title: The relationship between ambulatory arterial stiffness index and blood pressure variability in hypertensive patients.
abstract: OBJECTIVE
  Ambulatory arterial stiffness index (AASI) is well known as a predictor of cardiovascular mortality in hypertensive patients. Mathematically, AASI reflect the standard deviation (SD) of blood pressure (BP) variation. AASI is measured higher levels in non-dipper than dipper. Thus, AASI has a possibility of not only reflecting arterial stiffness but also BP variability and/or autonomic nervous dysfunction.
  
  
  METHODS
  Consecutive data from 418 untreated hypertensive patients were analyzed retrospectively. We examined the association between the 24-hour ambulatory BP monitoring (ABPM) parameters and AASI.
  
  
  RESULTS
  AASI had a simple correlation with age (R=0.189, p<0.001), relative wall thickness (RWT) (R=0.115, p=0.019), left ventricular mass index (LVMI) (R=0.192, p<0.001), average systolic BP (SBP) (R=0.232, p<0.001), average pulse pressure (PP) (R=0.363, p<0.001), SD of diastolic BP (DBP) (R=-0.352, p<0.001), SD of PP (R=0.330, p<0.001), SD of heart rate (HR) (R=-0.268, p<0.001), and nocturnal dipping (R=-0.137, p=0.005). In multiple linear regression analysis model including clinical parameters and 24 hour-ABPM parameters, independent predictors of AASI were SD of PP (β=1.246, p<0.001), SD of DBP (β=-1.067, p<0.001), SD of SBP (β=-0.197, p<0.001), and non-dipper (β=0.054, p=0.033).
  
  
  CONCLUSIONS
  AASI is closely correlated with BP variability. The result of this study shows that AASI is not only a parameter for arterial stiffness, but also a parameter for BP variability.
authors: Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors: Hyung Tak
authors: HT
authors: Lee
authors: Young-Hyo
authors: YH
authors: Lim
authors: Bae Keun
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authors: Kim
authors: Kang Won
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authors: JH
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