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BALTIMORE – With proper supervision, toddlers and preschool children with Type I diabetes can safely and successfully use an external insulin pump rather than multiple daily injections to treat their disease, according to a recent study by Duke University Medical Center researchers. However, the scientists emphasized that further research is necessary before treatment guidelines recommend widespread use of pumps by young children.
Insulin pumps are small beeper-sized machines that infuse programmed amounts of insulin into the body via a catheter placed through the skin. These pumps are sometimes used in adolescents and adults as an alternative to the traditional injection-based treatment of diabetes, but they are rarely used in young children. Typically, diabetes in infants and toddlers is treated with two to four injections of insulin daily. However, multiple insulin injections cannot always stabilize blood glucose, and young children are at high risk for episodes of severe hypoglycemia (low glucose levels). Severe hypoglycemia can, in some cases, result in coma, seizures, learning disabilities and behavioral disorders.
"In young children, food intake and physical activity levels are unpredictable, and it is difficult to administer very low doses of insulin precisely," said Michael Freemark, M.D., chief of the division of pediatric endocrinology and diabetes at Duke. "Moreover, the child is often unable to convey symptoms of low blood glucose to parents and caretakers. These factors make diabetic control exceedingly difficult in this age group and increase the risk of severe hypoglycemia."
Freemark is senior author of the study, which was presented today (May 6) at the 2002 Pediatric Academic Societies' Annual Meeting.
There has been considerable controversy concerning the use of insulin pumps by young children, Freemark said.
"Some suggest that the insulin pump is inappropriate for preschool children because they lack the knowledge, skill and maturity to enable them to manage the essentials of pump therapy," he said.
Freemark and his colleagues, however, reasoned that conscientious parents and caretakers could provide the supervision necessary to use the insulin pump effectively and safely.
The study involved nine children between the ages of 20 and 58 months who had developed Type I diabetes between the ages of 10 and 40 months. After diagnosis, the children were treated with insulin injections for six months to establish baseline levels of their disease before being placed on insulin pumps. Families also received extensive diabetes education, dietary counseling, and training in the use of insulin pumps before the start of the trial.
The children were treated with insulin pumps for seven to 19 months. Throughout the study, parents monitored their children's blood glucose levels at least four times each day.
The effect of pump therapy on diabetic control was assessed through measurements of hemoglobin A1c, frequency and severity of diabetic complications and parental satisfaction. Hemoglobin A1c is a blood test that reflects average blood glucose levels during the previous 60 to 90 days. The normal value for non-diabetic children and adults is 4.3 percent to 6 percent. Before initiating insulin pump therapy, the children in the study averaged 9.5 percent.
"During pump therapy, hemoglobin A1c levels declined in all nine patients. The mean value at the time of the last clinic visit was 7.9 percent," Freemark said. "Importantly, the decrease in HbA1c was achieved with a fivefold decline in the number of episodes of severe hypoglycemia. While on insulin injections, the children averaged 0.52 episodes per month of severe hypoglycemia. After initiation of pump therapy, the frequency of these episodes declined to 0.09 per month."
The frequency of physician or emergency room visits remained the same before and during the use of the insulin pump. The frequency of parental contacts with medical staff, however, declined precipitously after pump therapy began, dropping from one contact every 5.9 days to one contact every 46.3 days by six months into the study.
"In conversations, parents stressed their increasing level of comfort with diabetes management, their sense of improvement in quality of life for all family members and their high levels of satisfaction with pump therapy," Freemark said.
Freemark also noted that during the study there were no changes in growth rates or weight gain, no pump site infections and no episodes of pump failure.
"The improvement in blood glucose concentrations, accompanied by a reduction in the number of episodes of severe hypoglycemia in these children, indicates that diabetic control could be established safely without increasing the risk of seizures or coma," Freemark said. "This is particularly important in young children, as they are at highest risk for cognitive and behavioral deficits following episodes of severe low glucose levels. Our pilot study suggests that insulin pump therapy may provide an effective alternative for selected infants, toddlers and younger children with Type I diabetes."
Freemark cautioned, however, that insulin pump therapy is not suited for all children.
"Continuous insulin administration should not be employed in all toddlers and young children. It requires strong parental motivation, a capacity to understand the technology and to use the pump properly, continuous oversight of the child and pump and frequent blood glucose monitoring," he said.
Joining Freemark in the study, which was funded by Duke, were Duke colleagues Jean Litton, R.N., Alan Rice, M.D., Nancy Friedman, M.D., Jon Oden, M.D., and Mary Lee, M.D.