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Closing the Loop for 36 Hours in Adolescents With Type 1 Diabetes: Evaluation of Reduced Meal Bolusing

This study has been completed.
Sponsor:
Collaborator:
Cambridge University Hospitals NHS Foundation Trust
Information provided by (Responsible Party):
Dr Roman Hovorka, University of Cambridge
ClinicalTrials.gov Identifier:
NCT01629251
First received: April 5, 2011
Last updated: June 25, 2012
Last verified: June 2012
History of Changes
  Purpose

The main focus of our research is the development of a closed-loop system for glucose control in people with type 1 diabetes. After having demonstrated the safety and efficacy of overnight closed-loop insulin delivery, we are extending the evaluation of closed-loop to the daytime. Meal-related insulin dosing can be challenging and prandial insulin overdosing can be associated with the occurrence of postprandial hypoglycaemia, thus representing a confounding factor of hypoglycaemia free glucose control during the day. A further investigation is needed to evaluate alternative strategies for prandial insulin dosing. We will study eight adolescents with type 1 diabetes during closed-loop insulin delivery combined with either standard or reduced insulin doses with the meals, in a randomised crossover design. Stable glucose isotopes will be administered to collect data for modelling of glucose turnover around the meals, during daily activities and overnight.

The information provided by the use of glucose isotopes would be very helpful to increase our understanding of the physiology of glucose turnover and to facilitate the development of an improved control algorithm. Ultimately this study will help with the development of a closed-loop system to match insulin infusions to change in glucose levels in real life conditions.


Condition Intervention Phase
Type 1 Diabetes
 Device: Closed-loop insulin delivery
 Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment

Resource links provided by NLM:

U.S. FDA Resources

Further study details as provided by University of Cambridge:

Primary Outcome Measures:
  • Primary efficacy endpoint [ Time Frame: 36hours ] [ Designated as safety issue: No ]
    The primary outcome measure is time spent with plasma glucose concentration in the target range (3.9-10.0mmol/L) between 24:00 on Day 1 and 08:00 on Day 3 (32 hours) as obtained with closed-loop insulin delivery in comparison with conventional insulin pump therapy.


Secondary Outcome Measures:
  • Secondary efficacy endpoints [ Time Frame: 36 hours ] [ Designated as safety issue: No ]
    • Total and basal insulin delivery between 24:00 on Day 1 and 08:00 on Day 3 (36 hours)
    • CGM glucose levels between 24:00 on Day 1 and 08:00 on Day 3 (36 hours)
    • Overnight glucose levels between 24:00 on Day 1 and 08:00 on Day 2 (8 hours), and between 24:00 on Day 2 and 08:00 on Day 3 (8 hours)


Enrollment: 8
Study Start Date: April 2011
Study Completion Date: September 2011
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Closed-loop with standard meal insulin bolus
Subcutaneous basal insulin delivery will be adjusted following the advice by a computer-based algorithm, based on subcutaneous sensor glucose readings. Standard meal insulin dosing will be performed at each meal, following individual standard clinical practice.
 Device: Closed-loop insulin delivery
Subcutaneous basal insulin delivery will be adjusted following the advice by a computer-based algorithm, based on subcutaneous sensor glucose readings. Standard or reduced meal insulin dosing will be performed in a randomised design.
Experimental: Closed-loop with reduced meal insulin bolus
Subcutaneous basal insulin delivery will be adjusted following the advice by a computer-based algorithm, based on subcutaneous sensor glucose readings. The standard meal insulin dose will be reduced by 20 to 50%.
 Device: Closed-loop insulin delivery
Subcutaneous basal insulin delivery will be adjusted following the advice by a computer-based algorithm, based on subcutaneous sensor glucose readings. Standard or reduced meal insulin dosing will be performed in a randomised design.

  Eligibility

Ages Eligible for Study:   12 Years to 18 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • The subject is between 12 and 18 years of age (inclusive).
  • The subject has had type 1 diabetes, as defined by WHO for at least 1 year or is confirmed C-peptide negative.
  • The subject will have been on insulin pump user for at least 3 months, with good knowledge of insulin self-adjustment.
  • HbA1c ≤ 12 % based on analysis from central laboratory

Exclusion Criteria:

  • Non-type 1 diabetes mellitus including those secondary to chronic disease
  • Any other physical or psychological disease likely to interfere with the normal conduct of the study and interpretation of the study results
  • Current treatment with drugs known to interfere with glucose metabolism such as systemic corticosteroids, non-selective beta-blockers and MAO inhibitors
  • Known or suspected allergy against insulin
  • Subjects with clinical significant nephropathy, neuropathy or proliferative retinopathy as judged by the clinician
  • Total daily insulin dose >= 2 IU/kg
  • Post-menarchal girls who are pregnant or intending to become pregnant or are breastfeeding
  • Any coexisting cardiac and respiratory condition
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01629251

Locations
United Kingdom
Wellcome Trust Clinical Research Facility, Addenbrooke's Hospital
Cambridge, United Kingdom, CB20QQ
Sponsors and Collaborators
University of Cambridge
Cambridge University Hospitals NHS Foundation Trust
Investigators
Principal Investigator: Roman Hovorka, PhD University of Cambridge
  More Information

Publications:

Responsible Party: Dr Roman Hovorka, Principal Research Associate, University of Cambridge
ClinicalTrials.gov Identifier: NCT01629251     History of Changes
Other Study ID Numbers: DAN02
Study First Received: April 5, 2011
Last Updated: June 25, 2012
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by University of Cambridge:
Closed-loop insulin delivery
Post-prandial hypoglycaemia
Meal insulin dosing

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 1
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
 Immune System Diseases
Insulin
Hypoglycemic Agents
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on May 21, 2013