Comparing Long-acting Insulins During Exercise in Type 1 Diabetes
Comparing Long-acting Insulins During Exercise in Type 1 Diabetes
Exercise is an important part of a healthy lifestyle, and many people with Type 1 Diabetes
 like to take part in regular sport and exercise. The majority of people with Type 1 Diabetes
 are treated with a "basal bolus" insulin regimen, with background insulin provided by
 long-acting "basal" insulin doses, and "bolus" doses of short-acting insulin used to
 accompany food intake. Evidence shows that the main factor preventing people with diabetes
 from pursuing a more active lifestyle is fear of low blood glucose (hypoglycaemia). A
 previous study has shown that the type of background insulin affects the likelihood of an
 individual suffering hypoglycaemia during exercise and for 2 and a half hours afterwards. The
 aim of this study is to examine this further.

 The two most commonly used long-acting insulins, insulin glargine and insulin detemir, will
 be compared. Previous data suggests that there is a greater likelihood of hypoglycaemia with
 insulin glargine than insulin detemir. Exercise intensity can have an influence on the
 likelihood of hypoglycaemia, and in this previous study exercise intensity was measured using
 heart rate. This study will use a more formal definition of exercise intensity. The
 investigators will study blood glucose during exercise, but also metabolism as measured by
 hormones affecting blood glucose levels as well as markers of fat metabolism. The
 investigators will also use a continuous glucose monitoring system (CGMS) to consider
 hypoglycaemia on thei night following exercise as this is a recognised consequence of
 exercise in type 1 diabetes.

 The null hypothesis to be tested in this study is that there is no difference between the two
 insulins in their effect on blood glucose levels and metabolism during exercise and rates of
 nocturnal hypoglycaemia after exercise.
A1: At the first appointment, potential participants will be screened regarding the inclusion
 criteria, and if eligible to take part the study information sheet will be discussed with
 them in detail. Written, informed consent will be obtained if participants are willing to
 take part in the study. Participants will be given advice and support from this point in
 order to optimise basal insulin therapy using their usual basal insulin.

 A2: Following a period of at least 3 weeks from recruitment into the study, participants will
 have their maximal oxygen uptake (VO2 MAX - a measure of capacity for physical exercise)
 assessed.

 A3: After at least 4 weeks following recruitment , to allow time for optimisation of basal
 insulin therapy, and at least one week following A2, the participant's metabolism will then
 be assessed during and after 60 minutes of exercise at 50% VO2 MAX. Participants will be
 fitted with a continuous glucose monitoring system (CGMS) to monitor glucose levels for the
 24 hours after exercise finishes.

 A4: At least 24 hours and no more than 7 days after A3 the participant will switched to using
 the other trial insulin for basal insulin therapy. Again, participants will be provided with
 advice and support in order to optimise treatment.

 A5: At least 4 weeks following A4, the participant's metabolism will once again be assessed
 during and after 60 minutes of exercise at 50% VO2 MAX. Participants will again be fitted
 with CGMS to monitor glucose levels for the 24 hours after exercise finishes.

 A6: Once the 24 hours after exercise are complete, the study finishes and participants
 re-start their usual basal insulin.
Inclusion Criteria:

 -  Participant is willing and able to give informed consent for participation in the
 study.

 -  Male or Female, aged between 18 and 65 years

 -  Diagnosed with Type 1 Diabetes Mellitus (T1DM)

 -  HbA1c < 10% or 86 mmol/mol

 -  Treated with a basal bolus regimen using either insulin glargine or insulin detemir as
 the basal insulin

 -  Exercising regularly for at least 1 hour per week on average

 Exclusion Criteria:

 -  People with any one of the following complications of diabetes:

 -  stage 2+ diabetic retinopathy

 -  renal impairment (with creatinine >150micromol/l)

 -  known history or symptoms of cardiovascular disease

 -  foot ulceration

 -  peripheral vascular disease

 -  Pregnancy or breastfeeding

 -  Untreated or unstable respiratory disease

 -  Known hypoglycaemia unawareness

 -  Treatment with drugs known to interfere with glucose metabolism

 -  Known or suspected allergy to or intolerance of any of the trial drugs or related
 products

 -  Receipt of any investigational drug within four months prior to Visit 0

 -  Known or suspected abuse of alcohol, narcotics or illicit drugs

 -  Any clinically significant disease or disorder which in the investigator's opinion
 could interfere with the results of the trial