LAUSR

Background: Epidemiological information on extracranial carotid atherosclerosis (ECA) among Amerindians is limited. We aim to determine the prevalence of subclinical ECA and its correlation with cardiovascular risk factors in community-dwelling adults of Amerindian ancestry living in a rural Ecuadorian village. Methods: Utilizing a population-based design, stroke-free individuals aged ≥40 years were invited to undergo carotid ultrasound. Subclinical ECA was defined as an intima-media thickness (cIMT) >1mm and/or the presence of carotid plaques (focal intima thickening >1.5mm that protrudes into the lumen). Degree of luminal stenosis was calculated and considered significant if >50%. We investigated the association between these biomarkers and cardiovascular risk factors. Results: Of 728 candidates, 559 (77%) stroke-free individuals underwent carotid sonographic evaluation and were included. The mean age was 62.3 ±12.5 and 238 (43%) were men. The mean value of the cIMT was 0.85 ± 0.17mm (median cIMT: 0.83mm; IQ range: 0.74-0.92 mm). The prevalence of increased cIMT, carotid plaques, and increased cIMT and/or carotid plaques were 14%, 23.8%, and 26.1%, respectively. Table depicts the association of these biomarkers with cardiovascular risk factors. A multinomial logistic regression model, using individuals with normal carotids as the referent category, showed significant associations of ECA with increasing age, male gender, smoking and high blood pressure. Significant carotid stenosis was found in 19 subjects (3.4%). Conclusions: About one-fourth of Amerindians living in a rural setting have subclinical ECA. Increasing age, male gender, smoking and high blood pressure were independent determinants of the burden of ECA, while elevated glucose and total cholesterol showed no significant association. Obesity was inversely associated with ECA in univariate analysis, but such association disappeared in the multivariate model.