Aldosterone synthase (CYP11B2) -344 C/T polymorphism is associated with left ventricular structure in human arterial hypertension

OBJECTIVES: This study examined the association between the -344 C/T polymorphism of the human aldosterone synthase promoter and left ventricular structure in arterial hypertension. BACKGROUND: Because of conflicting results from different studies, the mechanism of such an association, if any, has not been determined. METHODS: We examined the aldosterone synthase promoter genotype in 120 young (age: 26 ± 3 years) male, white subjects with normal or mildly elevated blood pressure. Left ventricular structural parameters and urinary sodium excretion over 24 h before and after additional oral sodium load (6 g/day over 1 week) were determined. RESULTS: Hypertensive subjects with the CC genotype had a greater left ventricular end-diastolic diameter but smaller relative wall thickness than those with the TT genotype (54 ± 2 vs. 50 ± 4 mm, and 0.37 ± 0.07 vs. 0.44 ± 0.06 mm, respectively; p < 0.05). Hypertensive subjects with the TT genotype (n = 15) had a greater increase in urinary sodium excretion after oral sodium load than those with the CC genotype (n = 11) (135 ± 95 vs. 24 ± 133 mmol/liter/day; p < 0.05). Serum aldosterone levels were found to be decreased after oral sodium load in hypertensive subjects with the TT and CT genotypes only (-37 ± 45 and -38 ± 51 pg/ml, respectively; all p < 0.01) but not in those with the CC genotype (-12 ± 30 pg/ml, n.s.). Such differences were not found in normotensive subjects. CONCLUSIONS: Hypertensive subjects with the -344 CC genotype of the aldosterone synthase promoter are characterized by a pattern of early eccentric left ventricular hypertrophy. Differences in renal sodium handling across the genotypes might contribute to this finding.