[Alterations in thyroid hormones and thyrotropin response to TRH in cirrhotic patients with or without hyperammonemia...

Serum concentrations of thyroid hormones and TSH response to TRH are studied in normal controls and in patients with liver cirrhosis. T3 levels are significantly diminished in the cirrhotic group while the mean total T4 concentration, the basal TSH and the magnitude of the peak response to TRH are similar in cirrhotic and control patients. However when the cirrhotic patients are separated in two groups according to the level of arterial ammonemia, it appears that the group with hyperammonemia (n = 10) has a significantly higher peak response than the control group. Since hyperammonemia is a wittness of hepatic encephalopathy it is suggested that TSH release or synthesis may be modified by this situation resulting from a cerebral accumulation of false neurotransmitters and a depletion of aminergic mediators.