Background: Sympathetic nervous activity, which is regulated by the beta-adrenergic receptor (beta-AR), is an important determinant of the arterial wall-stiffening process. This study examines the genetic influence of beta-AR gene polymorphisms (beta(1)-AR Arg389Gly, beta(2)-AR Arg16Gly, and beta(3)-AR Trp64Arg) on arterial stiffness in black and white young adults.
Methods: The study cohort included 366 black and 891 white adults, aged 19 to 44 years, enrolled in the Bogalusa Heart Study. Aorta-femoral pulse-wave velocity (af-PWV) was measured by echo-Doppler in a subsample (n = 614).
Results: Pulse pressure and heart rate were significantly associated with af-PWV in both races, but not with the three polymorphisms. The af-PWV values differed significantly among the beta(1)-AR Arg389Gly genotype groups in whites (P = .007) and in the total sample (P = .005), with those who were homozygous for Gly389 showing higher values than those who were homozygous for Arg389, after adjusting for cardiovascular risk factors. The beta(3)-AR Arg64 allele was associated with higher af-PWV values in blacks (P = .022) and in the total sample (P = .015). The beta(2)-AR Arg16 allele was associated with af-PWV only in blacks (P = .020). In multivariate regression analysis for the total sample, age, pulse pressure, heart rate, beta(1)-AR Arg389Gly, beta(3)-AR trp64Gly, and smoking status were, in descending order, associated with af-PWV. Furthermore, af-PWV values significantly increased with the increasing number of beta(1)-AR Gly389, beta(2)-AR Arg16, and beta(3)-AR Arg64 alleles (P for trend = .0003).
Conclusions: These results indicate that the beta-AR gene polymorphisms influence arterial stiffness in black and white young adults in an additive manner.