The landmark Diabetes Control and Complications Trial, which ended in 1993, confirmed the long-held belief of Joslin's founder, Elliott P. Joslin, M.D., that good blood glucose control is necessary to help stave off diabetes-related complications, such as heart disease, blindness and nerve damage. Among the 1,441 people evaluated in the DCCT, about 200 were adolescents. It was not surprising that this small group generally had higher blood glucose levels than the adults.

Now a new study led by Lori Laffel, M.D., M.P.H., and her colleagues in Joslin Diabetes Center's Pediatric, Adolescent and Young Adult Section reveals some good news for youngsters with type 1 diabetes. The study found that adolescents are doing a better job controlling their blood glucose levels than they were previously, thanks in part to tools like insulin pumps and insulin analogs that have become available in recent years. The study appears in the March edition of the Journal of Pediatrics.

"The good news is that we have shown that teens are able to better control diabetes than they were in the DCCT study," said Dr. Laffel, Chief of Joslin Pediatrics, Investigator in the Genetics and Epidemiology Section and Associate Professor of Pediatrics at Harvard Medical School.

The researchers studied more than 400 youth with type 1 diabetes who were ages 8 to 16 years and divided into two groups. The first group of 299 youngsters began being studied in 1997; the second group of 152 began being followed by the researchers in 2002. Each group was followed for a two-year period. As five years separated the two study groups, the researchers were able to track the improvements in control from the first group to the second group.

"We found about 40 percent of the first group were checking their blood glucose at least four times per day, and in the second group, it was 72 percent," Dr. Laffel said. In regard to insulin delivery systems, no patients in the first group were on insulin pumps when they entered the study, compared to 23 percent of the youth in the second group.

The researchers also found fewer hospitalizations, emergency room visits and severe low blood glucose episodes (hypoglycemia) with the second group. Furthermore, they did not see evidence of increased weight gain with the second group, which can be associated with increased intensity of insulin usage.
The improved control paid off for the second group with lower A1C values, which reflect a patient's average blood glucose over several months. The average A1C at the start of the study was 8.7 percent for the first group, compared to 8.4 percent for the second group. Furthermore, only 30 percent of patients in the first group met a target A1C of 8 percent or below, while close to half of the patients in the second group met this goal. "Of course there's still room for improvement. We want to see 100 percent of patients achieving tight control," said Dr. Laffel. "Nonetheless, there was considerable improvement between the two groups," she added.

"While it took the general medical community some time to adopt intensive therapy and to provide patients and families with the skills necessary to carry out tight diabetes control, we at Joslin were quick to translate the DCCT findings to clinical care," Dr. Laffel said. "In Joslin's pediatrics program, about 80 percent of patients were put on insulin analogs early on," she said.

"It's not acceptable that only half the people in the second group reached the A1C target goal. Further technologic advances are still needed. For example, we are excited to be starting two new studies at Joslin evaluating the use of continuous glucose monitoring devices. We hope that this technology will be able to further help our patients achieve