Age-specific findings on lifestyle and trajectories of cognitive function from the Korean Longitudinal Study of Aging

Abstract

Background: There is a paucity of longitudinal studies in the literature which have investigated age-related differences in the relationship between lifestyle factors and cognitive decline. Thus, the purpose of this study was to investigate which lifestyle factors at baseline would slow the longitudinal rate of cognitive decline in young-old (55-64 years), middle-old (65-74 years), and old-old (75+ years) individuals. Methods: We conducted an 11-year follow-up of 6189 older adults from the Korean Longitudinal Study of Aging, which is a cohort of community-dwelling older Koreans. Lifestyle factors including physical activity (PA), social activity (SA), smoking, and alcohol consumption were assessed at baseline. Cognitive function was measured at 2-year intervals over a duration of 11 years. Latent growth curve modeling (LGM) and multigroup analyses (MGA) were performed. Results: The influence of lifestyle factors on the rate of cognitive decline differed by age. Smoking at baseline (−0.05, 95% CI −0.11 to −0.001, per study wave) accelerated the cognitive decline in young-old individuals while frequent SA participation at baseline (0.02, 95% CI 0.01 to 0.03, per study wave) decelerated the cognitive decline in middle-old individuals. None of the lifestyle factors in this study decelerated the cognitive decline in old-old individuals. Conclusion: Cognitive strategies through modifiable lifestyle factors such as smoking cessation in the young-old and frequent SA participation in the middle-old age groups may have great potential in preventing cognitive decline. Since the influence of lifestyle factors varies by age group, age-specific approaches are recommended for promoting cognitive health.