Background: It has been proposed that physical activity (PA) could prevent cognitive decline.
Objective: To evaluate the association between changes in PA and changes in cognitive function in a cohort of adults with metabolic syndrome.
Methods: Longitudinal observational study including 5,500 adults (mean age 65 years, SD = 5; women = 49.3% ) with metabolic syndrome. Participants underwent physical activity measurements and cognitive evaluation at baseline and at two-years of follow-up. PA was quantified using the Minnesota questionnaire-shortened version. Cognitive function was evaluated using a battery of tests: Mini-Mental Test Examination, Clock Drawing Test, Trail Making Test A and B, Verbal Fluency Test, and Digit Span. The primary outcome was two-year change in cognition, measured through the Global Composite Score (GCS) of all neuropsychological tests. Multivariable-adjusted linear regression models were fitted with baseline PA and their changes as the main exposures and changes in cognitive function as the outcome.
Results: No significant association was found between PA levels (or their changes) in the GCS of cognitive function. A greater increase in PA levels was associated with a more favorable two-year change in the Trail Making Test A (Q4 versus Q1: b = - 2.24s, 95% CI -4.36 to -0.12s; p-trend = 0.020). No significant association was found for other neuropsychological test.
Conclusion: Our results do not support an association between increases in PA and the evolution of the global cognitive function at two-year in an intervention trial which included PA promotion in one of its two randomized arms, but they suggested a possible beneficial effect of PA on attentional function in older adults.
Keywords: Alzheimer’s disease; cognitive function; dementia; metabolic syndrome; physical activity; prevention.