Hybrid Closed Loop in High Risk Youth With Type 1 Diabetes
Condition: Type 1 Diabetes
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 1
Study type: Interventional

Summary: 
      The use of insulin pumps and continuous glucose monitors for Type 1 diabetes (T1D) has been
      shown to improve glycemic control while also decreasing the risk for acute and chronic
      complications. Unfortunately, there are vast disparities in access to this technology;
      non-Hispanic black youth with public healthcare insurance are the least likely to have access
      to these technologies. We propose to conduct a non-randomized interrupted time series study
      to assess the impact of hybrid closed loop (HCL) insulin delivery in underserved youths with
      poorly controlled T1D. Patients will complete standard diabetes education before beginning to
      use this technology and will be followed for 6-months after starting HCL to assess its impact
      on glycemic control and health-related quality of life.
    

Detailed description: 
      T1D is among the most common chronic childhood illness, affecting an estimated 1 in 400
      American children.2 The care of children and adolescents with type 1 diabetes aims to
      optimize glycemic control to prevent acute and chronic complications of both hypoglycemia and
      hyperglycemia.

      CGMs are minimally invasive devices that use a subcutaneous sensor to report and record
      changes in interstitial glucose values every 5 minutes to 15 minutes.6 This technology can
      alert patients to hypoglycemia and hyperglycemia and also allows them to make diabetes
      treatment decisions without the need for a confirmatory fingerstick blood glucose level.
      Improvements in the accuracy and usability of CGM, better insurance coverage, and greater
      acceptance by both clinicians and patients have led to dramatic increases in the use of this
      technology over the past decade.1,7-15 In 2011, just 6% of all patients in the United States
      Type 1 Diabetes Exchange (T1DX) registry were using CGM as compared to 27% in the period from
      2016-2018.1 The use of CGM therapy has been associated with decreased hypoglycemia and severe
      hypoglycemia,16,17 improvements in A1c,1 reduced fear of hypoglycemia,18 and improved
      diabetes treatment satisfaction.19 Insulin pump therapy provides a continuous subcutaneous
      infusion of rapid acting insulin that allows for more physiologic insulin delivery as
      compared to multiple daily injection therapy. The use of insulin pump therapy in children
      with T1D has been associated with improved glycemic control, decreased rates of DKA, lower
      risk for microvascular complications, as well as psychosocial benefits.

      Recently, input from CGM has been used to guide automated insulin delivery through insulin
      pumps in what is referred to as HCL insulin delivery. The Control IQ algorithm developed by
      Tandem Diabetes Care, Inc. uses a Dexcom G6 to adjust insulin delivery according to predicted
      glucose levels in 30 minutes to maximize TIR. Control IQ was FDA approved for patients with
      T1D ≥ 14 years of age in December 2019 and for patients ≥ 6 years of age in June 2020. A
      6-month randomized controlled study of the Control IQ algorithm showed improvements in mean
      glucose, TIR, time in hypoglycemia, and time in hyperglycemia.25 Although Control IQ was
      shown to have positive impacts on glycemic control, its impact on those in poor glycemic
      control remains largely unknown. Prior studies included only a selected population: 86% of
      participants were white, 86% of participants had at least a bachelor's degree, 62% had an
      annual household income >$100,000, and the average A1c on enrollment was 7.4 ± 1.0%.

      The increasing use of insulin pumps and continuous glucose monitors (CGM) among people with
      Type 1 diabetes (T1D) has been associated with worsening already existing healthcare
      disparities among people of different races, ethnicities, and socioeconomic statuses. Studies
      have shown that CGM use is more likely among participants with higher household incomes,
      greater levels of parental education, and those with private healthcare insurance.8 The
      disparities in access to these technologies persist even after controlling for these factors,
      which raises concern for clinician bias in prescribing these technologies despite evidence
      from an RCT that CGM use is equally beneficial for children of different racial and ethnic
      groups.26 There has been an ongoing push to better understand the various factors
      contributing to these disparities in access to diabetes technologies.27 Evidence that
      technology use varies according to geographic location speaks to the role of provider
      preference as well as patient socioeconomic status.28 The association between black race and
      higher rates of DKA and mortality in patients with T1D <25 years of age may impact provider
      insulin pump prescribing practices.29 While ongoing work is necessary to better understand
      factors impacting prescribing practices, the addition of data supporting the effectiveness of
      HCL therapy without higher rates of DKA in underserved patients can only help to strengthen
      this argument.

      We aim to explore the effect of HCL insulin therapy with the Control IQ system on glycemic
      control as measured by time in range (TIR) in underserved youths ≥ 6 to < 21 years of age
      with poorly controlled T1D. For the purposes of this study, because of the lowest rates of
      diabetes technology use in this group, underserved patients will be defined as: non-Hispanic
      black with public healthcare insurance being managed with insulin regimens using either NPH
      or sliding scales. Poorly controlled T1D will be defined as: at least two A1c values ≥10% in
      the preceding year. We have specifically chosen these inclusion criteria for the purposes of
      this pilot study because we wish to show the effectiveness of using these technologies in
      patients who are the least likely to have access to diabetes technologies.
    

Intervention name(s): Control IQ
Intervention type(s): Device
Intervention description(s): We aim to conduct a non-randomized prospective interrupted time series pilot study to investigate the effect of HCL insulin delivery on glycemic control in underserved adolescents with poorly controlled T1D.
Intervention model: Single Group Assignment
Intervention model description: non-randomized interrupted time series
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: hybrid closed loop insulin delivery; healthcare disparities; diabetes technology