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Trial registered on ANZCTR


Registration number
ACTRN12612000246886
Ethics application status
Approved
Date submitted
27/02/2012
Date registered
28/02/2012
Date last updated
1/09/2024
Date data sharing statement initially provided
1/09/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Long term follow-up of the effect of Constant Positive Airway Pressure treatment on blood glucose control in patients with type 2 diabetes mellitus and obstructive sleep apnoea (GLYCOSA follow-up study)
Scientific title
Long term follow-up of the effect of CPAP treatment on glycaemic control in patients with type 2 diabetes mellitus and obstructive sleep apnoea (GLYCOSA follow-up study)
Secondary ID [1] 280032 0
Nil
Universal Trial Number (UTN)
Trial acronym
GLYCOSA follow-up study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
type 2 diabetes 285947 0
obstructive sleep apnoea 285948 0
Condition category
Condition code
Metabolic and Endocrine 286135 286135 0 0
Diabetes
Respiratory 286136 286136 0 0
Sleep apnoea

Intervention/exposure
Study type
Observational
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
This is a follow-up study (without intervention) of participants involved in the earlier study (GLYCOSA study). ClinicalTrials.gov Identifier: NCT00509223
The follow-up of participants will be done to determine the long-term impact of CPAP treatment on glycaemic control, cardiovascular outcomes and improvement in quality of life. There will be 2 visits during which information from participants will be collected. Participants in the GLYCOSA study were randomised between 2007 and 2011 and will be followed-up between April 2012 and March 2013.
Intervention code [1] 284357 0
Not applicable
Comparator / control treatment
This is an observational study of participants involved in the GLYCOSA study, which had 2 groups: treatment group (Constant Positive Airway Pressure therapy and lifestyle advice) and control group (lifestyle advice only).
Control group
Active

Outcomes
Primary outcome [1] 286608 0
Participants with diagnosed type 2 diabetes (T2D) and obstructive sleep apnoea (OSA) will show sustained improvement in their glycaemic control following previous intensive use of Constant Positive Airway Pressure (CPAP) therapy. Participants will have a blood sample taken to measure the HbA1c level. Also, participants will be required to perform a 7-point blood glucose monitoring on two days.
Timepoint [1] 286608 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.
Secondary outcome [1] 296260 0
Assessment of the long-term effectiveness of CPAP therapy on glycaemic control in patients with OSA and T2D. All participant will be reqquired to bring CPAP equipment for the follow-up visit. During the visit CPAP compliance data will be downloaded and analysed. Diabetes control will be assesed as per the Primary Outcome 1.
Timepoint [1] 296260 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.
Secondary outcome [2] 296261 0
Assessment of the long term CPAP compliance and adherence. All participant will be reqquired to bring CPAP equipment for the follow-up visit. During the visit CPAP compliance data will be downloaded and assessed for compliance and adherence to the therapy.
Timepoint [2] 296261 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.
Secondary outcome [3] 296262 0
Assessment of changes in severity of OSA. A whole night respiratory monitoring will be perfomed on all participants to determine severity of OSA, using the ResMed Apnea Link with oximetry).
Timepoint [3] 296262 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.
Secondary outcome [4] 296263 0
Assessment of improvements in cardiovascular outcomes. All participants will require to perform a 24-hour ambulatory blood pressure monitoring as well as 3 blood pressure reading will be taken after seating for 5 minutes.
Timepoint [4] 296263 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.
Secondary outcome [5] 296264 0
Examination of potential improvement in quality of life, using the SF-36 instrument, which is a multi-purpose, short-form health survey with 36 questions.
Timepoint [5] 296264 0
Follow-up of participants involved in the GLYCOSA study and randomised between 2007 and 2011. There will be 2 visits in total for each participant. Anticipated commencement date of this study 01/04/2012. Anticipated completion date of this study 01/03/2013. Therefore, participants will be followed-up anywere between 1 and 5 years post randomisation in the GLYCOSA study.

