How People with Type 1 Diabetes Think When Their Blood Sugar Levels Change

Variations in blood sugar levels can have a variety of effects on thinking abilities in individuals with type 1 diabetes, according to recent research.

Researchers focused on two areas in particular: attention and cognitive processing speed, which measures how quickly people receive new information.

“Our results demonstrate that people can differ a lot from one another in how their brains are impacted by glucose,” said study co-senior author Laura Germine.

“We found that minimizing glucose fluctuations in daily life is important for optimizing processing speed, and this is especially true for people who are older or have other diabetes-related health conditions,” Germine said.

She is the director of the Brain and Cognitive Health Technology Laboratory at Boston’s McLean Hospital.

The researchers note that it has long been recognized that individuals with type 1 diabetes may experience cognitive impairments due to significant fluctuations in blood sugar levels. However, how much of this occurs and does it vary from person to person?

They employed smartphone-based cognitive tests and wearable digital glucose sensors to gather data on 200 type 1 diabetics as they went about their daily lives.

Every five minutes for fifteen days, the sensors were used to gather data on each subject’s blood sugar levels. The cognitive tests were finished by the participants three times a day.

The Boston researchers discovered that whether blood sugar levels were extremely high or very low, cognitive abilities decreased as predicted. But only in terms of processing speed—not attention—were decreases noted.

They postulated that while attention may only be influenced by longer-term highs or lows in blood sugar, processing speeds may respond to rapid, moment-to-moment variations in blood sugar.

The researchers also discovered that some type 1 diabetes patients were far more susceptible than others to the impact of glucose levels on brain function, such as elderly persons or people with specific medical conditions.

The results were released in the journal npj Digital Medicine on March 18.

Lead author of the study Zoë Hawks stated in a McLean Hospital news release that “our research shows that it is important to consider not only how people are similar, but also how they differ in trying to understand how diabetes impacts the brain.” She works at McLean as a research investigator.

One unexpected conclusion was that people with type 1 diabetes typically performed at their best intellectually when their blood sugar levels were marginally above normal.

“People with diabetes frequently report feeling better at a glucose level that is higher than what is considered healthy,” said co-senior study author Naomi Chaytor, a Washington State University medical professor. “This was an important finding.”

“It could be that your brain habituates to a glucose level that it is used to,” she added. “So, a next step in this research is to see whether the glucose level associated with peak performance shifts down into the normal range when the amount of time spent above range is reduced.”