Purpose: To determine whether the use of continuous subcutaneous glucose monitoring will help in detecting unrecognized nocturnal hypoglycemia and in lowering hemoglobin A1c (HbA1c) levels (without increasing the risk for severe hypoglycemia) in children with type 1 diabetes.
Methods: Eleven children with type 1 diabetes and HbA1c values consistently >8.0% were randomized either to the Continuous Glucose Monitoring System (CGMS) group or to the control group. The CGMS group used 6 3-day sensors within a 30-day period. Both groups self-monitored their blood glucose levels a minimum of 4 times daily. HbA1c levels were measured at the start, at 1-month, and after 3 months of study.
Results: The 5 children using the CGMS had 17 asymptomatic episodes (85%) of glucose levels below 60 mg/dL (3.25 mmol/L) and 3 symptomatic episodes (15%) during the night in the study month. The 6 control children had 4 symptomatic nocturnal low episodes during the month. After the 30-day period of wearing the CGMS, the 5 children had a significantly lower mean HbA1c value compared with their initial value (mean +/- standard error of the mean [SEM] decrease =.36% +/-.07%). The mean decrease for the controls was.2% +/-.2%. After 3 months, 4 of the 5 children who used the CGMS continued to have lower HbA1c values in comparison to their initial values (mean +/- SEM decrease = 1.04% +/-.43%). Three of the 6 control participants also had lower HbA1c values at 3 months (mean +/- SEM decrease for the group =.62% +/-.44%). No severe hypoglycemic events occurred in either the CGMS or the control groups.
Conclusion: In this pilot trial, continuous subcutaneous glucose monitoring was helpful in detecting asymptomatic nocturnal hypoglycemia as well as in lowering HbA1c values without increasing the risk for severe hypoglycemia in children with type 1 diabetes.