BOSTON – Real-world experience with the Medtronic MiniMed 670G, a hybrid closed-loop insulin delivery system, showed the device was associated with improved average glucose readings and more time in euglycemia in 26 patients with type 1 diabetes.
The findings go beyond the safety data from the clinical trial of the MiniMed 670G system, Kathryn Weaver, MD, of the University of Washington, Seattle, and her colleagues reported in a poster presented at the annual meeting of the American Association of Clinical Endocrinologists.
The clinical trial included a 2-week run-in period during which the system was used in manual mode before it was switched to automated mode. Mean sensor glucose readings for participants went from 150.2 mg/dL during run-in to 150.8 mg/dL at the end of 3 months, which was not a statistically significant difference (JAMA. 2016;316[13]:1407-8).
In the real-world study, average sensor glucose readings dropped from a mean 169.46 mg/dL at baseline to 157.08 mg/dL at the end of the 3-month study period (P = .05). Also, the time spent with blood glucose levels greater than 180 mg/dL fell from 26.5% to 20% (P = .007), while the amount of time with glucose readings between 70 and 180 mg/dL increased from 61.7% to 71.1% (P = .02). Periods of hypoglycemia and severe hypoglycemia were already low at baseline and did not change, Dr. Weaver said.
“It is important to note that the initial pivotal trial was a study designed to evaluate safety not a study designed to evaluate effectiveness. And the [trial] group did demonstrate safety; they had a very significant reduction in the amount of hypoglycemia” with the pump, said Dr. Weaver. “We did not show a significant reduction in hypoglycemia in our [real-world] group, likely because we had a very low rate of hypoglycemia going into the study.”
Two of the study coauthors are employees of Medtronic, which manufactures the MiniMed 670G insulin pump/continuous glucose monitor. Medtronic did not provide funding support for the study or provide the closed-loop systems, and Dr. Weaver reported that she had no relevant financial disclosures.
SOURCE: Weaver K et al. AACE 2018, Abstract 210.