The white-coat effect is unrelated to the difference between clinic and daytime blood pressure and is associated with greater reactivity to public speaking

Objective: To compare the blood pressure (BP) response to doctor's visit with the BP reaction to a psycho-social challenge and with the difference between clinic and daytime BP (Delta C-D). Subjects: We studied 64 young stage-1 hypertensive subjects and 33 normotensive controls. Main outcome measures: Relationship between direct and surrogate measure of white-coat effect (WCE) and assessment of BP response to public speaking in subjects with normal or increased reaction to BP measurement. Methods: The responses to BP measurement by a doctor and to public speaking were assessed with beat-to-beat Finapres recording. Delta C-D was calculated on the basis of two BP monitorings and used as a surrogate measure of WCE. Results: BP and heart rate changes elicited by the visit were unrelated to Delta C-D and were correlated to the changes caused by the speech test [P<0.001 for systolic BP (SBP), P=0.01 for diastolic BP (DBP), and P<0.001 for heart rate]. Hypertensive subjects with SBP response to doctor's visit above the median (hyper-reactive) showed increased reactivity also to public speaking (61 +/- 15 mmHg), while those with BID response below the median (normo-reactive) had a response to the psycho-social challenge (40 +/- 21 mmHg, P