Patterns and risk factors of cognitive decline among community-dwelling older adults in South Korea

Abstract

Dementia prevalence is increasing worldwide. Thus, the global impact of cognitive impairment and dementia have become significant public health issues. This study assessed the patterns of and investigated risk factors associated with cognitive decline over time in community-dwelling Korean adults (age ≥65 years). We enrolled 1,369 older adult respondents without cognitive decline in the baseline survey of the Korean Longitudinal Study of Aging (2006-2016) in South Korea. The risk of first-ever mild-to-moderate or severe cognitive decline during the 10-year follow-up (2006-2016) was comparatively evaluated between the cognitive decline group (comprising participants with mild-to-moderate or severe cognitive decline; n = 728) and the normal cognition group (participants without a cognitive decline event; n = 641). The cognitive decline-free survival rates for up to ten years were measured using Kaplan-Meier analysis. The generalized estimation equations model was used to analyze changes in K-MMSE over time from 2006 to 2016. The adjusted Cox proportional hazards model revealed that increased age, female, lower education level, no religious status, and living in a small city were factors that were associated with a higher risk of cognitive decline, as were health-related factors, including lower handgrip strength, a higher number of chronic diseases, and depressive symptoms. Regular exercise, non-drinking status, and active social engagements reduced the risk of cognitive decline. The identified risk factors could facilitate the development of cognitive decline-prevention programs incorporating individualized risk-modification interventions to prevent cognitive decline in older adults.