title: Beta1-adrenergic receptor polymorphisms associated with atrial fibrillation in systolic heart failure.
abstract: BACKGROUND
  The sympathetic nervous system is of great importance in the pathogenesis of atrial fibrillation in systolic heart failure. The identification of polymorphisms in the beta1-adrenergic receptor gene (ADBR1) represents an important step in understanding this pathogenesis.
  
  
  OBJECTIVE
  This study assessed the association between the two functional polymorphisms of the beta1-adrenergic receptor gene (ADBR1), Ser49Gly and Arg389Gly, and the presence of atrial fibrillation in patients with systolic heart failure.
  
  
  METHODS
  Case-control study with 144 patients with systolic heart failure, including 24 with atrial fibrillation (cases) and 120 without atrial fibrillation (controls). Genomic DNA was extracted from peripheral blood leukocytes and the genotypes of Ser49Gly and Arg389Gly polymorphisms were identified in all individuals by PCR/RFLP (polymerase chain reaction / restriction fragment length polymorphism).
  
  
  RESULTS
  Mean age was 59 ± 13 years, 70% of patients were males, 42% had ischemic causes and 74% had hypertension. Genotypes Ser49Ser and Arg389Arg were significantly associated with atrial fibrillation (p = 0.005 and p = 0.01, respectively). After logistic regression, both adjusted for left atrial size and age, the significant association persisted (Arg389Arg - odds ratios: 2.78, 95% confidence interval = 1.02 to 7.56 and Ser49Ser - odds ratios: 8.02, 95% confidence interval = 1.02 to 63.82).
  
  
  CONCLUSIONS
  Both genotypes were associated with atrial fibrillation in patients; however, only Ser49Gly polymorphism was is in Hardy-Weinberg equilibrium.
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brasil. brcnascimento@gmail.com
authors.forename: Bruno Costa de
authors.initials: BC
authors.lastname: Nascimento
authors.forename: Sabrina Bernardez
authors.initials: SB
authors.lastname: Pereira
authors.forename: Georgina Severo
authors.initials: GS
authors.lastname: Ribeiro
authors.forename: Evandro Tinoco
authors.initials: ET
authors.lastname: Mesquita
mesh_terms: D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000235:genetics*; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D005838:Genotype; D054143:Heart Failure, Systolic / Q000235:genetics*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics*
chemical_list: D018342:Receptors, Adrenergic, beta-1