Blood pressure variability with different measurement methods: Reliability and predictors. A proof of concept cross sectional study in elderly hypertensive hospitalized patients

Blood pressure variability (BPV) is an independent cardiovascular risk factor in hypertensive patients. The best method for quantifying BPV is still an object of debate. The existence of different BPV patterns, particularly age and arterial stiffness related, is postulated. Our aims were: i).. to compare BPV using different blood pressure (BP) measurement methods; ii).. to compare different calculation approaches; iii).. to analyze the predictors of BPV. Cross-sectional study in 108 elderly hypertensive hospitalized patients. Each patient underwent blood pressure measurements with 5 different modalities: 24 hour BP and pulse wave velocity (PWV) monitoring (24hBPM), measurement by nurses or physicians, self-measurement and beat-to-beat monitoring. Differences between maximum and minimum values (ΔBP), averages of the absolute differences between consecutive values (ARV) and coefficients of variation (CV) were calculated. ΔBP showed the wider values’ dispersion (Δ systolic blood pressure (SBP): 66.4 ± 22.9 and Δ diastolic blood pressure [DBP]: 45.0 ± 13.5 mmHg). ARV and CV were highest with nurses’ measurements (SBP-ARV 9.2 ± 6.2; DBP-ARV 6.9 ± 5.2; SBP-CV 7.6 ± 5.3; DBP-CV 9.6 ± 5.5). The strongest correlation was found comparing physicians’ SBP measurements and 24hBPM ARVs (R2 0.23, P <.05). 24hBPM ΔSBP in a multivariate analysis was significantly associated with age (β −3.85, SE 0.83; P <.001) and PWV (β 20.29, SE 3.70; P <.001). Calcium antagonists were associated with a lower ΔSBP (β −14.6, SE 6.1, P <.05) while diuretics and alpha-blockers with a significant increase (β 14.4 SE 5.4, P <.01; β 26.9 SE 11.7, P <.05). Age, PWV, diuretics, alpha-blockers, but also measurements obtained by nurses, increase BP variability while calcium antagonists reduce it. BP profiles in elderly in-hospital patients potentially provide important information; they should, however, be interpreted cautiously.