Automated insulin delivery systems for people with diabetes have progressed significantly in recent years, to the point where insulin pumps can coordinate with continuous glucose monitoring (CGM) systems to deliver insulin based on glucose readings throughout much of the day.
These are known as hybrid closed-loop systems — “closed-loop” meaning that glucose levels are regulated automatically at times, and “hybrid” meaning that some manual entering of information at meals is still necessary.
While closed-loop systems have been shown to be safe and effective across most of the Type 1 diabetes population, trials involving very young children have mostly been limited to short time periods and specific, usually supervised, settings.
But in a new study, published in the April 2019 edition of the journal Diabetes Care, researchers looked at unrestricted use of a closed-loop system in young children for weeks on end.
System found safe using different insulin concentrations
Part of the reason the researchers conducted this study was to find out whether the concentration of insulin used in a closed-loop system had any effect on outcomes in young children.
Because very young children with Type 1 diabetes tend to require much less insulin than adults, small differences in how much insulin is delivered can have an outsize effect on their blood glucose levels. For this reason, many doctors recommend using a diluted form of insulin (known as U20) in some young children.
For the study, the researchers tracked 24 children with Type 1 diabetes who ranged from 1 to 7 years old, each of whom used a closed-loop system during two different 21-day periods.
During one of these test periods, each child received standard (U100) insulin. During the other period, diluted (U20) insulin was used. The order of the two periods was random.
The researchers found no significant differences in a variety of measured outcomes between the two concentrations of insulin. This included average glucose levels (144 mg/dl for diluted vs. 148 mg/dl for standard), glucose variability and proportion of time with glucose below 70 mg/dl (4.5 percent for diluted vs. 4.7 percent for standard).
Total daily insulin use didn’t vary based on insulin concentration, and no cases of severe hypoglycemia (low blood glucose) or ketoacidosis occurred.
Age alone no reason to restrict system
The researchers concluded that for very young children, using a closed-loop insulin delivery system full-time for extended periods was “feasible and safe.” Furthermore, there were no benefits from using diluted instead of standard insulin.
Based on these determinations, it’s up to doctors to decide whether a closed-loop system makes sense for an individual child, rather than ruling out the system based on the child’s age alone.
According to the researchers, limitations of this study included its small size, the lack of participants with very low insulin requirements, and the lack of a control group using a different means of insulin delivery. They aim to address these issues in a future follow-up study.
Want to learn more about caring for a child with Type 1 diabetes? Read “Type 1 Diabetes and Sleepovers or Field Trips,” “Writing a Section 504 Plan for Diabetes,” and “Top 10 Tips for Better Blood Glucose Control.”
