Early detection of thiamine deficiency by non-thyroidal illness syndrome in a hemodialysis patient.

An 88-year-old male patient on maintenance hemodialysis (HD) therapy experienced gradual losses in appetite and liveliness during the course of 1 month. Physical examinations revealed no abnormalities. However, blood testing indicated non-thyroidal illness syndrome (NTIS) typically observed in patients with severe illness, with serum levels of thyroid stimulating hormone, free triiodothyronine, and free thyroxine of 0.17 μIU/mL, < 1.0 pg/mL, and 0.23 ng/dL, respectively. Brain magnetic resonance imaging to exclude the possibility of central hypothyroidism unexpectedly displayed slight abnormalities inside of the thalami that were characteristic of Wernicke's encephalopathy. Additional examination disclosed low serum thiamine of 20 ng/mL. Thiamine injections of 100 mg at every HD treatment rapidly restored his appetite, liveliness, and NTIS findings. HD patients are at a particularly high risk of thiamine deficiency (TD) and associated severe symptoms due to losses of thiamine during HD sessions. However, its non-specific initial symptoms, including decreases in appetite and liveliness, as well as undetectability in routine blood tests complicate early detection, resulting in underdiagnosis and more severe outcomes. In the present case, TD manifested only as non-specific symptoms and was ultimately revealed by the presence of NTIS, which was resolved with thiamine supplementation. Thus, NTIS might assist in the early detection of TD as an initial sign in HD patients.