OBJECTIVETo determine whether the blood pressure (BP) response to hydrochlorothiazide (HCTZ) was associated with the angiotensin converting-enzyme (ACE) I/D and aldosterone synthase (CYP11B2)-344T/C polymorphisms.

METHODSThe BP response to HCTZ 12.5 mg once daily for 6 weeks was assessed in 829 subjects with mild or moderate essential hypertension, and compared across the ACE and CYP11B2 genotypes.

RESULTSOf the 829 enrolled subjects, 785 completed the study. The systolic BP response differed according to the ACE (DD 9.4 +/- 15.7 mm Hg, ID 4.8 +/- 16.3 mm Hg, and II 5.1 +/- 14.8 mm Hg, P < 0.01), but not the CYP11B2 genotype (P > 0.05). Subjects with the combination of ACE DD and CYP11B2 CC genotypes tended to have a more pronounced systolic BP reduction than the other genotypic combinations of these 2 genes. Multiple linear regression analyses showed that the ACE DD genotype and serum aldosterone concentration at baseline were associated with the systolic BP reduction after treatment. None of the genetic associations with changes in diastolic BP or mean arterial pressure reached statistical significance (P > 0.05).

CONCLUSIONSThe present study suggested that the ACE DD genotype was associated with the systolic BP response to HCTZ, and that the subjects with the combination of ACE DD and CYP11B2 CC genotypes might have a better BP response to HCTZ than the other genotypic combinations of these 2 genes.