Clinical trial NCT00944619: Closing the Loop in Adults With Type 1 Diabetes - Alcohol Consumption
Official title: Randomised, Two-Period Crossover Study to Assess the Efficacy of Overnight Computer-based Glucose Control Compared With Conventional Pump Therapy Following the Consumption of Alcohol in Adults With Type 1 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 1 Diabetes
Lead sponsor: University of Cambridge
Sponsor class: OTHER
Collaborators: name: Cambridge University Hospitals NHS Foundation Trust
First posted: 2009-07-23
Enrollment: 12
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The main objective is to assess the efficacy and safety of overnight automated closed loop glucose control using a computer-based algorithm compared with conventional insulin pump therapy in adults with type 1 diabetes following the consumption of a moderate amount of alcohol at dinnertime.

Detailed description: People with type 1 diabetes need regular insulin injections or continuous delivery of insulin using an insulin pump. Keeping blood sugars in the normal range is known to reduce the risk of long term complications involving the eyes, kidneys and heart. However, achieving treatment goals can be very difficult as the tighter we try to control blood glucose levels, the greater the risk of the person developing episodes of low glucose levels (hypoglycaemia). One solution is using a system where the amount of insulin injected closely matches the blood sugar levels on a continuous basis. This can be achieved by what is known as a "closed loop system" where a small glucose sensor placed under the skin communicates with a computer containing an algorithm that drives a subcutaneous insulin pump. This system is being developed in Cambridge and is undergoing trials in children and adults with type 1 diabetes. Results thus far show that the system is very effective at preventing hypoglycaemia and maintaining blood glucose levels in target range.

We plan to test the closed loop in various challenging conditions faced by patients in daily life. One of these is the consumption of alcohol, which can give rise to delayed hypoglycaemia in patients with diabetes. The studies will be done in a clinical research facility under supervised conditions. Subjects will attend for two study nights where they will receive a specific volume of alcohol with an evening meal. On one night this will be followed by closed loop algorithm control of their insulin overnight. On the other (control) night subjects will remain on their usual pump therapy regime overnight.

Eligibility criteria: Inclusion Criteria:

* Type 1 diabetes, as defined by WHO for at least 6 months or confirmed C-peptide negative
* On insulin pump therapy for at least 3 months

Exclusion Criteria:

* Non-type 1 diabetes mellitus
* Any physical/psychological disease likely to interfere with the study
* Taking medication likely to interfere with interpretation of results
* Known/suspected allergy against insulin
* Clinically significant nephropathy, neuropathy or retinopathy as judged by the investigator
* Unstable blood glucose control, including recurrent severe hypoglycaemia as judged by the investigator
* Current pregnancy/breastfeeding
* Total daily insulin dose \> 1.4 IU/kg
* HbA1C \> 10% within the last 3 months
* Unable/unwilling to consume the necessary quantity of alcohol stated in the study protocol

Primary outcomes:
measure: Percentage of plasma glucose values in target (3.9-8.0 mmol/L)
timeFrame: 2200-1200hr
Secondary outcomes:
measure: Percentage of CGM (continuous glucose monitoring) values in target (3.9-8.0 mmol/L)
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Percentage of plasma glucose and CGM values in target (3.9-8.0 mmol/L)
timeFrame: 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Percentage of plasma glucose and CGM values below 3.9 mmol/L
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Percentage of plasma glucose and CGM values above 8.0 mmol/L
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Average plasma and CGM glucose
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Average plasma insulin concentration
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Total dose of insulin administered
timeFrame: 2200-1200hrs
measure: Low blood glucose index (LBGI) score
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: High blood glucose index (HBGI) score
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
measure: Percentage of plasma glucose and CGM values below 3.0 mmol/L
timeFrame: 2200-1200; 0000-0400; 0400-0800; 0800-1200; 0300-1200hrs
Other outcomes:
Locations:
city: Cambridge
country: United Kingdom
facility: Addenbrooke's Hospital
Study officials:
affiliation: University of Cambridge, UK
name: Mark L Evans, MD FRCP
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Cambridge, UK
name: Roman Hovorka, PhD
role: STUDY_DIRECTOR
References:
citation: Hovorka R, Kumareswaran K, Harris J, Allen JM, Elleri D, Xing D, Kollman C, Nodale M, Murphy HR, Dunger DB, Amiel SA, Heller SR, Wilinska ME, Evans ML. Overnight closed loop insulin delivery (artificial pancreas) in adults with type 1 diabetes: crossover randomised controlled studies. BMJ. 2011 Apr 13;342:d1855. doi: 10.1136/bmj.d1855.