Background: A unique advantage of ambulatory blood pressure (ABP) monitoring is the assessment of nocturnal blood pressure (BP) and the detection of non-dippers. This study assessed nocturnal BP and non-dippers using a novel home BP (HBP) monitor.
Methods: Eighty-one hypertensives performed within 2 weeks ABP (24-h, Microlife WatchBP O3) and HBP monitoring (Microlife WatchBPN) during daytime (6 days, duplicate morning and evening measurements) and nighttime (automated asleep measurements, 3 nights, 3 readings/night). Patients' preference in using ABP or HBP was assessed by a questionnaire.
Results: Strong associations were found between ABP and HBP (intraclass correlation coefficients for awake systolic/diastolic 0.75/0.81; asleep 0.87/0.85). No statistically significant difference was found between HBP and ABP (mean difference ± SD awake systolic/diastolic 1.5 ± 10.1/-1.1 ± 6.0 mm Hg, P = 0.20/0.09; asleep -0.4 ± 7.8/-1.0 ± 5.3, P = 0.63/0.09). There was substantial agreement (74%, kappa 0.2) between ABP and HBP in the detection of non-dippers, which was similar to the previously reported test-retest reproducibility of repeated ABP monitoring in the diagnosis of non-dippers. Moderate to severe disturbance from ABP monitoring was reported by 18% of the participants and severe restriction of their daily activities by 9, vs. 3 and 1.5%, respectively for HBP (P < 0.001/ <0.01, for comparisons respectively). Nighttime BP monitoring and cuff discomfort were the main complaints for ABP (46 and 32%, respectively) and HBP (34 and 28%), whereas 89% reported more nighttime sleep disturbance by ABP than HBP (P < 0.001).
Conclusions: HBP monitoring appears to be a reliable and well accepted by users alternative to ABP for the assessment of nocturnal BP and the detection of non-dippers.