Relationships between serum levels of thyroid hormones and serum concentrations of asymmetric dimethylarginine (ADMA) and N-terminal-pro-B-type natriuretic peptide (NT-proBNP) in patients with Graves' disease.

Endothelial dysfunction as well as abnormal thyroid hormone levels may be responsible for increased cardiovascular risk in Graves' disease (GD). Asymmetric dimethylarginine (ADMA) and N-terminal-pro-B-type natriuretic peptide (NT-proBNP) are new markers of endothelial and myocardial dysfunction, respectively. The purpose of this study was to investigate the relationship among the serum levels of ADMA, NT-proBNP, and thyroid hormones in GD patients. This was a cross-sectional investigation conducted in a university teaching hospital. Two hundred and thirty-nine GD (Female: 182, Male: 57) patients and 81 normal controls were enrolled in this study. Serum levels of ADMA were positively related with FT3 (r = 0.584, P < 0.001), FT4 (r = 0.551, P < 0.001), and TRAb levels (r = 0.502, P < 0.001). Serum NT-proBNP levels were positively associated with FT3 (r = 0.243, P < 0.001) and FT4 levels (r = 0.274, P < 0.001), as well as heart rate (r = 0.271, P < 0.03). The elevation of serum ADMA and NT-proBNP levels were also observed in patients with controlled hyperthyroidism. It is thus concluded that serum ADMA and NT-proBNP levels were increased in GD patients. Future studies may determine the usefulness of these two biomarkers to detect early signs of endothelial dysfunction, vascular stiffness, and fluid volume in GD patients.