Some areas of the brain grow more slowly in children with Type 1 diabetes than those without, according to findings published this week in Diabetes. Researchers also found that children with the highest and most variable blood sugar levels had the slowest brain growth.
Glucose, the main form of sugar in our blood, is the brain’s primary fuel, and in Type 1 diabetes, the body loses the ability to produce a key hormone needed to regulate blood sugar levels. Type 1 diabetes treatment for children has often focused on making sure their glucose levels don’t get too low, since very low glucose can quickly put someone into a coma. But it’s emerging that chronically-high sugar is also bad for the brain.
The better the glucose control, the more likely that a child’s brain development will be unimpeded.
The new study, conducted at Stanford and four other universities, tracked brain structure and cognitive function in 144 young children with Type 1 diabetes and a comparison group of 72 children without diabetes over 18 months. MRI scans showed that the brains of both groups of kids were growing, but gray- and white-matter growth was slower in several areas of the brain in the diabetic children.
“These studies provide strong evidence that the developing brain is a vulnerable target for diabetes complications,” the researchers wrote. The affected brain areas have a variety of roles, including visual-spatial processing; auditory, language and object processing; executive function; spatial and working memory; and integration of information from sensory systems.
I asked two of the paper’s Stanford authors for more thoughts about what they found.
“The magnitude of the group differences in brain growth over time was surprising,” said Allan Reiss, MD, the study’s senior author. “I actually thought these differences would be more subtle — they were not.”
Past studies have found cognitive and brain-structure changes associated with diabetes in older patients, but this research stands out because the kids included were so young — at the start of the study, their ages ranged from 4 to just under 10, with an average age of 7 — and because the study had a prospective design, following children forward in time. In addition to examining brain structure, the researchers also tested the kids’ cognitive function with standard tests of IQ, learning and memory, and mood and behavior, among others. They saw no significant differences in cognitive function between the two groups, a finding Reiss said did not surprise him.
“The human brain, and in particular a child's brain, is remarkably resilient and has the capacity for functional compensation in the face of adverse circumstances,” he said. However, he cautioned, with many years of exposure to high and fluctuating glucose levels, this ability to compensate could run out. The children in the new study will be followed for another five years, so researchers will have a chance to see if they develop differences in cognitive function.
What do the findings mean for doctors and parents who care for young children with Type 1 diabetes? Pediatric endocrinologist Bruce Buckingham, MD, the principal investigator for the Stanford arm of the trial, said he hopes that clinicians will realize that hyperglycemia as well as hypoglycemia can be harmful to developing brains.
“It is not easy to manage diabetes in these young children,” Buckingham said. “We need to do the best we can, balancing the risks of both hypo- and hyperglycemia on brain development. We cannot ignore either extreme. We need to work with some of the newer technology such as continuous glucose sensors to try and minimize both the lows and highs.”
“The better the glucose control, the more likely that a child's brain development will be unimpeded,” Reiss concluded.
Previously: Stanford team develops nanotech-based microchip to diagnose Type 1 diabetes, One family’s story caring for their children with Type 1 diabetes and Tips for parents on recognizing and responding to Type 1 diabetes