A multicentre study on unattended automated office blood pressure measurement in treated hypertensive patients
Abstract
Aims: Unattended automated office blood pressure (uAutoOBP) may eliminate white-coat effect. In the present study, we studied its relationships to attended office blood pressure (BP) and ambulatory BP monitoring (ABPM).Material and methods: Stable treated hypertensive subjects were examined in four Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP was measured six times: three times with auscultatory method (AuscOBP) by the physician followed optionally by three oscillometric measurements (OscOBP).
ABPM was performed within one week from the clinical visit.Results: Data on 172 subjects aged 63.712.4 years with AuscOBP 127.6 +/- 12.1/77.6 +/- 10.0mm Hg are reported. uAutoOBP was by 8.5 +/- 9.0/3.0 +/- 6.1mm Hg lower than AuscOBP. The AuscOBP-uAutoOBP difference increased with the AuscOBP level and it did not depend on any other factor.
OscOBP differed by 8.6 +/- 8.6/1.9 +/- 5.7mm Hg from uAutoOBP. 24-hour mean BP was by 4.2 +/- 12.1/3.5 +/- 7.8mm Hg lower than AuscOBP and by 4.3 +/- 11.0/0.5 +/- 6.9mm Hg higher than uAutoOBP; the correlation coefficients of 24-hour mean BP with AuscOBP and with uAutoOBP did not differ (p for difference.13). In the lowest BP group (systolic AuscOBP<120mm Hg or diastolic AuscOBP<70mm Hg), both AuscOBP and uAutoOBP were lower than 24-hour mean BP, while in the highest BP group (systolic AuscOBP140mm Hg or diastolic AuscOBP90mm Hg), they were higher.Conclusions: Compared to uAutoOBP, attended BP measurement gives higher values, both when measured with auscultatory or oscillometric method.
Inter-individual variability of AutoOBP - uAuscOBP difference, as well of uAutoOBP - ABPM difference, is large. We did not prove that uAutoOBP would be associated to 24-hour ambulatory BP more closely than attended BP.