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NCT Number: NCT07001215

Effect of CPAP Versus APAP in Patients With Obesity Undergoing Bariatric Surgery Protocol

Introduction Obstructive sleep apnea (OSA) is a common disorder in obese patients, especially those undergoing bariatric surgery. OSA is characterized by upper airway obstruction during sleep, leading to intermittent hypoxia and sleep fragmentation. Obesity and OSA are closely related conditions that can exacerbate each other. Positive airway pressure therapy is essential for managing OSA, but adherence to therapy can be challenging, particularly in patients who experience rapid physiological changes after bariatric surgery.

Objective This study aims to determine whether automatic positive airway pressure therapy (APAP) improves nightly usage hours compared to continuous positive airway pressure therapy (CPAP) in obese patients undergoing bariatric surgery. Secondary objectives include evaluating the percentage of nights with therapy use over 4 hours, reduction of the residual apnea-hypopnea index (AHI), changes in daytime sleepiness, pressure requirements, side effects, sleep-related quality of life, reduction in in-person visits, and optimization of healthcare resources.

Methodology A randomized, parallel-group, open-label, controlled clinical trial will be conducted. Adult patients eligible for bariatric surgery with a diagnosis of moderate to severe OSA (AHI > 15) requiring positive pressure therapy will be included. Participants will be randomized to receive either APAP or CPAP. Follow-up will be conducted over 12 months after surgery, with assessments at 3, 6, and 12 months. Data will be collected on treatment adherence, residual AHI, OSA symptoms, daytime sleepiness, quality of life, and treatment costs.

APAP therapy is expected to improve nightly usage hours compared to CPAP. It is also expected that APAP will show better adaptation to changing pressure needs after bariatric surgery. Data will be analyzed to evaluate the effectiveness and cost-efficiency of both therapies.

This study will provide evidence on the efficacy of APAP compared to CPAP in obese patients undergoing bariatric surgery. The results will help optimize the treatment of OSA in this population and improve patients' quality of life. Additionally, the study is expected to contribute to the optimization of healthcare resources by reducing in-person visits and repeated sleep studies.

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Key information

Conditions

Sleep Apnea, Obstructive Apnea Bariatric Surgery Behavior Body Weight Continuous Positive Airway Pressure (CPAP) Dyssomnias Health Behavior Nervous System Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Sleep Apnea Syndromes Sleep Disorders, Intrinsic Sleep Wake Disorders Treatment Adherence and Compliance

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hospital Universitario Ramón y Cajal,

Madrid, Spain, 28034

Location contact

Laura Pozuelo-Sánchez, Nurse

CONTACT

[email protected]

913368000 ext. 489059

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subjects aged 18 to 80 years who meet the criteria for bariatric surgery and are on the surgical waiting list after approval by the bariatric surgery committee (BMI ≥35, or BMI ≥30 with comorbidities).
  • Diagnosis of moderate or severe sleep apnea, defined by an Apnea-Hypopnea Index (AHI) >15, requiring treatment according to protocol ("Patients with an AHI of 15 or higher will be treated with CPAP if they have hypertension, excessive daytime sleepiness, or sleep-related symptoms not explained by other causes" [17]).
  • Patients must be able to read and understand the informed consent and provide signed consent.

Exclusion criteria

  • Patients with central sleep apnea or periodic breathing
  • Patients with any active neoplasm
  • Patients with severe uncontrolled psychiatric disorders, alcoholism, or active drug addiction
  • Patients with unacceptable surgical/anesthetic risk
  • Patients who have undergone previous surgery for OSA or who have been treated with positive airway pressure and did not tolerate it

Treatment and study plan

In the intervention group, patients will be treated with auto-adjusting APAP, providing variable pressures throughout the sleep hours.

Device

AutoCPAP will be prescribed to patients undergoing bariatric surgery.

Other names: APAP, Automatic Positive Airway Pressure

CPAP

Device

In the control group, patients will be treated with CPAP.

Other names: Continuous Positive Airway Pressure

Primary outcomes

  1. APAP vs. CPAP: Impact on Nightly Usage in Obese Patients Undergoing Bariatric Surgery

    Time frame: Obese patients undergoing bariatric surgery will be evaluated during the 3 months prior to surgery and at 3, 6, and 12 months postoperatively in patients with OSA undergoing bariatric surgery.

