Cardiovascular Disease Risk Burden, Cognitive Impairments and Incident Dementia among Community-Dwelling Middle-Aged and Older Adults: An 8-Year Longitudinal Follow-up Study.

OBJECTIVES: To evaluate the associations between cardiovascular disease (CVD) risk burden (estimated by the World Health Organization (WHO) algorithm) and cognitive impairments (e.g., incident dementia, global and domain-specific impairments) among CVD-, dementia- and disability-free, community-dwelling middle-aged and older adults during an 8-year follow-up. DESIGN: A community-based longitudinal cohort study. SETTING: Yuanshan township in Yi-Lan County, Taiwan. PARTICIPANTS: A total of 889 community-dwelling residents aged 50 years or older. MEASUREMENTS: Age, sex, educational level, employment status, alcohol status, body mass index, physical activity, gait speed, depressive symptoms, WHO region-specific CVD risk scores (10-year CV risk, low: <10% vs. moderate-to-high: ≥ 10%), Chinese version of the Mini-Mental State Examination (MMSE), verbal memory by the delay-free recall in the Chinese Version Verbal Learning Test (CVVLT), language function by the Boston Naming Test and the category (animal) Verbal Fluency Test, visuospatial function by the Taylor Complex Figure Test, executive function by the digit backward and the Clock Drawing Test. RESULTS: Compared to those with low CVD risk, middle-aged and older adults with moderate-to-high CVD risk were at greater risk for cognitive impairments with respect to the MMSE (adjusted odds ratio (aOR) 1.60 [95% confidence interval (CI) 1.19-2.15], P=0.002), verbal memory (aOR 1.97 [1.43-2.70], P< 0.001) and language (aOR 1.99 [1.46-2.70], P< 0.001), as well as incident dementia (aOR 2.40 [1.33-4.33], P=0.004). After adjusting for all covariates, CVD risk was not associated with other domains of cognitive impairment. CONCLUSIONS: Among healthy, community-dwelling, middle-aged and older adults, those with moderate-to-high cardiovascular risk burden were significantly associated with incident dementia and global and domain-specific cognitive impairments (verbal memory and language), which suggests the existence of a relationship between early cognitive deficits and CVD risk burden. Further studies are needed to elucidate the pathophysiological mechanism of the link between CVD risk burden and cognitive impairment.