Clinical trial NCT01629251: Closing the Loop for 36 Hours in Adolescents With Type 1 Diabetes: Evaluation of Reduced Meal Bolusing
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Type 1 Diabetes
Keywords: Closed-loop insulin delivery
Post-prandial hypoglycaemia
Meal insulin dosing
Lead sponsor: University of Cambridge
Sponsor class: OTHER
Collaborators: name: Cambridge University Hospitals NHS Foundation Trust
First posted: 2012-06-27
Enrollment: 8
Sex: ALL
Minimum age (years): 12
Maximum age (years): 18
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief 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.


Eligibility 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

Primary outcomes:
measure: Primary efficacy endpoint
timeFrame: 36hours
Secondary outcomes:
measure: Secondary efficacy endpoints
timeFrame: 36 hours
Other outcomes:
Locations:
city: Cambridge
country: United Kingdom
facility: Wellcome Trust Clinical Research Facility, Addenbrooke's Hospital
Study officials:
affiliation: University of Cambridge
name: Roman Hovorka, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.