Accumulation of Biopsychosocial Risk Factors and Cognitive Impairment: The Impact of Slower Gait, Depression, and Low Education in Community-Dwelling Older Adults

BACKGROUND: Cognitive decline in older adults, a prodromal stage of dementia, requires early preventive attention as a major public health concern. Cognitive decline in older adults involves complex interactions among physical, psychological, and social factors. This study applied the biopsychosocial model to examine how these multidimensional domains jointly influence cognitive function and to evaluate cumulative risks associated with multidimensional vulnerabilities. METHODS: Data from 661 community-dwelling older adults aged 65 years or older who participated in a community health screening were analyzed. Cognitive function (Cognitive Impairment Screening Test), physical performance (Timed Up and Go test log-transformed [TUG_log]), depressive symptoms (Korean version of the Short Geriatric Depression Scale [SGDS-K]), and education were measured. Age-specific TUG_log cut-offs were obtained by ROC analysis. Dual- and triple-risk groups were defined based on TUG risk, low education (≤6 years), and depression (SGDS-K ≥8). Correlation, regression, and mediation analyses were performed. RESULTS: Slower gait speed, lower education, and higher depressive symptoms were significantly associated with poorer cognitive function (p<0.05). Compared with participants with no risk factors, those with two risk factors had 5.07-fold higher odds of cognitive impairment, while those with all three risk factors had 18.13-fold higher odds. Mediation analysis showed that depression did not directly affect cognition but had a significant indirect effect through impaired physical performance (bootstrap 95% confidence interval, -0.1765 to -0.0530). CONCLUSION: Cognitive function in older adults is shaped by interacting physical, psychological, and social factors. The accumulation of multidimensional vulnerabilities markedly increases cognitive decline risk, underscoring the need for integrated, multidomain prevention strategies.