Endocrine Abstracts

Graves’ disease and type 1 DM (T1DM) both have an autoimmune aetiology. Also, Thyrotoxicosis (TT) has previously been described as a possible precipitant of diabetic ketoacidosis (DKA) in patients with T1DM. Due to the similarities in their clinical presentation, DKA can mask the diagnosis of TT and vice versa. We report two cases of the simultenous presentation of thyrotoxicosis and diabetic keto-acidosis in two previously healthy men. Case 1: A 27-year-old man with no history of any disease presented to the emergency department (ED) with unintentional weight loss of 15 kg in 1 month, excessive sweating, abdominal pain, anxiety and tremors of the extremities. On examination, the patient appeared anxious, dehydrated. Blood pression was 107/68 mmHg and heart rate at 98 beats/min. He had palpable goitre. Investigations revealed that HbA1c was 10.7%, blood glucose was 19 mmol/l with 3+ ketonuria and compensated mild acidosis. Thyroid function test revealed TSH (0.01 mIU/L), free T4 (35 pmol/L). Thyroid scintigraphy revealed a diffuse hypercaptating goiter. Both anti-GAD and anti-TSH receptor antibody were positives. The patient was managed with carefully administered intravenous fluids, intravenous insulin and electrolyte replacement. After resolution of DKA, the patient was transitioned to subcutaneously administered insulin and Carbimazole 20 mg was added. Case 2: A 24-year-old man with familial history hashimoto’s disease presented to the emergency department (ED) with unintentional weight loss of 14 kg in 6 months, excessive sweating and palpitations. On examination, Blood pression was 121/64 mmHg and heart rate at 104 beats/min. He had palpable goitre. Investigations revealed that HbA1c was 14.9 %, blood glucose was 19 mmol/l with 2+ ketonuria and compensated mild acidosis. Thyroid function test revealed TSH (0.006 mIU/L), free T4 (57 pmol/L). Thyroid scintigraphy revealed a diffuse hypercaptating goiter. The patient was managed with carefully administered intravenous fluids, intravenous insulin and electrolyte replacement. After resolution of DKA, the patient was transitioned to subcutaneously administered insulin and Carbimazole 30 mg was added.

Discussion: Thyroid hormones affect glucose metabolism at the cellular level by causing insulin resistance, upregulating glucose production by glycolysis and gluconeogenesis pathways and increasing gut absorption of glucose. Thyroxine also decreases serum insulin levels by increasing renal excretion. The resulting state of insulinopenia and insulin resistance causes disinhibition of hormone-sensitive lipase. This leads to unchecked lipolysis and fatty acid oxidation with increased ketones production.