ESPE Abstracts

Background: Difficulty of glycemic control varies among subjects with type 1 diabetes (T1D). Influence of residual endogenous insulin detected by serum C-peptide (CPR) levels has noted to be on glycemic control. Flush glucose monitoring (FGM) detects glucose concentration in intercellular fluid (sensor glucose) every 15 minutes to reveal daily glucose profiles.

Aims: We tried to clarify the relationship between serum CPR and the excursion of blood glucose using FGM in Japanese children and adolescents with T1D.

Subjects and methods: Eighteen (male 6: female 12) childhood onset T1D were enrolled at Saitama Medical University Hospital (6–24 years old, median: 12.5 years old). HbA1c, glycated albumin (GA) and CPR of non-fasting blood sample were measured. Sensor glucose values were measured using FreeStyle Libre Pro (Abbott Diabetes Care Inc.). Mean (SGM), standard deviation (SGSD) and coefficient of variation (SGCV=SGSD/SGM) of sensor glucose values were calculated. The subjects were divided into 2 groups of depletion and non-depletion defined at the level CPR ≤0.01 ng/ml. We analyzed the relationship between serum CPR as the objective variable and glycemic control markers (HbA1c, GA, SGM, SGSD and SGCV) using Spearman’s rank correlation coefficient, and compared glycemic control markers between 2 groups using Wilcoxon signed-rank test.

Results: CPR, HbA1c and GA were 0.01–1.51 ng/ml (median 0.01 ng/ml), 7.1–10.4% (54–90 mmol/mol) (median 8.1% (65 mmol/mol)) and 17.9–33.9% (median 24.7%), respectively. SGM, SGSD and SGCV were 174–276 mg/dl (median 224 mg/dl), 78–154 mg/dl (median 96 mg/dl) and SGCV 29–57% (median 45%), respectively. There was a significant inverse correlation between SGCV and casual CPR (ρ=−0.515, P<0.05). However, any other parameter did not show the correlation with serum CPR. SGCV showed significant difference between depletion group (n=12) and non-depletion group (n=6), 42.1% and 48.6% (P=0.02), respectively.

Conclusions: The glycemic excursion in childhood onset T1D was associated with residual endogenous insulin. Non-fasting serum CPR which is simple blood collect test can be a useful marker to estimate the excess excursion of glycemic control in T1D.