Prevalence and Risk Factors of Dementia and MCI in Community-dwelling Elderly Koreans

Abstract

Background: We investigated the prevalence of dementia and mild cognitive impairment (MCI) and their risk factors in an urban community-dwelling elderly people over 65 years old. Methods: A two-phase investigation was performed from January 2010 to December 2011. In Phase I, all subjects (n=9,485) responded to the Korean version of the Mini-Mental State Examination (K-MMSE). Based on the K-MMSE score the subjects were classified into two groups (‘Normal’ and ‘Cognitive decline’). In Phase II, cognitive decline subjects were diagnosed as dementia or MCI according to the neuropsychological tests and doctor’s interview. We also surveyed the socioeconomic and medical factors in Normal, Dementia and MCI groups. And we compared and analyzed the socioeconomic and medical risk factors by multiple logistic regressions in Dementia and MCI group. Results: The prevalence of dementia and MCI was obtained 5.4% and 4.3%, respectively. Old age, alcohol intake, living together, low economic status, jobless in the past, diabetes mellitus, previous stroke, lower BMI and family history of dementia were associated with the increased dementia risk. Higher education, hypertension and physical activity were associated with the decreased dementia risk. And old age, alcohol intake, higher education, previous stroke, lower BMI and physical activity were common risk factors in MCI group. Conclusions: The prevalence of dementia and MCI was obtained much lower than previous reports. Dementia and MCI patients had common socioeconomic and medical risk factors. It is also important to control the risk factors earlier to prevent the increase of patients in dementia. And in order to prove the hypothesis that early control of the risk factors can decrease the occurrence of dementia, the further prospective studies are needed.