Aim:
to assess the relationship of changes in pulse wave velocity (PWV), a marker of target organ damage, with the variation in BP over time, as assessed by three different methods of measurement: office and 24h-ambulatory peripheral BP as well as aortic BP.
Methods:
Observational prospective study in hypertensive subjects with impaired glucose metabolism consecutively recruited from Spanish Hypertension Units. Aortic BP and carotid-femoral PWV were evaluated by radial applanation tonometry (Sphygmocor®) at baseline (
b
) and after 12 months of follow-up (
fu
). Peripheral BP measurements were also recorded at baseline and at 12 months follow-up: office BP was obtained as the average of triplicate measurements taken at 1 min-intervals after 5 min of seated rest, using validated oscillometric devices; 24h-ambulatory BP recordings were taken with a validated device (Spacelabs®-90207) at 20-minute intervals throughout both the self-reported awake and asleep periods. Clinical and anthropometric features were also recorded.
PWV variation (Δ) over time was calculated as follows: Δ PWV= [(PWV
fu
- PWV
b
) / PWV
b
] x 100. BP variation over time was calculated with the same formula applied to BP values obtained with the different measurement techniques.
Correlations (Spearman “Rho”) of Δ PWV and Δ BP were calculated.
Results:
n=209 patients; mean age: 61.8 ± 11.2 y; 39% (81 of 209) were female; 80% (167 of 209) had type 2 diabetes. Other risk factors: hypertension: 100%; dyslipidemia: 69% (144 of 209); smokers: 13% (28 of 209); body mass index: 30.9 ± 4.4 Kg/m
2
. Baseline office systolic/diastolic BP (mmHg): oSBP = 143 ± 20; oDBP = 82 ± 12. Follow-up office systolic/diastolic BP (mmHg): oSBP = 136 ± 20; oDBP = 79 ± 12. Baseline PWV: 10.01 ± 3.5 m/s. Follow-up PWV: 10.19 ± 3.21 m/s.
Δ PWV correlated with: Δ oSBP (Rho=0.212; p=0.002), Δ 24h-SBP (Rho=0.254; p<0.001), Δ daytime-BP (Rho=0.232; p=0.001), Δ nighttime-BP (Rho=0.320; p<0.001) and Δ aortic-SBP (Rho=0.320; p<0.001).
Conclusion:
Modification over time of PWV, a marker of target organ damage, parallel to changes in systolic BP, both office and 24h-ambulatory peripheral BP variation as well as aortic BP variation, at 12 months of follow-up. Among them, aortic SBP and nighttime peripheral SBP both showed the best correlation.
24-Hour Blood Pressure Monitoring: Association Between AASI (Ambulatory Arterial Stiffness Index) and Subclinical Target Organ Damage
