Setting Thresholds to Varying Blood Pressure Monitoring Intervals Differentially Affects Risk Estimates Associated With White-Coat and Masked Hypertension in the Population

Abstract

Outcome-driven recommendations about time intervals during which ambulatory blood pressure should be measured to diagnose white-coat or masked hypertension are lacking. We cross-classified 8237 untreated participants (mean age, 50.7 years; 48.4% women) enrolled in 12 population studies, using ≥140/≥90, ≥130/≥80, ≥135/≥85, and ≥120/≥70 mm Hg as hypertension thresholds for conventional, 24-hour, daytime, and nighttime blood pressure. White-coat hypertension was hypertension on conventional measurement with ambulatory normotension, the opposite condition being masked hypertension. Intervals used for classification of participants were daytime, nighttime, and 24 hours, first considered separately, and next combined as 24 hours plus daytime or plus nighttime, or plus both. Depending on time intervals chosen, white-coat and masked hypertension frequencies ranged from 6.3% to 12.5% and from 9.7% to 19.6%, respectively. During 91 046 person-years, 729 participants experienced a cardiovascular event. In multivariable analyses with normotension during all intervals of the day as reference, hazard ratios associated with white-coat hypertension progressively weakened considering daytime only (1.38; P=0.033), nighttime only (1.43; P=0.0074), 24 hours only (1.21; P=0.20), 24 hours plus daytime (1.24; P=0.18), 24 hours plus nighttime (1.15; P=0.39), and 24 hours plus daytime and nighttime (1.16; P=0.41). The hazard ratios comparing masked hypertension with normotension were all significant (P<0.0001), ranging from 1.76 to 2.03. In conclusion, identification of truly low-risk white-coat hypertension requires setting thresholds simultaneously to 24 hours, daytime, and nighttime blood pressure. Although any time interval suffices to diagnose masked hypertension, as proposed in current guidelines, full 24-hour recordings remain standard in clinical practice.

Short-term variability and nocturnal decline in ambulatory blood pressure in normotension, white-coat hypertension, masked hypertension and sustained hypertension: a population-based study of older individuals in Spain

“…Although any time interval suffices to diagnose masked hypertension, as proposed in current guidelines, full 24-hour recordings remain standard in clinical practice. 37 The higher 24-hour BP variability in subjects with whitecoat hypertension may help to explain the higher rates of cardiovascular risk that have been reported in previous studies of these patients. [33][34][35] BP variability depends on sympathetic vascular modulation and changes in arterial distensibility.…”

Masked Hypertension and Cardiovascular Outcomes: An Updated Systematic Review and Meta-Analysis

“…Prior studies showed inconsistent results in cardiovascular outcomes between the patients with masked HTN and white-coat HTN. 16,32 We found significant increase in composite cardiovascular events and all-cause mortality Integrated Blood Pressure Control 2018:11 submit your manuscript | www.dovepress.com…”

Masked hypertension

“…In 8,237 untreated persons, mean age 50.7 years, in 12 population studies, the prevalence of masked hypertension ranged from 9.7% to 19.6% (10). At followup, compared to normotensive persons, persons with masked hypertension had a 1.76 to 2.03 times increase in cardiovascular events (10).…”

“…Masked hypertension was diagnosed by ambulatory blood pressure monitoring in 14% of persons and by home blood pressure monitoring by 11% of persons (6). It may be reasonable to screen for masked hypertension with ambulatory blood pressure monitoring or with home blood pressure monitoring if the office systolic blood pressure is 120 to 129 mmHg or if the office diastolic blood pressure is 75 to 79 mmHg (6)(7)(8)(9)(10).…”