How good are standardized blood pressure recordings for diagnosing hypertension? A comparison between office and ambulatory blood pressure.

Ambulatory blood pressure monitoring was compared with office blood pressure in 48 normotensive, 81 borderline hypertensives and 35 untreated hypertensives. The studied groups were chosen from a geographically defined population of middle-aged men in southern Sweden. The mean 24-h ambulatory blood pressure values for the normotensives, borderline hypertensives and untreated hypertensives were 120/76, 127/82 and 140/92 mmHg, respectively. The diurnal mean ambulatory blood pressure in the three groups was 126/80, 134/86 and 146/96 mmHg, respectively. The percentage of 24-h diastolic blood pressure peaks greater than or equal to 95 mmHg in the groups were 7%, 22% and 53%, respectively. The corresponding values greater than or equal to 90 mmHg were 16%, 38% and 69%, respectively. In the untreated hypertensive group, there was a more pronounced (P less than 0.05) systolic blood pressure increase during the morning hours (0600-1000 h) than in the normotensive and borderline hypertensive groups. Fourteen per cent of the hypertensives showed normal blood pressure values during 24-h blood pressure monitoring. Fifteen per cent of the borderline hypertensives were normotensive during ambulatory blood pressure monitoring despite repeated office diastolic blood pressure greater than or equal to 90 mmHg. The opposite (increased blood pressure during ambulatory blood pressure monitoring and at screening but normal office blood pressure) was seen in 14% of the borderline hypertensives. Normotensives were characterized by lower mean blood pressure values, fewer blood pressure peaks and a lower systolic blood pressure increase during the morning hours than hypertensives in this study of middle-aged men. The established way of diagnosing hypertension, borderline hypertension and normotension correlated well with the results of ambulatory blood pressure monitoring.