Bionic Pancreas for Type 1 Diabetes Glycemic Control

Introduction

As a complex metabolic disease, diabetes mellitus does not lend itself to a wide variety of interventions, and curing the disease does not appear to be an event that medicine will see in the near horizon. For these reasons, and because diabetes can be such a devastating condition, research that shows promise of positively impacting its course is greeted with enthusiasm by the medical community and the public alike.

Blood glucose levels must be strictly regulated in order to avoid the complications that diabetes can create. A substantive stumbling block is the difficulty of achieving consistent glycemic control without occurrences of hypoglycemia. Indeed, this factor is a primary obstacle to obtaining regulatory approval of an artificial pancreas. Earlier research focused on automatic systems that monitor glucose levels and stop insulin flow when blood glucose drops too low. While this is a viable approach, it can only limit — but not eliminate — the impact of hypoglycemia.

Dr. Steven Russell at Massachusetts General Hospital is taking a different approach: his research focuses on automated systems that use glucagon to prevent hypoglycemia. The systems Russell is developing combine closed-loop glucagon and closed-loop insulin delivery — in effect, functioning as a bionic pancreas.

The Research

Russell et al. (2014) are conducting a line of research that is receiving considerable attention: automated glycemic management through the use of an automated, wearable "bionic" pancreas. The effectiveness and safety of this type of system has recently been subjected to multiday, random-order, crossover studies. Russell et al. (2014) developed and compared two interventions: (1) glycemic control with a wearable, bihormonal, automated, "bionic" pancreas; and (2) glycemic control with an insulin pump. Over a period of five days, 20 adults and 32 adolescents with type 1 diabetes mellitus participated in the study. The bionic pancreas automatically adapted to the continuous stream of data sent by the glucose monitor in order to control the appropriate delivery of subcutaneous glucagon and insulin.

Results

The wearable, automated, bihormonal bionic pancreas was found to improve mean glycemic levels in both the adults and the adolescents with type 1 diabetes mellitus. In addition, hypoglycemic episodes occurred less frequently than they did with the insulin pump. The specific results for each comparison are presented separately for adults and adolescents below.

Findings for Adults

"[T]he mean plasma glucose level over the 5-day bionic-pancreas period was 138 mg per deciliter (7.7 mmol per liter), and the mean percentage of time with a low glucose level (<70 mg per deciliter [3.9 mmol per liter]) was 4.8%" (Russell et al., 2014). "After 1 day of automatic adaptation by the bionic pancreas, the mean (±SD) glucose level on continuous monitoring was lower than the mean level during the control period (133±13 vs. 159±30 mg per deciliter [7.4±0.7 vs. 8.8±1.7 mmol per liter], P<.001) and the percentage of time with a low glucose reading was lower (4.1% vs. 7.3%, P=0.01)" (Russell et al., 2014).

Findings for Adolescents

"[T]he mean plasma glucose level was also lower during the bionic-pancreas period than during the control period (138±18 vs. 157±27 mg per deciliter [7.7±1.0 vs. 8.7±1.5 mmol per liter], P=0.004), but the percentage of time with a low plasma glucose reading was similar during the two periods (6.1% and 7.6%, respectively; P=0.23)" (Russell et al., 2014). "The mean frequency of interventions for hypoglycemia among the adolescents was lower during the bionic-pancreas period than during the control period (one per 1.6 days vs. one per 0.8 days, P<.001)" (Russell et al., 2014).

References

Progress in artificial pancreas development: Preventing and treating low blood glucose. (2014, September 11). American Diabetes Association. ADA–Novo Nordisk Award in Hypoglycemia and Diabetes. Supported by Novo Nordisk Inc. Retrieved from

Russell, S. J., El-Khatib, F. H., Sinha, M., Magyar, K. L., McKeon, K., Goergen, L. G., Balliero, C., Hillard, M. A., Nathan, D. M., & Damiano, E. R. (2014, July 24). Outpatient glycemic control with a bionic pancreas in type 1 diabetes. New England Journal of Medicine, 371(4), 313–325. doi:10.1056/NEJMoa1314474