Effect of Physical Inactivity on Cognitive Performance after 2.5 Years of Follow-Up Longitudinal Results fromthe Survey of Health, Ageing, and Retirement (SHARE)

Objective: To examine the association between physical activity and cognitive performance in a longitudinal study. Methods: We analyzed data from 17.333 noninstitutionalized persons aged 50 years or older in 11 European countries who participated in Wave 1 (2004/2005) and Wave 2 (2006/2007) of the Survey of Heath, Ageing, and Retirement in Europe (SHARE). Physical activity at baseline was measured as self-reported frequency of sports or activities requiring vigorous activity, and frequency of activities demanding a moderate level of activity. Cognitive function was measured at baseline and after a mean of 2.5 years of follow-up by delayed word recall and verbal fluency tests. The effects of physical activity at baseline on cognitive performance at follow-up were assessed in hierarchical multilevel random effectsmodels adjusted for sociodemographic variables (age, education), somatic comorbidities, functional impairment (basic and instrumental activities of daily living, maximum grip strength), depressive symptoms, and body mass index. Results: After adjusting for potential confounders, we found physical inactivity (neither moderate nor vigorous) to be associated with a higher rate of cognitive decline over a mean follow-up of 2.5 years (beta= -1.79 (SE = 0.17) for verbal fluency; beta = -0.35 (SE = 0.04) for delayed word recall). Further analyses showed that vigorous activities more than once a week were especially related to change in cognition over time. Conclusion: Engagement in moderate and vigorous physical activities protects against cognitive decline in older age. Participation in physical activities may be of particular importance when other risk factors for cognitive decline are present.