Introduction. Dysregulation of vascular tone (VT) is one of the cardiovascular risk factors that significantly worsens the quality of life, and can be a predictor for persistent hypertension (HTN). The identification of preclinical stages of vascular pathology is the most promising for prevention of hypertension. Therefore, it is important to investigate the polymorphism of genes which end products are involved in the regulation of blood pressure (BP) and predispose to VT dysregulation.
Objective. To investigate the clinical and prognostic significance of the AGT and AGTR1 polymorphic variants associated with increased cardiovascular risk in young and relatively healthy subjects and patients with HTN.
Materials and methods. The study involved 90 young healthy subjects and 62 patients with hypertension. The exclusion criteria for young subjects were as follows: organic cardiovascular and central nervous system disorders and smoking. The exclusion criteria for patients with HTN were identical. Additionally, the patients with uncontrolled HTN were not included. The VT regulation was assessed by the active standing test in which the changes in blood pressure (BP) and heart rate (HR) were measured. The polymorphism was identified using DNA pyrosequencing.
Results. The relationship between BP and HR and the AGTR1 A1666C A>C and AGT M268T T>C variants was established. Both in young subjects and hypertensive patients was found that the C allele of the AGTR1 A1666C A>C variant was associated with lower HR in supine compared with subjects without this allele. The risk allele C of the M268T T>C polymorphism was associated with lower sBP and dBP during the 1st minute of upright posture. The identified features can probably be explained by the vascular tone increased at baseline in the presence of these polymorphic variants which was manifested by smaller changes in BP and HR during the active standing test compared to subjects without these allelic variants. The C allele of the AGTR1 A1666C A>C variant was associated with earlier onset of HTN.
Conclusion. The identification of the AGTR1 A1666C A>C and AGT M268T T>C variants can be informative for clarifying the risk of HTN when the young subjects are examined, as well as the probability of early onset of hypertension.