Association of periodontitis with cognitive decline and its progression: Contribution of blood-based biomarkers of Alzheimer's disease to this relationship

Aim: To assess whether periodontitis is associated with cognitive decline and its progression as well as with certain blood-based markers of Alzheimer's disease. Materials and Methods: Data from a 2-year follow-up prospective cohort study (n = 101) was analysed. Participants with a previous history of hypertension and aged ≥60 years were included in the analysis. All of them received a full-mouth periodontal examination and cognitive function assessments (Addenbrooke's Cognitive Examination (ACE) and Mini-Mental State Examination [MMSE]). Plasma levels of amyloid beta (Aβ)_1-40, Aβ_1-42, phosphorylated and total Tau (p-Tau and t-Tau) were determined at baseline, 12 and 24 months. Results: Periodontitis was associated with poor cognitive performance (MMSE: β = −1.5 [0.6]) and progression of cognitive impairment (hazard ratio [HR] = 1.8; 95% confidence interval: 1.0–3.1). Subjects with periodontitis showed greater baseline levels of p-Tau (1.6 [0.7] vs. 1.2 [0.2] pg/mL, p <.001) and Aβ_1-40 (242.1 [77.3] vs. 208.2 [73.8] pg/mL, p =.036) compared with those without periodontitis. Concentrations of the latter protein also increased over time only in the periodontitis group (p =.005). Conclusions: Periodontitis is associated with cognitive decline and its progression in elderly patients with a previous history of hypertension. Overexpression of p-Tau and Aβ_1-40 may play a role in this association.