In a recent trial, a bionic pancreas that automatically delivers insulin proved more effective than pumps or injections at lowering blood glucose levels in people with type 1 diabetes.
Type 1 diabetes is a serious condition that causes a person’s level of glucose, or sugar, to become too high because the pancreas can’t produce enough insulin, a hormone that keeps blood glucose under control. People with type 1 diabetes need to monitor their glucose levels and take insulin every day.
The bionic pancreas, a credit card-sized device called an iLet, monitors a person’s levels around the clock and automatically delivers insulin when needed through a tiny cannula, a thin tube inserted into the body. It is worn constantly, generally on the abdomen. The device determines all insulin doses based on the user’s weight, and the user can’t adjust the doses.
A Harvard Medical School team has submitted its findings from the study, described in the New England Journal of Medicine, to the FDA in the hopes of eventually bringing the product to market in the US. While a team from Boston University and Massachusetts General Hospital first tested the bionic pancreas in 2010, this is the most extensive trial undertaken so far.
The Harvard team, working with other universities, provided 219 people with type 1 diabetes who had used insulin for at least a year with a bionic pancreas device for 13 weeks. The team compared their blood sugar levels with those of 107 diabetic people who used other insulin delivery methods, including injection and insulin pumps, during the same amount of time.
The blood sugar levels of the bionic pancreas group fell from 7.9% to 7.3%, while the standard care group’s levels remained steady at 7.7%. The American Diabetes Association recommends a goal of less than 7.0%, but that’s only met by approximately 20% of people with type 1 diabetes, according to a 2019 study.
Other types of artificial pancreas exist, but they typically require the user to input information before they will deliver insulin, including the amount of carbohydrates they ate in their last meal. Instead, the iLet takes the user’s weight and the type of meal they’re eating, such as breakfast, lunch, or dinner, added by the user via the iLet interface, and it uses an adaptive learning algorithm to deliver insulin automatically.
That means if the person’s glucose levels are too high, the system will adjust itself to provide a higher dose of insulin, and if the levels are too low, it will deliver less.
The device could remove the need for a person with diabetes to calculate the amount of carbohydrates in a meal, which is a significant benefit, says Duane Mellor, the lead for nutrition and evidence-based medicine at Aston Medical School, in Birmingham, UK, who was not involved in the study.
“Being able to take carbohydrate counting out of the equation is a really big advantage, because it’s a burden,” he says. “On the flip side, they have to relinquish control [of determining the insulin dose], which could be difficult for people who’ve had diabetes for a long time.”
The aim of the project is to democratize good glucose control, says Steven Russell, an associate professor of medicine at Harvard Medical School, who led the study.
“There are plenty of people who are struggling right now because they don’t have the right tools, and I think the iLet could help a lot of them have much better glucose control,” he says.
“This will reduce their risk of diabetes complications in the long run, and is also going to make their life easier.”