Lower Physical Activity Is Associated With Objective But Not Subjective Cognitive Impairment In Older Adults Without Dementia

Abstract

AbstractBackgroundPhysical activity has been associated with better performance on cognitive assessments for older adults in both observational and interventional studies. Older adults who exercise the 150 minutes a week recommended by the Physical Activity Guidelines for Americans were also less likely to report subjective cognitive decline on the Behavioral Risk Factor Surveillance System than those with lower levels of physical activity. Potential explanations for a cognitive benefit from exercise include reduction of vascular risk factors, preservation of brain mass and neuronal structural integrity, and promotion of psychological health and self‐efficacy.MethodCross‐sectional data on exercise habits, self‐reported memory problems, and cognition were collected for 137 older adults without dementia as part of a larger observational study. Participants were categorized as meeting (3 or more hours a week of physical activity) or not meeting (< 3 hours) physical activity recommendations. We used multivariable logistic regression to evaluate the association between exercise and self‐reported memory problem, and linear regression for association between exercise and total score on the Montreal Cognitive Assessment (MoCA) after adjusting for potential confounders including age, sex, level of education, cognitive status (CDR global score of 0 vs 0.5), and Geriatric Depression Scale score.ResultData on baseline exercise was available for 103 cognitively normal older adults and 34 with mild cognitive impairment (MCI). Mean participant age was 66.6 years and 58.4% were female. 48 participants (35%) reported exercising at least 3 hours per week. Participants with at least 3 hours a week of physical activity had significantly higher scores on the MoCA compared with those with less than 3 hours a week (B = 1.22, p = 0.040) after adjusting for age, sex, level of education, cognitive status, and depressive symptoms. There was no association between physical activity and participant‐reported memory symptoms using the same covariates (B = ‐0.50, p = 0.223).ConclusionWeekly physical activity levels consistent with current guidelines were associated with better performance on a cognitive assessment in older adults without dementia. Physical activity was not associated with presence or absence of a self‐reported memory problem in this sample.