Lack of association of G-protein subunit gene C825T polymorphism with left ventrucular hypertrophy in essential hypertension

Background: The aim of the present study was to determine if there is an association of G-protein beta 3 subunit (GNB3) gene polymorphisms and left ventricular hypertrophy (LVH) in patients with essential hypertension (EH) in a St. Petersburg population. Material/Methods: We examined 135 patients (mean age 48 +/- 7 yrs) with mild to moderate EH recruited from the general population of an outpatient hypertension clinic. Left ventricular mass was measured by echocardiography, and the left ventricular mass index (LVMI) was calculated. The GNB3 C825T genotype was determined by polymerase chain reaction and restriction digestion. Results: 67 patients (50%) were homozygous for the C allele (CC), 56 were heterozygous (CT) (41%) and twelve (9%) were homozygous for the T allele (TT). The distribution of genotypes among the patients was in Hardy-Weinberg equilibrium and did not differ significantly when comparing patients with or without LVH. The frequency of the T allele was only slightly higher in patients with LVH (32%) compared to those without LVH (28%), NS, and the LVMI was similar in patients with the CC, CT and TT genotypes (122.3 +/- 29.8; 118.8 +/- 29.9 and 115.2 +/- 18.3 g/m(2), respectively). No significant discrepancies were found among the various genotype groups in posterior wall thickness, interventricular septum thickness, or functional parameters such as ejection fraction, isovolumetric relaxation time and E/A ratio. Conclusions: These observations clearly suggest the lack of association between left ventricular structure or function and the CNB3 gene variant in the studied population.