Prevalence of Nocturnal Hypoventilation in Obese Subjects Fiited With Continuous Positive Airway Pressure for Obstructive Sleep Apnea / Hypopnea Syndrome

NCT07152990 | Not Yet Recruiting

• 2 other identifiers: RC31/24/02902025-A00694-45
• Study Type: interventional
• Target: 139
• Locations: 1 country
• Sites: 1

Brief Summary

CAPNOSOH study is a single-center study conducted at Toulouse University Hospital, aiming to estimate the prevalence of obese and apneic subjects maintaining nocturnal hypoventilation under continuous positive airway pressure (CPAP).

Conditions

Nocturnal Hypoventilation; Obesity; Sleep Apnea Hypopnea Syndrome

Keywords

Nocturnal hypoventilation; obesity; sleep apnea syndrome; continuous positive pressure; transcutaneous capnography

Outcome Measures

Primary Outcomes (1)

• Prevalence of nocturnal alveolar hypoventilation

  Prevalence of nocturnal alveolar hypoventilation will be diagnosed by transcutaneous oxy-capnography. Nocturnal alveolar hypoventilation is defined with PTcCO2 \> 49 mmHg more than 10% of the time of capnographic recording.

  1 month

Study Arms (1)

Obese Patients with Obstructive Sleep Apnea/Hypopnea

OTHER

Other: Transcutaneous Oxy-Capnography; Other: Quality of life questionnaires; Other: Arterial gasometry; Other: Body plethysmography; Other: Spirometry with reversibility test; Other: Clinical examination

Interventions

Transcutaneous Oxy-Capnography OTHER

Patients will be monitored using transcutaneous oxy-capnography to evaluate the prevalence of nocturnal alveolar hypoventilation in these population. Nocturnal alveolar hypoventilation is defined with PTcCO2 \> 49 mmHg more than 10% of the time of capnographic recording.

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Quality of life questionnaires OTHER

Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and the "Patient-Reported Hypoventilation Questionnaire".

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Arterial gasometry OTHER

Arterial blood gas analysis will be performed only in patients presenting nocturnal hypoventilation.

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Body plethysmography OTHER

Plethysmography will be performed only in patients presenting nocturnal hypoventilation. It will be used to measure lung volume and assess pulmonary function. This non-invasive procedure involves the patient breathing into a device that measures changes in pressure within a sealed chamber.

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Spirometry with reversibility test OTHER

The intervention will be performed only in patients presenting nocturnal hypoventilation. Spirometry with a reversibility test will be performed to assess lung function and evaluate the response to bronchodilators. The procedure involves measuring forced expiratory volume and forced vital capacity before and after the administration of a bronchodilator.

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Clinical examination OTHER

Clinical exam will be performed only in patients presenting nocturnal hypoventilation. It will consists of standard interview/clinical examination: vital signs, cardiological, pulmonary, abdominal, neurological examination, search for clinical signs of nocturnal hypoventilation, search for signs of hypoxia/hypercapnia, pulmonary auscultation.

Obese Patients with Obstructive Sleep Apnea/Hypopnea

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Obese patients (Body Mass Index \> 30 kg/m2)
• Fitted by one of the following providers: ASTEN, Vitalaire, Orkyn, ISIS, RespiO2, BASTIDE for \> 3 months with compliance of more than 4 consecutive hours per night in average during 3 months
• "Good quality" criteria for continuous positive airway pressure (CPAP) treatment: compliance \> 4 consecutive hours per night, unintentional leaks \< limit defined by the manufacturer, residual AHI \< 10/h
• Aged 18 to 80
• Affiliated or beneficiaries of the social security system or equivalent
• Having given written informed consent
• Able to understand instructions and information given

You may not qualify if:

• Patient under legal protection measure
• Non-compliant patients
• Pregnant or breast-feeding women (assessed on questioning)

Sponsors & Collaborators

• University Hospital, Toulouse: lead
• Fonds de dotation Agir pour les Maladies Chroniques: collaborator

Study Sites (1)

CHU de Toulouse Hôpital Larrey

Toulouse, Occitanie, 31059, France

Location

MeSH Terms

Conditions

Obesity; Sleep Apnea, Obstructive; Sleep Apnea Syndromes

Interventions

Restraint, Physical

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Behavior Control; Therapeutics; Immobilization; Investigative Techniques

Central Study Contacts

Sandrine PONTIER

CONTACT

05 67 77 18 46; pontier.s@chu-toulouse.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: All patients will undergo transcutaneous oxy-capnography and answer quality of life questionnaires. Only patients presenting nocturnal hypoventilation defined with PTcCO2 \> 49 mmHg more than 10% of the time of capnographic recording will continue the study with additional interventions. Patients without nocturnal hypoventilation will finish the study after the capnographic recording visit.

Study Record Dates

• First Submitted: August 25, 2025
• First Posted: September 3, 2025
• Study Start: September 1, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: September 3, 2025

Record last verified: 2025-08

Locations

FR (1)