Novel genetic variants in the α-adducin and guanine nucleotide binding protein β-polypeptide 3 genes and salt sensitivity of blood pressure

Background We examined the association between 12 single-nucleotide polymorphisms (SNPs) in the α-adducin (ADD1) and guanine nucleotide binding protein (G protein) Β-polypeptide 3 (GNB3) genes and systolic (SBP), diastolic (DBP), and mean arterial (MAP) pressure responses to salt intake.MethodsA 7-day low-sodium (51.3 mmol sodium/day) followed by a 7-day high-sodium intervention (307.8 mmol sodium/day) was conducted among 1,906 Han participants from rural North China. Blood pressure (BP) measurements were obtained at baseline and at the end of each intervention period using a random-zero sphygmomanometer.ResultsWe identified a significant association between a rare ADD1 variant rs17833172 and SBP, DBP, and MAP responses to high sodium (P values 0.0001) and DBP response to low sodium (P value = 0.002). Participants homozygous for the variant A allele of this marker had SBP, DBP, and MAP responses (95% confidence interval) to high salt of 1.6 (1.8, 4.9), 0.8 (5.6, 4.0), and 0.1 (4.0, 3.9) mm Hg, respectively, vs. corresponding responses of 4.6 (2.5, 6.6), 1.7 (0.2, 3.6), and 2.7 (0.9, 4.4) mm Hg, respectively, for those who were heterozygous or homozygous for the G allele. In addition, participants with at least one copy of the A allele of SNP rs1129649 of the GNB3 gene had significantly decreased MAP response to low salt compared to homozygotes for the C allele (P value = 0.004) with responses of 3.4 (3.8, 3.0) vs. 4.2 (4.6, 3.8) mm Hg, respectively.ConclusionsThese data support a role for the ADD1 and GNB3 genes in BP salt sensitivity. Future studies aimed at replicating these novel findings are warranted.