Ambulatory blood pressure in healthy normotensive males.

Noninvasive ambulatory blood pressure examinations were obtained during 24 hours in 72 healthy normotensive males. Blood pressure and heart rate measurements were analyzed for the mean 24-hour work, home, and sleep periods, for the percent of elevated blood pressure readings, and for the hourly maximum and minimum blood pressure by age per decade. Mean 24-hour ambulatory blood pressure showed no significant differences (p greater than 0.05) for systolic blood pressures among the age groups, but lower diastolic blood pressures were found in males younger than age 40 (p less than 0.05). Few differences existed between mean ambulatory systolic and diastolic blood pressures obtained during the work or home periods, but a significant (p less than 0.01) lowering of mean systolic and diastolic blood pressure occurred during sleep for each age group. There was a trend of an increasing percent of elevated blood pressure measurements with increasing age, although mean blood pressures within each activity period showed few differences. Ninety-two percent of subjects showed their hour of maximum blood pressure during wake activity with broad variability in either the work or home period, whereas 86% of subjects uniformly demonstrated their minimum blood pressure in the early morning hours.