ROLE OF AMBULATORY BLOOD PRESSURE MONITORING FOR THE DIAGNOSIS OF „WHITE-COAT HYPERTENSION” IN PRIMARY CARE
Background: White coat hypertension (WCH) is defined as a clinic BP 140/90 mm Hg on at least three occasions with at least two measurements of less than 140/90 mm Hg in non-clinical settings.
The objective of the study was to identify the incidence, risk factors, characteristics and complications of „white-coat hypertension” by ambulatory blood pressure monitoring (ABPM) in primary care offices.
Material and methods: A number of 4652 hypertensive patients from 14 family medicine offices from Timiº County were evaluated concerning demographic data, cardiovascular risk factors, CV events, therapy and other complications. Laboratory data, ECG and ABPM were also obtained.
Results: From the 787 patients with validated ABPM, 176 cases (22, 3%) presented at ABPM differences between the clinic measurements and the 24 hour average BP, which confirmed WCH. The incidence of WCH was higher at women, 141 cases, 80.1% (p<0,001), smokers 134 cases, 76.1%, ( p<0,001). At ABPM the WCH group presented mean systolic BP/24h of 125±8 mm Hg, diastolic BP/24h of 81±7mm Hg, daytime SBP of 127±6 mm Hg, daytime DBP of 82±4 mm Hg, mean nighttime SBPof 110±10mm Hg and mean nighttime DBP of 71±6 mm Hg. There were no significant differences between the „white-coat hypertension” group and the other hypertensive patients, concerning total cholesterol and BMI. There were significant differences (p<0.001) regarding a low incidence of organ damage and complications (present at only 3 cases of WCH (1.7%).
Conclusions: ABPM 24-hour diurnal and nocturnal values were normal in patients with WCH, especially regarding nighttime BP, where the dipper pattern was characteristic. ABPM is the best method to identify “white-coat hypertension”, a condition that has a lower prevalence of cardiovascular risk factors, target organ damage and in which antihypertensive drug treatment has no benefit.