Comparison of Office Blood Pressure, Automated Unattended Office Blood Pressure, Home Blood Pressure, and 24-Hour Ambulatory Blood Pressure Measurements

Background: Although previous studies have reported differences of blood pressure (BP) according to BP measurement methods, studies in Korean population were scarce. This study aimed to compare BP differences according to different BP measurement methods and assess hypertension phenotype. Methods: This prospective study recruited 183 individuals (mean 55.9 years; 51.4% males). The BP measurements included office BP (auscultatory attended office BP [ausAOBP], automated attended office BP [aAOBP], and automated unattended office BP [aUAOBP]) and out-of-office BP (home BP [HBP] and ambulatory BP [ABP]) measurements taken within one week of each other. Results: The mean systolic/diastolic BP differences between ausAOBP and other BPs according to different BP measurement methods were 3.5/2.3 mmHg for aAOBP; 6.1/2.9 mmHg for aUAOBP; 15.0/7.3 mmHg for daytime ABP; and 10.6/3.4 mmHg for average HBP. The increasing disparity between ausAOBP and other BPs in multivariable regression analysis was significantly associated with increasing BP. The prevalence of white-coat hypertension and masked hypertension in 107 individuals not taking antihypertensive medication was 25.4-26.8% and 30.6-33.3% based on ausAOBP, daytime ABP, and average HBP, respectively. The prevalence of white-coat uncontrolled hypertension and masked uncontrolled hypertension in 76 of those taking antihypertensive medication was 31.7-34.1% and 17.1- 37.1%, respectively. Conclusion: This study showed a large disparity between office BP and out-of-office BP which became more pronounced when office BP by auscultation increased, suggesting that various BP measurement methods should be used to more accurately assess BP status.