Tang Weihong, Devereux Richard B, Kitzman Dalane W, Province Michael A, Leppert Mark, Oberman Albert, Hopkins Paul N, Arnett Donna K
Division of Epidemiology, University of Minnesota, Minneapolis, Minnesota 55454, USA.
Am J Hypertens. 2003 Nov;16(11 Pt 1):945-51. doi: 10.1016/s0895-7061(03)01001-x.
beta-Adrenergic receptors (ARs), including beta1- and beta2-AR, are involved in modulation of cardiac contractility and heart rate. Arg16Gly, a functional polymorphism in the beta2-AR gene, has been reported to influence exercise capacity in heart failure patients. This study examined the association of the beta2-AR Arg16Gly polymorphism with left ventricular (LV) systolic function in a biethnic population-based sample.
Echocardiograms and the beta2-AR Arg16Gly polymorphism were analyzed in 267 normotensive (54% African Americans) and 252 severe hypertensive (53% African Americans) adults without coronary heart disease or diabetes.
The frequencies of Gly16Gly16, Arg16Gly16, and Arg16Arg16 were 28.1%, 54.3%, and 17.6%, respectively, in normotensives, and 31.4%, 47.6%, and 21.0%, respectively, in hypertensives. In normotensives, the Gly16Gly16 homozygotes displayed greater fractional shortening (35.9% +/- 4.3% v 34.1% +/- 4.7% v 34.0% +/- 3.9%, P =.01), ejection fraction (65.0% +/- 5.8% v 62.5% +/- 6.4% v 62.6% +/- 5.4%, P =.01), midwall shortening (18.6% +/- 1.6% v 17.9% +/- 1.9% v 18.0% +/- 1.6%, P =.02), and stress-corrected midwall shortening (110.1% +/- 9.3% v 106.1% +/- 10.6% v 108.1% +/- 10.8%, P =.03) compared to the Arg16Gly16 and Arg16Arg16 groups. These associations were independent of age, sex, ethnicity, heart rate, body mass index, systolic blood pressure, LV end-diastolic dimension, and field center. No significant associations between the beta2-AR Arg16Gly polymorphism and echocardiographic measures were found in hypertensives.
The Arg16Gly polymorphism of beta2-AR may be a marker for LV chamber function and contractility in normotensive adults.
β-肾上腺素能受体（ARs），包括β1-和β2-AR，参与调节心脏收缩力和心率。据报道，β2-AR基因中的功能性多态性Arg16Gly会影响心力衰竭患者的运动能力。本研究在一个基于双种族人群的样本中，检测了β2-AR Arg16Gly多态性与左心室（LV）收缩功能之间的关联。
对267名无冠心病或糖尿病的血压正常成年人（54%为非裔美国人）和252名重度高血压成年人（53%为非裔美国人）进行了超声心动图检查及β2-AR Arg16Gly多态性分析。
在血压正常者中，Gly16Gly16、Arg16Gly16和Arg16Arg16的频率分别为28.1%、54.3%和17.6%；在高血压患者中，其频率分别为31.4%、47.6%和21.0%。在血压正常者中，与Arg16Gly16和Arg16Arg16组相比，Gly16Gly16纯合子的缩短分数更高（35.9%±4.3%对34.1%±4.7%对34.0%±3.9%，P = 0.01）、射血分数更高（65.0%±5.8%对62.5%±6.4%对62.6%±5.4%，P = 0.01）、室壁中层缩短率更高（18.6%±1.6%对17.9%±1.9%对18.0%±1.6%，P = 0.02）以及应力校正室壁中层缩短率更高（110.1%±9.3%对106.1%±10.6%对108.1%±10.8%）。这些关联独立于年龄、性别、种族、心率、体重指数、收缩压、左心室舒张末期内径和研究中心。在高血压患者中，未发现β2-AR Arg16Gly多态性与超声心动图测量指标之间存在显著关联。
β2-AR的Arg16Gly多态性可能是血压正常成年人左心室腔功能和收缩力的一个标志物。
