Alterations in circulating thyroid hormones and thyroxine-binding globulin levels during diabetic ketoacidosis

During diabetic ketoacidosis, in 17 adult patients, significant decreases in serum TBG and total T4 levels were observed, without significant alteration of the T4 to TBG binding property. In addition, serum free T4 (FT4) was moderately elevated and the TSH response to TRH was markedly blunted. No correlation, however, was found between TSH blunting and FT4 elevation. Correlation of these serum anomalies required at least 5 days of adequate control of the diabetes. Thus, diabetic ketoacidosis in euthyroid patients is characterized by multiple alterations in thyroid function parameters and caution is recommended in the interpretation of thyroid tests during and in the days following this severe metabolic disorder.