Thyroid function changes and cytokine alterations following major surgery

Abstract

To establish whether cytokine release is implicated in thyroid hormone changes during surgical stress we studied 36 adult patients (20 men; mean age +/- SD: 68.5 +/- 10.5 years) undergoing elective major abdominal operations. We measured tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8 and IL-10 and thyrotropin (TSH), free thyroxine (FT(4)) and triiodothyronine (T(3)) before scheduled non-emergency surgery, immediately postoperatively, on the 1st postoperative day (post-1) and on the 2nd postoperative day (post-2). TNF-alpha, IL-6 and IL-8 peaked on day post-1 whereas IL-10 peaked immediately postoperatively. Fourteen of 36 patients had low T(3) levels after surgery, indicating non-thyroidal illness (NTI). Significant negative correlations were noted among TNF-alpha, IL-6 and IL-8 against T(3) and FT(4). Cytokines are responsible, at least in part, for NTI following major operations.