White coat hypertension and blood pressure variability

The objective of this cross-sectional study was to investigate blood pressu re variability and pulse pressure in white coat hypertensives in comparison to established hypertensives and normal subjects. Four hundred and twenty patients were referred consecutively from general practice with newly diagn osed untreated essential hypertension. One hundred and forty-six control su bjects were drawn at random from the Danish national register. Seventy-six patients from the former group were considered white coat hypertensive usin g a normalcy cutoff level of 135/90 mm Hg. Mean, standard deviation, and coefficient of variation of the blood pressur es from the automated clinic readings, daytime, nighttime, and full 24-h pe riods were extracted from 24-h ambulatory blood pressure monitorings. Mean arterial pressure, pulse pressure, white coat effect, and dip were calculat ed in all three groups of subjects. The main findings were that white coat hypertensives did not differ significantly from normotensives regarding var iability data except for the white coat effect. However, the white coat hyp ertensives had a significantly lower pulse pressure than the established hy pertensives, according to clinic blood pressure and ambulatory readings. We conclude that white coat hypertension evaluated with indirect ambulatory blood pressure monitoring is not a state with a generally higher blood pre ssure variability than normotension or established hypertension. The patien ts with white coat hypertension have pulse pressure at the same level as no rmal controls, but significantly lower than established hypertensives. (C) 1999 American Journal of Hypertension, Ltd.