Brain May Work Less Efficiently in Kids with Type 1 Diabetes
Children with Type 1 diabetes show subtle but important differences in brain function compared to non-diabetic children, according to a new study led by researchers at the Stanford University School of Medicine.
Type 1 diabetes occurs when the pancreas fails to make insulin, a hormone that helps regulate blood sugar. Patients are given insulin via injections or an insulin pump. But even with treatment, their blood levels of glucose, the main sugar in blood, fluctuate much more than in healthy individuals.
“Our findings suggest that, in children with Type 1 diabetes, the brain isn’t being as efficient as it could,” said Lara Foland-Ross, Ph.D., senior research associate at the Center for Interdisciplinary Brain Sciences Research at Stanford. Foland-Ross shares lead authorship of the paper with Bruce Buckingham, M.D., professor emeritus of pediatrics at Stanford.
“Kids with diabetes have chronic swings in blood-glucose levels, and glucose is important for brain development.”
Brain cells need a steady supply of glucose for fuel. Previous research has shown brain-structure changes and mild performance impairment on cognitive tasks in children with Type 1 diabetes, but the mechanism had never been studied.
“It was important to capture what is going on in the brains of these kids functionally,” she said.
Using functional magnetic resonance imaging (MRI), the researchers found that the brains of diabetic children displayed a set of abnormal brain-activity patterns that has been seen in many other disorders, including cognitive decline in aging, concussion, attention-deficit hyperactivity disorder and multiple sclerosis.
“The takeaway from our study is that, despite a lot of attention from endocrinologists to this group of patients, and real improvements in clinical guidelines, children with diabetes are still at risk of having learning and behavioral issues that are likely associated with their disease,” said the study’s senior author, Allan Reiss, M.D., professor of psychiatry and behavioral sciences at Stanford.
The researchers also found that the abnormal brain-activity patterns were more pronounced in children who had had diabetes longer.
The research team conducted fMRI brain scans on 93 children with Type 1 diabetes recruited at five sites: Nemours Children’s Health System in Jacksonville, Florida; Stanford; Washington University in St Louis; the University of Iowa; and Yale.
An additional 57 children who did not have the condition composed the control group. All participants were 7-14 years old. Standard behavioral and cognitive tests were given to all the children before brain scanning.
In the fMRI scanner, the children performed a cognitive task called “go/no-go”: Different letters of the alphabet were shown in random order, and participants were asked to press a button in response to every letter except “X.” The task is often used in brain-scanning studies to evaluate what is happening in the brain while participants are concentrating.
The results show that, although the children with diabetes performed the task as accurately as those in the control group, their brains were behaving differently. In children with diabetes, the default-mode network, which is the brain’s “idle” system, was not shutting off during the task.
To compensate for the abnormal activation of the default-mode network, the brain’s executive control networks, responsible for aspects of self-regulation and concentration, were working harder than normal in the children with diabetes.
These abnormalities were more pronounced in children who had been diagnosed with diabetes at younger ages, suggesting that the problem may worsen with time.
“The longer the exposure you have to dynamic changes in blood-glucose levels, the greater the alterations in brain function with respect to the default-mode network,” Foland-Ross said. Studies in adults with diabetes suggest that in the later stages of the disease, the brain eventually loses its ability to compensate for this problem, she added.
The findings are published online in the journal PLOS Medicine.
Source: Stanford Medicine