ADRB2 and Hypertension: When study participants were stratified by genotype of the ADRB2 Arg16Gly A > G locus (AA, AG, and GG), baseline characteristics did not differ significantly among the three groups (Table 1), except for hypertension, which was slightly less prevalent among patients with the AA genotype (84.4% for AA genotype group, 89.6% for the AG genotype group, and 89.1% for the GG genotype group; P < 0.001).