Longitudinal association of chronic periodontitis with all-cause dementia, Alzheimer disease, vascular dementia, and mild cognitive impairment: a distributed network analysis.

Chronic periodontitis (CPO) is prevalent among older adults and may elevate dementia risk. Evidence regarding its association with dementia subtypes and the effect of disease progression remains unclear. This study aimed to assess the relationship between CPO and dementia development, including subtypes, and evaluated whether the clinical course modifies this risk. Electronic health records of patients aged ≥ 60 years from six institutions were analyzed. A 10-year longitudinal analysis assessed the incidence of all-cause dementia, Alzheimer disease (AD), vascular dementia (VaD), and a composite outcome of all dementia or mild cognitive impairment (MCI). After propensity score stratification, hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. Institutional results were pooled by meta-analysis. Sensitivity analyses using 5-year lag periods and subgroup analyses by surgical treatment or tooth extraction after CPO diagnosis were performed. Among 19,421 patients with CPO and 860,383 without, 24,173 cases of all-cause dementia were identified. CPO was associated with increased risk of all-cause dementia (HR: 1.51; 95% CI: 1.42-1.60), AD (HR: 1.57; 95% CI: 1.45-1.70), VaD (HR: 1.60; 95% CI: 1.39-1.85), and dementia or MCI (HR: 1.55; 95% CI: 1.47-1.64). These associations persisted across lag periods. Among patients with CPO, those who underwent surgical treatment had higher dementia risk than those without (HR: 1.71 vs. 1.45; p = 0.045). Tooth extraction was also linked to increased risk (HR: 1.75 vs. 1.44; p = 0.008). CPO was associated with elevated dementia risk across subtypes. The higher risk observed among patients undergoing surgical treatment or tooth extraction suggests that the severity of chronic periodontitis is related to cognitive decline. These findings underscore the importance of oral health management in dementia prevention among older adults.