In this retrospective study we found that switching from glargine to degludec for 12 months in patients with T1D and APS is associated with a decrease in BMI and WC, HbA1c, hypoglycaemic episodes, insulin requirement, improvement of glucose variability and increase in HDL-C, but most of all with an improvement of VAI and FRS. The gene discussed is INS; the disease is type 1 diabetes mellitus.