Obesity Hypoventilation Syndrome (OHS)CABS for OHSNCT07020689
Transdisciplinary Intervention for Obesity Hypoventilation Syndrome
An observational study of Obesity Hypoventilation Syndrome (OHS) and Obstructive Sleep Apnea (OSA), run by Chang Gung Memorial Hospital at 1 site in Taiwan.
Trial summary
The aims of this prospective observational cohort study are threefold: (1) to assess the prevalence of obesity hypoventilation syndrome (OHS) in individuals with obesity and obstructive sleep apnea (OSA) and identify associated risk factors, (2) to determine clinical predictors of OHS, and (3) to evaluate the… Read more about this study
- Who is it for?
- Ages 20 to 65 years
- Conditions the study is for
- Obesity Hypoventilation Syndrome (OHS), Obstructive Sleep Apnea (OSA)
- What is being tested?
- CABS
- Type of treatment
- Surgery or procedure
- How many people
- 36 participants
- Where
- 1 siteTaiwan
- Study dates
- 1 Sep 2022to 30 Nov 2024
- How long will I take part?
- 12 Months
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This study enrolled consecutive patients with obesity and OSA at the tertiary referral sleep center of Linkou Chang Gung Memorial Hospital from September 1, 2022, to August 31, 2024. OHS was diagnosed based on the presence of BMI ≥ 30 kg/m², PaCO₂ ≥ 45 mmHg on ABG analysis, and sleep-disordered breathing, following the exclusion of other potential causes of alveolar hypoventilation using pulmonary function tests.
Who may be able to join
- BMI ≥ 30 kg/m², and (2) AHI ≥ 5 events/hour.
Who cannot join
- persistent decompensated hypercapnic respiratory failure (arterial pH < 7.3), (2) acute respiratory failure requiring invasive mechanical ventilation, (3) significant neuromuscular disease, chest wall deformities, or pulmonary disease contributing to hypoventilation, (4) unstable coronary artery disease, or (5) cognitive impairment precluding informed consent or protocol adherence.
Trial locations and contacts
1 site in 1 country.
Taiwan1 site
Department of ENT, Linkou Chang Gung Memorial Hospital
Taoyuan City, 33305
About this study
Official title: Combined Airway & Bariatric Surgery (CABS) for Obesity Hypoventilation Syndrome
The aims of this prospective observational cohort study are threefold: (1) to assess the prevalence of obesity hypoventilation syndrome (OHS) in individuals with obesity and obstructive sleep apnea (OSA) and identify associated risk factors, (2) to determine clinical predictors of OHS, and (3) to evaluate the therapeutic outcomes of combined airway and bariatric surgery (CABS) in this population.
Read the detailed description
This study was approved by the Institutional Review Board of Chang Gung Medical Foundation on August 8, 2022 (IRB No. 202201000A3). Written informed consent was obtained from all participants. All procedures adhered to the principles outlined in the Declaration of Helsinki and were reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROCSS) guidelines.
This was a two-year prospective observational cohort study conducted at the tertiary referral sleep center of Linkou Chang Gung Memorial Hospital from December 1, 2022, to November 30, 2024. Obesity hypoventilation syndrome (OHS) was diagnosed based on the presence of BMI ≥ 30 kg/m², PaCO₂ ≥ 45 mmHg on arterial blood gas (ABG) analysis, and sleep-disordered breathing, following the exclusion of other potential causes of alveolar hypoventilation using pulmonary function tests.
Adults aged 20 to 65 years were eligible if they met the following inclusion criteria: (1) BMI ≥ 30 kg/m², and (2) AHI ≥ 5 events/hour. Individuals were excluded if they had (1) persistent decompensated hypercapnic respiratory failure (arterial pH < 7.3), (2) acute respiratory failure requiring invasive mechanical ventilation, (3) significant neuromuscular disease, chest wall deformities, or pulmonary disease contributing to hypoventilation, (4) unstable coronary artery disease, or (5) cognitive impairment precluding informed consent or protocol adherence.
Following diagnosis, individuals with OHS were counseled on therapeutic options, including continuous positive airway pressure (CPAP) therapy, body weight reduction, or combined airway and bariatric surgery (CABS). The final decision was made through a shared decision-making process.
Outcome measures included (1) Polysomnography: All participants underwent attended level I polysomnography using the Nicolet UltraSom System (Nicolet, Madison, WI). AHI was the primary sleep parameter, defined as the total number of apneas (≥ 90% airflow reduction for ≥10 seconds) and hypopneas (> 50% airflow reduction with ≥ 3% oxygen desaturation or arousal) per hour of sleep. Scoring was performed by a single blinded sleep specialist. (2) Pulmonary function testing: Spirometry was performed using a handheld spirometer in accordance with international guidelines. Parameters included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and FEV₁/FVC ratio. (3) Gas exchange: ABG analysis was conducted during daytime hours with the participant seated and breathing room air after resting for at least 60 minutes. (4) Epworth sleepiness scale: Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS), a validated 8-item questionnaire with total scores ranging from 0 to 24; higher scores indicate greater daytime sleepiness.
