Comparison of glycemic variability in Japanese patients with type 1 diabetes receiving insulin degludec versus insulin glargine using continuous glucose monitoring: A randomized, cross-over, pilot study

Abstract Aims To compare glucose variability in patients with type 1 diabetes (T1D) treated with insulin glargine (IGla) versus insulin degludec (IDeg) using continuous glucose monitoring (CGM). Methods Thirteen patients with T1D were randomly assigned to receive IDeg once-daily followed by IGla twice-daily or vice versa. They were evaluated for glucose variability by CGM after >4 weeks of treatment with either insulin, and then were crossed over to the other, and evaluated by CGM after >4 weeks. Results The total daily insulin dose (TDD) (U/kg/day) and the total daily basal insulin dose (U/kg/day) in the patients were significantly lower while taking IDeg than while taking IGla (mean [95% confidence interval] 0.72 [0.61–0.83] vs. 0.76 [0.64–0.88]; P  = 0.001, 0.29 [0.22–0.36] vs. 0.33 [0.26–0.40]; P  = 0.001), although no significant difference was noted in the patients while on IDeg versus while on IGla in 24-h mean glucose and SDs of 24-h glucose. Again, the range of postprandial glucose increase was not significantly different between the meals in the patients while taking IDeg ( P  = 0.288) but significantly different in the patients while taking IGla ( P  = 0.033). Conclusions The use of once-daily IDeg leads not only to similar glycemic control to that seen with twice-daily IGla even in those who received IGla prior to the study, but also to significant decreases in TDD and long-acting basal insulin dose.