THE RELATIONSHIP BETWEEN 24-HOUR AMBULATORY BLOOD PRESSURES AND LABORATORY MEASURES OF CARDIOVASCULAR REACTIVITY

The relationship between 24-hour ambulatory blood pressures (ABP) and blood pressures (BP) obtained during laboratory stressors was examined . Thirty normotensives (equal males and females) underwent ABP monitor ing on three occasions separated by a week. They also underwent a labo ratory assessment which included standard stressors (ie., mental arith metic, cold pressor, orthostatic response, treadmill exercise). Correl ational analyses found laboratory pressures to be significantly correl ated with ambulatory pressures, with laboratory baseline BPs showing h igher correlations to the ambulatory BPs than the BPs obtained during laboratory stressors. In addition, gender effects were examined. In th e correlational analyses between ABPs and laboratory BPs, males and fe males did not differ significantly in the strength of the correlations . In terms of absolute values, males were found to have significantly higher SBP during ambulatory monitoring, random-zero recordings, calib ration readings, and during baselines of the laboratory assessment. Th ere were no gender effects for these measures with respect to diastoli c blood pressure or heart rate. There were also no gender effects on r eactivity to laboratory stressors as measured by change scores. Explor atory analyses found no significant effect of history of familial hype rtension on either the ABPs or the laboratory pressures.