Hybrid closed-loop system boosts time in range for pregnant women with type 1 diabetes
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Key takeaways:
- Use of the CamAPS FX hybrid closed-loop system improved time in range by more than 10 percentage points in AiDAPT.
- Similar glycemic benefits have not been observed with other hybrid closed-loop systems.
Pregnant women with type 1 diabetes achieved a higher time in range and had fewer complications with use of a hybrid closed-loop insulin delivery system compared with continuous glucose monitoring alone, according to a speaker.
As Healio previously reported in the AiDAPT study, pregnant women with type 1 diabetes who used the CamAPS FX (CamDiab) hybrid closed-loop system had a greater increase in time in range than women receiving multiple daily injections or insulin pump therapy plus a CGM. Helen R. Murphy, MB, BCh, BAO, MD, FRACP, professor of medicine at the University of East Anglia and honorary consultant physician at Norfolk & Norwich University Hospital NHS Trust in the U.K., said pregnant women with type 1 diabetes can benefit from the use of hybrid closed-loop therapy, but not all hybrid closed-loop systems may be able to improve glycemic control.
“Hybrid closed-loop, but not just any hybrid closed-loop, specifically only CamAPS FX, should be offered to all women before or during type 1 diabetes pregnancy,” Murphy said during a presentation at the International Conference on Advanced Technologies & Treatments for Diabetes.
Struggles with time in range
The risks for complications that women with type 1 diabetes face during pregnancy are strongly associated their HbA1c level in the first trimester. Data from the National Pregnancy in Diabetes Audit conducted in the U.K. in 2021 and 2022 confirm that women with a higher HbA1c during the first trimester had greater risks for complications such as stillbirth or a serious heart or birth defect.
“If we want to improve pregnancy outcomes across a population, then it is vitally important that we do not just target those who have more optimal glycemic control, we need technologies that can be appliable across a whole population and across all of the maternal glucose categories,” Murphy said.
CGM use is embedded in routine clinical care among pregnant women with type 1 diabetes in the U.K. According to the National Diabetes Audit, 95% of pregnant women with type 1 diabetes used a CGM in 2022. In data from the National Pregnancy in Diabetes Audit reported in The Lancet Diabetes & Endocrinology in 2024, pregnant women who used CGM had improved glucose levels as well as fewer large for gestational age babies, preterm births and neonatal care admissions than women who did not use CGM. Rates of serious adverse pregnancy outcomes such as birth defects, stillbirth and baby deaths were lower among CGM users compared with women not using CGM.
The findings were extremely encouraging, Murphy said, but previous studies have shown that even with CGM use pregnant women with type 1 diabetes struggle to achieve the tight time in range of 63 mg/dL to 140 mg/dL that is recommended during pregnancy, adding that said several factors make glycemic control during pregnancy more difficult.
“During pregnancy, you have changes in insulin sensitivity, you have rising post-meal insulin resistance, we have week-by-week changes, we have day-to-day changes in variability of insulin pharmacokinetics, we have the real fear of hyperglycemia and the consequences it has on the baby, and the huge burden of self-management for women with type 1 diabetes,” Murphy said.
Benefits of hybrid closed-loop
A study published in The New England Journal of Medicine in 2023 showed that hybrid closed-loop insulin delivery could be the solution for boosting time in range among pregnant women with type 1 diabetes. The AiDAPT trial enrolled 124 pregnant women with type 1 diabetes who were receiving intensive insulin therapy and had an HbA1c of 6.5% to 10% at baseline. Women were randomly assigned to use a hybrid closed-loop insulin delivery system consisting of the CamAPS FX smartphone app, the Dana Diabecare RS insulin pump (Sooil) and the Dexcom G6 CGM or a standard care group that used a CGM and received multiple daily insulin injections or insulin pump therapy. The standard care group had all insulin dosing adjustments made by their care team. Time in range of 63 mg/dL to 140 mg/dL from 16 weeks gestation to delivery was the study’s primary endpoint.
