Status of glycemic excursions and hypoglycemia in patients with type 1 diabetes 2 months after first initiation of intermittently scanned continuous glucose monitoring: a pilot study

Objective: To investigate glycemic excursions and changes in time in hypoglycemia (hyT) in Japanese type 1 diabetes (T1D) patients 2 months after the first initiation of intermittently scanned continuous glucose monitoring (isCGM). Methods: We enrolled 15 adult T1D patients on insulin therapy to evaluate changes in the parameters for glycemic excursions 2 months after initiating isCGM by using the Wilcoxon signed-rank test. Binomial logistic regression analyses were also used to identify predictors of hypoglycemia. Results: A total of 14 patients were available for analysis. Median HbA1c decreased significantly from 7.6% (interquartile range, 6.9–8.3%) to 7.2% (6.7–7.8%) (P = 0.047). Mean glucose, standard deviation of glucose, time in range, and time above range were not significantly different from baseline, while time below range (from 2.2 [1.0–6.9] to 5.0 [2.0–10.8]%; P = 0.016), hyT (from 26.8 [14.5–75.5] to 56.8 [21.7–110.9] min/day; P = 0.030), and time in severe hypoglycemia (shT, from 4.3 [0.0–8.9] to 11.0 [0.0–24.3] min/day; P = 0.022) increased significantly. Additionally, shT increased significantly only during daytime. The factor associated with hyT was found to be the reduction in total insulin dose after 2 months. Conclusions: In T1D patients with a median HbA1c of 7.6%, HbA1c was significantly decreased 2 months after initiating isCGM, while hyT increased, particularly during daytime. Study results suggest that a reduction in the total insulin dose of about 0.10 U/kg may be required in some cases. These findings need to be taken into account when initiating isCGM.