Measures of carotid atherosclerosis and cognitive function in midlife: The Jerusalem LRC longitudinal study

Abstract

BackgroundCarotid atherosclerosis may be associated with cognitive decline in elderly stroke-free non-demented individuals. However the studies are few, especially amongst adults in midlife. Rarely was socioeconomic status adequately accounted for. MethodsIn a cross-sectional examination of the population-based Jerusalem Lipid Research Clinic (LRC) cohort, carotid intima-media thickness (IMT), plaque and volumetric flow were determined by ultrasound in 507 cohort members, aged 48–52. At the same visit, global cognitive function and its five specific component domains were assessed with a NeuroTrax computerised test battery. Multivariable linear regression and logistic models were applied. ResultsIn sex-adjusted, but not in multivariable-adjusted linear regression models, IMT and plaque were significantly inversely associated with measures of cognition. However, in binary logistic models adjusted for sex, age, education, childhood and adult SES, and multiple cardiovascular risk factors, IMT was associated with low-ranked (lowest fifth) global cognition (OR per 0.1mm, 1.25, 95%CI 1.01–1.55, p=0.044); this association was confirmed in multinomial logistic modelling. The presence of atheromatous plaque was associated with elevated risk for low-ranked global cognitive function in midlife (OR, 1.93, 95%CI, 1.04–3.59, p=0.037). Common carotid volumetric flow was not associated with cognitive function, and adjustment for volumetric flow did not materially affect the associations of IMT or plaque with global cognition. ConclusionIn this population-based cohort in midlife, subclinical carotid atherosclerosis measured as higher IMT and the presence of atherosclerotic plaque was associated with low-ranked global cognitive function. In light of the absence of an independent association of carotid volumetric flow with cognition, and although reverse causation cannot be excluded in this cross-sectional study, we infer that carotid atherosclerosis in midlife may be a marker of intracranial atherosclerosis and possible resulting lower cognitive function.