Endocrine Abstracts

Background: Hyperthyroidism is a common endocrine disorder that is linked to increased cardiovascular morbidity and mortality. Thrombospondin, the matricellular protein, is an important player in the process of cardiac remodelling with complex effects on cardiovascular disease (e.g. prothrombotic and antiangiogenic effects vs potential protective effects in heart failure). Adiponectin is an adipose tissue-derived hormone that shows beneficial effects on atherogenesis, endothelial function, vascular remodelling and insulin resistance. Effects of treatment of thyrotoxicosis on serum adiponectin and thrombospondin concentrations have been poorly investigated, so far.

The aim of this study was to evaluate the circulating levels of adiponectin and thrombospondin-1 in patients with hyperthyroidism before and after normalisation of thyroid function.

Methods: We studied 15 patients (four males), (age 51.8±15.3 (mean±S.D.) years) with hyperthyroidism due to Graves’ disease, toxic adenoma or toxic multinodular goitre, treated with thiamazole. Thyroid function was normalised after 6–10 weeks. Patients were evaluated at time of diagnosis and again after normalisation of thyroid function with appropriate therapy. Serum concentration of free T₃, free T₄, TSH, adiponectin and thrombospondin-1 were measured in all subjects before and after treatment with thiamazole.

Results: There was a significant decrease in free T₃ and free T₄ concentrations (from 8.74±4.79 to 3.54±2.40 pg/ml, and from 4.48±2.21 to 1.02±1.07 ng/ml, P<0.001), for free T₃ and free T₄ respectively. There were, however, no significant differences in adiponectin (30807.3±12996.2 vs 32755.3±16638.8 ng/ml, P=NS) and thrombospondin-1 levels (37400.7±11097.7 vs 40850.7±9426.4 ng/ml, P=NS) between patients evaluated at time of diagnosis and again after normalisation of thyroid function.

Conclusions: Our results suggest that reductions of cardiovascular risk due to immediate effects of treatment of thyrotoxicosis are unlikely to be directly related to changes in serum adiponectin and thrombospondin-1.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.