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