Biochemical parameters of endothelial dysfunction in cardiological syndrome X

Abstract

The endothelial dysfunction in cardiological syndrome X has been studied mainly by invasive methods and by measuring vasoactive mediator (nitric oxide (NO), endothelin-1) levels. Other parameters evaluating this dysfunction (defined as an imbalance between vascular relaxing and contracting factors, between procoagulant and anticoagulant or growth-inhibiting and growth-promoting substances) have not been used. Methods : Twenty-five non-diabetic patients (16 men, 9 women) with cardiological syndrome X and 10 healthy volunteers (5 men, 5 women) were examined. Biochemical parameters : ET-1, the end products of nitric oxide metabolism (NO x ), VEGF, vWF, g TG, tPA, PAI-1 were measured before and during an ECG exercise tolerance test. The blood concentrations of testosterone and estradiol in men and LH, FSH and estradiol in women were tested. Results : A significantly lower basal concentration of NO x (p = 0.01), lower basal NO x /ET-1 ratio (p < 0.05) and higher levels of VEGF (p < 0.05) were observed in patients with cardiological syndrome X. The male patients also had higher concentrations of estradiol (p < 0.05). A significant decrease in tPA concentration and increase in g TG was noticed during exercise, but with no differences between the study groups. Conclusions : Endothelial dysfunction in cardiological syndrome X manifests mainly in the regulation of vessel wall tonus, which was revealed by the decrease of NO x level and NO x /ET-1 ratio. VEGF elevation in syndrome X may result from chronic tissue ischaemia due to endothelial dysfunction. Exercise augments the prothrombotic activity of the blood, since a significant elevation in g TG and decrease in tPA were observed after exercise.