In order to better define the relationship between nocturnal hypoglycemia and awakening from sleep, Bernd Schultes and colleagues studied 16 patients with T1DM and 16 healthy controls in two experimental conditions: (1) insulin-induced hypoglycemia (40 mg/dl) during sleep together with polysomnographic measurements and serial determination of the hormonal counterregulatory response, and (2) the same experimental protocol, but with maintenance of euglycemia. This evidence concerns the gene INS and type 1 diabetes mellitus.