Prevalence of masked hypertension evaluated by home blood pressure monitoring in a large sample of patients with office blood pressure <140/90 mmHg

AIM: Patients with masked hypertension have a higher incidence of target organ damage, including increased left ventricular mass and carotid atherosclerosis and cardiovascular events when compared with normotensive patients. The adverse cardiovascular risks are even greater in patients already taking antihypertensive medication. OBJECTIVE: To identify the prevalence and clinical characteristics of masked hypertension in a large multicenter Brazilian sample that underwent office and home blood pressure monitoring. METHODS: This was an observational cross-sectional analytical study based on secondary data from the teleMRPA online platform, which included 32 cities from 15 states in the five regions of Brazil. The database included 3704 outpatient participants with office blood pressure <140/90 mmHg who performed home blood pressure monitoring for diagnostic investigation (diagnosis group; n = 1819) or treatment (treatment group; n = 1885) of hypertension in 2018. RESULTS: The prevalence of masked hypertension was 18.0% in the whole studied population and 15.4% and 20.4% in the diagnostic and treatment group, respectively. Masked hypertension was more frequently detected in patients with office blood pressure classified as high normal [systolic blood pressure (SBP) = 130-139 mmHg or diastolic blood pressure (DBP) = 85-89 mmHg], followed by those classified as normal (SBP = 120-129 mmHg or DBP = 80-84 mmHg) and optimal (SBP < 120 mmHg and DBP < 80 mmHg), with respective prevalence of 28.3, 13.4 and 4.4% in the diagnostic group and 30.8, 18.8 and 7.1% in the treatment group. CONCLUSION: Masked hypertension has a significant prevalence among individuals with office blood pressure <140/90 mmHg, which is greater with patients with high normal office blood pressure and even higher in patients already using antihypertensive medication.