Associations of carotid atherosclerosis with cognitive function and brain health: Findings from a UK tri-ethnic cohort study (Southall and Brent Revisited).

Background: Cognitive function has an important role in determining the quality of life of older adults. Cardiovascular disease (CVD) is common in older people and may compromise cognitive performance; however, the extent to which this is related to carotid atherosclerosis is unclear.

Aim: We investigated associations between carotid atherosclerosis and cognitive function and neuroimaging markers of brain health in a UK multi-ethnic community-based sample including older people of European, South Asian, and African-Caribbean ethnicity.

Methods: Carotid plaques and intima-media thickness (cIMT) were assessed using ultrasound in 985 people (mean age 73.2y, 56 % male). Associations of carotid atherosclerosis with cognitive function (memory, executive function, language and CSI-D, a global measure of cognitive state) and neuroimaging measures (total brain volume, hippocampal volume, white matter (WM) lesion volume and coalescence score) were analysed using regression analyses, with and without adjustment for potential confounders using two models: 1) adjustment for age, sex, and ethnicity; 2) model 1 plus education, physical activity category, body mass index, hypertension, diabetes, total and high density lipoprotein cholesterol, atrial fibrillation, smoking, previous CVD, alcohol consumption, and presence of chronic kidney disease.

Results: People with carotid plaque or higher cIMT had lower CSI-D score, poorer memory poorer executive function and higher WM lesion volume and coalescence. Language was poorer in people with plaque but was not correlated with cIMT. Associations with plaque were preserved after full adjustment (model 2) but relationships for cIMT were attenuated. Associations with other plaque characteristics were generally unconvincing after adjustment.

Conclusions: This multi-ethnic cohort study provides evidence that presence of carotid plaque, is associated with poorer cognitive function and brain health.