Thyroid status in fifty patients with alcoholic cirrhosis

Because the liver is of considerable importance in metabolism of thyroid hormones, plasma levels of thyroxine (T4), triiodotyronine (T3) with their unbound fractions (FT4 and FT3), reverse T3 (rT3)--an inactive isomer of T3-tyrotropin (TSH) and TSH response to thyrotropin releasing hormone (TRH; 250 micrograms i.V.) were determined by radioimmunoassays in 50 clinically euthyroid patients with alcoholic cirrhosis. T4 mean concentration (7.3 micrograms/dl) did not differ from normal values but T3 was decreased (101 vs 154 ng/dl; p less than 0.001) and was correlated with the degree of liver damage appreciated by a clinico-biological index. FT4 was elevated in patients (17.1 vs 13.1 pg/ml; p less than 0.02) although FT3 was slightly decreased (3.4 vs 4.5 pg/ml; p less than 0.10) with an increased FT4: FT3 ratio (7.0 vs 3.0; p less than 0.02). rT3 was elevated (592 vs 206 ng/100 ml; p less than 0.001) and correlated with FT4/FT3: rT3/T3 ratio (p less than 0.01) and with the severity of the cirrhosis. Basal TSH levels (3.3 microU/ml) and TSH responsiveness to TRH was normal though very scattered, and independant from T3 and T4 values. It may be concluded that: 1. euthyroidy in cirrhosis assessed by a normal responsiveness to TRH, results from a compensatory increase in FT4. 2. The low T3 and FT3 levels may proceed from an impairment of peripheral T4 in to T3 conversion with a deviation pathway towards rT3. 3. T3 and rT3 levels provide valuable index of the severity of the cirrhosis.