Serum levels of thyroid hormones in liver diseases

Concentrations of thyroid hormones and thyrotropin (TSH) were measured in sera of clinically euthyroid patients with various liver diseases and compared with normal controls. The mean serum concentration of 3,3',5'-triiodothyronine (reverse T3, rT3) was significantly increased in patients with decompensated liver cirrhosis (p less than 0.01). This increase seemed to be dependent upon the hepatic damage, although it was not significant in patients with acute hepatitis, chronic hepatitis and compensated liver cirrhosis. The mean serum concentration of 3,3',5-triiodothyronine (T3) was significantly decreased in patients with decompensated liver cirrhosis (p less than 0.05). However, in patients with acute hepatitis, chronic hepatitis and compensated liver cirrhosis, the mean concentration of T3 was above the normal. The mean value of rT3/T3 ratios in patients with acute hepatitis, chronic hepatitis and compensated liver cirrhosis were similar to that of normal controls, but in patients with decompensated liver cirrhosis, the mean value of rT3/T3 ratios was markedly higher than that of normal controls. The rT3/T3 ratios have little or no correlation with some standard liver function tests. These results suggest that marked alterations of peripheral conversion of thyroxine (T4) to rT3 or T3 may be found only in a state of decompensated liver cirrhosis among the various liver diseases.