Endothelial dysfunction in subjects with subclinical hyperthyroidism

Abstract

Numerous clinical and experimental reports suggest that a high von Willebrand factor (vWf) level reflects endothelial damage or endothelial dysfunction. The present study was designed to evaluate vWf in subclinical hyperthyroidic subjects compared with euthyroidic subjects. We selected 20 subclinical hyperthyroidic subjects and 20 euthyroidic control subjects matched for age, gender and body mass index. The level of vWf was significantly higher in the subclinical hyperthyroidic group than in the euthyroidic group (42.9+/-9.6 vs 37.6+/-6.4%, p=0.026). In conclusion, our results suggest that subjects with subclinical hyperthyroidism tend to have an endothelial dysfunction. Endothelial dysfunction could contribute to increasing the cardiovascular risk in subclinical hyperthyroidism.

Decreased Number of Circulating Endothelial Progenitor Cells in Patients with Graves’ Hyperthyroidism

“…Accordingly, increased plasma concentrations of von Willebrand Factor (vWF), which is an indicator of endothelial damage and dysfunction (25,26), were reported in patients with hyperthyroidism, and were demonstrated to decrease below normal limits in patients who became euthyroid after anti-thyroid treatment (8). Increased circulating levels of vWF may be observed already in patients with subclinical hyperthyroidism (10). Recently, it has been suggested that the number of EPC may represent an indicator of the presence of vascular injury and also an expression of reparative mechanisms and vascular protection, which are of primary importance for the integrity of the endothelium.…”

“…In addition, chronic inflammation has been shown in active GD, as well as in autoimmune thyroid disorders, and production of acute-phase proteins and proinflammatory cytokines [such as interleukin (IL)-12, IL-18, and tumor necrosis factor-α (TNF-α)] (7). Hemodynamic and metabolic changes may lead to vascular injury, as suggested by an increase of markers of endothelial damage observed in GD (8)(9)(10). In the last years, endothelial progenitor cells (EPC) have been recognized to play important roles in post-natal neovascularization and vascular repair, and, therefore in maintaining endothelial integrity and function (11,12).…”

Subclinical hyperthyroidism and blood pressure in a population-based prospective cohort study

“…Several previous studies found associations of subclinical hyperthyroidism with cardiovascular disorders such as endothelial dysfunction (1), left ventricular hypertrophy (2), thickened artery walls (3) or atrial fibrillation (4). The cardiovascular disorders associated with subclinical hyperthyroidism may be a direct effect of thyroid hormone disturbance.…”

Thyrotoxic Cardiomyopathy

“…ST has been recently shown to have a prothrombogenic effects (Horne et al, 2004;Erem, 2006). Increased activity of Von Willebrand factor (Coban et al, 2006) and elevated fibrinogen level (Dörr et al, 2001) were demonstrated at ST.…”