Influence of selected genetic polymorphisms of angiotensinogen, angiotensin-converting enzyme and type-1 angiotensin II receptor on arterial pressure and large artery stiffness parameters - depending on sodium intake

Abstract

Background In a population-based and family-based approach we investigated, to what extent blood pressure and large artery stiffness relate to the AGT G-6A, ACE D/I and AGT1R A1166C gene polymorphisms, as well as the interaction between genetic and environmental factors and their joint influence on the aforementioned parameters.
Materials and methods We recruited 52 families (82 parents and 103 offspring). Peripheral pressures were derived from conventional and 24h-ambulatory blood pressure measurements, respectively. Central pressures and large artery stiffness parameters were assessed by pulse wave analysis. All participants collected a 24-h urine sample for the measurement of sodium excretion as well as blood sample for the evaluation of genetic analyses.
Results In single gene analyzes, significant findings were revealed for ACE D/I polymorphism with respect to 24h-ambulatory and central systolic (SBP_A, SBP_C) and pulse (PP_A, PP_C) pressures. In further analyzes, we found an interaction between ACE D/I genotype and 24-h urinary sodium excretion in relation to SBP_C, conventional pulse pressure (PP_P), PP_C and augmentation pressure (AG). In the third tertile of the distribution of sodium excretion we observed significantly increased SBP_C, PP_P, PP_A, PP_C and AG in ACE II homozygotes compared to D allele carriers, which was not observed in first and second tertile.
Conclusions In the examined group, the interactions between D/I polymorphism of the ACE gene and daily sodium excretion in the urine were revealed, in relation to the parameters of blood pressure and arterial wall stiffness.The D allele of ACE gene showed a protective role in the group of subjects with high daily sodium intake.