Hyperthyroidism and hepatic dysfunction. A case series analysis.

Liver dysfunction in hyperthyroid patients has not been well characterized. We analyzed the clinical records of 43 patients with hyperthyroidism to define the spectrum of clinical and liver test abnormalities. The patients were divided into three categories: (a) 18 patients with uncomplicated hyperthyroidism (HT) (b) 19 with hyperthyroidism and congestive heart failure (HT/CHF), and (c) 6 with hyperthyroidism and concomitant unrelated liver disease (HT/ULD). Hepatomegaly and/or spenomegaly were noted in 15 of 19 (79%) patients with HT/CHF as compared to 6 of 18 (33%) patients with HT and 3 of 6 (50%) patients with HT/ULD. Four patients with HT/CHF had ascites. Serum aminotransferase levels greater than 250 IU/L were noted in only 1 of 37 (3%) patients without unrelated liver disease. Patients with HT/ULD or HT/CHF had markedly low prothrombin time. Serum bilirubin levels as high as 323 microM were noted in patients with HT. No characteristic liver histology due to hyperthyroidism was noted. Severe liver test abnormalities, including deep jaundice and prolonged prothrombin time, can occur in patients with hyperthyroidism alone or with HT/CHF. This makes the diagnosis of concomitant, unrelated liver disease difficult until the hyperthyroidism has been controlled.