Late-Life Cognitive Trajectories and their Associated Lifestyle Factors

Abstract

Significant variability exists in the trajectories of late-life cognitive decline; however, their associated lifestyle factors remain less studied. We examined these trajectories among elderly participants from the recent five waves (at three-year intervals) of the Chinese Longitudinal Healthy Longevity Study (CLHLS) from 2002 to 2014. Participants from this cohort were included if they completed at least four waves of measurements. Mini-Mental State Examination (MMSE) scores, demographics, medical diagnoses (e.g., hypertension, diabetes, and heart disease), and lifestyle-related information (e.g., smoking, drinking alcohol, and exercise) were collected from participants (N = 2,584; mean age at baseline = 73.3) at least four times across 12 years. MMSE scores were entered into a latent class mixed model analysis. Subsequently, demographic, medical, and lifestyle predictors were entered into multinomial logistic regression models to predict the trajectories. One of the four emerged classes (no decline) was characterized by an absence of cognitive decline; the other three exhibited various degrees of cognitive decline. The inclusion of lifestyle factors significantly improved the prediction of the different trajectories, above and beyond demographics and medical variables; the 'no decline' class was significantly more likely to report exercising regularly. Changes in cognitive functioning across the late-life period are characterized by multiple trajectories. Cognitive decline is not inevitable across the late-life period; the absence of such cognitive decline is partly explained by certain lifestyle factors.