Authors: Alper GÜRLEK, Veli ÇOBANKARA, Miyase BAYRAKTAR
Abstract: We investigated liver biochemical tests at diagnosis and after 6-week treatment with propylthiouracil (PTU) in forty-three patients with hyperthyrodism. At diagnosis, 60.5% of the patients had a least one liver biochemical abnormality. Elevation of alkaline phosphatase (ALP), alanine (ALT) and aspartate (AST) aminotransferase, g-glutamyl transpeptidase (GGT) levels were observed in 19 (44.2%), 10 (23.3%), 6 (14%) and 6 (14%) of the patients , respectively. There was no significant correlation between liver biochemical tests and serum thyroxine, triiodothyronine, and thyroid-stimulating hormone levels at diagnosis. Patients with abnormal liver biochemical test(s) were significantly older than those who had normal tests. After 6-week treatment with PTU, seven (16.3%) of the patients developed subclinical hepatotoxicity, as evidenced by elevation of ALT levels despite reductions in serum thyroxine levels. Hyperbilirubinemia was absent in all patients, Age, sex, type of goiter (either diffuse or multinodular) and presence or absence of abnormal liver biochemical tests at the diagnosis were not significant in determining the possibility of the development of PTU-induced hepatotoxicity. These data suggest that liver biochemical test abnormalities are frequently observed in hyperthyroid patients and are not related to thyroid function tests at diagnosis. Furthermore, presence or absence of these abnormalities do not indicate to the development of subclinical hepatoxicity during 6-week PTU therapy.
Keywords: Hyperthyroidism; propylthiouracil; hepatotoxicity; liver biochemical tests.