Early Detection of Type 1 Diabetes Mellitus Due to Nivolumab by Self-measurement of Urinary Glucose Levels in a 71-year-old Woman

Abstract

A 71-year-old woman with recurrent esophageal cancer was treated with nivolumab. For the early detection of type 1 diabetes caused by immune-related adverse events (irAEs), the patient was instructed to self-measure urinary glucose levels at the start of drug therapy. After 22 courses of treatment, the patient tested positive for urinary glucose and presented to our hospital with fatigue. Laboratory investigations revealed hyperglycemia (blood glucose, 352 mg/dL); however, her glycosylated hemoglobin (HbA1c) level was relatively low at 6.6 %, with no urinary ketones or acidosis. Due to her rapidly rising blood glucose levels, we suspected the development of type 1 diabetes mellitus caused by nivolumab and initiated insulin therapy. Subsequently, the chemotherapy regimen was changed; however, the patient was hospitalized because of diabetic ketoacidosis. Therefore, the patient was diagnosed with type 1 diabetes caused by irAEs due to low C-peptide levels in her blood and urine. At our hospital, we instruct patients to self-monitor their urine glucose levels when they were being treated with immune checkpoint inhibitors. This guidance may help to detect the onset of type 1 diabetes at an early stage and prevent the development severe disease.