Ambulatory monitoring to assess real-life cardiovascular reactivity in Type A and Type B subjects.

The blood pressure (BP) of 107 normotensive adults, classified as either Type A or Type B, was monitored for 24 hours on two workdays a month apart. Daytime BP measures were adjusted for sleep BP measures to estimate behavioral ('higher') regulatory influences on BP that were relatively freed from nonbehavioral ('lower') influences. Adjusted daytime diastolic BP variability and diastolic BP levels during four common activities (talking, walking, drinking a caffeinated beverage, drinking an alcoholic beverage) were higher in Type A subjects than in Type B subjects. The results imply that Type A behavior itself, directly or indirectly, caused BP hyper-responsiveness to the stressors of routine daily living in the natural environment. Potential "carryover" of BP effects from wakefulness to sleep and potential incomplete removal of sleep BP variance from daytime BP variance limit the certainty of the above interpretation of results.