Blood levels of apelin and its receptor will be determined in patients and controls, and correlated with hypertension and coronary artery disease. And the allelic and genotypic frequencies of the G212A single polymorphism nucleotide of the apelin receptor gene and the -1860T\>C single polymorphism nucleotide of the apelin gene in the study groups. And evaluation the functional role of A allele in hypertension. As well as investigating the association between: the genotypes of the apelin gene and the levels of apelin in the plasma, the genotypes of the apelin receptor gene and the levels of APJ in the plasma in the study groups. And link the polymorphism of the apelin gene with the polymorphism of the apelin receptor gene. And to determine the correlation between the presence of the studied SNPs and some traditional risk factors for coronary artery disease, which are age, hypertension, the onset age of hypertension, smoking, BMI, cholesterol and triglyceride levels in the blood, and family history of CAD.