This is illustrated in Fig. 1, which shows that, when subjected to an identical glucose-lowering stimulus (a constant low-dose insulin infusion), participants with type 1 diabetes who had undergone 2–6 months of intensive insulin therapy [resulting in a change in HbA1c from 81 ± 12 mmol/mol (9.6 ± 1.1%) to 54 ± 8 mmol/mol (7.1 ± −0.7%] demonstrated markedly suppressed counterregulatory hormonal and symptomatic responses to hypoglycaemia compared with baseline. Here, INS is linked to type 1 diabetes mellitus.