Adjustment of insulin doses when switching from glargine 100 U/ml or detemir to degludec: an observational study

BACKGROUND: Degludec is a long-acting insulin with a longer duration of action and a greater day-to-day reproducibility of absorption in comparison with previous long-acting insulin formulations. The aim is the definition of the change in insulin needs in patients switching from detemir/glargine to degludec in real-life conditions. METHODS: In this retrospective cohort observational study, all outpatients with either type 1 or type 2 diabetes, starting therapy with degludec insulin-after a prior treatment with either detemir or glargine insulin for at least 6 months-were included. RESULTS: The analysis was performed on 266 patients, 172 and 96 with type 1 and type 2 diabetes, respectively. The equations describing the relationship between baseline and follow-up doses of basal insulin (6 months) were Y = 3.39 + 0.78X and Y = 0.44 + 0.69X, in patients receiving detemir/glargine either once or twice daily, respectively (Y = degludec dose at 6 months and X = basal insulin dose at switch). The corresponding equations for prandial insulin doses were y = 1.83 + 0.83*x and y = 2.85 + 0.80*x for those on pre-switch once or twice-daily basal insulin, respectively. In type 2 diabetes, the switch was associated with a reduction of basal insulin doses only in those with a prior twice-daily treatment with basal insulin. The reduction of prandial insulin reached statistical significance only in patients previously treated with basal insulin once daily. CONCLUSIONS: The present results provide a suggestion for a simple method for the adjustment of basal and prandial insulin doses in type 1 diabetic patients, switching from glargine or detemir to degludec.