Improvement in Glycemic Control Through Changes in Insulin Regimens: Findings from a Japanese Cohort of Children and Adolescents with Type 1 Diabetes

Objective: Although insulin analogs have dramatically changed diabetes treatment, scarce evidence is available on those effects. We aimed to explore whether glycemic control had improved, the use of insulin analogs had been increased, and hypoglycemic events had decreased over time in Japanese pediatric patients with type 1 diabetes (T1D).

Methods: Glycated hemoglobin A1c (HbA1c) values, proportion of insulin regimens, incidence of severe hypoglycemic events, and pubertal increase in HbA1c were compared in three cohorts of childhood-onset Japanese T1D patients (567 subjects in the 1995 cohort, 754 subjects in the 2000 cohort, and 806 subjects in the 2008 cohort).

Results: Mean HbA1c values tended to decrease [78.5 mmol/mol (9.33%) in the 1995 cohort, 68.2 mmol/mol (8.39%) in the 2000 cohort, and 61.2 mmol/mol (7.75%) in the 2008 cohort; P < .0001]. The proportion of patients who received basal-bolus treatment tended to increase with statistical significance, as did the proportion on insulin analogs. The incidence of severe hypoglycemic events (events/100 patients/y) had decreased (19.1 in the 2000 cohort and 8.7 in the 2008 cohort; P = .02). The pubertal increase in HbA1c tended to decrease [males, 12.0 mmol/mol (1.10%) in 1995, 9.4 mmol/mol (0.85%) in 2008, and 9.4 mmol/mol (0.86%) in 2008; P = .55; females, 14.0 mmol/mol (1.28%) in 1995, 10.3 mmol/mol (0.94%) in 2000, and 4.2 mmol/mol (0.38%) in 2008; P = .0003].

Conclusions: Glycemic control and incidence of severe hypoglycemic events were chronologically improved, especially in female adolescents.