Endocrine Abstracts

Introduction: Nowadays is believed that primary aldosteronism (PA) is the most frequent cause of secondary hypertension and reaches 10% of whole hypertensive population. The activity of the mineralocorticoid hormone may be change by polymorphism of aldosterone synthase gene (CYP11B2) e.g. in promoter -344T/C region. Aim of this study was to find differences in baseline plasma aldosterone concentration (PAC), plasma renin activity (PRA), aldosterone – renin ratio (ARR) and plasma aldosterone concentration post saline infusion suppression test (SIST) in genetic model of CYP11B2 -344T/C (TT, TC, CC).

Material and methods: The study group consist 151 patients who were diagnosed because of a suspicion of primary aldosteronism. Normality data distribution was checked by Shapiro – Wilk test. The significance of differences between the groups was evaluated through Student’s t-test. The differences in frequencies between categorical data were tested for statistical significance with χ² tests.

Results: There were no significant differences in distribution of these alleles in comparison with distribution described in European population in “1000 Genome” Study. The statistical significance was demonstrated between homozygotes (TT and CC) only in ARR. In TT genetic model ARR was markedly higher than was in CC genetic model (P=0.048 CI 95%). Finally, 18 (11.9%) patients were diagnosed with PA, 11 (13.25% of all TC) with TC allele, six with TT (20% of all TT) and only one with CC (2.6% of all CC).

Conclusion: Genetic model consisting thymine instead cytosine in -344 region of promotor CYP11B2 suggest predisposition to primary aldosteronism which is expressed mainly by impairment of ARR. TT genetic model in comparison with CC model significantly raises ARR but changes in PAC and PRA almost remains unnoticeable. This suggest TT genetic model as factor slightly decreases PRA and simultaneously slightly increases PAC what giving quotient PAC and PRA markedly elevated.