Fine particulate matter and intima media thickness: Role of endothelial function biomarkers.

Background: Ambient fine particulate matter (PM) is a risk factor for atherosclerosis disease. We aimed to assess whether nitric oxide stable metabolites (NOx) and l-arginine mediate the association between PM and carotid intima media thickness (cIMT) increase.

Methods: We selected 251 participants from the control group of GEA (Genetics of Atheroslerosis Disease Mexican) study (2008-2013) in Mexico City.

Cholesterol 7 alpha-hydroxylase () gene polymorphisms are associated with increased LDL-cholesterol levels and the incidence of subclinical atherosclerosis.

The cholesterol 7 alpha-hydroxylase (CYP7A1) enzyme plays an important role in the conversion of cholesterol to bile acid, contributing to the reduction of cholesterol plasma levels in normal conditions. Nonetheless, recent studies have shown that some genetic variants in the enhancer and promoter regions of the CYP7A1 gene reduce the expression of the CYP7A1 enzyme, increasing plasma lipid levels, as well as the risk of developing coronary heart disease. The aim of this work was to explore whether the genetic variants (rs2081687, rs9297994, rs10107182, rs10504255, rs1457043, rs8192870, and rs3808607) of the CYP7A1 gene are involved in subclinical atherosclerosis and plasma lipid levels.

Selection scan in Native Americans of Mexico identifies rs174616: Evidence of gene-diet interactions affecting lipid levels and Delta-6-desaturase activity.

Searching for positive selection signals across genomes has identified functional genetic variants responding to environmental change. In Native Americans of Mexico, we used the fixation index (F) and population branch statistic (PBS) to identify SNPs suggesting positive selection. The 103 most differentiated SNPs were tested for associations with metabolic traits, the most significant association was /rs174616 with body mass index (BMI).