Objective: To use continuous glucose monitoring (CGM) to compare glycemic variability in patients with type 1 diabetes (T1D) treated with insulin degludec (IDeg) versus insulin detemir (IDet).
Methods: Ten patients with T1D were randomly assigned to receive once-daily IDeg, followed by twice-daily IDet, or vice versa. Glucose variability was evaluated by CGM after >4 weeks of the first insulin and again after crossover to the second insulin.
Results: The total daily insulin dose (U/kg/day) and the total daily basal insulin dose (U/kg/day) were significantly lower during treatment with IDeg than with IDet [median (interquartile range): 0.55 (0.54-0.73) vs. 0.64 (0.54-0.83); P = 0.028, 0.24 (0.19-0.36) vs. 0.30 (0.19-0.39); P = 0.027]. The 24-hour mean glucose levels were not significantly different. However, their standard deviation (SD) was significantly smaller during treatments with IDeg than those with IDet [59.5 (39.5-71.0) vs. 72.8 (61.8-92.8); P = 0.008]. Their mean fasting glucose levels and the mean postprandial peak levels after breakfast and after dinner were significantly lower with IDeg.
Conclusions: A CGM-based comparison demonstrated that once-daily IDeg showed fewer glycemic fluctuations than twice-daily IDet. IDeg appears to stabilize blood glucose levels better during both daytime and nighttime (particularly, before and after breakfast) with a lower insulin dosage.
Keywords: Clinical trial; basal-bolus insulin therapy; continuous glucose monitoring; insulin degludec; insulin detemir; type 1 diabetes.