DETERMINANTS OF THE WHITE-COAT EFFECT IN HYPERTENSIVE SUBJECTS

To determine the magnitude and the relationships of the difference bet ween office and awake ambulatory blood pressures (BP) (white-coat effe ct) in ambulatory hypertensive patients, 64 consecutive patients refer red to the ambulatory BP monitoring laboratory were studied. All subje cts were evaluated prospectively by study nurse, study doctor, and amb ulatory BP measurements. Order of measurements was randomized and obse rvers were blinded to each others readings. No differences were found in the white-coat effects among study nurse (22/14 +/- 20/9 mm Hg), st udy doctor (27/12 +/- 20/10 mm Hg) and referring doctor (19/11 +/- 18/ 10 mm Hg). Similarly, female and male patients exhibited similar white -coat effects on the day of ambulatory monitoring. Older patients (gre ater than or equal to 65 years) displayed higher mean systolic white-c oat effects than younger patients (29 +/- 18 mm Hg vs 19 +/- 19 mm Hg, P = 0.04). Multivariate analysis using the mean average systolic whit e-coat effect as the dependent variable and age, gender, treatment sta tus, body mass index (BMI) and duration of hypertension as independent variables showed a significant independent role for age. In contrast, no clinical correlates of the diastolic white-coat effect were found. Older patients are more likely to display a systolic white-coat effec t in the medical care environment.