Sintilimab-related fulminant autoimmune diabetes mellitus manifesting as diabetic ketoacidosis and rare insulin resistance: A case report and literature review

The incidence of immune checkpoint inhibitor (ICI)-induced type 1 diabetes mellitus (ICI-T1DM) has increased as the use of ICIs has increased. Autoimmune ICI-T1DM often presents as diabetic ketoacidosis, resulting from insulin deficiency, among which insulin resistance is extremely rare. Here, we describe a patient with advanced myxoid liposarcoma who developed sintilimab-induced fulminant autoimmune diabetes associated with insulin resistance and metabolic disorders. The patient eventually required the combined use of insulin, metformin, liraglutide, and dapagliflozin to reduce blood glucose due to erratic glycaemic excursions and high insulin requirements during his duration of hospital stay. Metformin, dapagliflozin and liraglutide were discontinued because of weight loss half a year after discharge, and intensive insulin therapy was continued. The patient's blood glucose control was poor, and liraglutide and metformin were then added again, half a year later. Together, metformin, dapagliflozin and liraglutide in combination with insulin may help control blood glucose in ICI-induced DM patients with insulin resistance.