A Case of Type 2 Diabetes Mellitus with Lung Cancer Suffered from Euglycemic Diabetic Ketosis Accompanied by Adrenal Insufficiency after Immune Checkpoint Inhibitors

A 74-year-old patient with type 2 diabetes mellitus received basal-bolus insulin, insulin secretagogues, and sodium glucose transporter 2 (SGLT2) inhibitors. After immune checkpoint inhibitor treatment for lung cancer, he suffered from depressed consciousness with a urinary ketone body (3+). When all hypoglycemic treatments were discontinued, his serum blood glucose remained at 121 mg/dL. He was diagnosed with euglycemic diabetic ketosis. Endocrine loading tests revealed isolated adrenocorticotropic hormone (ACTH) deficiency as an immune-related adverse event. It was suggested that euglycemic diabetic ketosis was induced by the self-suspension of insulin and insulin secretagogues, adrenal insufficiency, SGLT2 inhibitors, and carbohydrate intake shortage.