Pulse Wave Velocity: Relevance of Age in Normotensive, Essential Hypertensive and Borderline Hypertensive Patients

Background: Among the various parameters used to describe arterial function, pulse wave velocity (PWV) is the only oneallowing direct measurement of arterial stiffness. Loss of arterial elastic capacity with increasing age, a process known asvascular aging, is enhanced in hypertensive patients.Objectives: The aim of this study was to normalize PWV in normotensive (NT), essential hypertensive (HT) and borderlinehypertensive (BL) patients and differentiate the effects of aging on PWV from those associated to hypertension.Methods: A total of 221 consecutive male and female patients were included in the study. They were classified into threegroups according to their blood pressure (BP) values: NT (n=120, 46±13 years): BP 140/90 mmHg; and BL (n=41, 47±12 years): BP=135-139/85-89 mmHg. They were then stratified into fourgroups according to age: GI 60 years. Mechanographic transducersand computerized calculation were used to measure PWV. Data analysis was performed using ANOVA, Newman-Keuls, andmultivariate linear regression tests.Results: Pulse wave velocity increased with age in all age groups (p<0.05). Mean PWV (m/s) in G1 was: NT (n=42): 8.6±1.1,HT (n=16): 9.5±1.3, BL (n=10): 9.0±0.5; in GII: NT (n=24): 9.5±1.2, HT (n=16): 10.7±1.2, BL (n=14): 9.8±0.8; in GIII:NT (n=30): 10.3±1.5, HT (n=12): 12.1±1.5, BL (n=11): 11.0±1.3; and in GIV: NT (n=24): 11.4±1.8, HT (n=16): 14.1±2.4,BL (n=6): 13.3±1.1.Regression equations were: for NT, PWV=0.08 × age+0.04 × systolic blood pressure (SBP)+1.07 (r=0.71); for HT, PWV=0.12× age+0.06 × SBP-2.51 (r=0.81); and for BL, PWV=0.10 × age+0.02 × SBP+2.90 (r=0.73) (p<0.05).Conclusions: Pulse wave velocity increased with age, and was higher in HT patients for each age group. Borderline hypertensivepatients presented intermediate values between the other two groups. These results suggest additional vascular impairmentinduced by hypertension over that of aging. This surplus effect could be estimated from the regression equation obtainedfor each group.