Impact of Asleep and 24-Hour Blood Pressure Data on the Prevalence of Masked Hypertension by Race/Ethnicity

BACKGROUND: We pooled ambulatory blood pressure monitoring data from 5 US studies, including the Jackson Heart Study (JHS), the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Masked Hypertension Study, the Improving the Detection of Hypertension Study, and the North Carolina Masked Hypertension Study. Using a cross-sectional study design, we estimated differences in the prevalence of masked hypertension by race/ethnicity when out-of-office blood pressure (BP) included awake, asleep, and 24-hour BP vs. awake BP alone. METHODS: We restricted the analyses to participants with office systolic BP (SBP) <130 mm Hg and diastolic BP (DBP) <80 mm Hg. High awake BP was defined as mean SBP/DBP ≥130/80 mm Hg, high asleep BP as mean SBP/DBP ≥110/65 mm Hg, and high 24-hour BP as mean SBP/DBP ≥125/75 mm Hg. RESULTS: Among participants not taking antihypertensive medication (n = 1,292), the prevalence of masked hypertension with out-of-office BP defined by awake BP alone or by awake, asleep, or 24-hour BP was 34.5% and 48.7%, respectively, among non-Hispanic White, 39.7% and 67.6% among non-Hispanic Black, and 19.4% and 35.1% among Hispanic participants. After multivariable adjustment, non-Hispanic Black were more likely than non-Hispanic White participants to have masked hypertension by asleep or 24-hour BP but not awake BP (adjusted odds ratio [OR] 2.14 95% confidence interval [CI] 1.45-3.15) and by asleep or 24-hour BP and awake BP (OR 1.61; 95% CI 1.12-2.32) vs. not having masked hypertension. CONCLUSIONS: Assessing asleep and 24-hour BP measures increases the prevalence of masked hypertension more among non-Hispanic Black vs. non-Hispanic White individuals.