Human β2-adrenergic receptor polymorphisms: No association with essential hypertension in black or white Americans

Background and Objectives The most common polymorphisms of the human β2-adrenergic receptor-Arg16Gly and Gln27Glu-are associated with alterations in β2-adrenergic receptor responses, both in vitro and in vivo. β2-Adrenergic receptor–mediated vascular responses are affected by ethnicity, blood pressure, and genotype. We tested the hypothesis that these two common β2-adrenergic receptor genetic variants are associated with essential hypertension in black or white Americans. Subjects and Methods In a population-based case-control association study, the relationship between β2-adrenergic receptor genotypes and hypertension was examined in 307 normotensive subjects (128 black and 179 white) and 356 hypertensive subjects (155 black and 201 white). A polymerase chain reaction–based single-stranded conformational polymorphism method with direct sequencing of the bands of interest was used to detect the two frequently occurring β2-adrenergic receptor variants (Arg16Gly, Gln27Glu). Results No significant differences in the distributions of alleles and genotypes of the tested β2-adrenergic receptor variants were found between normotensive and hypertensive groups from either black or white Americans (all P > .05). There was a marked interethnic difference in the frequency of the Gln27Glu β2-adrenergic receptor polymorphism in both normotensive and hypertensive subjects. In normotensive white subjects, the variant Glu27 allele (35.2% versus 18.0%; P < .0001) and Glu27 homozygous genotype (14.0% versus 4.7%; P < .01) were more common than in black subjects. Similarly, in hypertensive white subjects, the variant Glu27 allele (35.8% versus 18.4%; P < .0001) and the Glu27 homozygous genotype (15.9% versus 2.6%; P < .0001) were more common than in black subjects. Conclusions These data suggest that although there are marked ethnic differences in their distribution, the common genetic polymorphisms of the human β2-adrenergic receptor gene do not cosegregate with the presence of hypertension in either black or white Americans. Clinical Pharmacology & Therapeutics (2000) 67, 670–675; doi: 10.1067/mcp.2000.106293