Endothelial dysfunction in adolescents with arterial hypertension: results of rheovasographic evaluation and heart rate variability analysis

Abstract

Background As a major regulator of local vascular homeostasis, the endothelium maintains vascular tone through the balance between vasodilatation and vasoconstriction. Upsetting this tight balance leads to endothelial dysfunction . The latter is thought to be a marker of future cardiovascular events in hypertensive patients. The purpose of this research was to assess endothelial vasomotor function with relation to heart rate variability in adolescents with arterial hypertension.
Material and methods 56 adolescents (33 males, 23 females, aged 22 ± 2 years) were subdivided into equal groups (regarding gender, age, body mass index and genetic burden) according to hypertension appearance and smoking habits. All of them underwent forearm rheovasography with measurements of reactive hyperemia test heart rate variability being taken (a five-minute recording). As reliable values for evaluating endothelial function, relative changes in the peak blood flow velocity (DdZ/ /dT) and pulse blood volume (DdV) at the 1st min after reperfusion were used. The following parameters of the time (RRNN, SDNN, RMSSD, pNN50, CV) and frequency (TP, VLF, LF, HF; LF/HF) domain analysis were used for assessing heart rate modulation.
Results Our analysis elicited a significant difference in both velocity and volume characteristics between hypertensive smokers and healthy individuals. Endothelial function in hypertensive non-smoking patients and normotensive smokers was also impaired. Heart rate variability was decreased and sympathetic tone prevailed in hypertensive adolescents. Both are associated with endothelial dysfunction.
Conclusions Endothelial function is likely to be impaired in hypertensive adolescents, particularly among those who smoke. Moreover, heart rate variability is decreased and sympathetic tone prevails with relation to endothelial dysfunction towards the autonomic imbalance.