Healthy lifestyle factors outweigh influence of APOE genetic risk on extending cognitively healthy life expectancy among Chinese older adults: evidence from a nationwide cohort study

Abstract

INTRODUCTION: Understanding the interplay between genetic factors and lifestyle choices in cognitive health is crucial for enhancing late-life quality. This study examines the effects of Apolipoprotein E (APOE) genotypes and healthy lifestyles on life expectancy with and without cognitive impairment (CI) in Chinese older adults. METHODS: Data from 6488 participants aged at least 65 in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were analyzed using continuous-time three-state Markov models. Cognitive function was assessed with the Mini-Mental State Examination (MMSE). RESULTS: APOE ε4 allele carriers had a higher risk of transitioning from cognitively healthy (CH) to impaired, while ε2 carriers had a reduced risk of transitioning from healthy to death. Participants with 4 or 5 healthy lifestyle factors experienced significant protective effects, extending the cognitively healthy life expectancy. DISCUSSION: These findings underscore the importance of promoting healthy lifestyles to delay cognitive decline, regardless of genetic predispositions, particularly in the Asian context. Highlights: Compared with ε3 homozygotes, APOE ε4 carriers in China have a higher risk of transitioning from CH to CI, and APOE ε2 carriers with CH have a lower risk of transitioning to death. Healthy lifestyles can extend life expectancy, primarily extending CH life expectancy. Healthy lifestyles reduce the risk of CI and delay its onset in later life, regardless of APOE genetic risk.