Carotid intima-media thickness value distributions in The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Objective: Carotid intimaemedia thickness (IMT) is a noninvasive measurement of early atherosclerosis. Most IMT studies have involved populations with low rates of racial blending. The aim of the present article is to describe IMT value distributions and analyze the influence of sex and race on IMT values in a large Brazilian sample, a setting with a high rate of racial admixture. Methods: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a multicenter cohort of 15,105 adult (aged 35-74 years) civil servants in six Brazilian cities. Baseline assessment included IMT measurements in both common carotid arteries. Race was self-reported. We studied the association between sex and race with IMT values using multiple linear regression models. We conducted analyses in all and low-risk individuals, defined as those without classical cardiovascular risk factors. Results: We analyzed complete IMT data from 10,405 ELSA-Brasil participants. We present nomograms by age for all and low-risk individuals, stratified by sex and race. We found that men had significantly higher maximal IMT values compared with women (beta = 0.058; P < 0.001). This association remained for low-risk individuals (beta = 0.027; P = 0.001). In addition, Brown and White individuals had lower maximal IMT values compared with Black individuals for all (beta = -0.034 and beta = -0.054, respectively; P < 0.001) and low-risk individuals (beta = -0.027; P = 0.013 and beta = -0.035; P < 0.001, respectively). Conclusion: We found significantly higher IMT values in men. We found significantly higher IMT values in Black individuals than White and Brown individuals. These results persisted when analyses were restricted to low-risk individuals. (C) 2014 Elsevier Ireland Ltd. All rights reserved.