Determinants of the ambulatory arterial stiffness index in 7604 subjects from 6 populations.
The ambulatory arterial stiffness index (AASI) is derived from 24-hour ambulatory blood pressure recordings. We investigated whether the goodness-of-fit of the AASI regression line in individual subjects (r(2)) impacts on the association of AASI with established determinants of the relation between diastolic and systolic blood pressures. We constructed the International Database on the Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes (7604 participants from 6 countries). AASI was unity minus the regression slope of diastolic on systolic blood pressure in individual 24-hour ambulatory recordings. AASI correlated positively with age and 24-hour mean arterial pressure and negatively with body height and 24-hour heart rate. The single correlation coefficients and the mutually adjusted partial regression coefficients of AASI with age, height, 24-hour mean pressure, and 24-hour heart rate increased from the lowest to the highest quartile of r(2). These findings were consistent in dippers and nondippers (night:day ratio of systolic pressure >or=0.90), women and men, and in Europeans, Asians, and South Americans. The cumulative z score for the association of AASI with these determinants of the relation between diastolic and systolic blood pressures increased curvilinearly with r(2), with most of the improvement in the association occurring above the 20th percentile of r(2) (0.36). In conclusion, a better fit of the AASI regression line enhances the statistical power of analyses involving AASI as marker of arterial stiffness. An r(2) value of 0.36 might be a threshold in sensitivity analyses to improve the stratification of cardiovascular risk.
Adiyaman
Ahmet
A
Department ofCardiovascular Diseases, Division of Hypertension and Cardiovascular Rehabilitation, Studies Coordinating Centre, University of Leuven, Leuven, Belgium.
Dechering
Dirk G
DG
Boggia
José
J
Li
Yan
Y
Hansen
Tine W
TW
Kikuya
Masahiro
M
Björklund-Bodegård
Kristina
K
Richart
Tom
T
Thijs
Lutgarde
L
Torp-Pedersen
Christian
C
Ohkubo
Takayoshi
T
Dolan
Eamon
E
Imai
Yutaka
Y
Sandoya
Edgardo
E
Ibsen
Hans
H
Wang
Jiguang
J
Lind
Lars
L
O'Brien
Eoin
E
Thien
Theo
T
Staessen
Jan A
JA
D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D018660:Blood Pressure Monitoring, Ambulatory / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000208:ethnology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012044:Regression Analysis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014583:Uruguay / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*