We conducted this study to determine whether 'office hour', defined as time period from 0800 to 1800 hours, ambulatory blood pressure monitoring (ABPM) predicts daytime ('waking-hour') and 24-h ABPM results, and to examine the impact of sleep disturbance on ABPM and nocturnal dip. Eighty-four patients (mean age 49+/-18 years, 47 males) were studied. Systolic, diastolic and mean 4-, 6-, 8-, 'office-hour' as well as 'waking-hour' blood pressures (BPs) were obtained from 24-h ABPM readings. Of these, no statistical differences were found between 8-h and 'office-hour' systolic, diastolic and mean BPs compared to 'waking-hour' values. There was complete concordance between 'office-hour' and 'waking-hour' ABPM diagnosis based on British Hypertension Society definitions. Sleep disturbance was found in 22 patients (26%). Although nocturnal dip was not significantly different in either sleep-disturbed or non-disturbed patients, patients who reported sleep disturbance had significantly higher proportion of borderline/abnormal BP diagnosis compared to non-sleep-disturbed counterpart during both 'waking hour' and night time. In patients without sleep disturbance, there was complete concordance between 'office-hour', 'waking-hour' and 24-h ABPM diagnosis based on British Hypertension Society definitions. 'Office-hour' ABPM is predictive of 'waking-hour' and 24-h ambulatory BP readings. Sleep disturbance is common in patients undergoing the test, and significantly raises the BP readings. We therefore propose 'office-hour' ABPM as an accurate, reliable and comfortable method of continual non-invasive BP monitoring, and omitting routine night time BP monitoring.
Journal of Human Hypertension (2006) 20, 440-443. doi:10.1038/sj.jhh.1002022; published online 6 April 2006.