Reproducibility of white-coat and masked hypertension in ambulatory BP monitoring

Background White-coat hypertension and masked hypertension have clinical and prognostic consequences. However, reproducibility of these phenomena is unknown. We examined the reproducibility of the white-coat and masking effects with real-life ambulatory blood pressure monitoring (ABPM). Methods In a retrospective analysis of a prospectively assembled ABPM database there were 196 subjects (age 58 ± 16 years, 59% female, 73% treated for hypertension) who underwent repeat ABPM for standard clinical indications. White-coat hypertension (or isolated manual uncontrolled hypertension) was defined as normal (< 135/85 mmHg) awake blood pressure (BP) and abnormal (≥ 140/90 mmHg) manual BP. Masked hypertension (or isolated ambulatory uncontrolled hypertension) was defined as abnormal awake BP with normal manual BP. Results Treated and untreated subjects had similar distribution among hypertension subgroups; 16% white-coat hypertension (in treated subjects, isolated manual uncontrolled hypertension), 13% masked hypertension (in treated subjects, isolated ambulatory uncontrolled hypertension), 59% uncontrolled hypertension, 12% normal blood pressure (or controlled hypertension). In the second session the prevalence of white-coat and masked hypertension increased. Of 31 subjects with white-coat hypertension in the first session 19 (61%) remained ambulatory normotensive in the second session, while 18 of 25 (72%) masked hypertensive subjects remained ambulatory hypertensive. The reproducibility of the systolic manual–awake blood pressure difference was not inferior to that of other ambulatory variables. In untreated subjects the reproducibility of white-coat hypertension, masked hypertension and the white-coat effect was even better. Conclusion In a real-life ABPM database, we found white-coat hypertension and the masking phenomenon to be reasonably reproducible, as compared to other BP variables.