Magnitude, reproducibility, and components of the pressor response to the clinic.

Abstract

We investigated the magnitude of the pressor response to the clinic with ambulatory monitors by comparing blood pressure readings related to the medical visit with all clinic-unrelated readings during the day. One hundred studies were conducted on 51 hypertensive patients who were placed either on placebo (67) or on monotherapy with hydrochlorothiazide, atenolol, or the converting enzyme inhibitors captopril or zofenopril. On placebo, clinic-related systolic (162±2), diastolic (101±l), and pulse (61 ±2) pressures (mm Hg) were significantly higher than the respective clinic-unrelated values (149±2, 93±1, and 56±1 mm Hg). Heart rates were not different. Despite significant reductions of blood pressure, the same pattern was found during treatment. After initiating the monitoring and while in transit to job or home (initial component of the clinic-related readings), systolic (166±2 mm Hg) and pulse (64±2 mm Hg) pressures were higher than those during return to the office the next day (final component, 158±3 and 58±2 mm Hg). Blood pressures of both components, however, were significantly higher than the clinic-unrelated ones. In 19 repeat studies carried out 2-24 months apart on placebo, the average pressor response did not change from the first (13±3/11±2) to the second (13±4/11±2 mm Hg) procedure. No correlation, however, was found between the first and second study responses of individual patients. We conclude that the pressor response to the clinic 1) has a magnitude of 13±2/9±1 mm Hg (p<0.001), 2) is not altered by antihypertensive therapies with different mechanisms of action, 3) is not reproducible, 4) is associated with increased pulse pressure, and 5) has a hitherto undescribed component that differs from the "white coat phenomenon" in that it precedes the encounter with the physician. (Hypertension 1990;15(suppl I):I-161-I-165)

Factors Influencing White-coat Effect

“…11 Additionally, Elijovich et al in a smaller study with SH patients showed a WCE value of 13/9 mm Hg. 12 The discrepancy between these results and ours could be explained by the higher percent of women participating in these studies 11,12 and the lower prevalence of NT subjects. 11 By contrast, Gualdiero et al documented lower WCE values (7/5 mm Hg) in hypertensive patients than we did.…”

Differential effects of antihypertensive drugs with differing pharmacological properties on the basal ambulatory blood pressure

“…Basing the antihypertensive therapy on the clinic BP can induce an overestimation [26][27][28][29] or underestimation of its efficacy mainly due to white-coat effect. [29][30][31][32] The prevalence of isolated clinic hypertension (white coat hypertension) in drug trials seems to be extremely high. 33 In the present study, 10.3% of subjects with clinic SBP у150 and DBP у90 mm Hg had isolated clinic hypertension when normotension was defined as ambulatory SBP Ͻ135 and DBP Ͻ80 mm Hg.…”

Masked hypertension: a clinical entity or statistical gymnastics?

“…Individuals who are normotensive during the day but hypertensive in the office ("the white coat syndrome") have been the object of extensive research documenting that they are at intermediate risk for target organ damage, compared to normotensive and hypertensive subjects [11]. Also, this research has identified a similar phenomenon (the "pressor response to the clinic") that occurs in authentically hypertensive patients ("white coat responders") [2].…”