Physical Activity, APOE Genotype, and Cognitive Decline: Exploring Gene-Environment Interactions in the UK Biobank.

Background: Apolipoprotein E (APOE) genotype affects the risk of Alzheimer's disease (AD) with inconclusive evidence on the opportunity to mitigate related adverse effects by lifestyle changes.

Objective: To examine the individual and interactive associations of APOE and objectively-measured physical activity (PA) and sedentary activity with cognitive decline.

Methods: We used data from middle-aged and older UK Biobank participants with repeat tests on visuospatial memory (n = 52,767) and fluid intelligence (n = 19,713), and who also took part in the accelerometer sub-study.