Purpose: The purpose of this study was to investigate the association between level of physical activity and risk of cognitive decline at older age and its variation across carriers and noncarriers of the apolipoprotein e4 allele.
Methods: The association was studied in a cohort of 347 elderly Dutch men. Mean age of the study subjects was 74.6 +/- 4.3 yr in 1990. Physical activity was categorized in "maximal 1 h per day" versus "more than 1 h per day." Cognitive decline was defined as a drop MMSE score > 3 points between 1990 and 1993.
Results: After adjusting for age, education, alcohol consumption, smoking and cognitive functioning at baseline, subjects with maximal 1 h of physical activity per day had a two-fold increased risk of cognitive decline (OR 2.0, 95% CI: 0.9-4.8) as compared with the rest. Risk of cognitive decline was particularly strong in carriers of the APOE*4 allele (adjusted OR 3.7, 95% CI: 1.1-12.6).
Conclusion: The authors conclude that promotion of physical activity at older age may reduce the risk of cognitive decline. The existence of subgroups with a particularly high risk may have important implications for prevention strategies.