Abnormalities of liver function tests in patients with hyperthyroidism

Chae, Kyung Hoon; Kwon, Dae Soon; Nam, Kwan Woo; Kang, Sun Hyung; Kim, Jeong Il; Heo, Won Seok; Jung, Jae Hoon; Kang, Hyun Mo; Kang, Yoon Sae; Kim, Yeon Soo; Kim, Seok Hyun; Seong, Jae Kyu; Lee, Byung Seok; Lee, Heon Young

Abstract

BACKGROUND: Abnormalities of liver function tests are common in patients with hyperthyroidism and may reflect thyroid hormone status. The aim of our study was to analyze the frequency of abnormal liver function tests in the patients with hyperthyroidism at diagnosis and the association with the thyroid function state after antithyroid therapy.
METHODS
Three hundred seventy eight patients with hyperthyroidism who visited Chungnam National University Hospital from June 2004 to May 2005 and had no other causes for abnormal liver function tests were examined. At diagnosis, 272 of 378 patients had various abnormalities seen on the liver function tests. Among 272 patients, 65 were followed up for liver function tests and were analyzed for sex, age, use of an antithyroid drug, and thyroid function tests after administration of an antithyroid drug. We analyzed the frequency of liver function abnormalities and the relevance between abnormalities of liver function and the thyroid function state.
RESULTS
Abnormalities in AST, ALT, total bilirubin, alkaline phosphatase and GGT were observed in 16.4%, 31.0%, 3.2%, 48.7% and 26.9% of the 378 patients with hyperthyroidism, respectively. The level of alkaline phosphatase was the most common abnormal parameter. After antithyroid therapy, 48 (73.8%) of 65 patients had normalization of their liver function abnormalities. The normalization rate for AST, ALT, alkaline phosphatase and GGT were higher in the euthyroid status group than the sustained hyperthyoid status group. The normalization rate for ALT was significantly higher in the female group than in the male group, but the effect of antithyroid drug use and age on the normalization rate was not statistically significant.
CONCLUSIONS
These findings indicate that abnormalities of liver function tests are common in patients with hyperthyroidism and these abnormalities are strongly associated with thyroid hormone status.