Disclosures: Beck reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
May 24, 2021
3 min read

‘Loop’ artificial pancreas software safe, effective with community support

Disclosures: Beck reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
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The Loop open-source system for a do-it-yourself automated insulin delivery system can be initiated with community-developed resources and used safely and effectively by adults and children with type 1 diabetes, real-world data show.

Roy W. Beck

“This large prospective study of the popular Loop open-source DIY automated insulin delivery system showed that adults and children with type 1 diabetes can successfully initiate the system, use it safely, and improve their glucose control with it,” Roy W. Beck, MD, PhD, president and medical director of the Jaeb Center for Health Research Foundation Inc., told Healio. “This was true even for Loop users whose baseline glucose control was very good, and positive results were seen in spite of the fact that most users relied primarily on community-developed resources to build and operate the system, with limited informal digital resources and support.

Source: Adobe Stock

As Healio previously reported, DIY artificial pancreas systems are considered an off-label use of diabetes devices and are not approved by the FDA. Still, many patients with type 1 diabetes seeking optimal glucose management want to give such systems a try. “Looped,” a Facebook group created in November 2016 designed to make basic, DIY closed-loop technology widely available, currently has more than 22,000 members. Other popular open-source systems include OpenAPS and AndroidAPS.

Real-world, DIY data

In a prospective, real-world observational study, Beck and colleagues analyzed data from 558 adults and children with type 1 diabetes who initiated Loop either on their own or with community-developed resources and provided data for 6 months.

Researchers found that mean time in range, defined as glucose level between 70 mg/dL and 180 mg/dL, increased from 67% at baseline to 73% at 6 months, for a mean change from baseline of 6.6% (95% CI, 5.9-7.4). Time in range increased for adults and children, across the full range of baseline HbA1c, and among participants with both high- and moderate-income levels.

Median time spent in severe hypoglycemia, defined as a glucose level of less than 54 mg/dL, was 0.4% at baseline and fell by a mean of –0.05% (95% CI –0.09 to –0.03). Mean HbA1c was 6.8% at baseline and decreased to 6.5% at 6 months, for a mean difference of –0.33% (95% CI, –0.4 to –0.26).

The incidence rate of reported severe hypoglycemia events was 18.7 per 100 person-years, a reduction from the incidence rate of 181 per 100 person-years during the 3 months before the study. Among the 481 users providing Loop data at 6 months, median continuous glucose monitoring use was 96% and median time Loop modulating basal insulin was at least 83%.

Beck noted that the observational study included a highly motivated population of people with type 1 diabetes, with most having an HbA1c of 7% or lower before starting Loop.

“Most were of high socioeconomic status and were already familiar with CGM and insulin pump devices, likely making it easier to obtain the components and the information needed to build and operate the system successfully,” Beck told Healio. “Therefore, formally evaluating Loop in a more heterogeneous study population would help determine how generalizable these results are to the broader type 1 diabetes community.”

A more accessible ‘Loop’

In June 2019, Healio reported that the nonprofit company Tidepool and Medtronic announced a partnership to create an interoperable automated insulin pump system; Tidepool is currently working to get FDA approval for a version of the Loop software so that it can become more widely accessible and easier to initiate and use.

“Tidepool’s FDA submission is relying on the Loop Observational Study data to support the efficacy and safety of Loop,” Beck said. “There are two interesting points here, which Tidepool is combining in its efforts to bring Tidepool Loop to market. First is the use of real-world study data, as is found in the Loop Observational Study, and second is the growth and popularity of do-it-yourself, open-source programs like Loop in the diabetes community.”

Beck called Tidepool’s work “unique and compelling.”

“Tidepool is combining real-world evidence from an observational study of a do-it-yourself system, building upon the foundation of a popular, community-developed open-source system, and doing so within the context of a regulated environment and their regulatory quality management system,” Beck said.

For more information:

Roy W. Beck, MD, PhD, can be reached at rbeck@jaeb.org.