White coat hypertension and haemostatic/fibrinolytic balance disorders

White coat hypertension (WCH) or isolated clinic hypertension is generally accepted to be a benign condition, although some reports have suggested that it may be associated with an increased cardiovascular event rate or other cardiovascular alterations. It has been previously shown that essential hypertension (EH) is associated with abnormalities in haemostatic/fibrinolytic balance and endothelial function. The aim of our study was to assess the impact of WCH on fibrinolytic balance and endothelial function by measuring plasma levels of plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (tPA), fibrinogen, and thrombomodulin. These markers were determined in 71 patients with EH, 26 with WCH and 87 normotensive healthy control subjects. The three groups were not different with respect to age, gender, smoking habits, BMI and blood lipids. Subjects with WCH were found to have increased plasma levels of PAI-1, tPA, fibrinogen and thrombomodulin compared to controls, but less compared to hypertensive ones. Our results suggest that WCH may be associated with decreased fibrinolytic potential and endothelial dysfunction, indicating that WCH may not be a completely harmless trait.