Aldosterone synthase (CYP11B2) -344 C/T polymorphism is related to antihypertensive response: result from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA) trial

BACKGROUND: Our aim was to determine whether the aldosterone synthase (CYP11B2) -344 C/T polymorphism was associated with the blood pressure (BP)-lowering response to antihypertensive treatment. METHODS: Patients with mild-to-moderate primary hypertension and left ventricular hypertrophy were randomized in a double-blind study to receive treatment with either the angiotensin II type 1 (AT1) receptor antagonist irbesartan (n = 43), or the beta1-adrenergic receptor blocker atenolol (n = 43). The aldosterone synthase (CYP11B2) -344 C/T polymorphism was analyzed using solid-phase minisequencing and related to BP reduction after 3 months treatment. Serum aldosterone levels were measured. RESULTS: After 3 months treatment the mean reductions in BP were similar for both treatment groups. When assessing the systolic BP reduction in the irbesartan group, patients with the TT variant had a more pronounced reduction (-21 +/- 19 SD mm Hg, n = 17) than both the TC (-14 +/- 18 mm Hg, n= 18) and CC (0 +/- 17 mm Hg, n = 8) genotypes (P = .04). There was no association between this polymorphism and the diastolic BP response. The -344 C/T polymorphism was not associated with the BP response to atenolol. Nor was it related to the baseline serum aldosterone level. CONCLUSIONS: The aldosterone synthase -344 C/T polymorphism was related to the BP-lowering response in hypertensive patients treated with the AT1-receptor antagonist irbesartan.