The aim of this study was to test the agreement between nighttime home and nighttime ambulatory blood pressure (BP) and to compare their associations with hypertensive end-organ damage for the first time in the general population.Design and Method:
A population sample of 248 participants underwent measurements for nighttime home BP (3 measurements on 2 nights with a timer-equipped home device), nighttime ambulatory BP, pulse wave velocity (PWV), carotid intima-media thickness (IMT) and echocardiographic left ventricular mass index (LVMI).Results:
No significant differences were observed between mean nighttime home and ambulatory BPs (systolic/diastolic difference: 0.7 ± 7.6/0.2 ± 6.0 mmHg, p = 0.16/0.64). Furthermore, no systematic differences in systolic or diastolic nighttime BPs were identified between the two methods in Bland-Altman plots (Figure). All nighttime home and ambulatory BPs were positively correlated with PWV, IMT and LVMI (p < 0.01 for all). Correlation coefficients for BP indices and end-organ damage and their comparisons are shown in the Table. No significant differences in Pearson's correlation coefficients between end-organ damage and nighttime home or ambulatory BP were observed (p ≥ 0.11 for all comparisons using Dunn and Clark's Z), except for a slightly stronger correlation between PWV and ambulatory systolic BP than for home systolic BP (r = 0.57 vs. 0.50, p = 0.03). The adjusted R2 of all multivariable-adjusted models for PWV, IMT or LVMI that included nighttime home or ambulatory systolic/diastolic BP were within 2/1%.Conclusions:
Our study demonstrates that nighttime home and ambulatory measurements produce similar BP values that have comparable associations with end-organ damage in the general population even when a clinically feasible measurement protocol is used for measuring nighttime home BP. In the future, nighttime home BP measurement may offer a feasible and easily accessible alternative to ambulatory monitoring for the measurement of nighttime BP.