    To determine whether APAP therapy increases nightly usage hours compared to CPAP therapy in obese patients undergoing bariatric surgery. Unit of Measure: Average hours of PAP use per night (measured via device data).

Secondary outcomes

  1. Therapy Adherence Over Time

    Time frame: 3 months before bariatric surgery and at 3, 6, and 12 months postoperatively.

    To measure and compare the percentage of nights with therapy usage exceeding 4 hours in both groups (APAP and fixed CPAP). Unit of Measure: Percentage of nights with ≥4 hours of PAP use.

  2. Reduction in Residual AHI

    Time frame: 3 months before bariatric surgery and at 3, 6, and 12 months postoperatively.

    To evaluate the reduction in the residual Apnea-Hypopnea Index (AHI) in both groups. Unit of Measure: Residual AHI (events per hour).

  3. Daytime Sleepiness

    Time frame: 3, 6, and 12 months postoperatively

    To assess changes in daytime sleepiness using validated scales (e.g., Epworth Sleepiness Scale) in both groups. Unit of Measure: Total ESS score (range: 0-24; higher scores indicate greater sleepiness).

  4. Pressure Requirement Trends

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To evaluate and compare changes in positive airway pressure (PAP) requirements, measured in cm H₂O, in patients treated with APAP or CPAP over time.

    Unit of Measure: Pressure level (cm H₂O).

  5. Pressure Adaptability of APAP

    Time frame: 3, 6, and 12 months postoperatively

    To assess the adaptability of APAP therapy to varying pressure requirements over time, compared to fixed-pressure CPAP, in patients with OSA following bariatric surgery.

    Unit of Measure: Variability in delivered pressure (cm H₂O).

  6. Side Effects Monitoring

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To measure and compare the presence of side effects (e.g., nasal dryness, skin irritation) in both groups. Unit of Measure: Incidence of reported side effects (percentage of patients affected).

  7. Sleep Quality (assessed using the Pittsburgh Sleep Quality Index)

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To assess sleep quality using the validated Pittsburgh Sleep Quality Index (PSQI) questionnaire.in both groups. Unit of Measure: Total PSQI score (range: 0-21; higher scores indicate poorer sleep quality).

  8. General Quality of Life (assessed using the EuroQol-5D)

    Time frame: 3 months pre-surgery and 3, 6, and 12 months postoperatively.

    To assess general quality of life using the validated EuroQol-5D (EQ-5D) questionnaire. Unit of Measure: EQ-5D Utility Index and Visual Analogue Scale (VAS) score 0-100.

  9. Reduction in Outpatient Visits

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To analyze the potential reduction in outpatient clinic visits in the APAP group compared to the CPAP group. Unit of Measure: Number of outpatient visits per patient.

  10. Healthcare Resource Optimization

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To evaluate the reduction in repeated sleep studies as an indicator of healthcare resource optimization in patients treated with APAP compared to CPAP.

    Unit of Measure: Number of repeated sleep studies per patient.

  11. STOP-BANG Questionnaire Accuracy

    Time frame: (3 months pre-surgery and 3, 6, and 12 months postoperatively).

    To assess the sensitivity and specificity of the STOP-BANG questionnaire for detecting OSA in bariatric patients, and to determine whether a new cutoff point is needed to optimize its performance in this population. Unit of Measure: STOP-BANG total score (range 0 to 8); sensitivity and specificity percentages for different cutoff points.

Study contacts

Contact information is provided by the study sponsor or research team.

Aldara García-Sánchez, PhD Pneumology Consultant

CONTACT

[email protected]

913368000 ext. 489060

Laura Pozuelo- Sánchez, Nurse

CONTACT

[email protected]

913368000 ext. 489059

Sponsors and collaborators

Lead sponsor

Hospital Universitario Ramon y Cajal

Other

Collaborators

  • Fundacion para la Investigacion Biomedica del Hospital Universitario Ramon y Cajal

Registry information

Acronym: ObesAOS

Important dates

Study start
2025
Primary completion
2027
Study completion
2028
First posted
Jun 3, 2025
Registry last updated
Jul 23, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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