'Office-hour' ambulatory blood pressure monitoring is sufficient for blood pressure diagnosis

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 nondisturbed 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.