Investigation of risk factors for the conversion of mild cognitive impairment to dementia

Abstract

Background Mild cognitive impairment (MCI) is an intermediate state between normal aging and dementia and is characterized by pathological cognitive decline. The study aimed at revealing the risk of MCI progressing to dementia through a follow-up investigation. Methods In 2011, 441 MCI subjects were recruited, and the disease status was tracked by the follow-up survey in 2017. Subjects with MCI stable (MCIs; N = 356) and MCI progressed into dementia (MCIp; N = 77) were analysed in our study. Community-dwelling old people of age ≥ 55 were recruited from 30 streets and 24 committees (or communities) of the Pudong New District (Shanghai, China). Neuropsychological tests of MMSE, MoCA, 17-item HAMD-17, ADL and HIS were performed. Additionally, the correlations of neuropsychological items and MCIp were explored by univariate and multivariate regression analyses. Results MCIp patients had the lower MMSE and MoCA total scores, whereas the ADL, and HIS total score in MCIp group were higher than in MCIs group. The univariate analysis revealed age, attention (MoCA), visuospatial/executive, number of births, marital status and attention and calculation were significant predictors of MCI progression. In multivariate analysis, age was an independent risk factor of MCI aggravating, while attention (MoCA) was independent protective factor for MCI progression. Conclusions Age and worsening attention but not depression in MCI patients were independently associated with the progression of dementia in a 6-year follow-up period.