The Relationship of Thyroid and Kidney Health Issues
Thyroid hormones are essential for an adequate growth and development of the kidney. Conversely, the kidney is not only an organ for metabolism and elimination of thyroid hormones, but also a target organ of some of the iodothyronines actions. Thyroid dysfunction causes remarkable changes in glomerular and tubular functions and hydroelectrolitic metabolism. Hypothyroidism is accompanied by a decrease in glomerular filtration, hyponatremia, and an alteration of the ability for water excretion. Excessive levels of thyroid hormones generate an increase in glomerular filtration rate and renal plasma flow. Renal disease, in turn, leads to significant changes in thyroid function. The association of different types of glomerulopathies with both hyper- and hypofunction of the thyroid has been reported. Less frequently, tubulointerstitial disease has been associated with functional thyroid disorders. Nephrotic syndrome is accompanied by changes in the concentrations of thyroid hormones due primarily to loss of protein in the urine. Acute renal failure and chronic renal disease are accompanied by notable effects on the hypothalamus-pituitary-thyroid axis. The secretion of pituitary thyrotropin (TSH) is impaired in uremia. Contrary to other non-thyroidal chronic disease, in uremic patients it is not unusual the sick euthyroid syndrome with low serum triiodothyronine (T3) without elevation of reverse T3 (rT3). Some authors have reported associations between thyroid cancer and kidney tumors and each of these organs can develop metastases in the other. Finally, data from recent research suggest that thyroid hormones, especially T3, can be considered as a marker for survival in patients with kidney disease.
Iglesias P & Díez JJ. THYROID DYSFUNCTION AND KIDNEY DISEASE. Eur J Endocrinol. 2008 December Dept of Endocrinology, Ramon y Cajal, Segovia, Spain.