Type 2 diabetes mellitus, prediabetes, obstructive sleep apnoea Nutritional, Metabolic, Endocrine
Conditions
Interventions
This is a randomised crossover trial where participants will be randomised to one of the following two groups:
1. Stop their normal CPAP and use sham CPAP for one week, followed by at
Sponsors
University of Oxford
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Willing and able to give informed consent for participation in the trial 2. Male or Female, aged =18 years 3. Objectively confirmed obstructive sleep apnoea (at the time of original diagnosis) with an oxygen desaturation index (ODI =4% dips) of >20 /h, and/or an apnoea/hypopnoea index of >20 /h (this threshold will exclude subjects with borderline OSA, in whom there may be little treatment effect) 4. Type 2 diabetes mellitus or HbA1c =6.0% (42 mmol/l) at the screening visit. 5. In the Investigator’s opinion, is able and willing to comply with all trial requirements 6. Willing to allow his or her General Practitioner and consultant, if appropriate, to be notified of participation in the trial 7. Currently >20 /h oxygen desaturations (=4% dips) returning on any night during a screening period of ambulatory nocturnal pulse oximetry performed during a 4-night period without CPAP 8. Treated with CPAP for >3 months, minimum compliance 6 h per night, where available an AHI <10 with treatment (according to machine download data), and ODI <10 confirmed on CPAP during screening oximetry
Exclusion criteria
Exclusion criteria: 1. Diabetes mellitus requiring treatment with regular insulin therapy 2. Previous ventilatory failure (awake resting arterial oxygen saturation 6 kPa) or severe respiratory disorders other than OSA 3. Unstable, untreated coronary or peripheral artery disease, severe arterial hypertension (>180/110 mmHg), severe arterial hypotension (<90/60 mmHg) 4. Poorly controlled diabetes with HbA1c =10.0% (86 mmol/mol) 5. Unstable diabetic retinopathy requiring or currently undergoing specialist treatment 6. Previously diagnosed with Cheyne-Stokes breathing 7. Current professional driver or vigilance critical occupation 8. Any sleep-related accident 9. Mental or physical disability precluding informed consent or compliance with the protocol 10. Non-feasible trial follow-up (for example the distance from follow-up centre, or physical inability)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The effect of continuous positive airway pressure (CPAP) withdrawal on continuous interstitial glucose measurements (CGM) measured using a CGM sensor overnight, between 00:00 and 07:00, on 5, 6, and 7 days of CPAP withdrawal | — |
Secondary
| Measure | Time frame |
|---|---|
| The effect of continuous positive airway pressure (CPAP) withdrawal on continuous interstitial glucose measurements (CGM) measured using a CGM sensor for 24 h on 5, 6, and 7 days of CPAP withdrawal | — |
Countries
England, United Kingdom
Outcome results
None listed