Gender-Specific Incidence and Predictors of Cognitive Impairment among Older Koreans: Findings from a 6-Year Prospective Cohort Study

OBJECTIVE This study investigated gender-specific incidence and predictors of cognitive impairment among community-dwelling older adults in South Korea. METHODS Using data from the 2006 and 2012 Korean Longitudinal Study of Ageing (KLoSA), 925 females and 834 males aged 65 and over without cognitive impairment at 2006 were analyzed separately. Cognitive impairment was measured based on the Korean version of the Mini-Mental State Exam (K-MMSE) normative score. Generalized Estimating Equations (GEE) was conducted to examine the predictors of cognitive impairment at 6-year follow up. RESULTS Incidence of cognitive impairment at 2012 was significantly higher for women (30.5%) than men (26.1%). GEE result showed that depression was significantly associated with cognitive impairment for both genders (female: OR=2.26, 95% CI=1.63-3.12; male: OR=3.26, 95% CI=2.19-4.83). Having IADL limitations (OR=1.15, 95% CI=1.03-1.28), high blood pressure (OR=1.72, 95% CI=1.27-2.34), poor hearing (OR=1.94, 95% CI=1.29-2.92), regular exercise (OR=0.67, 95% CI=0.45-0.99), and normal weight (OR=1.39, 95% CI=1.03-1.86) were significant predictors of cognitive impairment only among women. In contrast, age (OR=1.04, 95% CI=1.01-1.07) and ADL limitations (OR=1.48, 95% CI=1.21-1.82) were significant predictors of cognitive impairment at follow-up only among men. CONCLUSION Findings of this study show gender-specific predictors of cognitive impairment among older Koreans. This study can provide information for clinicians and policy makers to develop different intervention strategies considering gender differences in the progress of cognitive impairment.