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NCT Number: NCT06325202

Closed Loop and Education for Hypoglycemia Awareness Restoration

The purpose of the CLEAR study is to determine the effect on counterregulatory responses (CRR) of intervening (by attempting to strictly avoid hypoglycemia) to improve awareness of hypoglycemic symptoms among adults with type 1 diabetes (T1D) who have impaired awareness of hypoglycemia (IAH). IAH affects 20-25% of adults with T1D, and rises with increasing duration of T1D.

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Key information

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Melbourne, Fitzroy, Victoria, Australia

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About this study

Individuals with IAH exhibit blunted symptomatic and CR hormonal responses to hypoglycemia and, as such, have an impaired ability to respond to hypoglycemia. Thus, rates of severe hypoglycemia are up to 6-fold greater in those affected. Intensive management of T1D is necessary in preventing long-term complications, but can be complicated by recurrent episodes of hypoglycemia which lead to and sustain the CRR deficits of IAH. Technologies such as continuous glucose monitoring (CGM) and hybrid closed-loop (HCL) systems can reduce severe hypoglycemia (and also may reduce IAH) but the ability of technology to reverse impaired CRR (as assessed with experimental hypoglycemia clamp) remains unclear. Behavioral and psycho-educational interventions targeting knowledge/skills gaps, as well as particular cognitions and behaviors driving recurrent hypoglycemia, can also reduce severe hypoglycemia and improve awareness. No studies have compared technology with such behavioral interventions in terms of assessing their impact on IAH or the CRR (as a primary outcome). Unanswered questions include the degree of reduction in hypoglycemia required to restore awareness. Furthermore, participants may respond to different interventions according to their characteristics. For example, it remains unclear whether older individuals benefit from such interventions since they usually are excluded from studies. Therefore, there is an urgent need to determine effective interventions that can reverse IAH in a large representative population of adults with T1D and IAH. The investigators propose to study the effect of specific interventions aimed at restoring

  • the CRR (tested via an experimental hypoglycemia clamp procedure)
  • hypoglycemia awareness (self-reported via the Towler Questionnaire during the experimental hypoglycemia clamp procedure)

The study will use a Sequential Multiple Assignment Randomized Trial (SMART) design. At baseline, all participants who are HCL naïve will be randomized to HCL or Usual Care (UC) plus brief education (My HypoCOMPaSS) with a follow-up of two years. UC will consist of real-time continuous glucose monitoring (CGM) and insulin delivery via pump or multiple daily injections. Participants who fail to increase their CRR at 12 months will be randomized, or assigned, to a second intervention consisting of a small-group educational program focusing on motivations and unhelpful cognitions acting as barriers to hypoglycemia avoidance (HARPdoc). At baseline, all participants who are HCL non-naïve will be randomized to optimized HCL or HCL plus My HypoCOMPaSS; those with non-responsive CRR at 12 months will be randomized to either continue HCL (on the basis they need a longer period to reverse impaired CRR and total symptomatic responses) or to the HARPdoc intervention. Participants randomized to an HCL device are expected to wear the device continually, as well as a CGM. The My HypoCOMPaSS education requires 4-5 hours of training, whereas, the HARPdoc education requires four training sessions of seven hours each during weeks 1,2,3, and 6.

The specific aims and hypotheses are as follows:

Aim 1: To determine the effect on CRR (epinephrine increase ≥ 125 pg/ml over baseline) and total symptom responses (Towler Questionnaire increase ≥ 20% over baseline) during a hyperinsulinemic-hypoglycemic clamp procedure (glucose < 50 mg/dl) after 12 months of HCL versus Usual Care plus My HypoCOMPaSS Educational Intervention among adults with T1D and IAH who have never used HCL therapy previously.

Hypothesis 1: At 12 months, those allocated to Usual Care plus My HypoCOMPaSS will be more likely to have improved CRR and total symptomatic responses than those allocated to HCL.

Aim 2: To determine the effect on CRR and total symptom responses at 12 months of HCL plus My HypoCOMPaSS versus HCL alone among adults with T1D and IAH who are currently using HCL therapy prior to entering the study.

Hypothesis 2: At 12 months, those allocated to HCL plus My HypoCOMPaSS will be more likely to have improved hypoglycemic awareness and improved CRR than those using HCL alone.

Aim 3: To determine the durability of effect over 24 months of the intervention that improves CRR at 12 months among adults with type 1 diabetes and IAH at baseline.

Hypothesis 3: At 24 months, CRR will improve further among those who had restored CRR at 12 months.

