PREVALENCE OF WHITE-COAT AND MASKED HYPERTENSION AT DIFFERENT OFFICE BLOOD PRESSURE LEVELS IN UNTREATED SUBJECTS

Abstract

Objective: The European Guidelines for the management of arterial hypertension support the use of out-of-office blood pressure (BP) measurements for confirming the diagnosis of hypertension and detecting BP phenotypes such as white-coat hypertension (WCH) and masked hypertension (MH), especially in patients with grade 1 hypertension and subjects with high normal BP. However, it is not clear enough, whether out-of-office blood pressure measurements should be performed in patients with higher grades of hypertension as well as in subjects with normal or optimal BP. The aim of our study was to investigate the prevalence of WCH in untreated patients with grade 1, grade 2 and grade 3 hypertension as well as the prevalence of MH in never treated subjects with high normal, normal and optimal BP values. Design and method: A total of 2357 untreated subjects referred to our Hypertension Unit for evaluation underwent 24-h ambulatory BP monitoring. According to their office BP levels were divided into 6 categories: optimal (<120/80mmHg), normal (120/80 – 129/84mmHg), high normal (130/85 – 139/89mmHg), grade 1(140/90 – 159/99mmHg), grade 2 (160/100 – 179/109mmHg) and grade 3 (> = 180/110mmHg). Subjects with office BP> = 140/90mmHg and 24-h BP<130/80mmHg were defined as WCHs and patients with office BP<140/90mmHg and 24-h BP> = 130/80mmHg as MHs. Statistical analysis was performed by means of chi-square test and one-way ANOVA. Results: The percentages of WCH were 53%, 31% and 24% for patients with grade 1, grade 2 and grade 3 hypertension, respectively. The percentages of MH were 34%, 29% and 17% for patients with high normal, normal and optimal BP, respectively. Conclusions: The prevalence of WCH is significantly higher in grade 1 hypertension, however patients with grade 2 and 3 hypertension present also high rates of WCH. Similarly, MH is more common in subjects with high normal BP, however high percentages are observed in subjects with normal and optimal BP. Our results support that out-of-office BP measurements should be performed across all office BP range for the optimal detection of WCH and MH.