Introduction: Endothelial damage is an early step in the pathogenesis of atherosclerosis which begins in early childhood after exposure to atherogenic risk factors such as arterial hypertension. Atherosclerosis is becoming a common disease even in children and adolescents. Its progression may lead to very severe cardiovascular complications. Thrombomodulin (TM), a specific marker of endothelial cell damage, is a transmembranous glycoprotein with vasoprotective and anti-coagulant properties. TM-thrombin complex becomes an activator of protein C which inactivates factor Va and VIIIa and thereby inhibits the blood coagulation cascade. TM may be cleaved to its soluble (sTM) form by proinflammatory mediators and then detected in the circulation.
Aim: The aim of the present study was to investigate if sTM plasma concentration--one of biochemical markers of endothelium injury--is higher in children and adolescents with arterial hypertension (AH).
Materials and methods: We studied 32 children with hypertension (9 girls and 23 boys, age range 10.5-17.2 years), and 17 healthy controls, without family history of cardiovascular diseases. Hypertension was detected after 24 hrs ABPM (Ambulatory Blood Pressure Monitoring). We measured plasma concentration of sTM, blood lipids profile, body mass index (BMI) and, as sTM is excreted by the kidney, we also measured plasma level of creatinine and its clearance.
Results: Plasma concentration of sTM in the group with essential hypertension was significantly higher than that in the control group (4.01 +/-1.05 vs 3.42+/-0.4; p<0. 05). There were no significant associations between sTM and age or sex. Analyzing lipids profile (cholesterol, LDL-c, HDL-c, triglycerides) we did not find any differences in their levels between groups. We observed statistically significant correlation between sTM and systolic and diastolic blood pressure during the day and night. In addition BMI ratio was higher in AH group but there was no significant correlation between sTM and BMI.
Conclusion: Statistically higher level of sTM in children with AH compared with healthy individuals makes us sure that endothelium cells, even in children who were shortly exposed to atherogenic risk factors such as essential hypertension, are noticeably damaged. These results constitute an additional signal that a lot of effort should be put into the endeavors to eliminate atherogenic risk factors in children in order to prevent cardiovascular events.