GCG and Hyperglycemia: Interestingly, islets isolated from normoglycemic glutamic acid decarboxylase autoantibody (GADA)–positive donors showed preserved stimulation of insulin secretion, but already lost suppression of glucagon secretion by hyperglycemia, supporting a defect in glucose sensing in α-cells at the early stages of islet autoimmunity prior to β-cell destruction (160).