios among participants with mild/intermediate-PPC, severe-PPC or edentulism (vs. periodontal healthy) were 1.22[1.00-1.48], 1.15[0.88-1.51] and 1.90[1.40-2.58]. Results were stronger among younger (<62 years) participants, p-value for interaction=0.02.

Conclusion: Periodontal disease was modestly associated with incident MCI and dementia in a community-based cohort of black and white participants.