title: Increased wave reflection rather than central arterial stiffness is the main determinant of raised pulse pressure in women and relates to mismatch in arterial dimensions: a twin study.
abstract: OBJECTIVE
  Our aim was to examine the relative contributions of the first systolic shoulder (P1) and augmentation pressure (DeltaP(aug)) to central pulse pressure (cPP), their relation to central arterial stiffness (pulse wave velocity [PWV]) and arterial diameters, and their respective heritability estimates.
  
  
  BACKGROUND
  cPP is augmented above P1 by DeltaP(aug) due to pressure waves reflected from the periphery of the circulation.
  
  
  METHODS
  Women (n = 496) from the Twins UK adult twin registry (112 monozygotic, 135 dizygotic pairs) age 21 to 81 years were studied. cPP, P1, and DeltaP(aug) were estimated using the SphygmoCor system (Atcor, West Ryde, Australia) from transformed radial waveforms. Carotid-femoral PWV was measured using the same system. Aortic and femoral artery diameters were measured by ultrasonography. Heritability was estimated using structural equation modeling.
  
  
  RESULTS
  P1 and DeltaP(aug) accounted for 22% and 76%, respectively, of the variance in cPP. After adjustment for mean arterial pressure and heart rate, P1 strongly independently positively correlated with PWV (standardized regression coefficient, beta = 0.4, p < 0.0001), whereas DeltaP(aug) did not independently correlate with PWV but independently negatively correlated with the ratio of the diameter of the femoral to that of the abdominal aorta (beta = -0.12, p < 0.001). Estimates of heritability (h(2)) of cPP, PWV, P1, and DeltaP(aug) were 0.43, 0.34, 0.31, and 0.62, respectively, after adjustment for mean arterial pressure and heart rate.
  
  
  CONCLUSIONS
  These results suggest that, in women, DeltaP(aug) is highly heritable, is associated with the ratio of distal to proximal arterial diameters, and, independent of PWV, is a major determinant of cPP.
authors.affiliation: King's College London, Cardiovascular Division, London, UK.
authors.forename: Marina
authors.initials: M
authors.lastname: Cecelja
authors.forename: Benyu
authors.initials: B
authors.lastname: Jiang
authors.forename: Karen
authors.initials: K
authors.lastname: McNeill
authors.forename: Bernet
authors.initials: B
authors.lastname: Kato
authors.forename: James
authors.initials: J
authors.lastname: Ritter
authors.forename: Tim
authors.initials: T
authors.lastname: Spector
authors.forename: Phil
authors.initials: P
authors.lastname: Chowienczyk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000502:physiology; D001158:Arteries / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000295:instrumentation / Q000379:methods; D004548:Elasticity; D005260:Female; D005263:Femoral Artery / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology; D012044:Regression Analysis; D013599:Systole / Q000502:physiology; D014655:Vascular Resistance; D055815:Young Adult