title: Relationship between aortic augmentation index and blood pressure during metaboreflex activation in healthy young men.
abstract: BACKGROUND
  Heightened aortic augmentation index (AIx; surrogate of arterial stiffness) is associated with an elevated risk of cardiovascular events; however, it is currently unclear whether peripheral blood pressure (BP) modulates AIx.
  
  
  OBJECTIVE
  Given this, we studied the relationship between AIx and BP under resting conditions as well as during skeletal muscle metaboreflex activation, which is a maneuver that generates steady elevations in BP.
  
  
  METHODS
  In nine healthy male participants (23±2 years), the graded activation of the muscle metaboreflex was achieved by postexercise ischemia (PEI) following moderate and high-intensity static handgrip performed at 30 and 40% maximum voluntary contraction. Heart rate (ECG), arterial BP, and AIx (SphygmoCor) were measured.
  
  
  RESULTS
  Compared with rest, mean arterial pressure was significantly increased during PEI30% (+24±4 mmHg, P<0.05 vs. rest) and was further augmented during PEI40% (+34±4 mmHg, P<0.05 vs. PEI30%). Similarly, AIx@HR75 increased significantly from rest during PEI30% (rest -9±3% vs. PEI30% +9±5%, P<0.05) and was further augmented during PEI40% (17±4%, P<0.05 vs. PEI30%). At rest, there was no relationship between AIx and BP. However, at PEI30%, there was a significant association between AIx and diastolic BP and mean arterial pressure (r=0.92, 0.87, respectively; P<0.05) and this association was maintained at PEI40% (r=0.94, 0.91, respectively; P<0.05).
  
  
  CONCLUSIONS
  Our results indicate that acute elevations in peripheral BP are an important determinant of AIx during muscle metaboreflex activation in healthy men.
authors.affiliation: aLaboratory of Exercise Sciences, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro bFaculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil cSchool of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Eliza
authors.initials: E
authors.lastname: Prodel
authors.forename: James P
authors.initials: JP
authors.lastname: Fisher
authors.forename: Thales C
authors.initials: TC
authors.lastname: Barbosa
authors.forename: Igor A
authors.initials: IA
authors.lastname: Fernandes
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Nobrega
authors.forename: Lauro C
authors.initials: LC
authors.lastname: Vianna
mesh_terms: D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D006801:Humans; D008297:Male; D059289:Vascular Stiffness / Q000502:physiology*