To Örebro University

BACKGROUND: the association between cholesterol profiles and risk of cognitive decline among older adults was inconclusive.

OBJECTIVE: to examine the association between cholesterol profiles and risk of cognitive decline in older adults with or without vascular risk factors (VRFs) in the prospective phase of the Shanghai Aging Study.

DESIGN: a prospective community-based cohort study.

SETTING: Shanghai, China.

PARTICIPANTS: we prospectively followed 1,556 dementia-free participants aged ≥60 years with a baseline cholesterol profile for 5.2 years on average. Participants with at least one of obesity, diabetes, hypertension, stroke, and coronary artery disease were categorised to the VRFs group, and those free of any VRFs were categorised to the non-VRFs group.

METHODS: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol in serum were measured at baseline. At follow-up, consensus diagnosis of incident dementia and Alzheimer's disease (AD) were established based on medical, neurological, and neuropsychological examinations. Cox regression was used to assess the association between cholesterol and incident dementia/AD; multivariate linear regression was used to examine the relationship between cholesterol and an annual rate of Mini Mental State Examination (MMSE) score decline in participants with or without VRFs.

RESULTS: among VRFs-free participants, TC (HR 0.62, 95%CI 0.40-0.95) and LDL-C (HR 0.47, 95%CI 0.28-0.80) were inversely associated with incident dementia, LDL-C was inversely associated with incident AD (HR 0.50, 95%CI 0.28-0.90). A significant correlation was found between incremental TC (β = 0.08), LDL-C (β = 0.09), and a slower annual decline of MMSE score.

CONCLUSIONS: effect of cholesterol on cognitive decline may be modified by VRFs.