HIGH PREVALENCE OF ISOLATED NOCTURNAL HYPERTENSION IN MASKED AND MASKED-UNCONTROLLED HYPERTENSION

Abstract

Objective: Little is known about the diurnal blood pressure (BP) characteristic of masked hypertension and masked uncontrolled hypertension. Design and method: Among the 1128 participants (age range 20–70 years), 1004 individuals who had valid 24-hour ambulatory BP monitoring were analyzed. Hypertension by office BP was defined as >=140/90 mmHg. Hypertension by ambulatory BP was defined as 24-hour BP >=130/80 mmHg and/or daytime BP >=135/85 mmHg and/or nighttime BP >=120/70 mmHg. Results: The study group consist of 500 (49.8%) normotension and controlled hypertension (NT), 9 (0.9%) white-coat and white-coat controlled hypertension (WH), 369 (36.8%) masked and masked uncontrolled hypertension (MH), and 126 (12.5%) sustained and uncontrolled sustained hypertension (SH). Systolic and diastolic BP dipping of MH group (5.3 ± 7.9 and 7.3 ± 9.0%, respectively) was lower than that of NT group (9.7 ± 6.0 and 13.0 ± 7.4 % respectively) and SH group (8.7 ± 8.2 and 10.8 ± 9.6%, respectively) (p < 0.001). MH group had higher prevalence of SBP and DBP non-dipper (74.0% and 62.9%) compared to NT (54.0% and 33.6%) and SH group (58.7% and 45.2%). Daytime hypertension was more prevalent in individuals with SH group compared to MH group (79.4% vs 42.0%, p < 0.001). On the contrary, the prevalence of isolated nocturnal hypertension was higher in MH group than in SH group (58.0% vs 20.6%, p < 0.001). Isolated nocturnal hypertension was an independent determinant of masked and masked uncontrolled hypertension (OR 39.1, 95%CI 23.1 – 66.0). Conclusions: Nocturnal non-dipping and high prevalence of isolated nocturnal hypertension are unique features and might be a mechanism of worse prognosis of masked and masked uncontrolled hypertension.