New research shows how to keep diabetics safer during sleep

Life with type 1 diabetes requires an astonishing number of health-related decisions – about 180 per day. But patients’ vigilant monitoring of their daytime blood sugar, food intake, insulin and activity levels is perhaps less exhausting than the worries they face about getting a safe night’s sleep. During sleep, diabetics often fail to sense when their blood glucose veers too low. Low blood sugar levels can cause seizures and even, in rare cases, death.

“At night you lose control,” said Bruce Buckingham, MD, a pediatric endocrinologist who treats children with diabetes at Lucile Packard Children’s Hospital Stanford. “It’s when things can happen.” Among children with diabetes, about 75 percent of hypoglycemic seizures occur at night, he said.

That’s why Buckingham and his colleagues across the United States and Canada have been testing various methods to automate blood sugar control during sleep. Our press release on their new research describes an approach that could make a big difference – automated shut-offs of patients’ insulin pumps to keep their sugar levels above the hypoglycemia danger zone:

The new study, which [appeared] online May 7 in Diabetes Care, coupled a glucose sensor worn under the skin to an insulin pump that was connected wirelessly to a computer at the bedside. The computer ran an algorithm that calculated when a low blood-sugar level might occur and then temporarily suspended insulin delivery until the sugar level was trending upward. This occurred without waking the patient. The shutoffs reduced the cumulative time patients spent with low blood sugars during sleep by 81 percent, with only a minimal increase in nighttime glucose levels.

“A system like this should dramatically decrease diabetics’ risk of having a seizure overnight,” said Bruce Buckingham, MD, professor of pediatric endocrinology at Stanford, who led the trial and is a co-author of the study. “Patients and parents will be able to have a better night’s sleep, knowing that there is a much lower risk of severe hypoglycemia at night.”

During the study, the researchers monitored close to 2,000 nights of sleep in 45 people with type 1 diabetes. The patients, who were 15 to 45 years of age, slept in their own homes and didn’t know ahead of time which nights their insulin pumps could be shut off by the computer and which nights their pumps operated normally. Several measures of hypoglycemia indicated that patients were safer on treatment versus control nights. Morning blood sugar levels were slightly higher after treatment nights, but still within the healthy range.

To get a sense of what the results mean for patients and their families, I spoke with Jack Leguria, whose 14-year-old daughter, Rosa, has had type 1 diabetes for almost 10 years. Rosa participated in the second phase of Buckingham’s research, which is now testing whether the benefits his team documented for older teenagers and adults will extend to children as young as 3. Seeing the new technology in action was exciting for Rosa and her parents.

“This is going to be life-altering for us,” Leguria said. “In four years, Rosa will be ready for college. For a child with type 1 diabetes who is not able to recognize low blood sugar at night, that’s a very difficult prospect for us.”

Like most parents whose children have type 1 diabetes, Rosa’s mom and dad regularly get up during the night to check her blood sugar. That’s fine for now, but what happens when she moves away?

“She’s a bright kid,” Leguria said, adding that unlike many parents of teenagers, he has no doubt that his daughter will maintain the grades and motivation to pursue higher education. “But how does she safely live in a dorm or apartment at 19 or 20?”

Buckingham anticipates that getting the method approved by the FDA will take a bit of time – he estimates two years at a minimum.

“But there are no technical hurdles,” he said. “All the technology exists already. This is going to make it much easier for diabetics and parents of children with diabetes to feel more comfortable going to bed at night.”

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A version of this story first appeared on the Scope blog.