Effect of Hyperglycemia-Related Acute Metabolic Disturbance on Thyroid Function Parameters in Adults

Non-thyroidal illness (NTI) is a condition in which the hypothalamic-pituitary-thyroid system and thyroid hormone metabolism are abnormal due to non-thyroidal diseases. Although NTI has been reported to occur in hyperglycemic emergencies in children, there have been few studies in adult cases. In this study, we examined adult patients with hyperglycemia regarding the frequency of NTI and its triggers. Adult diabetic patients who were hospitalized for diabetic ketosis (DK), diabetic ketoacidosis (DKA), or hyperglycemic hyperosmolarity syndrome (HHS) were included in the study. Compared with the DK group, the DKA and HHS groups had higher admission blood glucose, Anion Gap, serum osmolality, creatinine, and urea nitrogen, and lower pH and eGFR. The frequency of NTI in the DKA, HHS, and DK groups was 80%, 70%, and 50%, respectively, and thyroid stimulating hormone (TSH) and free thyroxine 3 (FT3) were significantly improved after treatment for hyperglycemia. Multiple regression analysis showed a significant correlation between the decrease in FT3 level and 3-hydroxybutyrate and albumin. Acute metabolic failure associated with hyperglycemia tends to be associated with a high rate of NTI and low FT3 levels at the start of treatment. The data in this study clearly shows that transient NTI is frequently observed in subjects with acute metabolic disorders such as DKA, HHS and DK. In addition, we should bear in mind that thyroid hormone replacement therapy is not necessary in subjects with NTI due to DKA, HHS and DK, especially when overt symptoms of hypothyroidism are not observed.