Intense Diabetes Therapy OK for Brain
Tight Control of Type 1 Diabetes Poses No Risk to Mental Skills
May 2, 2007 -- Intensive treatment of type 1 diabetes doesn't appear to worsen long-term mental skills.
That news comes from a study of more than 1,100 type 1 diabetes patients who were followed for 18 years, on average.
The researchers included Alan Jacobson, MD, who heads the Behavioral and Mental Health Research Section at Boston's Joslin Diabetes Center and is a psychiatry professor at Harvard Medical School.
The study, published in The New England Journal of Medicine, "provides further support for the safety of intensive diabetes therapy," Jacobson says in a Joslin Diabetes Center news release.
Type 1 Diabetes Study
The patients enrolled in the study between 1983 and 1989. At the time, they were 13-39 years old.
First, the patients took tests of memory and other mental skills. Next, they were randomly split into two groups.
One group got intensive treatment. Each of those patients wore an insulin pump or gave themselves at least three daily insulin injections.
For comparison, patients in the other group were assigned to give themselves one or two daily insulin injections.
In 1993, intensive therapy was recommended for all participants, "since it had been shown to be highly effective in reducing long-term complications of diabetes," Jacobson's team writes.
At the time, there was no sign of any negative effects on the patients' mental skills, based on a second round of mental skills tests.
But patients who got intensive treatment were more likely to experience episodes of severe hypoglycemia (low blood sugar) leading to coma or seizure, and the long-term mental effects of those episodes weren't clear. So the researchers extended the follow-up period until 2005, for a total of 18 years.
No Mental Risks Seen
At the end of the 18-year period, the researchers tested the patients' mental skills. Intensive treatment wasn't associated with a substantial decline in test scores.
The patients who got intensive treatment from the study's start weren't more likely to have a big drop in their mental skills test scores during the 18-year period, even though a greater percentage of them (44%) had at least one episode of severe hypoglycemia, compared with 34% of patients who weren't originally assigned to intensive treatment.