Short-Term Reproducibility of Masked Hypertension Among Adults Without Office Hypertension

The 2017 American College of Cardiology/American Heart Association blood pressure (BP) Hypertension Clinical Practice Guidelines recommends ambulatory BP monitoring to detect masked hypertension. Data on the short-term reproducibility of masked hypertension are scarce. The IDH study (Improving the Detection of Hypertension) enrolled 408 adults not taking antihypertensive medication from 2011 to 2013. Office BP and 24-hour ambulatory BP monitoring were performed on 2 occasions, a median of 29 days apart. After excluding participants with office hypertension (mean systolic BP ≥130 mm Hg or diastolic BP ≥80 mm Hg), the analytical sample included 254 participants. Using the κ statistic, we evaluated the reproducibility of masked awake hypertension (awake systolic/diastolic BP ≥130/80 mm Hg) defined by the 2017 BP guideline thresholds, as well as masked 24-hour (24-hour systolic/diastolic BP ≥125/75 mm Hg), masked asleep (asleep systolic/diastolic BP ≥110/65 mm Hg), and any masked hypertension (high awake, 24-hour, and asleep BP). The mean (SD) age of participants was 38.0 (12.3) years and 65.7% were female. Based on the first and second ambulatory BP recordings, 24.0% and 26.4% of participants, respectively, had masked awake hypertension. The κ statistic (95% CI) was 0.50 (0.38-0.62) for masked awake, 0.57 (0.46-0.69) for masked 24-hour, 0.57 (0.47-0.68) for masked asleep, and 0.58 (0.47-0.68) for any masked hypertension. Clinicians should consider the moderate short-term reproducibility of masked hypertension when interpreting the results from a single ambulatory BP recording.