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

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. 13 patients with T1D were randomly assigned to receive IDeg once-daily followed by IGla twicedaily 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 twicedaily IGla even in those who received IGla prior to the study, but also to significant decreases in TDD and longacting basal insulin dose.