ANZCTR - Registration

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]

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

obstructive sleep apnoea

Condition category

Condition code

Metabolic and Endocrine

Diabetes

Respiratory

Sleep apnoea

Intervention/exposure

Study type

Observational

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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

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]

Commercial sector/Industry

Name [1]

ResMed Ltd

Country [1]

Australia

Primary sponsor type

Commercial sector/Industry

Name

ResMed Ltd

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Alfred Hospital Ethics Committee

Ethics committee address [1]

The Alfred Hospital, 
55 Commercial Road, 
Melbourne, 
Victoria 3004

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

20/02/2012

Approval date [1]

17/04/2012

Ethics approval number [1]

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

Public notes

Contacts

Principal investigator

Name

Prof Jonathan Shaw

Address

Baker heart and Diabetes Institute
Level 4, 99 Commercial Rd, Melbourne, VIC 3004

Country

Australia

Phone

+61 0385321800

Email

jonathan.shaw@baker.edu.au

Contact person for public queries

Name

Elena Vulikh

Address

Baker IDI Heart and Diabetes Institute
Level 4, 99 Commercial Rd
Melbourne, VIC, 3004

Country

Australia

Phone

61 3 8532 1840

Email

elena.vulikh@bakeridi.edu.au

Contact person for scientific queries

Name

A/Professor Jonathan Shaw

Address

Baker IDI Heart and Diabetes Institute
Level 4, 99 Commercial Rd
Melbourne, VIC, 3004

Country

Australia

Phone

61 3 8532 1821

Email

jonathan.shaw@bakeridi.edu.au

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