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.

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.

Status

Completed

Phases

Unknown

Study type

Observational

Source

ANZCTR

Registry ID

ACTRN12615000135516

Enrollment

Registered

2015-02-12

Start date

2015-03-05

Completion date

2017-06-08

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

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.

Interventions

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.

Eligibility

Sex/Gender

All

Age

18 Years to 75 Years

Healthy volunteers

Inclusion criteria

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

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

Outcome results