[Ultrasonographic evaluation of atherosclerotic changes in carotid and brachial arteries in children with growth hormone deficiency before GH replacement therapy].

Background: According to very well documented onset of atherosclerosis in early childhood, scientists are looking for good diagnostic methods for evaluating first changes in arterial blood vessels non-invasively. We want to know more about pathogenetic mechanisms and about changes in vessels especially in the group of young people with risk factors of premature atherosclerosis. The role of endothelial dysfunction in the very early phase of this process is known very well so far. High resolution echocardiography seems to be a good method which allows to examine arteries in children and adolescents. Because of localization, brachial and carotid arteries are a very good field for this kind of examinations.

Objectives: Evaluation with high resolution echocardiography, selected parameters of endothelial function in children with growth hormone deficiency before replacement therapy. We measured the intimal plus medial thickness in carotid communis arteries (IMT) also.

Material and methods: We examined a group of 24 children (19 boys and 5 girls) aged 8-16 yr (mean 12 yr) suffered from growth hormone (GH) deficiency. The control group consisted of 24 children in similar age and sex relation. Using high resolution echocardiography, B-mode images, we measured in end diastole, distance "m-m" in brachial arteries (distance between two "m" lines which are borders among media and adventitia of near and far wall of the artery) at rest, during reactive hyperaemia (with increased flow causing endothelium-dependent dilatation FMD), again at rest and after sublingual glyceryl trinitrate (causing endothelium-independent dilatation NTGMD). Using Doppler technique we evaluated baseline flow and calculated degree of reactive hyperemia. We also measured intimal plus medial thickness in every carotid artery three times and calculated mean value. In our analysis we estimated concentrations of cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides.

Results: In children with growth hormone deficiency the vessel size was smaller then in the control group and FMD was significantly impaired (10.05% v. 14.62%; p=0.058). NTGMD was similar to the control group (p=0.,371). We noticed higher IMT values in the whole examined group compared to the control group (0.52 mm v. 0.41 mm; p=0.0000). We noticed an important correlation between FMD and IMT in whole patients (examined plus control group) (p=0.004). The level of total cholesterol was higher in the examined group (p=0.039).

Conclusions: 1. FMD evaluated in brachial artery, seems to be an useful sign of impaired endothelial function in children suffering from the risk factors of atherosclerosis. 2. The evaluation of IMT in carotid arteries in patients with growth hormone deficiency showed a more advanced degree of atherosclerotic changes in this group compared to healthy controls. 3. Ultrasonographic evaluation of premature atherosclerosis in children with growth hormone deficiency is a basis for the future estimation of positive effects of the replacement therapy.