Thyroid Hormone Metabolism and Thyroid Diseases in Chronic Renal Failure

Abstract

Patients with ESRD have multiple alterations of thyroid hormone metabolism in the absence of concurrent thyroid disease. These may include elevated basal TSH values, which may transiently increase to greater than 10 mU/liter, blunted TSH response to TRH, diminished or absent TSH diurnal rhythm, altered TSH glycosylation, and impaired TSH and TRH clearance rates. In addition, serum total and free T3 and T4 values may be reduced, free rT3 levels are elevated while total values are normal, serum binding protein concentrations may be altered, and disease-specific inhibitors reduce serum T4 binding. Changes in T4 and T3 transfer, distribution, and metabolism resemble those of other nonthyroidal illnesses, while changes in rT3 metabolism are disease specific. Dialysis therapy minimally affects thyroid hormone metabolism, while zinc and erythropoietin administration may partially reverse thyroid hormone abnormalities. Thyroid hormone metabolism normalizes with renal transplantation; however, glucocorticoid therapy may induce additional changes. ESRD patients may have an increased frequency of goiter, thyroid nodules, thyroid carcinoma, and hypothyroidism. Goiter and hypothyroidism may be induced by iodide excess, due to reduced renal iodide excretion, and may be reversed with iodide restriction in some patients. The increased frequency of thyroid nodules and malignancies in ESRD may relate to secondary hyperparathyroidism. After renal transplantation, the higher frequency of thyroid malignancies may relate to the immunosuppressed state. Clinical symptoms and signs and biochemical features of hypothyroidism and hyperthyroidism may be altered by concurrent ESRD. ESRD patients with hyperthyroidism or follicular neoplasms require reduced dosages of Na 131-I depending upon type, frequency, and duration of dialysis therapy.

Sonographic assessment of thyroid gland in patients with chronic kidney disease undergoing hemodialysis

“…This finding is in agreement with Kaptein EM who reported a higher incidence of diffuse goiter is increased in HD patients, although some studies found no relationship between duration of analysis and morphological changes in the thyroid gland. [21,22] Selma and Emir reported that thyroid volume were increased in HD patients and diffuse goiter is significantly observed more frequent in HD compared to control group (p = .001). [23] These findings supported that the period of HD has a significant impact on thyroid volume and echotexture (p = .001, .00 respectively).…”

Hypothyroidism Induced Severe Rhabdomyolysis in a Hemodialysis Patient

“…Deterioration in kidney functions may lead to important alterations in thyroid functions for which a variety of mechanisms have been suggested [3, 4]. The most common thyroid function abnormality in patients with CKD is euthyroid sick syndrome (i.e., low T3 syndrome) and hypothyroidism frequency of which increases with the severity of CKD [1, 2].…”

“…The most common thyroid function abnormality in patients with CKD is euthyroid sick syndrome (i.e., low T3 syndrome) and hypothyroidism frequency of which increases with the severity of CKD [1, 2]. The frequency of subclinical hyperthyroidism, on the other hand, is the same as the general population [3, 17]. However, there is not enough information about whether to start antithyroid treatment in CKD patients with subclinical hyperthyroidism.…”

Thyroid Storm Masked by Hemodialysis and Glucocorticoid Therapy in a Patient with Rheumatoid Arthritis

“…One was maintenance HD for 4 years. CKD affects both the hypothalamus-pituitary-thyroid axis and peripheral metabolism of thyroid hormones [6, 7]. Serum thyrotropin concentrations are usually normal or elevated, and free and total T3 and T4 concentrations are normal or low in patients with CKD [6].…”

“…CKD affects both the hypothalamus-pituitary-thyroid axis and peripheral metabolism of thyroid hormones [6, 7]. Serum thyrotropin concentrations are usually normal or elevated, and free and total T3 and T4 concentrations are normal or low in patients with CKD [6]. It is possible that some of these patients had impaired renal handling of iodine, resulting in elevation of serum iodine levels with prolongation of the Wolff-Chaikoff effect [7, 8].…”