Association of leisure-time physical activity with cognition by apolipoprotein-E genotype in persons aged 60 years and over: the National Health and Nutrition Examination Survey (NHANES-III).

Objective: To test the hypothesis that aerobic-related leisure-time physical activity (PA) is associated with better cognitive function and that the effect varies among apolipoprotein E (APOE) genotype groups. Design: Cross-sectional study of persons examined in the Third National Health and Nutrition Examination Survey (NHANES-III; 1988-1994). Setting: US noninstitutionalized population. Participants and methods: From a sample of 7159, aged 6⩾0 years, we analyzed data for 1799 older American men and women who had information on PA, a short mental status examination (SMSE), and were genotyped at the apolipoprotein E gene locus. Results: In the initial bivariate analysis, non-ε4 carriers and ε4-heterozygotes performed better than ε4-homozygotes in the 60-69 age group. After controlling for multiple confounders including mobility limitation, PA correlated with a higher SMSE score in non-ε4 carriers (P = 0.014), but not in ε4 carriers (P = 0.887). At ⩾70 years, PA also correlated with higher adjusted SMSE scores in non-ε4 carriers (P = 0.02); but this association became nonsignificant after controlling for mobility limitation (P = 0.12). Conclusion: In a nationally representative sample, PA was associated with enhanced cognition, an effect that was differentially influenced by apolipoprotein E genotype. Experimental studies are needed to determine whether or not PA can attenuate cognitive decline [ABSTRACT FROM AUTHOR]