Association between the AHA Life's Essential 8 score and incident all-cause dementia: a prospective cohort study from UK Biobank.

AIM: This study aimed to investigate the association between the LE8 score and incident all-cause dementia (including Alzheimer's disease [AD] and vascular dementia) in UK Biobank.

METHODS: 259,718 participants were included in this prospective study. Smoking, non-HDL cholesterol, blood pressure, body mass index, HbA1c, physical activity, diet, and sleep were used to create the LE8 score. Associations between the score (both continuous and as quartiles) and outcomes were investigated using adjusted linear and nonlinear Cox proportional hazard models. The potential impact fractions of two scenarios and the rate advancement periods were also calculated.

RESULTS: Over a median follow-up of 10.6 years, 4,958 participants were diagnosed with any dementia. Higher LE8 scores were associated with lower risk of all-cause and vascular dementia in an exponential decay pattern. Compared with individuals in the healthiest quartile, those in the least healthy quartile had a higher risk of all-cause dementia (HR: 1.50 [95% CI: 1.37 to 1.65] and vascular dementia (HR: 1.86 [1.44 to 2.42]). A targeted intervention that increased, by 10-points, the score among individuals in the lowest quartile could have prevented 6.8% of all-cause dementia cases. Individuals in the least healthy LE8 quartile might develop all-cause dementia 2.45 years earlier than their counterparts.

CONCLUSIONS: Individuals with higher LE8 scores had lower risk of all-cause and vascular dementia. Because of nonlinear associations, interventions targeted at the least healthy individuals might produce greater population-level benefits.