Clinical Evaluation of Thyroid Functions in Chronic Hemodialysis Patients

Abstract

In order to obtain more precise information on thyroid functions in renal failure, attempts were made to analyze the Hypothalamo-hypophyseal axis in the regulation of thyroid function. TRH levels and other thyroidal function tests were carried out on sera and urine from patients with renal failure and thyroid diseases. Analysis of TRH in serum and urine was performed by mass fragmentography using a GC-MS combined method.
Fifteen out of 28 patients had enlarged thyroid glands, goiter in high prevalence. Thyroid function studies showed low serum thyroxine and triiodothyronine, and high serum thyrotropic hormone levels. Serum and urinary TRH in chronic renal failure were strikingly higher than the other thyroid diseases.
There were negative correlations between RIA-T₃, Resomat-T₄ and serum and urinary TRH levels respectively. There was a negative correlation between serum TSH and serum TRH, but no significant correlation was noticed between serum TSH and urinary TRH levels. There was a high positive correlation between serum TRH and urinary TRH levels.
From these findings, it is thought that serum and urinary TRH level values are a more reliable index for the clinical evaluation of thyroid functions in renal failure than the other sample under laboratory data. In patients with chronic hemodialysis, the prevalence of goiter is relatively high, and their thyroid functions are abnormal. However, the cause of the abnormalities is not clear. It is postulated that the possibility of a breakdown of compensation in the Hypothalamo-hypophyseal axis for the regulation of the thyroid function may be seen in chronic renal failure.