The Glu27 allele of the β2 adrenergic receptor increases the risk of cardiac hypertrophy in hypertension

Objective: Cardiac and vascular remodeling occur in response to hypertension. Genetic background appears to modify the development of target organ damage (TOD). We evaluated the impact on hypertension-associated TOD of a highly polymorphic gene with elevated significance for the regulation of the cardiovascular system, the β₂AR gene. Methods: We recruited 775 hypertensives (mean ± SE: age 53.5 ± 0.5, from 20 to 84 years; female 32.7%; systolic (SBP)/diastolic (DBP) blood pressure: 159 ± 1.2/ 101 ± 0.6 mmHg) referred to the departmental outpatient clinic and screened them for the Arg16Gly, Gln27Glu, and lle164Thr variants of β₂AR gene. We performed association analyses on clinical, anamnesis, anthropometrical and biochemical parameters as well as cardiac and vascular ultrasound. Results: We found that the three polymorphisms did not affect blood pressure levels. Cardiac TOD appeared to be related to the Glu27 variant. In fact, the Glu27 allele associates with a 1.4-fold higher risk of developing cardiac hypertrophy, and directly correlated with larger systolic and diastolic left ventricle internal diameters. Vascular TOD was not affected by the three polymorphisms. Ancillary to our finding we observed that the Glu27 variant is associated with a higher incidence of dyslipidemia. Conclusions: Our data indicate that β₂AR gene polymorphisms participate in the determination of cardiac TOD associated with hypertension.