title: Radial augmentation index: a useful and easily obtainable parameter for vascular aging.
abstract: BACKGROUND
  It has been shown that the systolic augmentation index (AI) in the central arteries, including the aorta and carotid arteries, changes with age. The AI can also be obtained from the peripheral arteries. The possible usefulness of AI obtained from the radial artery as an index for vascular aging was investigated.
  
  
  METHODS
  Radial arterial waveforms were obtained from 632 subjects with no cardiovascular disease, using radial tonometry. Radial AI was calculated as follows: (Second peak systolic blood pressure [SBP2] - diastolic blood pressure [DBP]) / (first peak SBP - DBP) x100 (%).
  
  
  RESULTS
  Radial AI was significantly higher in women than in men (81.1% +/- 16.1% compared with 69.5% +/- 16.3%, P < .001). Radial AI was positively related to age in healthy men and women (r = 0.619, P < .001, and r = 0.644, P < .001, respectively). When comparing subjects in their 20s to those in their 70s, radial AI increased 1.56 times (from 53.2% to 83.0%) in men and 1.49 times (from 64.6% to 96.4%) in women. Multiple regression analysis showed that age is a potent predictor of radial AI in addition to gender, DBP and pulse rate.
  
  
  CONCLUSIONS
  These findings indicate that simple and easily-obtainable radial AI is age-dependent and could be a useful index of vascular aging.
authors.affiliation: Department of Geriatric Medicine, Ehime University School of Medicine, Ehime, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kohara
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Tabara
authors.forename: Akira
authors.initials: A
authors.lastname: Oshiumi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Miyawaki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Miki
mesh_terms: D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011674:Pulse; D017534:Radial Artery / Q000502:physiology*; D012044:Regression Analysis