INS and type 2 diabetes mellitus: Our main findings were (1) almost half of the patients had an HbA1c<48 mmol/mol (<6,5%), and of these 72% (n = 1865, 36% of all patients) were not treated with a glucose-lowering medication and thus did not fulfil the diagnostic criteria of type 2 diabetes; (2) of the patients treated with one or more glucose-lowering medications (often including insulin and/or sulphonylureas), 20% had HbA1c-values below 42 mmol/mol (6%) and 1% had critically low HbA1c values <30 mmol/mol (<4.9%), indicating overtreatment.