Do laboratory tests of blood pressure reactivity predict blood pressure changes during everyday life?

This study was undertaken to examine whether blood pressure reactivity measured in the controlled setting of a laboratory could be correlated with blood pressure changes occurring during daily life. The subjects were 164 untreated hypertensives with mild hypertension, all of whom had a 24-hour ambulatory blood pressure recording, during which their activities were unrestricted. One hundred thirteen performed a treadmill exercise test, and 51 performed two active coping tasks (playing a video game or mental arithmetic). Blood pressure was monitored at baseline and during the tasks. Significant correlations were observed between the absolute levels of pressure measured during the laboratory tests and ambulatory monitoring, but these were higher for the active coping tasks (r = 0.53 to 0.75) than the exercise testing (r = 0.26 to 0.46) and were no higher for pressures measured during the tasks than at baseline. Correlations between the changes of blood pressure during the laboratory tasks and the changes occurring during ambulatory monitoring were analyzed in three ways, using simple, multiple, and canonical correlations. In no case were these correlations substantively significant. We conclude that blood pressure reactivity measured in the laboratory may not be readily generalized to changes of pressure in everyday life, as measured by noninvasive ambulatory recorders.