Renin-angiotensin system genetic polymorphisms and essential hypertension in the Spanish population

BACKGROUND: The goal of this study was to analyse the association between e ssential hypertension and the main genetic polymorphisms at the renin-angio tensin system in the Spanish population. PATIENTS AND METHOD: Case-control study including 185 essential hypertensiv e subjects (age [SD] 39.6 [7.5] years, 52% women, systolic blood pressure 1 51.2 [17.4] mmHg, diastolic blood pressure 96.0 [9.4] mmHg and 350 sex- and age-matched normotensive individuals selected from a sample of the general population of the Comunidad Valenciana, Spain (age 39.4 [8.0] years, 51.7% women, systolic blood pressure 116.0 [12.0] mmHg, diastolic blood pressure 69.6 [8.5] mmHg). A PCR was performed to determine I/D angiotensin convert ing enzyme (ACE) gene polymorphism, A-6G and M235T angiotensinogen gene pol ymorphism and A1166C polymorphism of the angiotensin II type I receptor. RESULTS: There were no differences between cases and controls with regard t o genotypic and allelic distributions. In hypertensive patients, there were no differences in genotypic or allelic distributions after considering the presence or absence of a familial history of hypertension or comparing ter tiles of systolic and diastolic blood pressure values. Only in women, the c ombination of a C allele of A1166C polymorphism with an A-6G angiotensinoge n polymorphism A allele (p = 0.007), or an M235T angiotensinogen polymorphi sm T allele (p = 0.007), was associated with a higher risk of hypertension. CONCLUSIONS: We found no association between essential hypertension risk an d I/D ACE gene, M235T and A-6G angiotensinogen gene, or A1166C angiotensin It type I receptor gene polymorphisms. An epistatic effect was observed in young women between angiotensin II type 1 receptor polymorphisms and angiot ensinogen polymorphisms.