The Relationship Between Coronary Artery Calcification and Carotid Intima Media Thickness and Hippocampal Volume: An Analysis From the Dallas Heart Study

Background: Higher rates of dementia are reported in people with a history of coronary artery disease. Smaller hippocampal volume (HV) is a risk factor for the development of dementia. Objective: This study assessed whether coronary artery calcification (CAC) and carotid intima media thickness (CIMT) are associated with HV in participants from the Dallas Heart Study, a community-based study of Dallas County, Texas, residents. Methods: Data from a total of n = 1821 participants in the Dallas Heart Study with brain magnetic resonance imaging, CAC, and CIMT information were included in the present study, after excluding those with a history of myocardial infarction or stroke. To evaluate the effect of CAC and CIMT on total HV, 4 linear regression analyses were conducted in which the primary predictor was (1) CAC as a continuous metric; (2) CAC as a binary metric (CAC = 0 vs. CAC >= 1); (3) CAC as a continuous metric but only for those with CAC >0; and (4) CIMT as a continuous metric. Demographic and cardiovascular disease risk factors, as well as intracranial volume, were entered into the model as covariates. Results: Participants were largely women (58.2%) with a mean age of 49.7 +/- 10.3 years. Forty-six percent of the sample reported being Black, and approximately 14% reported being Hispanic. All 3 variations of the CAC effect were nonsignificant predictors of total HV (beta = 20.013, P = 0.602; beta = 20.011, P = 0.650; beta = 0.036, P = 0.354, respectively), as was the effect of CIMT (beta = 0.009, P = 0.686). Conclusions: Current findings suggest nonsignificant relationships between both CAC and CIMT and between CAC and total HV, while controlling for other related factors in a large, diverse, community-based sample of people without a history of myocardial infarction or stroke. In the context of existing evidence that both coronary artery disease and smaller HV are associated with the development of dementia, the present findings suggest that neither marker of the cardiovascular disease examined here is associated with a reduction in HV in the population studied. Longitudinal studies are needed to assess relationships between CAC and CIMT and between CAC and HV over time.