Lack of association between Gly460Trp polymorphism of alpha-adducin gene and salt sensitivity of blood pressure in Polish hypertensives

Background: Previous studies have suggested that alpha-adducin (alpha-ADD) polymorphism may identify patients with a salt-sensitive form of hypertension.

Aim: To investigate the association between Gly460Trp polymorphism of alpha-ADD and the pattern of blood pressure response to subacute (1 week) salt loading and depletion in young adult thin Polish hypertensives.

Methods: The study group consisted of 44 subjects with salt-sensitive hypertension (SS) and 24 subjects with non-salt-sensitive hypertension (SR). Genomic DNA isolated from peripheral blood leukocytes was amplified by PCR method with primers flanking the polymorphic region. The mismatch near to 3'-end of the upstream primer was introduced to create a Nla III restriction site in Trp 460 allele. In addition, excreted fraction of filtered sodium (FENa), plasma renin activity (PRA) and plasma concentrations of aldosterone (ALDO) were determined on normal, low and high salt diets.

Results: FENa on normal or high salt diets were significantly lower in the SS hypertensives as compared with the SR patients. PRA in SS group was also significantly lower as compared with results in SR group, but only on high salt diet. No significant difference was detected in frequencies of genotypes and alleles of alpha-ADD gene between SS and SR subjects. An additional analysis with regard to genotype (Gly/Gly vs. Gly/Trp+Trp/Trp) showed no significant difference in changes of blood pressure as well as in results of laboratory investigations.

Conclusion: Our results suggest lack of association between Gly460Trp polymorphism of alpha-adducin gene and salt sensitivity of blood pressure in Polish hypertensives.