title: The white-coat effect is unrelated to the difference between clinic and daytime blood pressure and is associated with greater reactivity to public speaking.
abstract: 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 (DeltaC-D).
  
  
  METHODS
  We studied 64 young stage-1 hypertensive subjects and 33 normotensive controls.
  
  
  METHODS
  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. DeltaC-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 DeltaC-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 BP response below the median (normo-reactive) had a response to the psycho-social challenge (40 +/- 21 mmHg, 0.001 versus hyper-reactive) similar to that of the normotensive controls (38 +/- 17 mmHg). Epinephrine urinary output was greater in the hyper-reactive than the normo-reactive subjects (23 versus 12 microg/24 h, = 0.01). The SBP response to public speaking was greater in the hypertensive subjects with higher systolic daytime BP than in those with lower daytime BP (55.3 +/- 20.9 versus 45.1 +/- 20.6 mmHg, = 0.046).
  
  
  CONCLUSIONS
  Subjects with increased WCE have an exaggerated response also to psycho-social stimuli. Average daytime BP, which incorporates the BP reactions to many psycho-social triggers can, thus, not be taken as the basal BP of an individual. This helps explain why DeltaC-D does not reflect the true WCE.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy. palatini@unipd.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Palatini
authors.forename: Daniela
authors.initials: D
authors.lastname: Palomba
authors.forename: Olivo
authors.initials: O
authors.lastname: Bertolo
authors.forename: Rita
authors.initials: R
authors.lastname: Minghetti
authors.forename: Daniele
authors.initials: D
authors.lastname: Longo
authors.forename: Michela
authors.initials: M
authors.lastname: Sarlo
authors.forename: Achille C
authors.initials: AC
authors.lastname: Pessina
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D001795:Blood Pressure Determination; D018660:Blood Pressure Monitoring, Ambulatory; D016022:Case-Control Studies; D004837:Epinephrine / Q000652:urine; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000652:urine; D011584:Psychology; D013060:Speech / Q000502:physiology; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D009638:Norepinephrine; D004837:Epinephrine