Aim 4. To determine the effect on hypoglycemic awareness (Towler Questionnaire increase ≥ 20% over baseline) and CRR (epinephrine increase ≥ 125 pg/ml over baseline) during a hyperinsulinemic hypoglycemic clamp procedure at 24 months of an in-depth educational program (HARPdoc), initiated throughout months 12-24, among adults with T1D and IAH at baseline, for whom the intervention allocated at baseline did not restore CRR at 12 months.

Hypothesis 4: At 24 months, those allocated to HARPdoc for months 12-24 months will be more likely to have improved hypoglycemic awareness and CRR than those who continue with the therapy allocated at baseline.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Clinical diagnosis of type 1 diabetes
  • Gold Score or Clarke Score ≥ 4 (highly associated with IAH)
  • Random non-fasting C-peptide < 200 pmol/L
  • Diabetes duration ≥ 10 years
  • HbA1c < 10.5%
  • Total Daily Insulin Dose of < 1 unit/kg
  • Ability to read and speak English (because validated non-English versions of the cognitive tests and the educational interventions are not available)

Exclusion criteria

  • Medical conditions that limit participation in study activities, as determined by the PI (including but not limited to cognitive dysfunction, reduced hearing, reduced vision, cancer under active treatment, untreated angina, organ failure)
  • Active alcohol or drug abuse (as defined by DSM criteria of either 1) recurrent use of alcohol/drugs resulting in a failure to fulfill major role obligations at work, school, or home, 2) recurrent alcohol/drug use in situations in which it is physically hazardous, or 3) recurrent alcohol or drug-related legal problems)
  • Social determinants of health that limit participation in study activities, as determined by the PI (including but not limited to homelessness, food insecurity, inadequate social support)
  • Seizure disorder unrelated to hypoglycemia associated seizures, unless documented seizure-free for >12 months and on a stable regimen of anti-convulsant therapy
  • Skin conditions that would preclude the use of a CGM
  • Super-physiologic exposure to steroids within one month of enrollment
  • eGFR < 45 mL/min/1.73 m2
  • History of bariatric surgery that irreversibly alters gut innervation and structure
  • Hyper- or hypokalemia (serum potassium >5.5 or <3.5 mmol/L)*
  • Hemoglobin < 10 g/dL*
  • Medical condition that requires intermittent or continuous use of glucocorticoids at greater than physiological replacement doses
  • Pregnancy, plan for pregnancy, or breast feeding
  • Abnormal thyroid function tests of clinical significance, as determined by PI*
  • Liver transaminases > 3 times the upper limit of normal*
  • Hospitalization for mental illness in last year
  • History of adrenalectomy
  • At discretion of the PI, laboratory tests may be repeated once. If the participant is not eligible after the second attempt, then the participant. The participant may be screened again.

Treatment and study plan

Omnipod 5 or Medtronic 780G

Device

Omnipod 5 and Medtronic 780G are hybrid closed loop devices that provide automated insulin delivery.

My HypoCOMPaSS Education

Behavioral

My HypoCOMPaSS is a brief, standardized psycho-educational program delivered in small groups. Facilitated discussions focus on advocating rigorous avoidance of hypoglycemia while maintaining time in target glycemic range.

HARPdoc Education

Behavioral

The HARPdoc program targets cognitions around hypoglycemia that act as barriers to hypoglycemia avoidance and recovery of awareness using motivational and cognitive approaches, delivered by diabetes educators, trained and supported by a clinical psychologist, in small group format.

Primary outcomes

  1. epinephrine (pg/ml)

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    a change in epinephrine (pg/ml) that exceeds 125 pg/ml between (1) 12 months and baseline, and (2) 24 months and baseline

  2. Towler questionnaire

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    the Towler questionnaire consists of 12 questions each on a 0-6 Likert scale; a change in the questionnaire that exceeds 20% between (1) 12 months and baseline, and (2) 24 months and baseline

Secondary outcomes

  1. geometric mean of plasma glucagon

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    geometric mean of plasma glucagon

  2. geometric mean of plasma pancreatic polypeptide

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    geometric mean of plasma pancreatic polypeptide

  3. geometric mean of plasma free fatty acids

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    geometric mean of plasma free fatty acids

  4. glucose infusion rate

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    glucose infusion rate

  5. HbA1c

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    glycated hemoglobin

  6. % of time with sensor hypoglycemia <70 mg/dL

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    % of time with hypoglycemia <70 mg/dL determined from the continuous glucose monitor (CGM) sensor

  7. % of time with sensor hypoglycemia <54 mg/dL

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    % of time with hypoglycemia <54 mg/dL determined from the continuous glucose monitor (CGM) sensor

  8. number of hypoglycemia events

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    number of hypoglycemia events determined from the continuous glucose monitor (CGM) sensor

  9. % time with sensor glucose in range

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    % time with glucose in range determined from the continuous glucose monitor (CGM) sensor

