The relationship between the neck circumference and the carotid intima-media thickness in Amerindians. Potential links to health risks?

The carotid intima media thickness (cIMT) is a predictor of cardiovascular events. The neck circumference (NC) has been investigated as a risk factor for increased cIMT with contradictory results. This study assessed the relationship between NC and cIMT in Atahualpa residents aged ≥40 years who had sonographic examination of carotid arteries (n = 590). We also discussed on potential pathogenetic mechanisms underlying this association. Participants belonged to the Native Ecuadorian (Amerindians) ethnic group. Non-parametric regression models were used to assess the aforementioned relationship, after adjusting for relevant confounders. The mean age of participants was 60.9 ± 12.7 years (58% women). The mean value of the cIMT was 0.85 ± 0.19 mm. The mean NC was 35.8 ± 34 cm. The NC was normally distributed, but the cIMT was not. Mean values of NC and cIMT were significantly greater in men than in women. Non-parametric models showed significant differences in median cIMT values according to quartiles of NC. Predictive cIMT margins increased by quartiles of NC, significantly among individuals in the 1st quartile as compared to the 3rd quartile. In this population of Amerindians, smaller NC is associated with lower values of cIMT. The pattern of this association is different in men than in women. Sex-related differences in cervical fat tissue distribution probably accounted for such differences.