Total serum thyroxine (T4), total serum triidothyronine (T3), thyrotropin (TSH) and TRH induced TSH release have been measured in 50 clinically euthyroid men with alcoolic cirrhosis and compared to 20 age matched control men in order to determine the thyroid status in cirrhosis. Free serum thyroxin (FT4), free triiodothyronine (FT3) and reverse T3 (rT3), were measured in 34 patients. In these patients, a clinical and biological index was devised to score the severity of the disease. Finally, thyroxine-binding-globulin (TBG) levels were measured in 20 patients. In cirrhotics, the mean total T4 level is normal but the mean T3 level is markedly reduced: FT4 is slightly raised and FT3 is decreased. Serum rT3 levels are often very high and correlated in T3. Basal TSH concentration were slightly significantly higher than normal; the mean magnitude of TSH responses to TRH is comparable to controls but the individual responses are very variable, insufficient or exaggerated, and non correlated with other thyroid function tests. The mean TBG level is also normal and non correlated with total free thyroid hormones. Correlation of thyroid function tests with liver function showed significant correlations between T3, FT3, rT3 or TSH and serum albumin concentration and particularly between T3, rT3 and the clinical and biological index. So the ratio rT3/T3 may be proposed as a valuable index of prognosis and severity of the disease. In conclusion, in alcoholic cirrhosis, thyroid function and regulation are characterized by normal T4 and low T3 levels related to reduced extrathyroidal T4 and T3 conversion levels - and thus maintain the euthyroid state - and by a hypothalamo-pituitary dysfunction. These alterations are related to the degree of liver dysfunction.
In common forms of hyperthyroidism serum levels of triiodothyronin (T3) are higher than those of thyroxin (T4) and isolated elevations of serum T3 have even been noted. We report 9 cases of proven hyperthyroidism with normal or low levels of T3 and elevated T4 and reverse T3 (rT3). Most out of the patients were more than seventy years old and had associated diseases. Our data show that the low T3 with elevated rT3 syndrome--which has been noted in many metabolic and pathologic conditions--can coexist in hyperthyroidism. They emphasize the lack of diagnostic discrimination of T3 assays in thyroid dysfunction especially in the older patient or one with associated disease.