Physical Activity And Functional Walking Capacity Are Positively Correlated With Cognition In Unimpaired APOEe4 Carriers

The Apolipoprotein E epsilon 4 (APOE ε4) allele is a well-established genetic risk factor for Alzheimer’s disease (AD). Physical activity and cardiopulmonary fitness are positively correlated with cognitive performance in the general older adult population. It remains unknown how physical activity and functional walking capacity, a proxy for cardiopulmonary fitness, are correlated with cognitive functions in older, cognitively unimpaired APOE ε4 carriers. PURPOSE: This study aimed to determine the relationship between physical activity, cardiopulmonary fitness, and cognitive functions in individuals at genetic risk for AD. METHODS: One hundred forty-nine APOE ε4 carriers (mean age = 70 ± 9 years) were assessed for daily physical activity (PA) (steps/day), functional walking capacity (distance in 6 Minute Walking Test) and five areas of cognitive function: working memory (Digit Span, DS), verbal fluency (Controlled Oral Word Association Test, COWAT), information processing speed (Stroop Test), visuospatial memory (Brief Visuospatial Memory Test, BVMT), verbal memory (Rey Auditory Verbal Learning Test, RAVLT), and two measures of executive function (Trail Making Test, TMT); and Delis Kaplan Executive Function Sorting, DKEFS). RESULTS: Functional walking capacity correlated significantly with several cognitive measures: DS (r = 0.19, p = 0.02), COWAT (r = 0.29, p = 0.001), BVMT (r = 0.26, p = 0.002), TMT (r = -0.37, p = 0.001), and DKEFS (r = 0.30, p = 0.001). PA correlated significantly with COWAT (r = 0.22, p = 0.008), BVMT (r = 0.22 p = 0.009), Trails A (r = -0.27, p = 0.001), and DKEFS (r = 0.28 p = 0.001). In all cases, greater PA and functional walking capacity were associated with better cognitive performance. CONCLUSIONS: Both PA and cardiopulmonary fitness (functional walking capacity) impact a broad range of cognitive domains in older, cognitively unimpaired adults genetically at risk for AD. These results suggest greater levels of PA and cardiopulmonary fitness may preserve cognitive functioning in persons at genetic risk for AD. Supported by: NIH R01AG070736