The prevalence of OHS was calculated as the proportion of individuals diagnosed with OHS among those with concurrent obesity and obstructive sleep apnea (OSA). A multivariate logistic regression analysis with forward selection was conducted to identify independent predictors of OHS. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off points for various predictors. To evaluate the effects of the CABS intervention, pre- and post-operative changes in clinical parameters were compared.
- Being tested
- CABS
- Keywords
- Combined airway and bariatric surgery, Daytime hypercapnia, Obesity hypoventilation syndrome, Obstructive sleep apnea, Sleepiness, Transdisciplinary intervention
- Medical subject headings
- Obesity Hypoventilation Syndrome, Sleep Apnea, Obstructive, Sleepiness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CABSProcedure or surgery
Following diagnosis, individuals with OHS were counseled on therapeutic options, including CPAP therapy, body weight reduction, or CABS. The final decision was made through a shared decision-making process. The CABS procedure was conducted under general anesthesia and integrated bariatric and multilevel airway surgery within a single operative session. This transdisciplinary approach aimed to address both sleep-disordered breathing and obesity-related ventilatory compromise. A general surgeon performed the bariatric procedure, while an otorhinolaryngologist conducted the airway surgery sequentially during the same operation. For the bariatric component, laparoscopic sleeve gastrectomy (LSG) was the primary procedure, while laparoscopic Roux-en-Y gastric bypass was reserved for individuals with significant gastroesophageal reflux or poorly controlled diabetes. Airway surgery encompassed interventions at the nasal, palatal, and lingual levels.
| Study group | Role | What they receive |
|---|---|---|
| Obesity with OSA or OHS | Adults aged 20 to 65 years were eligible if they met the following inclusion criteria: (1) BMI ≥ 30 kg/m², and (2) AHI ≥ 5 events/hour. OSA was diagnosed by standard polysomnography. OHS was diagnosed based on the presence of BMI ≥ 30 kg/m², PaCO₂ ≥ 45 mmHg on arterial blood gas (ABG) analysis, and sleep-disordered breathing, following the exclusion of other potential causes of alveolar hypoventilation using pulmonary function tests. Receives: Procedure: CABS |
What is being measured
The primary outcome is the main question the study is designed to answer.
AHI
All participants underwent attended level I polysomnography using the Nicolet UltraSom System (Nicolet, Madison, WI). Apnea-hypopnea index (AHI) was the primary sleep parameter, defined as the total number of apneas (≥ 90% airflow reduction for ≥10 seconds) and hypopneas (> 50% airflow reduction with ≥ 3% oxygen desaturation or arousal) per hour of sleep. Scoring was performed by a single blinded sleep specialist.
Measured: From enrollment to the end of treatment at 12 months.
Secondary outcomes (3)
FEV₁/FVC ratio
Spirometry was performed using a handheld spirometer in accordance with international guidelines. Parameters included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and FEV₁/FVC ratio.
Measured: From enrollment to the end of treatment at 12 months.
PaCO₂
Arterial blood gas (ABG) analysis was conducted during daytime hours with the participant seated and breathing room air after resting for at least 60 minutes.
Measured: From enrollment to the end of treatment at 12 months
ESS score
Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS), a validated 8-item questionnaire with total scores ranging from 0 to 24; higher scores indicate greater daytime sleepiness.
Measured: From enrollment to the end of treatment at 12 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jun 2025
- Study start1 Sep 2022
- Primary completion31 Aug 2024
- Study completion30 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Obesity Hypoventilation Syndrome (OHS)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 36 participants (actual)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- Chang Gung Memorial Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hsueh-Yu Li, M.D., Principal investigator, Chang Gung Memorial Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07020689
- Sponsor's protocol ID
- 202201000A3
- Other IDs
- CMRPG1M0101 and CMRPG1M0102
- Acronym
- CABS for OHS
- Status last verified
- Aug 2022
- First submitted
- 5 Jun 2025
- Last updated
- 13 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Baird K, Comis LE, Joe GO, Steinberg SM, Hakim FT, Rose JJ, Mitchell SA, Pavletic SZ, Figg WD, Yao L, Flanders KC, Takebe N, Sarantopoulos S, Booher S, Cowen EW. Imatinib mesylate for the treatment of steroid-refractory sclerotic-type cutaneous chronic graft-versus-host disease. Biol Blood Marrow Transplant. 2015 Jun;21(6):1083-90. doi: 10.1016/j.bbmt.2015.03.006. Epub 2015 Mar 12.
PubMed 25771402