TNF and metabolic acidosis: These changes in thyroid parameters seen in CKD and ESRD patients may be due to alteration in the peripheral type 1,5′-monodeiodination of T4, as a result of increased circulating levels of some inflammatory cytokines such as tumor necrosis factor (TNF)–α and interleukin (IL)-1, metabolic acidosis, reduced levels of plasma protein, effects of drugs and presence of inhibitors of T4 binding to plasma proteins.