Associations of excess myocardial mass, echoreflectiveness and aldosterone synthase gene polymorphism in men with hypertension

Abstract

Hypertensive remodeling of the left ventricle (LV) is largely due to the influence of a number of control genes. In particular, the regulatory gene CYP11B2, which is responsible for the activity of aldosterone in blood plasma, affects the processes of cardiomyocyte hypertrophy, myocardial fibrosis and microcirculation. This study is devoted to the search for the effect of polymorphic aldosterone synthase carriers on the severity of the components of left ventricular hypertrophy in men with essential hypertension (EH) and representatives of the control group, residents of Podyllia region. The aim of the study was to determine associations between excess (inappropriate) myocardial mass, parameters of standard echocardiography and parameters of echoreflectivity in men with essential hypertension, carriers of different polymorphic variants of aldosteronesynthase gene. The study involved 150 men, aged 45-60 years, residents of the Podyllia region, who had no irreversible damage of target organs. Among them, 50 were in the control group, 58 - had EH of 1st stage and 42 men had EH of 2nd stage. All participants were measured for office blood pressure, performed a standard echocardiographic examination with the addition of standard EchoCG protocol by determination of the parameters of echoreflectivity and evaluation of propriateness of left ventricular l mass (LVM) to hemodynamic load, according to the formula de Simone et al. and calculating the excessiveness ratio (ER) and determined the C-344T polymorphism of the CYP11B2 gene in venous blood samples by PCR. Statistical processing of the obtained results is performed using a specialized statistical application "Statistica 12.0". It was found that the prevalence of CC polymorphism of the CYP11B2 gene in men with inappropriate LVM was almost twice higher than in men with appropriate to hemodynamic load LVM (p=0.015 by criterion χ 2). At the same time, men with inappropriate LVM were characterized by higher values of echoreflectivity parameters BB and mCSV. In contrast to patients of the control group and patients with EH of 1st stage, patients with EH of 2nd stage, actual LVM (287.4 (53.9) g) significantly (p<0.001) exceeded the predicted values (189 (37.8) g). According to the results of Spearman's rank correlation analysis, it was found that the carrier of the CC genotype of aldosterone synthase gene is associated with higher values of the LVM ER. Thus, patients carrying the polymorphic CC variant of CYP11B2 gene are characterized by more pronounced cardiomyocyte hypertrophy, greater excess of LV mass relative to individual hemodynamic needs, more aggressive processes of myocardial fibrosis.