Whole-day BP monitoring in ambulatory normotensive men.

Noninvasive automated ambulatory BP monitoring techniques were used to evaluate BP patterns in 34 healthy normotensive men. Daytime BPs (128 +/- 12/80 +/- 7 mm Hg) were significantly higher and nighttime BP averages (109 +/- 11/67 +/- 9 mm Hg) were significantly lower than the casual BPs (119 +/- 13/76 +/- 9 mm Hg) of the subjects studied. On the average, 15.6% of the readings in each tracing showed systolic BPs above 140 mm Hg, and more than 25% of these elevated readings were found in six of the 34 subjects. The average incidence of elevated diastolic BPs (greater than 90 mm Hg) observed during each monitoring period was 14.4%, but six subjects had incidences of more than 25%. The incidence of elevated BP readings was not age related. However, subjects with a family history of hypertension generally had more elevated systolic BPs than those with no family history of hypertension (24% v 9%).