Endocrine Abstracts

In terms of mechanism by which thyroid diseases lead the endothelial dysfunction, several aspects have been taking into consideration. One potential factor may be variation in plasma asymmetric dimethylarginine (ADMA) levels. ADMA, which is derived from the catabolism of proteins containing methylated arginine residues, competitively inhibits NOS. The relationship between thyroid disease and variation in plasma ADMA levels is still a potential research area. The aim of this study was to investigate the plasma ADMA levels in patients with thyroid dysfunctions. Three groups (25 healthy subjects, 25 hyperthyroid and 23 hypothyroid subjects) were studied. Concentrations of plasma ADMA were measured by high-performance liquid chromatography (HPLC).

Comparisons of multiple means were made by ANOVA followed by a Fisher’s protected least significant difference test. Probability values of P<0.05 denote statistical significance.

Plazma ADMA levels were significantly higher in both patients with hyperthyroidism (0.890±0.284 μmol/L) and hypothyroidism (0.665±0.364 μmol/L) than control subjects (0.403±0.077 μmol/L).

In conclusion, thyroid dysfunctions increased the ADMA concentration and increased ADMA levels may be one of the potential factor for developing of endothelial dysfunction in both hyper and hypothyroidism.