Alpha-adducin G460W polymorphism, urinary sodium excretion, and blood pressure in community-based samples

Abstract

Background There is limited evidence on the gene–environmental interaction among α-adducin G460W gene polymorphism, sodium intake, and blood pressure (BP) levels in a general population. One hypothesis is that the association between G460W polymorphism and BP is more evident among persons with higher sodium intake than those with lower sodium intake. Methods We conducted a population-based cross-sectional study of 2823 men and women aged 30 to 74 years in a Japanese rural community to examine the association of the α-adducin G460W polymorphism with BP levels stratified by salt intake, as estimated by 24-h urine collection and dietary questionnaire. Results There was no difference in systolic or diastolic BP levels among the GG, GW, and WW groups for women, but for men, mean systolic BP tended to be higher in the WW group than in the GG group. When we stratified men according to sodium excretion/intake, mean systolic BP was significantly higher in the WW group than in the GG group among men with higher urinary sodium excretion (138.8 v 133.6 mm Hg, P = .02) and tended to be higher among men with higher previous sodium intake. No genetic association was found among women or among men with lower urinary sodium excretion or lower sodium intake. Conclusions The α-adducin WW genotype was associated with higher systolic BP among men with a higher sodium intake.