ABSTRACT
Our previous randomized clinical trials evaluated CLOSED LOOP insulin delivery in over
120 subjects under FREE-LIVING UNSUPERVISED HOME settings in studies lasting 1 WEEK
to 3 MONTHS (total closed loop operation 81,120 hours/3,380days/9.3 years). All studies used
CAMBRIDGE model predictive control algorithm. We demonstrated the safety, efficacy, and
acceptability of closed loop insulin delivery over short to medium long investigations. Given its
potential to reduce the BURDEN OF HYPOGLYCAEMIA and diabetes SELF-MANAGEMENT,
application of closed-loop insulin delivery is of interest in older subjects due to the increased risk
of SEVERE HYPOGLYCAEMIA in this population.
The present project addresses the important question of FREE-LIVING UNSUPERVISED
HOME USE of closed loop by a system configured to PROTECT against HYPOGLYCEMIA in
OLDER PEOPLE with type 1 diabetes, by applying ADVANCED Android-phone closed loop
system with pump-integrated HYPOGLYCAEMIA safety feature (predictive low glucose suspend
to reduce the risk of hypoglycemia in case of Android-phone directed closed loop not being
operational).
Specifically, in the TEACHNICAL part of the project we will organize FOCUS GROUP meetings
with older subjects from participating clinical sites. We will assess what specific closed loop
FEATURES are required for this population. The additional feature(s) including personalized
TARGET GLUCOSE SETTINGS will be IMPLEMENTED, TESTED and OPTIMIZED on
Cambridge in silico population. REGULATORY DOCUMENTATION will be prepared.
In the CLINICAL part of the project, we will evaluate the performance of 4 MONTH 24/7
CLOSED LOOP in OLDER SUBJECTS aged 60 years with type 1 diabetes under FREE-LIVING
UNSUPERVISED HOME SETTINGS in a RANDOMISED CROSS-OVER design study. We will
use closed loop system comprising 640G PUMP and ENLITE 3 sensor (both Medtronic) and an
Android phone running CAMBRIDGE MODEL PREDICTIVE CONTROL ALGORITHM. The
system SAFETY will be ENHANCED by the use of predictive low glucose management,
INTEGRATED on 640G pump, and suspending insulin delivery when hypoglycemia is predicted
even when Android-driven closed loop is not operating. In total, 36 PARTICIPANTS will be
randomized to 4 month 24/7 CLOSED LOOP followed by SENSOR AUGMENTED PUMP
THERAPY, or vice versa, with a 8-week washout period in between the two interventions. The
study will compare BIOMEDICAL, PSYCHOSOCIAL, CARDIAC ARRYTHMIA EVENTS and
SLEEP QUALITY of the two study interventions. Time spent within GLUCOSE TARGET
RANGE measured by sensor glucose will be the primary endpoint. Biomedical outcomes
(HbA1c, mean glucose, time below/above target and other related glucose/insulin metrics) will
be complemented by assessments of psychosocial/human factors issues (focus groups and
questionnaires), CARDIAC ARRHYTHMIA (ambulatory Holter) and SLEEP QUALITY
(Actiwatch).