Hyperglycemia in patients treated with immune checkpoint inhibitors: key clinical challenges and multidisciplinary consensus recommendations

Immune checkpoint inhibitors (ICIs) have an expanding role in the management of numerous cancers. Hyperglycaemia is commonly seen in patients treated with ICIs. However, the differential diagnosis for hyperglycaemia is broad, and incorrect diagnosis can have serious consequences. Herein we review the available literature on causes of hyperglycaemia in ICI treated patients and expert guidelines on management and provide an updated synthesis of expert multidisciplinary recommendations. Our key recommendations are as follows: Intensity of screening for hyperglycaemia should be based on a patient's risk level, including assessment of factors such as corticosteroid use, pre-existing diabetes, baseline HbA1c and fasting blood glucose levels (BGL). People with new onset hyperglycaemia should undergo initial assessment to determine severity and aetiology, including bedside capillary BGL, and formal bloods including lipase, C-peptide with matching glucose, electrolytes and renal function and in some cases type 1 diabetes autoantibodies. People with BGL >15mmol/L (or those receiving SGLT2 inhibitors with BGL >10mmol/L) should additionally have ketones measured. Patients with a high risk of diabetic ketoacidosis (BGL>15 mmol/L, ketones >2 mmol/L) and/or risk of hyperosmolar hyperglycaemic state (BGL persistently >20 mmol/L or reading HI') should be referred directly to hospital for emergency assessment and management. Further management of hyperglycaemia should be tailored to the underlying cause(s).