Background: Continuous subcutaneous insulin infusion (CSII) is believed to decrease glycemic variability and clinical hypoglycemia compared with the multiple daily insulin (MDI) regimen. To compare the indices of glycemic instability between CSII and MDI, we analyzed the continuous glucose monitoring system (CGMS) (Medtronic MiniMed, Northridge, CA) profiles of a group of children with type 1 diabetes mellitus with history of frequent blood glucose (BG) fluctuations and hypoglycemia.
Patients and methods: Data from 14 (nine girls, five boys) patients (3.9-16.8 years old) on CSII and 14 age- and sex-matched (nine girls, five boys) patients (3.9-16.0 years old) on MDI with similar glycemic control (hemoglobin A1c: 7.9 +/- 1.0% vs. 7.9 +/- 1.5%) and body mass index (BMI) (20.1 +/- 4.3 vs. 19.9 +/- 4.1 kg/m(2)) were evaluated by the CGMS. Mean BG (MBG), absolute means of daily differences (MODD), mean amplitude of glycemic excursion (MAGE), and number of hypoglycemic events (BG <60 mg/dL) for 48 h were calculated.
Results: The MBG, MODD, MAGE, and number and mean duration of hypoglycemia events in the CSII group were similar to those in the MDI group. The MAGE had an inverse correlation with age (CSII: r (2) = 0.52, P = 0.003; MDI: r (2) = 0.29, P < 0.04) and BMI (CSII: r (2) = 0.38, P < 0.02; MDI: r (2) = 0.71, P < 0.0002). However, there was a positive relationship between MAGE and bolus:basal insulin ratio in the CSII (r (2) = 0.28, P < 0.05) and MDI (r (2) = 0.33, P < 0.03) groups. Also, the MAGE had a positive correlation with frequency of hypoglycemic events in the CSII (r (2) = 0.44, P < 0.01) and MDI (r (2) = 0.35, P < 0.03) groups.
Conclusions: The CSII and MDI regimens in children and adolescents with comparable glycemic control displayed similar patterns of glycemic excursions, implying that factors influencing glycemic instability in pediatric type 1 diabetes mellitus appear to be independent of treatment modality.