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NCT Number: NCT07006272

Cohort Study to Refine the Positioning of Closed-loop Therapy Versus Islet Transplantation in the Management of Patients With Unstable Type 1 Diabetes

Prospective, multicenter, descriptive cohort (RIPH3 study under the Jardé Act), STABILOOP study aims to describe whether BF may be an appropriate therapeutic option for the cohort of patients who are theoretically candidates for Islet transplantation, by describing Closed-Loop failures at 12 months in patients referred to an expert center for management of unstable diabetes.

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Key information

Conditions

Type 1 Diabetes (T1D) Autoimmune Diseases Diabetes Mellitus Diabetes Mellitus, Type 1 Endocrine System Diseases Glucose Metabolism Disorders Immune System Diseases Metabolic Diseases Nutritional and Metabolic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

HCL - Edouard Herriot Hospital, Lyon, Auvergne-Rhône-Alpes, France

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Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

Type 1 diabetic patients describing:

  • Significant glycaemic variability defined by the presence of one of these 3 criteria: - Standard deviation > 50% of the glycaemic mean or a MAGE index > 60 mg/dL
  • Coefficient of glycaemic variation > 36%
  • LBGI index > 5 or HYPOSCORE > 800
  • This glycaemic variability must be persistent, i.e. persist for more than 12 months despite optimal diabetes management by a multi-professional team. Optimum management involves :
  • Monitoring by a team with expertise in insulin pump and glucose sensor technologies
  • Training patients in functional insulin therapy, intensive self-monitoring of blood glucose levels, and prevention and management of situations where there is a risk of hypoglycaemia
  • Use of pump and glucose sensor therapy, with interruption before hypoglycaemia
  • Reinforced multi-professional support and monitoring, possibly combined with support via telemedicine.
  • This glycaemic variability must be considered as severe, i.e. causing unpredictable clinical and metabolic events that impair quality of life, such as severe, disabling and frequent hypoglycaemia (at least 2 Severe Hypoglycaemia with assistance from a third party in the last 12 months or at least 1 Severe Hypoglycaemia with life-threatening consequences in the last 12 months (coma, convulsions or trauma)) or ketosis ketoacidosis.

Exclusion criteria

  • Patients with type 1 diabetes who do not meet the criteria for islet transplantation
  • Patients already fitted with a closed loop
  • Kidney transplant patients
  • Persons covered by articles L1121-5 to L1121-8 of the CSP (corresponding to all protected persons)
  • Persons opposed to participation in research

Treatment and study plan

Primary outcomes

  1. Describe Closed Loop (CL) failures at 12 months in patients referred to an expert center for management of unstable diabetes.

    Time frame: 12 months

    Proportion of patients on CL who have had in the year following the introduction of CL therapy : at least 2 severe hypoglycaemias (HS) with assistance from a third party or 1 life-threatening HS (coma or convulsion)

Secondary outcomes

  1. Assess quality of glycaemic control in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Quality of glycaemic control for CL & IG patients :

    • Data sensor (TIR-TBR-TAR > Glycaemic Target 70-140 & 70-180), reported as percentage of time.

  2. Assess the variation of the glycaemia management index in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Variation of glycaemia management index for CL & IG patients :

    • Data sensor GMI (%)

  3. Assess glucose variability in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    glucose variability for CL & IG patients :

    • MAGE index

  4. Assess glycaemia variability in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Data sensor Glycaemia variability for CL & IG patients:

    • CV (%)

  5. Assess the level of mean glucose in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Level of blood glucose for CL & IG patients :

    • Data sensor average daily blood glucose

  6. Assess hypoglycemia awareness in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months for 1 year then every 6 months for 3 years

    Hypoglycemia awareness for CL & IG patients :

    • Clarke score every 3 months for 1 year then every 6 months for 3 years

  7. Assess balance between hypoglycaemia and hyperglycaemia in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Balance between hypoglycaemia and hyperglycaemia for CL & IG patients :

    • GRI glycaemic risk index

  8. Assess the evolution of insulin requirement in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Insulin requirement for CL & IG patients :

    • insulin doses (IU/kg/day)

  9. Assess glycaemia stability in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years 1st IG, depending on the date of inclusion in the study.

    Glycaemia stability for CL & IG patients :

    • HbA1c (%)

  10. Assess renal function in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Quality of renal function for CL & IG patients :

    • Creatininaemia (µmol/L) to estimate the glomerular filtration rate (mL/min/1.73m²)

  11. Assess occurence of sever diabetic related events in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    For CL & IG patients :

    • sever hypoglycaemia (with assistance from a third party) / ketosis or ketoacidosis

  12. Assess the level of endogenous production of insulin in patients treated with Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Level of C-peptide for IG patients :

    • Fasting and stimulated C-peptide (nmol/L)

  13. Assess the quality of the Islet Graft (IG)

    Time frame: Before CL initiation or quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after CL initiation or 1st IG, depending on the date of inclusion in the study.

    Quality of islet graft in IG patients :

    • Graft function assessed by IGLS 2.0 score

  14. Assess the antidiabetic management in patients treated with Islet Graft (IG)

    Time frame: Quarterly pre-transplant follow-up, then every 3 months during 2 to 4 follow-up years after 1st IG, depending on the date of inclusion in the study.

