closing the loop in adults with type 1 diabetes and hba1c<7.5% under free living conditions

Conditions: Type 1 Diabetes

Summary: the main objective of this study is to determine whether day and night closed-loop insulin delivery for 4 weeks under free living conditions is superior to usual insulin pump therapy in adults with type 1 diabetes and hba1c\<7.5%. this is an open-label, multi center, randomized, crossover design study, involving a 2-4 week run-in period, followed by two 4 weeks study periods during which glucose levels will be controlled either by an automated day- and night closed-loop system or by subjects usual insulin pump therapy in random order. a total of up to 34 adults (aiming for 24 completed subjects) aged 18 years and older with t1d on insulin pump therapy and hba1c\<7.5% will be recruited through diabetes clinics and other established methods in participating centers. subjects will receive appropriate training in the safe use of closed-loop insulin delivery system. subjects will have regular contact with the study team during the home study phase including 24/7 telephone support. the primary outcome is time spent in target range between 3.9 and 10.0 mmol/l as recorded by cgm during home stay. secondary outcomes are time spent with glucose levels above and below target, as recorded by cgm, and other cgm-based metrics.


Eligibility criteria:
inclusion criteria: * the subject has type 1 diabetes as defined by who * the subject is 18 years of age or older * the subject will have been on an insulin pump for at least 6 months with good knowledge of insulin self-adjustment including carbohydrate counting * the subject is treated with one of the rapid acting insulin analogues (insulin aspart, insulin lispro or insulin glulisine) * hba1c \<7.5% (58mmol/mmol) based on analysis from central laboratory or equivalent * the subject is willing to perform regular finger-prick blood glucose monitoring, with at least 6 measurements per day * the subject is willing to wear closed-loop system at home and at work place * the subject is willing to follow study specific instructions * the subject is willing to upload pump and cgm data at regular intervals * female subjects of child bearing age should be on effective contraception and must have a negative urine-hcg pregnancy test at screening. exclusion criteria: * non-type 1 diabetes mellitus * any other physical or psychological disease or condition likely to interfere with the normal conduct of the study and interpretation of the study results * current treatment with drugs known to have significant interference with glucose metabolism, such as systemic corticosteroids, as judged by the investigator * known or suspected allergy against insulin * subjects with clinically significant nephropathy, neuropathy or proliferative retinopathy as judged by the investigator * significantly reduced hypoglycaemia awareness as judged by the investigator * more than one episode of severe hypoglycaemia as defined by american diabetes association in preceding 6 months (severe hypoglycaemia is defined as an event requiring assistance of another person to actively administer carbohydrates, glucagon, or take other corrective actions). * random c-peptide \> 100pmol/l with concomitant plasma glucose \>4 mm(72 mg/dl) total daily insulin dose \> 2 iu/kg/day * subject is pregnant or breast feeding or planning pregnancy in near future (within next 3 months) * severe visual impairment * severe hearing impairment * subjects using implanted internal pacemaker * lack of reliable telephone facility for contact * subject not proficient in english (uk) or german (austria) * subjects who are living alone * additional exclusion criteria specific for austria: positive results on urine drug screen (amphetamines/metamphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, opiates). * additional exclusion criteria specific for austria:positive alcohol breath test.

Keywords: closed loop glucose control hypoglycemia type 1 diabetes hba1c<7.5%