Comparison between an adapted protocol for home and ambulatory measurement for evaluating night-time blood pressure behaviour.

Background: The diagnosis and treatment of hypertension rely on the accuracy of blood pressure (BP) measurements obtained both in and out of the office during awake and sleep periods.

Objective: To evaluate whether a home blood pressure monitoring (HBPM) protocol incorporating morning, afternoon, and evening measurements supports the assessment of blood pressure behaviour during sleep and enhances the diagnosis of hypertension.

Methods: This cross-sectional study included 40 patients (73% women; age = 62.0 ± 13.2 years) who underwent 24-h ambulatory blood pressure monitoring (ABPM) and (five-day HBPM) with measurements taken across three time periods. The association between the sleep-wake dip recorded by ABPM and the night-day difference measured by HBPM was examined. Additionally, the sensitivity, specificity, predictive values, concordance index, Kappa coefficient, and area under the ROC curve (AUC) of mean BP values obtained from HBPM were compared with those from ABPM.

Results: Mean BP values obtained from HBPM were 126.2 ± 13.3/79.2 ± 9.1 mmHg, (daytime), 125.9 ± 16.4/78.7 ± 10.5 mmHg (evening), and 126.1 ± 14.3/78.9 ± 9.6 mmHg (total). For ABPM, mean values were 120.3 ± 12.5/74.5 ± 8.9 mmHg (awake), 116.5 ± 10.9/69.3 ± 8.0 mmHg (asleep), and 119.4 ± 11.4/73.4 ± 8.0 mmHg (total). Total HBPM outperformed daytime and evening HBPM in detecting abnormalities on ABPM (daytime, night-time, and 24 h), with higher sensitivity, negative predictive value (NPV), AUC, concordance index, and Kappa coefficient. The correlation between the day-night dip in ABPM and the night-day difference in HBPM was weak.

Conclusion: Including night-time measurements in the HBPM protocol improves the accuracy of hypertension diagnosis when compared to ABPM. However, the night-day BP difference captured by HBPM does not correspond to the day-night dip measured by ABPM.