"Post-bariatric hypoglycemia is a profoundly life-altering condition for patients. Having unpredictable hypoglycemia that people cannot detect is really an unsafe situation," says Mary Elizabeth Patti, M.D., Associate Professor of Medicine at Harvard Medical School, Investigator at Joslin, and senior author on the paper. "This system provides a way to help individuals keep their glucose in a safe range."
Over two hundred thousand people in the United States have bariatric surgery each year. Some types of these surgeries not only shrink the size of the stomach, but also change the way food travels through the intestines. As a result, high levels of certain hormones are released from the intestine after eating, and these hormones increase insulin production. In some patients, the surgery can trigger the body to over-produce insulin, leading to sharp drops in blood glucose levels.
Current treatments for post-bariatric hypoglycemia include strictly regulated meal plans, and medications to reduce insulin production after meals. Once a low blood glucose develops, patients have to consume sugar. If the patient has lost consciousness, a family member may have to administer an emergency dose of glucagon, a medication that increases glucose. These treatments, however, are frequently not sufficient on their own and may lead to unhealthy swings in blood sugar.
"This new automated glucagon delivery system is an important development because it helps protect these patients from developing undetected or difficult to treat low blood sugars," says Christopher Mulla, MD, first author on the study. "Glucagon provides patients with a treatment that does not involve eating, which they are often afraid of doing, and it does not cause rebound high blood sugars, which can then trigger another low blood sugar."
The system grew from a collaboration between clinical and computational scientists at Joslin Diabetes Center and Harvard John A. Paulson School of Engineering and Applied Sciences. Work on this system began about four years ago, when Dr. Patti realized that artificial pancreas algorithms which had been developed to treat diabetes by study co-senior author Dr. Eyal Dassau, Director, Biomedical Systems Engineering Research Group at the Harvard John A. Paulson School of Engineering and Applied Sciences and his team, could similarly be developed to detect, treat, and prevent severe hypoglycemia.
The team tested whether a glucagon pump and CGM could communicate to provide an adequate dose of glucagon to treat an impending low. During this first phase, glucagon doses were administered by the study physicians. In this newly published paper, the team closed the loop and allowed Dr. Dassau's algorithm to sense impending low blood sugar levels and automatically deliver an appropriate glucagon dose under supervision by the medical team.
MEDICA-tradefair.com; Source: Joslin Diabetes Center