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Trial registered on ANZCTR


Trial ID
ACTRN12615000135516
Ethics application status
Approved
Date submitted
21/01/2015
Date registered
12/02/2015
Date last updated
17/01/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Benefits to early identification of Obesity Hypoventilation Syndrome (too shallow or too slow breathing) in obese patients by measuring blood carbon dioxide levels while lying flat and sitting upright.
Scientific title
A cross-sectional study to identify obese patients who are at risk of developing obesity hypoventilation syndrome (OHS) by investigating the relationship between daytime measures (including supine hypercapnia, distribution of body fat, and lung volumes) with the presence of hypoventilation during sleep.
Secondary ID [1] 285727 0
Nil
Universal Trial Number (UTN)
U1111-1164-4509
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity Hypoventilation Syndrome 293609 0
Obstructive Sleep Apnoea 293610 0
Condition category
Condition code
Respiratory 293896 293896 0 0
Sleep apnoea
Diet and Nutrition 294484 294484 0 0
Obesity

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
In a single 1 hour session, upright and supine arterialised capillary blood gases and simple bedside spirometry will be performed for each participant. In addition, neck, waist and hip measurements will also be obtained. Transcutaneous carbon dioxide levels and severity of oxygen desaturation will also be recorded throughout the duration of the single overnight sleep study.
Intervention code [1] 290682 0
Not applicable
Comparator / control treatment
None
Control group
Uncontrolled

Outcomes
Primary outcome [1] 293673 0
Erect to supine difference in blood pCO2
Timepoint [1] 293673 0
Blood samples will be obtained after 5 minutes of standing and again after 20 minutes of lying supine during the assessment period.
Secondary outcome [1] 311559 0
Sleep transcutaneous pCO2 monitoring and severity of oxygen desaturation


Timepoint [1] 311559 0
Measured throughout sleep during the sleep study using skin and finger probes.
Secondary outcome [2] 312709 0
Lung volume measurements
Timepoint [2] 312709 0
Spirometry will be performed after 5 minutes of sitting upright and again after 5 minutes of lying flat during the daytime assessment period. The forced expiratory time (FEV1) and forced and slow vital capacities will be assessed using a spirometer.
Secondary outcome [3] 312710 0
Anthropomorphic measurements
Timepoint [3] 312710 0
Measured while lying flat and standing upright during the daytime assessment period. These measurements will require less than 10 minutes to complete using a flexible tape measure.

Eligibility
Key inclusion criteria
1. Age 18 – 75 years old
2. Written informed consent
3. BMI>40kg/m2
4. Able to lie flat


Minimum age
18 Years
Maximum age
75 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Major psychiatric, neurological disorder or head injury
2. Neuromuscular disease or lung disease
3. Uncontrolled medical conditions including cardiac failure
4. Not proficient in English


Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Defined population
Timing
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 3203 0
Royal Prince Alfred Hospital - Camperdown
Recruitment postcode(s) [1] 8984 0
2050 - Camperdown

Funding & Sponsors
Funding source category [1] 290301 0
Self funded/Unfunded
Name [1] 290301 0
N/A
Address [1] 290301 0
N/A
Country [1] 290301 0
Primary sponsor type
Individual
Name
Sheila Sivam
Address
Department of Respiratory and Sleep Medicine
Royal Prince Alfred Hospital
Missenden Road
Camperdown NSW 2050
Country
Australia
Secondary sponsor category [1] 289011 0
None
Name [1] 289011 0
Address [1] 289011 0
Country [1] 289011 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292006 0
SLHD Ethics Review Committee (RPAH Zone)
Ethics committee address [1] 292006 0
Mailing Address:
c/- Research Development Office
Royal Prince Alfred Hospital
Missenden Road
CAMPERDOWN NSW 2050
Ethics committee country [1] 292006 0
Australia
Date submitted for ethics approval [1] 292006 0
25/11/2014
Approval date [1] 292006 0
20/02/2015
Ethics approval number [1] 292006 0

Summary
Brief summary
The aim of this study is to identify obese patients who are at risk of developing Obesity Hypoventilation Syndrome (OHS) by investigating the relationship between daytime measures (including supine hypercapnia (elevated carbon dioxide levels when lying flat), distribution of body fat, and lung volumes) with the presence of hypoventilation during sleep.

Hypothesis:

Supine hypercapnia is a useful marker for identifying sleep hypoventilation, an early sign of the development of OHS.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 53030 0
Dr Sheila Sivam
Address 53030 0
DEPT OF RESPIRATORY AND SLEEP MEDICINE
LEVEL 11, BUILDING 75
ROYAL PRINCE ALFRED HOSPITAL
MISSENDEN ROAD
CAMPERDOWN NSW 2050
Country 53030 0
Australia
Phone 53030 0
+61 2 9515 8708
Fax 53030 0
Email 53030 0
sheila.sivam@sydney.edu.au
Contact person for public queries
Name 53031 0
Dr Sheila Sivam
Address 53031 0
DEPT OF RESPIRATORY AND
SLEEP MEDICINE
LEVEL 11, BUILDING 75
ROYAL PRINCE ALFRED HOSPITAL
MISSENDEN ROAD
CAMPERDOWN NSW 2050
Country 53031 0
Australia
Phone 53031 0
+61 2 9515 8708
Fax 53031 0
Email 53031 0
sheila.sivam@sydney.edu.au
Contact person for scientific queries
Name 53032 0
Dr Sheila Sivam
Address 53032 0
DEPT OF RESPIRATORY AND SLEEP MEDICINE
LEVEL 11, BUILDING 75
ROYAL PRINCE ALFRED HOSPITAL
MISSENDEN ROAD
CAMPERDOWN NSW 2050
Country 53032 0
Australia
Phone 53032 0
+61 2 9515 8708
Fax 53032 0
Email 53032 0
sheila.sivam@sydney.edu.au