title: Beta2-adrenergic receptor gene and resting hemodynamics in European and African American youth.
abstract: BACKGROUND
  The beta2-adrenergic receptor (ADRB2) contributes to blood pressure (BP) regulation by mediating peripheral vasodilation. Associations between the Arg16Gly and Gln27Glu polymorphisms of the ADRB2 gene and BP among multiethnic adult samples have been mixed. The purpose of this study was to investigate the relationship between these polymorphisms and resting hemodynamic function in African American (AA) and European American (EA) youths.
  
  
  METHODS
  We studied 395 EA and 275 AA twins from the southeastern United States (mean age, 14.6 +/- 3.0 years; range, 10.0 to 25.9 years). The Arg16Gly and Gln27Glu polymorphisms were detected by polymerase chain reaction, followed by restriction enzyme digestion, and confirmed by direct sequence analysis. The effect of the polymorphisms on resting hemodynamics was analyzed using structural equation modeling.
  
  
  RESULTS
  For the Arg16Gly polymorphism, carriers of one or two Gly alleles exhibited significantly higher levels of systolic BP and pulse pressure in EA, respectively, explaining 2.6% and 2.8% of the variance. No significant associations were seen in AA. Carriers of the Glu allele of the Gln27Glu polymorphism showed an elevated systolic and diastolic BP, mean arterial pressure, total peripheral resistance index, and a lower stroke volume in EA. In AA, only diastolic BP showed a higher level in Glu carriers. Between 1.3% and 4.1% of the variance in these hemodynamic measures was explained by the Gln27Glu locus.
  
  
  CONCLUSIONS
  The findings suggest that vasodilatory related genetic factors play a particularly important role in BP control in EA youths.
authors.affiliation: Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia, Building HS-1640, Augusta, GA 30912, USA. hsnieder@mcg.edu
authors.forename: Harold
authors.initials: H
authors.lastname: Snieder
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Dong
authors.forename: Paule
authors.initials: P
authors.lastname: Barbeau
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Harshfield
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Dalageogou
authors.forename: Haidong
authors.initials: H
authors.lastname: Zhu
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Carter
authors.forename: Frank A
authors.initials: FA
authors.lastname: Treiber
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People / Q000235:genetics*; D002648:Child; D004200:Diseases in Twins / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D015144:Southeastern United States / Q000453:epidemiology; D014427:Twins / Q000235:genetics; D044465:White People / Q000235:genetics*; D001741:Black or African American
chemical_list: D018343:Receptors, Adrenergic, beta-2