Abnormal results of liver function tests in patients with Graves' disease

To determine the frequency of liver dysfunction in patients with hyperthyroidism.

We analyzed the clinical records of 30 consecutive patients with Graves' disease to identify the spectrum of abnormal results of liver function tests. The values for alkaline phosphatase (AP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma -glutamyltransferase (GGT), and total bilirubin were examined.

The frequencies of increased levels of AP, AST, ALT, GGT, and bilirubin in the current study group were similar to but somewhat lower than those reported in previous studies. Of the 30 study patients, 11 (37%) had at least one abnormal result of a liver function test. All 30 patients in the study had determinations of AP (not fractionated), of which 10 values (33%) were above normal (range, 124 to 283 U/L). Of the 30 patients who had determinations of AST, 5 (17%) had increased values that ranged from 36 to 71 U/L. Six of the 23 patients (26%) with determinations of ALT had increased values that ranged from 45 to 157 U/L. Of the 25 patients who had measurements of GGT, 6 had above normal results (range, 69 to 331 U/L). In addition, 2 of the 24 patients (8%) with determinations of total bilirubin had increased levels.

These findings indicate that abnormal results of liver function tests are common in patients with hyperthyroidism and make the diagnosis of concomitant, unrelated liver disease difficult until the euthyroid state has been established.