Glucagon Delivery System Treats Post-Bariatric Hypoglycemia

A new study describes a closed-loop system that automatically provides patients with an appropriate, as-needed dose of liquid glucagon to treat post-bariatric hypoglycemia (PBH).

Developed by researchers at the Joslin Diabetes Center (Boston, MA, USA) and Harvard University (Cambridge, MA, USA), the system is comprised of a continuous glucose monitor (CGM) device and a patch infusion glucagon pump. A glucose-responsive automated delivery system detects hypoglycemia, which is then mitigated via an algorithmic application that delivers up to two doses of glucagon when triggered. The closed-loop system allows patients to go about their daily activities without the fear of dipping into dangerous hypoglycemia.

In a study of the system that involved 12 patients (mean age 52 years), hypoglycemia was induced in each patient after being hooked up to the system, and the algorithm was allowed to sense impending low blood sugar levels and automatically deliver an appropriate glucagon dose, under supervision by the medical team. The results showed that nadir plasma glucose was higher with glucagon that with placebo and that no rebound hyperglycemia occurred. The study was published on November 12, 2019, in The Journal of Clinical Endocrinology & Metabolism.

“Post-bariatric hypoglycemia is a profoundly life-altering condition for patients. Having unpredictable hypoglycemia that people can't detect is really an unsafe situation. This system provides a way to help individuals keep their glucose in a safe range,” said senior author Mary Elizabeth Patti, MD, of Harvard Medical School and Joslin. “Using the system to detect an upcoming severe low and treat it before it gets unsafe would be so important to improve safety and quality of life of patients with this type of hypoglycemia.”

“The way that we look at it, it is very similar to how in your car, you have an airbag. You don't use that airbag every time that you stop at a traffic light, but when there is a severe event and there's a need to prevent catastrophe, the airbag will be deployed,” said study co-author Eyal Dassau, PhD, director of the Biomedical Systems Engineering Research Group at Harvard. “We employing the same idea for the glucagon system: we detect, we analyze and then we deliver automatically a mini dose of glucagon. You can start with a very low dose of glucagon as it's needed, and add an additional small dose if indicated without overdosing.”

PBH can occur in the context of the dumping syndrome, which can occur postoperatively in up to half of gastric bypass patients with ingestion of simple sugars. Early dumping, a result of rapid emptying of food into the jejunum due to surgically altered anatomy, is characterized by flushing, tachycardia, abdominal pain, and diarrhea. Late dumping occurs after meal ingestion and is a consequence of the brisk insulin response to the hyperglycemia that results from the rapid absorption of simple sugars from the proximal small intestine.

Related Links:
Joslin Diabetes Center
Harvard University