The effect of dishabituation on hypoglycaemia awareness in patients with type 1 diabetes and impaired hypoglycaemia awareness.

This is a pilot, single-centre, randomised, cross-over study in participants with both Type 1 diabetes and impaired awareness of hypoglycaemia (IAH) under free living conditions. Participants will be screened for IAH over the phone by our study doctor using the Clarke questionnaire. Once eligibility is confirmed, there will be a 2-week run in period where participants continue with their usual lifestyle. Participants will then be randomised into a 4-week period of either a tri-weekly low-intensity exercise or tri-weekly high-intensity exercise, with a 8-week wash-out in between the two exercise regimens after which, participants will be exposed to the alternative exercise programme for 4 weeks. A logbook will be provided to participants to enable them to record hypoglycaemia for 2 weeks. Logbooks will be used during the 2-week run in period and then in study weeks 5-7, 13-15 and 17-19. This will include a record of both autonomic and neuroglycopenic symptoms (Edinburg hypoglycaemia scale), with the severity of these symptoms being rated on a Likert scale from 1 to 7. (Appendix 6) All participants will be encouraged to record hypoglycaemia symptoms and glucose level in the logbook when at least one of the following conditions is met. a. Notification of urgent low alarm (3.1 mmol/l). b. Symptoms of hypoglycaemia as perceived by the participant c. Any time hypoglycaemia treatment (fast-acting carbohydrates) is instituted by the participant with glucose. Participants will be provided with an activity tracker watch (Garmin Forerunner 735xt) and Dexcom continuous glucose monitoring sensors if they do not have their own. Participants will be required to wear the Dexcom continuous glucose monitoring sensor for the whole study period. Participants will be given the option to wear the activity tracker for the whole study period or only when performing the exercise regimens. Research staff will conduct a home visit to the participant's house to deliver and set up a cycle ergometer (MaXx KH-805 Programmable Upright Exercise Bike). Under the supervision of the research staff members, participants will perform a 10 second sprint test to determine their maximum power output generated (in Watts). Low-intensity exercise for 4 weeks, 3 times a week. Participants will be required to cycle for 16 minutes at a low intensity corresponding to 15% of their peak power (measured during their peak power assessment at the familiarisation visit). High-intensity exercise for 4 weeks, 3-times a week. After a 2-min warm up performed at an intensity equivalent to 15% peak power, participants will be required to engage in four 15-second maximal sprint efforts each separated by a 4-min period of light cycling at 15% peak power, finishing with 2-min of light cycling at 15% peak power. Exercise to be performed at least 3 hours after the last insulin bolus and before the evening meal (dinner). The primary outcome is the acceptability and feasibility of HIE as a home-based intervention. This outcome will be determined by the semi-structured interview at the end of the study. Weekly text messages and when needed, phone calls will be made to each participant to monitor adherence to the intervention.