The aim of the present study was to assess whether a difference exists between endothelial function, intima–media thickness (IMT) and left ventricular mass index (LVMI) in healthy non-hypertensive, white-coat hypertensive (WCH) and sustained hypertensive (SH) adolescents.Design and Method:
All young people attending high school in Debrecen, Hungary (n = 10,359) participated in the study. Three blood pressure (BP) measurements were taken separated by 5 min intervals. If their BP exceeded the 90th percentile stratified for gender, age and height, the measurements were repeated 2 more times. Based on 9 readings we found 216 hypertensive individuals. All measurements were obtained by a validated Omron M4 device. Fifty-nine normotensive and 120 hypertensive adolescents were enrolled in this study. Hypertensive patients were classified into WCH (n = 47) and SH (n = 73) based on 24-h ambulatory blood pressure measurements. Both normotensive and hypertensive individuals underwent routine laboratory tests, IMT measurements on the common carotid arteries and transthoracic echocardiography to measure LVMI.Results:
The nitric-oxide level of WCH adolescents were lower than the normotensives (30.6 ± 11 μmol/l vs. 38.8 ± 7.9 μmol/l; p < 0.001) and their data did not differ from SH (28.7 ± 22.4 μmol/l). The endothelin-1 level was significantly higher in hypertensives compared to the control group 3.1 ± 3.9 fmol/ml vs 1.1 ± 1.1 fmol/l; p < 0.001). IMT was higher both in WCH and SH compared with healthy normotensive individuals (controls: 0.048 ± 0.01 cm, WCH: 0.056 ± 0.01 cm, SH: 0.054 ± 0.012 cm, both p < 0.001 compared with controls). There was no difference between the LVMI of control individuals and WCH (LVMI: 35.5 ± 10.3 g/m2.7 and 37.7 ± 11.2 g/m2.7). LVMI in sustained hypertension group (44.1 ± 14.1 g/m2.7) was significantly higher both compared with WCH (p < 0.05), and healthy adolescents (p < 0.001).Conclusions:
Target-organ damage develops in a stepwise fashion in adolescent hypertension. The endothelial dysfunction and the increased IMT can be demonstrated not only in sustained but also in white-coat form of adolescent hypertension, indicating that WCH is a potential abnormal condition.