Chronic kidney disease and hypothyroidism: an update

Abstract

Under normal circumstances, the kidney plays an important role in the metabolism, degradation and excretion of several kinds of thyroxine. Patients with chronic kidney disease (CKD) have an increased risk of hypothyroidism, and most of them are present as subclinical manifestations. Low T3 syndrome is the most common manifestation of patients with CKD, which is characterized by decreased levels of plasma free triiodothyronine (FT3) and total triiodothyronine (TT3), and normal levels of reverse triiodothyroxine (rT3), free thyroid hormone (FT4) and thyroid-stimulating hormone (TSH). Current research results show that low T3 syndrome was initially considered as an adaptive response to chronic diseases. It has been considered to be an important indicator of poor prognosis in patients with CKD. It may cause renal dysfunction and increase the risk of all-cause mortality and risk of cardiovascular diseases in patients with CKD. Thyroxine replacement therapy remains controversial in the treatment of hypothyroidism in patients with CKD. This article focuses on recent advances of mechanisms of increased risk of hypothyroidism in patients with CKD, and roles of hypothyroidism and thyroxine replacement therapy in prognosis of patients with CKD. Key words: Nephrosis, chronic; Thyroxine; Thyrotropin; Thyroxine-binding globulin; Hypothyroidism; Euthyroid sick syndromes