title: Relationship between augmentation index obtained from carotid and radial artery pressure waveforms.
abstract: OBJECTIVE
  Increased aortic and carotid arterial augmentation index (AI) has been directly linked with cardiovascular disease risk, mortality and morbidity. The aim of this study was to examine whether AI obtained directly from radial artery pressure waveforms (radial AI) can provide information comparable with carotid arterial AI measurements.
  
  
  METHODS
  In a cross-sectional study of 204 apparently healthy subjects (88 men and 116 women) aged 19-76 years (51 +/- 15 years, mean +/- SD), carotid AI [(second peak carotid systolic pressure - first peak carotid systolic pressure)/carotid pulse pressure*100] and radial AI [(second peak radial systolic pressure - diastolic pressure)/(first peak radial systolic pressure - diastolic pressure)*100] were measured using applanation tonometry.
  
  
  RESULTS
  Radial AI was strongly correlated with carotid AI (r = 0.86, P < 0.0001, SD of difference 10.0%), although radial AI was consistently approximately 66% higher than carotid AI. In 16 apparently healthy young adults (11 men and five women, aged 23 +/- 3 years) handgrip exercise was immediately followed by post-exercise muscle ischaemia (PEMI) to compare changes in carotid and radial AI during increased sympathetic nervous activity. PEMI caused parallel increases in carotid and radial AI (26 and 19%). Accordingly, changes in radial AI with PEMI were strongly correlated with corresponding changes in carotid AI (r = 0.86, P < 0.0001, SD of difference 7.3%).
  
  
  CONCLUSIONS
  These results suggest that AI obtained directly from radial arterial pressure waveforms could provide equivalent information to carotid arterial AI, and has potential as a surrogate marker of cardiovascular disease.
authors.affiliation: Institute for Human Science and Bioengineering, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan. jun.sugawara@aist.go.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Sugawara
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Komine
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Maeda
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods; D002318:Cardiovascular Diseases / Q000503:physiopathology; D002339:Carotid Arteries / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011673:Pulsatile Flow / Q000502:physiology*; D011674:Pulse; D017534:Radial Artery / Q000502:physiology*
chemical_list: D015415:Biomarkers