  10. sensor glucose coefficient of variation

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    sensor glucose coefficient of variation determined from the continuous glucose monitor (CGM) sensor

  11. sensor use as the average numbers of days per week

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    sensor use as the average number of days per week determined from the continuous glucose monitor (CGM) sensor

  12. glycemia risk index

    Time frame: measured during the four weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    glycemia risk index determined from the continuous glucose monitor (CGM) sensor

  13. Trail Making Test - Part B

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    amount of time required to complete the Trail Making Test - Part B

  14. Four Choice Reaction Time

    Time frame: measured during the clamp studies at 0 (baseline), 12, and 24 months

    Four Choice Reaction Time, which measures reaction time and motor coordination

  15. sleep duration

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    sleep duration determined from an activity monitor smartwatch

  16. sleep quality

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    sleep quality determined by an activity monitor smartwatch

  17. 24-hour step count

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    24-hour step count determined by an activity monitor smartwatch

  18. exercise bouts

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    exercise bouts determined by an activity monitor smartwatch

  19. resting heart rate

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    resting heart rate determined by an activity monitor smartwatch

  20. heart rate during exercise

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    heart rate during exercise determined by an activity monitor smartwatch

  21. heart rate variability

    Time frame: measured during the two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    heart rate variability determined by an activity monitor smartwatch

  22. Hypo-METRICS questionnaire

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Hypo-METRICS questionnaire, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  23. Hypoglycemic Confidence Scale

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Hypoglycemic Confidence Scale, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia, the range is 0 through 27 and higher scores correspond to higher confidence

  24. Hypoglycemia Fear Survey-II

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Hypoglycemia Fear Survey-II, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  25. Attitudes to Awareness of Hypoglycaemia

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Attitudes to Awareness of Hypoglycaemia, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  26. Type 1 Diabetes Distress Scale

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Type 1 Diabetes Distress Scale, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  27. Diabetes Self-Management Questionnaire

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Diabetes Self-Management Questionnaire, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  28. Diabetes Management Experiences Questionnaire

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    Diabetes Management Experiences Questionnaire, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  29. PROMIS Sleep Disturbance - Short Form 8a

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    PROMIS Sleep Disturbance - Short Form 8a

  30. Hospital Anxiety and Depression Scale

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months, the range is 0 through 42 and higher scores correspond to higher anxiety and depression

    Hospital Anxiety and Depression Scale

  31. 12-Item Hypoglycemia Impact Profile

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    12-Item Hypoglycemia Impact Profile, a Person-Reported Outcome Measure (PROM) specific to hypoglycemia

  32. EQ-5D-5L

    Time frame: measured two weeks prior to each clamp study at 0 (baseline), 12, and 24 months

    EQ-5D-5L, a quality-of-life scale with 5 dimensions

  33. device-related adverse events

    Time frame: throughout the duration of the 24 months of follow-up

    device-related adverse events

  34. severe hypoglycemic events, self-reported on a CLEAR data collection form

    Time frame: throughout the duration of the 24 months of follow-up

    severe hypoglycemic events, self-reported on a CLEAR data collection form

  35. diabetic ketoacidosis (DKA) events

    Time frame: throughout the duration of the 24 months of follow-up

    diabetic ketoacidosis (DKA) events

  36. number of participants with hospitalizations

    Time frame: throughout the duration of the 24 months of follow-up

    number of participants with hospitalizations

  37. number of participants with emergency room (ER) visits

    Time frame: throughout the duration of the 24 months of follow-up

    number of participants with emergency room (ER) visits

  38. major adverse cardiovascular events (MACE)

    Time frame: throughout the duration of the 24 months of follow-up

    major adverse cardiovascular events (MACE)

  39. all-cause mortality

    Time frame: throughout the duration of the 24 months of follow-up

    all-cause mortality

Study contacts

Contact information is provided by the study sponsor or research team.

Abid Kazi, PhD

CONTACT

[email protected]

717-531-0003 ext. 320036

Venus Grella, MPH

CONTACT

[email protected]

717-531-0003 ext. 343413

Sponsors and collaborators

Lead sponsor

Milton S. Hershey Medical Center

Other

Collaborators

  • AdventHealth
  • Jaeb Center for Health Research
  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  • University of California, San Diego
  • University of Kentucky
  • University of Leicester
  • University of Melbourne
  • University of Minnesota
  • University of Pennsylvania
  • University of Sheffield

Registry information

Official study title

Closed Loop and Education for Hypoglycemia Awareness Restoration (CLEAR), Conducted by the Impaired Awareness of Hypoglycemia Consortium (IAHC)

Acronym: CLEAR

Important dates

Study start
2025
Primary completion
2029
Study completion
2029
First posted
Mar 22, 2024
Registry last updated
Mar 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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