[One hundred years after the discovery of insulin: a new revolution for patients living with type 1 diabetes?]

The year 2021 saw the 100-year celebration of the discovery of insulin as a treatment for type 1 diabetes, saving lives of people previously condemned by the disease. However, insulin replacement, so different from physiological secretion, remains a challenge. Until the 1990s, people living with type 1 diabetes were treated with two injections of intermediate insulin and prandial regular insulin injections. Their kinetics led to frequent hypoglycemia, justifying meals taken at fixed times, with fixed amount of carbohydrates avoiding fast sugars. The development of rapid and then long acting insulin analogues in the 1990s and 2000s and the principle of patient empowerment have reduced these constraints by introducing the notion of functional insulin therapy, dissociating meals managed by rapid insulins from basal insulin (= insulin for living). Meals can be taken at variable times, with variable carbohydrate content and without food restrictions. But the revolution started 5 years ago, with the development of continuous glucose monitoring systems, freeing the patient from blood glucose controls, coupled thereafter to an insulin pump driven by artificial intelligence in the very recent hybrid closed-loop systems. These systems showed significant glucose control improvement, together with reduction of both the time spent in hypoglycemia and the mental burden on the individual, pending a cure for the disease for the next century.