    Antidiabetic drug used in IG patients :

    • Presence of antidiabetic drugs other than insulin (metformin, SLGT-2 inhibitor, GLP-1 analogues, DPP4 inhibitor, hypoglycaemic sulphonamides, glinides).

  15. Assessing quality of life related to diabetes disease in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, and at 6, 12 and 24 months after CL/1st IG.

    Describing quality of life questionnaires :

    DQOL (Diabetes Quality of Life Measure), score (0-100), higher scores = better quality of life

  16. Assessing global quality of life in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, and at 6, 12 and 24 months after CL/1st IG.

    Describing quality of life questionnaires :

    EQ-5D-5L (auto assessed health status questionnaire), score (0-1), higher scores = better health status

  17. Assessing diabetes burden (diabetes-related emotional distress) in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, and at 6, 12 and 24 months after CL/1st IG.

    Describing the burden of diabetes/questionnaires :

    T1-DDS (type 1 diabetes distress scale), score (28-168), higher scores = worse outcome

  18. Assessing diabetes burden (fear of hypoglycemia) in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, and at 6, 12 and 24 months after CL/1st IG.

    Describing the burden of diabetes:

    HFS (hypoglycemia fear score), score (0-132), higher scores = worse outcome

  19. Assessing diabetes burden (impact and severity of fatigue) in patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, and at 6, 12 and 24 months after CL/1st IG.

    Describing the burden of diabetes/questionnaires :

    FSS (fatigue severity scale), score (9-63), higher scores = worse outcome

  20. Assess overall patient satisfaction of patients treated with Closed Loop (CL) or Islet Graft (IG)

    Time frame: Before CL/1st IG, then at 6, 12, 24 months post-CL or post 1st IG (or just before a change in treatment modality such as failure of CL or IG)

    Describe patients' overall experience of their treatment modality(ies):

    • DTSQ (diabetes treatment satisfaction questionnaire), score (0-36), higher scores = better treatment satisfaction

  21. Assess overall patient satisfaction of patients treated with Closed Loop (CL)

    Time frame: Before CL/1st IG, then at 6, 12, 24 months post-CL or post 1st IG (or just before a change in treatment modality such as failure of CL or IG)

    Describe patients' overall experience of their treatment modality(ies):

    • INSPIRE questionnaire (insulin dosing systems: perceptions, ideas, reflections, and expectations), score (0-80), higher scores = more positive attitudes or greater perceived benefit/support

  22. Evaluate the clinical course of diabetes treated with Closed Loop (CL) Islet Graft (IG).

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Clinical evolution criteria to be reported (first occurence):

    HS with assistance of a third party, hypoglycaemic comas, convulsions, cardiovascular events (acute coronary syndrome (ACS), stroke, transient ischaemic attack (TIA), amputations, haemorrhage, thrombosis) cancers, ketosis, ketoacidosis, hospitalisations, infections.

    The data collected will be reported according to the CTCAE v6 classification (classification terminology criteria for adverse events).

  23. Identify the factors associated with Closed Loop (CL) treatment failures (hypoglycaemia)

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Identification if the "initial number of HS with assistance from a third party" prior to BF therapy is associated with the failure of BF therapy

  24. Identify the factors associated with Closed Loop (CL) treatment failures (diabetes-related emotional distress)

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Identification if the "initial level of depression/anxiety or distress related to type 1 diabetes (T1-DDS questionnaire)" is associated with the failure of BF therapy

  25. Identify the factors associated with Closed Loop (CL) treatment failures (fear of hypoglycemia)

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Identification if the "initial level of fear of hypoglycaemia (HSF questionnaire)" is associated with the failure of BF therapy

  26. Identify the factors associated with Closed Loop (CL) treatment failures (HbA1c)

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Identification if the "initial level of HbA1 (%)" si associated with the failure of BF therapy

  27. Identify the factors associated with Closed Loop (CL) treatment failures (TBR)

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Identification if the "initial level of % time below 70mg/dL" is associated with the failure of BF therapy

  28. Describe the frequency of occurrence of severe hypoglycaemia with third-party assistance

    Time frame: Throughout the follow-up period (from 2 to 4 years depending on the date of inclusion in the cohort)

    Incidence rate of severe hypoglycaemia with assistance of a third party

  29. Assess the medico-economic impact at 2 years of islet transplantation compared with Closed Loop (CL) therapy from the perspective of the French healthcare system.

    Time frame: At 2 years post-equipment or post-transplant

    The cost differential and the incremental cost-utility ratio (ICUR) will be analysed and expressed as the additional cost per healthy life-year gained with islet transplantation compared with CL therapy.

Study contacts

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

Myriam HADDOUCHE

CONTACT

[email protected]

+33476765509

Sponsors and collaborators

Lead sponsor

University Hospital, Grenoble

Other

Registry information

Acronym: STABILOOP

Important dates

Study start
2025
Primary completion
2030
Study completion
2031
First posted
Jun 5, 2025
Registry last updated
Jul 28, 2025

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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