title: Neurovascular control during exercise in acute coronary syndrome patients with Gln27Glu polymorphism of β2-adrenergic receptor.
abstract: BACKGROUND
  Gln27Glu (rs1042714) polymorphism of the β2-adrenergic receptor (ADRB2) has been association with cardiovascular functionality in healthy subjects. However, it is unknown whether the presence of the ADRB2 Gln27Glu polymorphism influences neurovascular responses during exercise in patients with acute coronary syndromes (ACS). We tested the hypothesis that patients with ACS homozygous for the Gln allele would have increased muscle sympathetic nerve activity (MSNA) responses and decreased forearm vascular conductance (FVC) responses during exercise compared with patients carrying the Glu allele (Gln27Glu and Glu27Glu). In addition, exercise training would restore these responses in Gln27Gln patients.
  
  
  RESULTS
  Thirty-days after an ischemic event, 61 patients with ACS without ventricular dysfunction were divided into 2 groups: (1) Gln27Gln (n = 35, 53±1years) and (2) Gln27Glu+Glu27Glu (n = 26, 52±2years). MSNA was directly measured using the microneurography technique, blood pressure (BP) was measured with an automatic oscillometric device, and blood flow was measured using venous occlusion plethysmography. MSNA, mean BP, and FVC were evaluated at rest and during a 3-min handgrip exercise. The MSNA (P = 0.02) and mean BP (P = 0.04) responses during exercise were higher in the Gln27Gln patients compared with that in the Gln27Glu+Glu27Glu patients. No differences were found in FVC. Two months of exercise training significantly decreased the MSNA levels at baseline (P = 0.001) and in their response during exercise (P = 0.02) in Gln27Gln patients, but caused no changes in Gln27Glu+Glu27Glu patients. Exercise training increased FVC responses in Gln27Glu+Glu27Glu patients (P = 0.03), but not in Gln27Gln patients.
  
  
  CONCLUSIONS
  The exaggerated MSNA and mean BP responses during exercise suggest an increased cardiovascular risk in patients with ACS and Gln27Gln polymorphism. Exercise training emerges as an important strategy for restoring this reflex control. Gln27Glu polymorphism of ADRB2 influences exercise-induced vascular adaptation in patients with ACS.
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.|School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors.forename: Larissa
authors.initials: L
authors.lastname: Ferreira-Santos
authors.affiliation: Faculty of Physical Education and Sports, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Martinez
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Nicolau
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Humberto G
authors.initials: HG
authors.lastname: Moreira
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Maria Janieire
authors.initials: MJ
authors.lastname: Alves
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
authors.affiliation: Universidade Nove de Julho (UNINOVE), São Paulo, Brazil.
authors.forename: Ivani C
authors.initials: IC
authors.lastname: Trombetta
authors.affiliation: Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil.|School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Negrão
authors.affiliation: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors.forename: Maria Urbana P B
authors.identifier: http://orcid.org/0000-0001-5738-1623
authors.initials: MU
authors.lastname: Rondon
mesh_terms: D054058:Acute Coronary Syndrome / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy; D005081:Exercise Therapy; D005260:Female; D005542:Forearm / Q000098:blood supply*; D005787:Gene Frequency; D056726:Genetic Association Studies; D018737:Hand Strength; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D020641:Polymorphism, Single Nucleotide; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D012307:Risk Factors; D014666:Vasomotor System
chemical_list: C553443:ADRB2 protein, human; D018343:Receptors, Adrenergic, beta-2