Automated ambulatory blood pressure monitoring: a study in age-matched normotensive and hypertensive men.

Noninvasive automated techniques have been used in this study in 29 ambulatory normotensive and hypertensive men to monitor blood pressure during a full 24-hour period. The two groups of men were carefully matched for age. The data were analyzed with respect to possible differences in the circadian pattern of blood pressure, in the variability of blood pressure, and differences in the prevalence of abnormal blood pressures between the two groups. The circadian pattern of blood pressure in hypertensive patients was displayed parallel to that in normotensive control subjects but at a significantly higher level. The difference between daytime and nighttime systolic blood pressure was greater in normotensive than in hypertensive men. However, variability of blood pressure was not different between the two subgroups. Hypertensive men showed on average a greater incidence of abnormal blood pressures than normotensive subjects. However, nine of the normotensive control subjects showed more than 25% of abnormal readings of systolic or diastolic blood pressures during a 24-hour recording period. In contrast, fewer than 25% of abnormal blood pressure readings were found in nine of the hypertensive patients. The data reported here may help to better define the use of ambulatory blood pressure monitoring techniques in the diagnosis of hypertension.