Technology in Type 1 Diabetes Gets Patients Closer to Targets

Miriam E. Tucker

June 13, 2022

The odds of a person with type 1 diabetes achieving target A1c levels and avoiding severe hypoglycemia increase with greater degrees of automation in the technology they're using, new real-world data show.

Most notably, the likelihood of experiencing a severe hypoglycemic episode in the prior year was more than double for those taking multiple daily injections (MDI) of insulin without use of a continuous glucose monitor (CGM) compared with those using hybrid closed-loop automated insulin delivery, also known as artificial pancreas systems.

"It seems that with each incremental increase in technology you see a decrease in A1c. CGM seems to add that extra jump," said Kellee M. Miller, PhD, MPH, who presented the findings from the T1D Exchange registry at the American Diabetes Association (ADA) 82nd Scientific Sessions.

A "High Tech Savvy" Cohort

Miller noted that the more than 17,000 T1D Exchange participants are "not representative of the general population. It's obviously a very high-tech savvy cohort but it does provide insight into outcomes outside of a clinical study setting."

"Observations from the T1D Exchange patient registry support findings of clinical trials showing glycemic benefit with hybrid-closed loop [artificial pancreas] use," added Miller, director of research & senior epidemiologist at the Jaeb Center for Health Research, Tampa, Florida.

When asked to comment, the initial response of session moderator Diana Isaacs, PharmD, CDCES, of the Cleveland Clinic, Ohio, was, "Wow, we can't let people be on MDI without CGM. That is really scary."

Isaacs said the overall data suggest that "clearly [insulin] pump plus CGM and having the connected superior...compared to MDI, and even MDI plus CGM. So we have to be sure we're offering it to everyone because otherwise there will be much worse outcomes later in life, given the A1c differences. We really need to work to close the gaps in disparities."

Results Mostly Consistent Across Age Groups

The study included a total of 10,653 participants aged 1 to 91 years with type 1 diabetes or their caregivers who completed a baseline questionnaire in 2020-2021. They were categorized into six groups based on their device use:

  1. Hybrid closed-loop (HCL): Systems that semi-automate insulin delivery, including open-source looping, Tandem Control IQ, or Medtronic 770G

  2. Predictive low glucose suspend (PLGS): Systems that shut off the pump to prevent hypoglycemia when the CGM trends downward but don't automate insulin delivery, including Tandem Basal IQ and Medtronic 640G

  3. Insulin pump + CGM: The two separate devices without any communication between them

  4. Insulin pump, no CGM

  5. MDI + CGM

  6. MDI, no CGM  

Participants were an average age of 38 years and had a type 1 diabetes duration of 17 years. Most (69%) were female, 88% were White, and 73% had private health insurance. Overall 71% were using insulin pumps and 86% CGMs.

Among the children (< 13 years), teens (13-17 years), and young adults (18-29 years), about 12% were using HCL, and 40% to 50% were using insulin pump + CGM without automated features. Less than 10% were not using CGMs.

Among the adults aged 30-55 and those aged > 55 years, about 15%-17% were using HCL and about the same proportion were using PLGS. About a third were using pump + CGM and 15% were not using CGM.

A1c Much Lower With the Artificial Pancreas

There were striking differences in mean hemoglobin A1c by device use, particularly in the young age groups. Among those younger than 13 years, the range was from 6.6% for those using HCL to 10.6% for the MDI group.

The A1c levels with MDI weren't quite as high among the adults, 8.4% for ages 30-55 and 7.6% for > 55 years, but with HCL they were much better, at 6.7% for both age groups.

The proportions achieving target A1c levels < 7% followed a similar pattern. For the youngest children, those ranged from 73% with HCL versus just 15% for MDI. For the teens and young adults, 64% and 58%, respectively, reached that goal with HCL versus just 3% of the teens and 14% of the young adults with MDI.

Again, the differences weren't quite as dramatic for the adults but were still significant. About two thirds achieved A1c < 7% with HCL, compared with only about one third with MDI.

Among adults, slightly higher proportions using PLGS achieved A1c < 7% compared with HCL. When asked about that, Isaacs said, "it makes me wonder what system they were using" because one is more likely to exit automode more often. "You have to account for those differences," she commented.

Overall, for the entire cohort, at least 60% with HCL were meeting the A1c target [< 7%], whereas less than 20% of those using no technology were meeting the target.

The data for self-reported severe hypoglycemia were a bit less predictable but still followed similar patterns, with HCL users having the lowest rates. The biggest differential occurred in the young adults, where 20% of HCL users reported having at least one severe hypoglycemia event in the past year compared to 45% with MDI.

Among the adults, the highest proportions reporting having had a severe hypoglycemia episode ranged from 49% to 56% among the MDI and pump-only groups, compared with just 31% and 26% with HCL in those aged 30-55 and > 55 years, respectively.  

T1DX is funded by the Helmsley Charitable Trust. Miller has reported no relevant financial relationships. Isaacs has served as a consultant for LifeScan, Lilly, and Insulet, and a speaker for Dexcom, Medtronic, Abbott, and Novo Nordisk.

ADA 2022 Scientific Sessions. Presented on June 6, 2022. 

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR's Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.

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