Association of renal function with the ambulatory arterial stiffness index and pulse pressure in hypertensive patients.

Arterial stiffness exemplified by the ambulatory arterial stiffness index (AASI) and pulse pressure (PP) predicts cardiovascular morbidity and mortality. The present cross-sectional study assessed the association of renal function with AASI and 24-h PP in hypertensive inpatients. Subjects included 948 hypertensive inpatients with drug treatment (mean age, 53.3 years; male, 67.1%). The AASI was defined as 1 minus the regression slope of diastolic over systolic blood pressure readings obtained from 24-h recordings. Renal function was evaluated by serum creatinine and urinary albumin excretion was expressed by the urinary albumin-to-urinary creatinine ratio (ACR), and estimated glomerular filtration rate (eGFR) was calculated by the modification of diet in renal disease formula and chronic kidney disease-epidemiology collaboration formula. As AASI and 24-h PP increased, serum creatinine concentrations and ACR increased, and eGFR decreased. Multiple linear regression showed that AASI and 24-h PP were associated with eGFR-EPI (B=-12.00, P=0.001 vs. B=-0.14, P=0.002) and ACR (B=0.56, P=0.004 vs. B=0.01, P=0.017) independent of other cardiovascular risk factors. After additional adjustment for 24-h PP, the association of AASI with eGFR-EPI had borderline significance (P=0.053), whereas the significant associations of 24-h PP with serum creatinine and ACR persisted (P=0.009 and P=0.006) after adjusting for confounding factors and AASI. Multiple logistic regression analysis showed that each s.d. increase in 24-h PP (that is, 13 mm Hg) was associated with a higher risk of suffering from microalbuminuria (MA) by 39% (P=0.038) after additional adjustment for AASI. In conclusion, AASI is more closely associated with eGFR compared with 24-h PP in hypertensive inpatients. However, for MA 24-h PP is a better predictor.