Although national and international groups have published detailed guidelines to improve surgical outcomes in people with diabetes, many people with diabetes are poorly prepared for surgery.6–8 In the European Multicenter Study on Coronary Artery Bypass Grafting (E-CABG) study, 54% of people with type 2 diabetes treated with non-insulin medications and 67% of those with insulin-treated diabetes had an HbA1c above 53 mmol/mol (7.0%) prior to cardiac surgery.5 Here, INS is linked to diabetes mellitus.