Non-invasive automated blood pressure monitoring in ambulatory normotensive men

Summary

In this study non-invasive automated ambulatory blood pressure monitoring techniques have been used to evaluate patterns of blood pressure in 34 healthy normotensive men. The results of the monitoring reveal that, as in hypertensive patients, blood pressure is highest during daytime and lowest at night in these volunteers. The average of daytime blood pressures (128± 12/80± 7 mmHg) were significantly higher (p <0.01) and nighttime blood pressure averages (109± 11/67±9 mmHg) were significantly lower (p < 0.01) than the conventionally measured casual blood pressure (119 ± 13/76±9 mmHg). On average, 15.6% of systolic blood pressure readings in each tracing were greater than 140 mmHg More than 25% of these elevated readings were found in 6 of the 34 subjects. The percentage of diastolic blood pressures greater than 90 mmHg in each tracing was 14.4%. Again, six subjects accounted for more than 25% of elevated diastolic blood pressures during the 24hour monitoring period. The incidence of these elevated blood pressure readings was not age-dependent. However, subjects with a positive family history for hypertension had, on average, more elevated systolic blood pressures than patients with a negative family history (24 vs. 9%, p < 0.05), even though casual blood pressures were not different between these groups. The correlation coefficient between casual and whole-day average systolic blood pressures was highly significant (r = 0.60, p < 0.001) as was the correlation coefficient between casual and whole-day average diastolic blood pressure (r = 0.72, p < 0.001). However, both correlation coefficients were stronger after substitution of casual blood pressures by the averages of blood pressure recorded between 8.00 and 10.00 a.m.

The data presented in this paper helps define blood pressure in healthy normotensive volunteers. Ultimately, these data may be used as an aid in the diagnosis of patients with high blood pressure.