Eligibility
Key inclusion criteria
People over the age of 18 with T2D and OSA, who have taken part in the GLYCOSA study
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Nil

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/04/2012
Actual
1/05/2012
Date of last participant enrolment
Anticipated
Actual
1/05/2013
Date of last data collection
Anticipated
Actual
1/05/2013
Sample size
Target
122
Accrual to date
Final
1
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 284789 0
Commercial sector/Industry
Name [1] 284789 0
ResMed Ltd
Country [1] 284789 0
Australia
Primary sponsor type
Commercial sector/Industry
Name
ResMed Ltd
Address
1 Elizabeth Macarthur Drive
Bella Vista
NSW
2153
Country
Australia
Secondary sponsor category [1] 283674 0
None
Name [1] 283674 0
Address [1] 283674 0
Country [1] 283674 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 286781 0
Alfred Hospital Ethics Committee
Ethics committee address [1] 286781 0
The Alfred Hospital,
55 Commercial Road,
Melbourne,
Victoria 3004
Ethics committee country [1] 286781 0
Australia
Date submitted for ethics approval [1] 286781 0
20/02/2012
Approval date [1] 286781 0
17/04/2012
Ethics approval number [1] 286781 0
Project 89/12

Summary
Brief summary
Obstructive Sleep Apnoea (OSA) affects approximately 4% (3% to 8%) of men and 2% of women in the general population, although among the obese population the prevalence is significantly higher. It is now fairly well accepted that OSA is independently associated with hypertension, and cardiovascular disease. More recently a number of studies have demonstrated an association between OSA and type 2 diabetes mellitus (T2D), insulin resistance, glucose intolerance and dyslipidemia. Indeed there is a growing body of research that suggests OSA is independently associated with insulin resistance and T2D. Furthermore, increasing insulin resistance has been correlated with increasing severity of OSA.

A number of studies have examined the prevalence of OSA among people with T2D. These studies have demonstrated the prevalence of OSA could be as high as 30%, which is well above the estimated prevalence of 2–8 % in the general population.

The GLYCOSA study is currently determining the direct effects of 6 months treatment with Constant Positive Airway Pressure (CPAP) on glycaemic control and other cardiometabolic factors in patients with T2D and OSA. In this study, participants with T2D were randomised into either a treatment (CPAP and lifestyle advice) group or a control (lifestyle advice only) group. Microchip downloadable S8 Autoset Spirit CPAP machines (ResMed) were used. This machine allows recording of CPAP use for at least 3 consecutive months based on time the mask is actually applied to a subject’s face (not machine run time). Data collection by the machine is not influenced by the type of mask used by the subject, provided leakage in the system is not excessively high. All subjects were counselled regarding adopting a healthy lifestyle and advised on the Heart Foundation nutrition and exercise recommendations. At the end of the 6 months, participants in the no treatment arm were offered CPAP treatment and this was done as per usual care clinical scenario.

Longer term follow-up of the participants would be valuable for several reasons. First, a number of trials in diabetes in recent years have shown that the benefits of the intervention only become fully manifest with further follow-up after the trial end, despite discontinuation of the randomised allocations. Thus, benefits not apparent at trial end may be present at a later follow-up. Second, since many of the GLYCOSA participants were asymptomatic, compliance with CPAP was difficult during the randomised phase; longer term follow-up will provide an opportunity to assess compliance outside the rigours of an on-going trial. It will also allow a determination of whether any benefits seen at the 6-month trial end are sustained over a longer period. Third, CPAP was offered to participants in the control (lifestyle) arm at the end of the 6-month trial. This was done in a non-trial setting, and a comparison of compliance with, and effects of, CPAP between the two groups will provide insights into the benefits of the more intensive CPAP support provided during the trial for the CPAP group compared to the less intensive non-trial CPAP support given to the control group.

The GLYCOSA has just completed all study visits and it is timely to conduct a follow-up of participants to determine the long-term impact of CPAP treatment on glycaemic control, cardiovascular outcomes and improvement in quality of life.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 33837 0
Prof Jonathan Shaw
Address 33837 0
Baker heart and Diabetes Institute
Level 4, 99 Commercial Rd, Melbourne, VIC 3004
Country 33837 0
Australia
Phone 33837 0
+61 0385321800
Fax 33837 0
Email 33837 0
[email protected]
Contact person for public queries
Name 17084 0
Elena Vulikh
Address 17084 0
Baker IDI Heart and Diabetes Institute
Level 4, 99 Commercial Rd
Melbourne, VIC, 3004
Country 17084 0
Australia
Phone 17084 0
61 3 8532 1840
Fax 17084 0
Email 17084 0
[email protected]
Contact person for scientific queries
Name 8012 0
A/Professor Jonathan Shaw
Address 8012 0
Baker IDI Heart and Diabetes Institute
Level 4, 99 Commercial Rd
Melbourne, VIC, 3004
Country 8012 0
Australia
Phone 8012 0
61 3 8532 1821
Fax 8012 0
Email 8012 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Not sure yet


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.