An experimental three-part wearable device to manage glucose levels outperformed standard monitoring and insulin pump management regimes in adults and adolescents with type 1 diabetes.

This “bionic pancreas,” which consist of a small subcutaneous glucose sensor, automated insulin and glucagon pumps, and a wirelessly connected iPhone with a monitoring app, can correct for blood plasma glucose levels that are too high or too low.

The device kept blood sugar lower and prevented fluctuations better than normal monitoring via stick tests and manual pumps.

“A cure is always the end goal,” said lead developer Dr. Ed Damiano, a biomedical engineer at Boston University in Massachusetts, US who has a son with type 1 diabetes.

“As that goal remains elusive, a truly automated technology, which can consistently and relentlessly keep people healthy and safe from harm of hypoglycemia, would lift an enormous emotional and practical burden from the shoulders of people with type 1 diabetes, including my child and so many others.”

The study included a group of 20 adults (age ≥21) and 32 young people aged 12-21 with at least a 1-year history of type 1 diabetes who were also using insulin-pump therapy. [NEJM 2014; doi:10.1056/NEJMoa1314474]

Patients’ blood plasma glucose levels were closely monitored in person and remotely over two 5-day periods of bionic pancreas intervention and self-management with their own insulin pumps. Daily activities, including food intake and exercise, were unrestricted and patients were encouraged to behave as normal.

Among the adults, there were 37 percent fewer instances of hypoglycemia that required intervention during the bionic pancreas period (43 cases) compared with the control period (68 cases, p=0.15).

Among the adolescents, the instances of hypoglycemia more than halved when patients used the bionic pancreas, with 97 cases compared with 210 cases during the control period (p=0.72).

Mean glucose levels in both groups improved significantly overall and remained more consistent when monitored and controlled by the bionic pancreas compared with the control period (133±13 vs 159±30 mg per dL, p<0.001 in adults; 142±12 vs 158±27 mg per dL, p=0.004 in adolescents). This improved outcome was particularly important through the night, when patients, especially younger patients, are in danger of becoming hypoglycemic.

The most common adverse event associated with bionic pancreas use was nausea and vomiting. Patients using the bionic pancreas still had to perform stick tests to make sure the monitor was accurate.

The researchers noted that the device can overcorrect for glycemic control in patients who are already poorly controlled, although the repercussions of this require more study. The bionic device also requires wireless connectivity but this may be solved in future iterations with a single-unit device.

However, the researchers reported the current prototype was already a more seamless device for type 1 diabetes patients, for whom constant monitoring and manual adjustment of plasma blood glucose can be a heavy burden.

“The performance of our system in both adults and adolescents exceeded our expectations under very challenging real-world conditions,” Damiano said.