Genetic polymorphisms of the renin-angiotensin system and essential hypertension

BACKGROUND: The renin-angiotensin system (RAS) plays an important role in b lood pressure (BP) regulation. A number of RAS polymorphisms have been link ed to essential hypertension (EH), but there is uncertainty about this asso ciation in other studies. We examined whether the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene, and the M235T and T174M polymorphisms of the angiotensinogen (AGT) gene are associated w ith EH in a Spanish sample of hypertensive patients. MATERIAL AND METHODS: We studied 75 patients with EH (BP > 160/100 mmHg), a ged 55 (8.5) years, 30 males, systolic BP (SBP) 182 +/- (22.1) mmHg, diasto lic BP (DBP) 109 +/- (9.9) mmHg (mean [SD]) and a strong family history of the disease. As a control group, 75 healthy subjects with no family history of cardiovascular disease were studied. The polymorphisms were determined by PCR amplification of genomic DNA, followed by enzyme digestion for the A GT gene polymorphisms. RESULTS: The genotype distribution and the frequencies of the alleles of th e three RAS polymorphisms were similar in hypertensive and control subjects . In addition, we did not find any compound effect of the I/D ACE gene and M235T AGT gene polymorphisms on BP levels in hypertensive and control subje cts. CONCLUSIONS: In this sample, the contribution of the ACE I/D polymorphism a nd the AGT M235T and T174M polymorphisms in the development of EH seems to be less important than previously estimated.