Women in the hybrid closed-loop therapy group had an increase in time in range from 48% at baseline to 68% during the trial, whereas the standard care group had a mean time in range increase from 45% at baseline to 56% during the trial. The closed-loop group had a greater increase in time in range compared with the standard care group (adjusted mean difference, 10.5 percentage points; 95% CI, 7-14; P < .001). Murphy said hybrid-closed-loop therapy was associated with a higher time in range at all times of the day, with the greatest difference seen in the early morning hours. The time in range increase was consistent regardless of maternal age, baseline HbA1c and insulin therapy at baseline.
Women receiving hybrid closed-loop therapy also had fewer hypertensive disorders and lower maternal weight gain than those receiving standard care.
Limitations with other systems
Findings from the AiDAPT trial support the use of the CamAPS FX hybrid closed-loop system. However, a more recent study published in Diabetes Technology & Therapeutics in February showed that other hybrid closed-loop systems may not provide the same benefit. The study assessed 124 pregnant women with type 1 diabetes, including 59 who used a commercial hybrid closed-loop system off-label in Spain. Of participants, approximately 80% used the Medtronic 780G, 10% used the Tandem t:slim X2 with Control-IQ and 10% used a Diabeloop hybrid closed-loop system. Of the participants with an early pregnancy HbA1c of more than 6.5%, only 5% achieved a time in range of at least 70%, with maternal gestational weight gain of up to 5.4 kg during pregnancy, and 69% had a large for gestational age infant.
During a Q&A session, Murphy said the reason for the difference in performance between the CamAPS FX system in the AiDAPT trial and the commercially available off-label systems was that the CamAPS algorithm had been adjusted for pregnant women, with lower glucose targets and a uniquely adaptive algorithm based on 15 years of testing and feedback from providers and patients.
“We waited to do the [AiDAPT] trial until we had sensors, pumps and algorithms that were suitable for widespread use across a type 1 diabetes pregnant population,” Murphy said. “It took time, and the sweet spot was there, the algorithm was good enough and the sensors were good enough.”
References:
Lee TTM, et al. N Engl J Med. 2023;doi:10.1056/NEJMoa2303911.
Quirós C, et al. Diabetes Technol Ther. 2024;doi:10.1089/dia.2023.0594.
Scott EM, et al. Lancet Diabetes Endocrinol. 2024;doi:10.1016/S2213-8587(24)00039-1.
Perspective
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The pace of diabetes technology advancement is faster now than ever before. Non-pregnant people living with type 1 diabetes have multiple therapeutic options, including different automated insulin delivery systems.
Murphy’s lecture added excitement to the field by sharing results from the AiDAPT Study where the CamAPS FX system, which has approval for use in pregnancy in some countries, helped participants experience a pregnancy-specific time in range that was 10.5% higher compared to standard of care. This is a high achievement.
Unfortunately, it is still unclear if automated insulin delivery systems that do not have pregnancy-specific glucose targets or algorithms can be beneficial when used off-label during pregnancy, though these are the only devices that many individuals are able to access. Pregnant individuals on non-pregnancy-approved automated insulin delivery systems may decide, along with their health care providers, to continue therapy. Experts suggest this option as helpful for carefully selected individuals, but that it is not a “one size fits all” approach (Szmuliowicz ED, et al. Diabetes Technol Ther. 2023;doi:10.1089/dia.2022.0540).
Three randomized controlled trials of off-label automated insulin delivery systems were recently or will soon be completed (Benhalima K, et al. Lancet Diabetes Endocrinol. 2023;doi:10.1016/S2213-8587(23)00116-X and Polsky S, et al. Diabetes Technol Ther. 2024;doi: 10.1089/dia.2024.0012). Also, a registry in the U.S. will start enrollment in 2024 for individuals with type 1 diabetes using continuous glucose monitoring or automated insulin delivery therapy during gestation. Thus, crucial information on this topic should emerge over the next few years.
In the meantime, it is reassuring to know that the group from AiDAPT and other teams are paying attention to this important area of research.
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Murphy HR. Should everyone with T1D be offered hybrid closed-loop? Presented at: International Conference on Advanced Technologies & Treatments for Diabetes; March 6-9, 2024; Florence, Italy (hybrid meeting).
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