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

Type 1 Diabetes Clinical Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01629251
• Other study ID #: DAN02
• Status: Completed
• Phase: Phase 2
• First received: April 5, 2011
• Last updated: June 25, 2012
• Start date: April 2011
• Est. completion date: September 2011

Study information

• Verified date: June 2012
• Source: University of Cambridge
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 8
• Est. completion date: September 2011
• Est. primary completion date: September 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 12 Years to 18 Years

Eligibility

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

Study Design

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

Related Conditions & MeSH terms

• Diabetes Mellitus, Type 1
• Type 1 Diabetes

Intervention

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.

Locations

Country	Name	City	State
United Kingdom	Wellcome Trust Clinical Research Facility, Addenbrooke's Hospital	Cambridge

Sponsors (2)

Lead Sponsor	Collaborator
University of Cambridge	Cambridge University Hospitals NHS Foundation Trust

Country where clinical trial is conducted

United Kingdom, 

References & Publications (1)

Hovorka R, Allen JM, Elleri D, Chassin LJ, Harris J, Xing D, Kollman C, Hovorka T, Larsen AM, Nodale M, De Palma A, Wilinska ME, Acerini CL, Dunger DB. Manual closed-loop insulin delivery in children and adolescents with type 1 diabetes: a phase 2 randomised crossover trial. Lancet. 2010 Feb 27;375(9716):743-51. doi: 10.1016/S0140-6736(09)61998-X. Epub 2010 Feb 4. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Primary efficacy endpoint	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.	36hours	No
Secondary	Secondary efficacy endpoints	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)	36 hours	No