[Genetic polymorphisms of the renin-angiotensin system and essential hypertension].

Background: The renin-angiotensin system (RAS) is known to regulate the blood pressure (BP). Several RAS polymorphisms have been associated with essential hypertension (EH), but there is uncertainty about this association. We examined whether the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene, and the M235T polymorphism of the angiotensinogen (AGT) gene were associated with EH in a sample of Spanish hipertensive patients.
Patients and Method: We studied 1,204 patients with EH (BP > 140/90 mmHg): 668 males, aged 50.8 (13.6) years with systolic BP 151.7 (19.1) and diastolic BP 94.3 (13) mmHg [mean (SD)] and 536 females, aged 52.4 (13.9) years with systolic BP 155.1 (19.8) and diastolic BP 94.5 (12.3) mmHg. As a control group, 367 men and 280 women with no family history of cardiovascular disease who had a normal blood pressure were included. Polymorphisms were determined by PCR amplification of genomic DNA, followed by enzyme digestion for the AGT gene polymorphism.
Results: The genotype distribution and allele frequencies of the two RAS polymorphisms were similar in hypertensive and control subjects. Similarly, there were no differences in BP level with regard to the genotype in male or female patients. 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 subjects.
Conclusions: This study suggests that in the population studied, the contribution of the ACE I/D polymorphism and the AGT M235T polymorphism in the development of EH is less important than previously estimated.