Abstract Background Coronary artery disease (CAD) and hypertension are major cardiovascular diseases (CVDs) influenced by both environmental and genetic factors. Endothelin-1 (ET-1), a potent vasoconstrictor encoded by the EDN1 gene, is involved in vascular regulation. The rs5370 (G + 691 T, Lys198Asn) polymorphism has been associated with CVD susceptibility, though findings differ by population. This study assessed the association between EDN1 rs5370 polymorphism, serum ET-1 levels, and CVD risk in the Duhok population. Methods A case–control study included 202 individuals (> 35 years) divided into four groups: controls, CAD-only, hypertension-only, and combined CAD-hypertension. Genomic DNA was genotyped using allele-specific PCR. Serum ET-1 was measured using ELISA. Statistical analyses included Chi-square, ANOVA, Pearson correlation, and ROC curve analysis. Results The TT genotype was significantly more prevalent in CAD (28.0%) and CAD + hypertension (21.3%) groups compared to controls (6.7%) ( P = 0.0002 and 0.0183, respectively). No significant differences were found in the hypertension-only group. Serum ET-1 levels were highest in the CAD + hypertension group. A strong positive correlation was found between TT genotype and ET-1 levels ( r = 0.7310). ROC analysis identified systolic pressure (AUC = 0.787) and age (AUC = 0.782) as key diagnostic markers. Conclusion The EDN1 rs5370 TT genotype is significantly associated with increased CAD and combined CVD risk in the Duhok population. While group differences in ET-1 levels were evident, genotype-dependent differences were only seen through correlation analysis. The rs5370 polymorphism may serve as a genetic marker for CAD susceptibility.
Ameen et al. (Thu,) studied this question.