Masked uncontrolled hypertension: Prevalence and predictors

BACKGROUND: There are limited data on ‘masked uncontrolled hypertension’ (MUCH) in patients with treated and apparently well-controlled BP is unknown. OBJECTIVES: To define the prevalence and predictors of MUCH among hypertensive patients with controlled office blood pressure. METHODS: One hundred ninety-nine hypertensive patients presented to the specialized hypertension clinics at two University Hospitals. All patients had controlled office blood pressure (less than 140/90 mmHg). Patients were assessed regarding history, clinical examination, and laboratory data. All patients underwent ambulatory blood pressure monitoring (ABPM) for 24 h, within a week after the index office visit. MUCH was diagnosed if average 24-h ABPM was elevated (systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg) despite controlled clinic BP. RESULTS: Sixty-six patients (33.2%) had MUCH according to 24-h ABPM criteria (mean age 53.5 ± 9.3 years, 60.6% men). MUCH was mostly caused by the poor control of nocturnal BP; with the percentage of patients in whom MUCH was solely attributable to an elevated nocturnal BP almost double that due to daytime BP elevation (57.3% vs. 27.1%, P < 0.001). The most common predictors of MUCH were smoking, DM and positive family history of DM. CONCLUSION: The prevalence of masked suboptimal BP control is high. Office BP monitoring alone is thus inadequate to ascertain optimal BP control because many patients have an elevated nocturnal BP. ABPM is needed to confirm proper BP control, especially in patients with high cardiovascular risk profile. Smoking, DM and positive family history of DM were the most common predictors of MUCH.