Clinical and Genetic Features of Uncontrolled, Complicated Arterial Hypertension in Hypertensive Patients of the Aral Sea Region

Abstract

The purpose of this study was to assess the clinical and genetic features of the course of hypertension, complicated by a hypertensive crisis in the inhabitants of the Aral Sea region. Methods and Results: The study included 132 patients (52 men and 80 women) with AH who applied at least 5 times (4.9±2.4) during 1 year to the Nukus Emergency Medical Care Center with a diagnosis of “Uncomplicated hypertensive crisis.” The mean age of the patients was 57.2±11.6 years, the mean duration of AH ‒ 8.85±3.4 years. The control group consisted of 50 healthy people (mean age of 52.7±6.4 years), women and men in equal proportions. A cardio Hypertension Panel of multiplex RT-PCR assay was used to detect 4 SNP [ADD1 rs4961 (G460T), GNB3 rs5443 (C825T), AGT rs4762 (C521T), and AGT rs699 (T704C)]. To assess the strength of the association between a genetic marker and AH, measured by the OR, we used multiplicative and additive models. According to the results of office BP measurement, the average SBP corresponded to AH Grade 3 (200.8±22.6 mmHg), and DBP corresponded to AH Grade 2 (105.4±7.62 mmHg). All AH patients, regardless of gender, were diagnosed with left ventricular hypertrophy and increased carotid intima-media thickness. Microalbuminuria was detected in 89 (67.4%) patients, proteinuria in 39 (29.6%) patients. Among AH patients, 88% had a high salt taste sensitivity threshold (STST) and 12% had a medium STST (χ²=269.455, P=0.0001). Analysis of the multiplicative and additive models for the AGT rs699 (Т704С) SNP showed a significant risk of AH with the carriage of the T allele (OR=3.70, 95% CI: 1.88-7.26, P=0.000) and the homozygous TT genotype and heterozygous CT genotype (OR=12.55, 95% CI: 0.72-218.80, P=0.000, and OR=2.67, 95% CI: 1.24-5.74, P=0.000, respectively). At the same time, the carriage of the C allele and CC genotype may be protective against the development of AH in individuals of the Aral Sea region. Analyzing the additive models, we also found a significant risk of AH with the carriage of the homozygous CC genotype of the AGT rs4762 (C521T) SNP (OR=5.92, 95% CI: 2.78-12.63, P=0.000). For the ADD1 rs4961 (G460Т) SNP and the GNB3 rs5443 (C825T) SNP, we did not find associations with the risk of AH. The presence of ethnic differences in the prevalence and associative links of AH candidate genes with the development of the salt-sensitivity phenotype require further extended searches in this direction, especially in the Aral Sea region.