G-Protein β 3 Subunit Gene Variant and Left Ventricular Hypertrophy in Essential Hypertension

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 35; no. 1; pp. 214 - 218
• Main Authors: Poch, Esteban, González, Daniel, Gómez-Angelats, Elisenda, Enjuto, Montserrat, Paré, Joan Carles, Rivera, Francisca, de la Sierra, Alejandro
• Format: Journal Article
• Language: English
• Published: 01-01-2000
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/01.HYP.35.1.214

Abstract
—A functional genetic variant consisting of a C825T substitution in the
GNB3
gene, encoding for the G-protein β
3
subunit, has been associated with enhanced G-protein activation and cell growth. The aim of the study was to investigate the association of this polymorphism with left ventricular hypertrophy (LVH) in a sample of patients with essential hypertension. Left ventricular mass was assessed by 2-mode echocardiography in 86 patients with essential hypertension, and
GNB3
C825T genotype was determined by polymerase chain reaction and restriction digestion. Thirty-seven (0.43) patients were homozygous for the C allele (CC), 40 (0.47) were heterozygous (CT), and 9 (0.10) were homozygous for the T allele (TT). The genotype distribution among the patients was in Hardy-Weinberg equilibrium. Values of left ventricular end-diastolic diameter (52.0±0.7 versus 48.9±0.9 mm,
P
=0.007), posterior wall thickness (11.3±0.2 versus 10.6±0.2 mm,
P
=0.042), and left ventricular mass index (152.7±4.4 versus 135.2±6.4 g/m
2
,
P
=0.023) were significantly higher in patients with CT and TT genotypes considered together (CT+TT) than in CC patients. The distribution of the genotypes was significantly different when comparing patients with LVH: 20 (0.33) CC and 40 (0.67) CT+TT patients had this complication, and 17 (0.65) CC and 9 (0.35) CT+TT patients did not (
P
<0.01). The frequency of the T allele was significantly different among patients with (0.40) and without (0.20) LVH (
P
<0.01). A logistic regression analysis showed that the association between the T allele and LVH was independent of age, mean blood pressure, body mass index, and alcohol consumption. The relative risk of LVH in patients bearing the T allele (CT+TT group) compared with CC hypertensive patients was 3.03 (95% CI 1.14 to 8.05). The findings suggest an association between LVH and the 825T allele in hypertensive patients.