BOSTON – A system to detect dropping blood glucose and suspend insulin delivery during sleep is safe and effective in children with type 1 diabetes as young as 4 years, according to results of a randomized controlled trial.
In a presentation to the annual scientific sessions of the American Diabetes Association, Dr. Bruce A. Buckingham of Stanford (Calif.) University showed that the system, which combines glucose monitoring with insulin pump connected wirelessly to a computer by the patient’s bedside, worked nearly as well in children as it had in a previous study enrolling adults (Diabetes Care 2014;37:1885-91).
Dr. Buckingham and his colleagues enrolled 36 children aged 4-10 years and 45 children aged 11-14 years. All the children had type 1 diabetes for a year or more and had been using an insulin pump at least 6 months. The youngsters had hemoglobin A1c levels of 8% or lower, and the investigators confirmed the presence of nighttime hypoglycemia during 2 weeks of pretrial monitoring. The children were then randomized to the active or inactive system for 42 nights, of which 21 were active. Patients were not aware whether the system was active on any given night.
Insulin delivery was suspended when the computer predicted glucose would fall below 80 mg/dL within 30 minutes, to anticipate and prevent further drops to levels of 60 mg/dL or lower that could, if prolonged, trigger a seizure.
Unlike other systems for continuous glucose monitoring that alert patients of dropping glucose, this one used alarms only when levels dropped below 60 mg/dL. More often than not, Dr. Buckingham said, “people do not awaken to alarms.” The idea “is for the system to work in the background – a good night’s sleep without a seizure.”
Dr. Buckingham and his colleagues found that among about 1,900 nights recorded in the 11- to 14-year-old subgroup, the active system reduced the number of nights children’s glucose fell below 60 mg/dL for 2 hours or more from 8% in the control group to 3% in the active system (P < .001). Among about 1,600 nights monitored in the 4- to 10-year-olds, prolonged hypoglycemia was reduced from 5% of nights in the control group to 1% in the active group (P < .001).
Although younger children have a higher risk of fasting ketonemia that can be increased with insulin pump shut-offs, no episodes of ketosis occurred during the study, and there were no seizures.
The National Institute of Diabetes and Digestive and Kidney Diseases funded the study. Dr. Buckingham disclosed advisory or consulting relationships with Medtronic, Sanofi, Novo Nordisk, Tandem, and ConvaTec.