Changes of HbA1c variability after the switch to a longer-acting insulin analog in people with type 1 diabetes.

This study investigated whether longer-acting basal analogs (insulin degludec and insulin glargine U300) could reduce visit-to-visit hemoglobin A1c (HbA1c) variability in patients with type 1 diabetes. Ninety adults with type 1 diabetes for whom the basal insulin was switched to a longer-acting insulin analog were analyzed retrospectively. The coefficient of variation of HbA1c levels (CV-HbA1c) during the year before and after the switch was compared. The CV-HbA1c after the switch was not significantly different from that before the switch (4.39 ± 2.24% vs 4.25 ± 2.07%; P = 0.506). The linear regression model revealed that CV-HbA1c before the switch was independently associated with the change of CV-HbA1c (regression coefficient per standard deviation = -0.568, P < 0.001), whereas the other variables were not (all P > 0.05). In conclusion, CV-HbA1c remained unchanged after the switch on average, but CV-HbA1c before the switch was associated with the decrease of CV-HbA1c in individuals with type 1 diabetes.