Common Carotid Artery Intima-Media Thickness: The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) Study Results

Background: Measurement of far wall common carotid artery intima-media thickness (CCAIMT) has emerged as a predictor of incident cardiovascular events. The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study was the first large-scale population-based assessment of both CCAIMT and cardiovascular risk factor prevalence in 7 Latin American cities; the relationship between CCAIMT and cardiovascular risk markers was assessed in these urban Latin American centers. Methods: CARMELA was across-sectional, population-based, observational study using stratified, multistage sampling. The participants completed a questionnaire, were evaluated in a clinical visit and underwent carotid ultrasonography. Clinical measurements were obtained by health personnel trained, certified and supervised by CARMELA investigators. Mannheim intima-media thickness consensus guidelines were followed for measurement of CCAIMT. Results: In all cities and for both sexes, CCAIMT increased with higher age. CCAIMT was greater in the presence of cardiovascular risk factors than in their absence. In all cities, there was a statistically significant linear trend between increasing CCAIMT and a growing number of cardiovascular risk factors (p < 0.001). After adjustment for age and sex, metabolic syndrome was strongly associated with increased CCAIMT (p < 0.001 in all cities), as were hypercholesterolemia, obesity and diabetes (p < 0.001 in most cities). By multivariate analysis, hypertension was independently associated with an increase in CCAIMT in all cities (p < 0.01). Conclusions: CARMELA was the first large-scale population study to provide normal CCAIMT values according to age and sex in urban Latin American populations and to show CCAIMT increases in the presence of cardiovascular risk factors and metabolic syndrome.