RELATION OF TOOTH LOSS TO COGNITIVE DECLINE AND STRUCTURAL BRAIN DIFFERENCES IN OLDER ADULTS: A POPULATION-BASED COHORT STUDY

Abstract

Poor dental health has been linked to cognitive decline, and cardiovascular disease (CVD) and inflammation seem to play a role in this association. We examined the relationship of tooth loss to cognitive decline and structural brain measures on magnetic resonance imaging (MRI) taking CVD and inflammation into account. From the population-based Swedish National study on Aging and Care–Kungsholmen, 2715, dementia-free participants aged ≥60 years were identified at baseline and followed for up to 9 years. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) at baseline and follow-ups. Information on dental status, medical history of CVD, and inflammation, assessed with blood C-reactive protein (CRP), was collected at baseline. A subsample (n =394) of the participants underwent MRI. Data were analyzed using mixed-effects models and linear regression with adjustment for potential confounders. At baseline, 404 (14.9%) people had partial tooth loss, and 206 (7.6%) had complete tooth loss. Partial (β: -0.21, 95% CI: -0.30 to -0.12) and complete (β: -0.49, 95% CI: -0.63 to -0.35) tooth loss were significantly associated with greater MMSE decline compared to no tooth loss. The association between tooth loss and cognitive decline remained significant when stratifying by CVD or CRP level (> 5 mg/l). Furthermore, people with tooth loss had significantly lower adjusted total brain (β: -35.05, CI: -57.03; -13.07), grey matter (β: -25.34, CI: -40.94; -9.74), and hippocampal (β: -0.28, CI: -0.53; -0.03) volumes, compared to no tooth loss. Tooth loss is associated with accelerated cognitive decline and neurodegenerative markers on MRI, and this association is not fully accounted for by vascular disorders or inflammation.