Obesity in Sleep Medicine - Focusing on OHS Phenotypes

Study Overview
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Brief Summary
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This study focuses on a comprehensive examination of obese patients with sleep-related breathing disorders including patients with OSA, sleep hypoventilation and OHS. The aim of this study is to (1) evaluate characteristics of and differences between severity levels of obesity-related breathing disorders, (2) discuss pathophysiological variables associated with hypoventilation during sleep or at daytime and (3) find functional parameters indicating sleep hypoventilation.

Official Title
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Obesity in Sleep Medicine - Focusing on OHS Phenotypes

Conditions
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Obesity Hypoventilation Syndrome (OHS)

Intervention / Treatment
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* Diagnostic Test: Sleep Study
* Diagnostic Test: Pulmonary Function Test
* Diagnostic Test: Hypercapnic ventilatory response
* Diagnostic Test: Cardiopulmonary Exercise Test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 years BMI ≥ 30 kg/m² Indication for sleep lab admission or indication for BiLevel or non-invasive ventilation therapy initiation due to existing hypoventilation/OHS Exclusion Criteria: Age <18 years Pregnancy, Lactation Any medical, psychological or other condition impairing the patient's ability to provide informed consent. Missing informed consent Participation in another clinical study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| OSA<br>Obstructive Sleep Apnea as confirmed by full-night attended in-lab polysomnography showing an apnea-hypopnea index of >=15 per hour or, alternatively, an apnea-hypopnea index >=5 with excessive daytime sleepiness as defined by an Epworth Sleepiness Scale score >9. | Diagnostic Test: Sleep Study<br>* Full-night attended in-lab polysomnography with accompanying transcutaneous capnometry<br>Diagnostic Test: Pulmonary Function Test<br>* Bodyplethysmographic assessment<br>Diagnostic Test: Hypercapnic ventilatory response<br>* Measurement of hypercapnic ventilatory response based on the method described by Read in 1967, using a rebreathing bag<br>Diagnostic Test: Cardiopulmonary Exercise Test<br>* Symptom-limited cardiopulmonary exercise test with a ramp protocol according to the ATS/ACCP and ERS recommendations<br>|
| OSA+SH<br>Obstructive Sleep Apnea as confirmed by full-night attended in-lab polysomnography showing an apnea-hypopnea index of >=15 per hour or, alternatively, an apnea-hypopnea index >=5 with excessive daytime sleepiness as defined by an Epworth Sleepiness Scale score >9. Furthermore, co-existing hypoventilation during sleep, defined by the presence of intermittent hypercapnia as measured by transcutaneous capnometry and arterialized capillary blood gas analysis. | Diagnostic Test: Sleep Study<br>* Full-night attended in-lab polysomnography with accompanying transcutaneous capnometry<br>Diagnostic Test: Pulmonary Function Test<br>* Bodyplethysmographic assessment<br>Diagnostic Test: Hypercapnic ventilatory response<br>* Measurement of hypercapnic ventilatory response based on the method described by Read in 1967, using a rebreathing bag<br>Diagnostic Test: Cardiopulmonary Exercise Test<br>* Symptom-limited cardiopulmonary exercise test with a ramp protocol according to the ATS/ACCP and ERS recommendations<br>|
| OHS<br>Obstructive Sleep Apnea as confirmed by full-night attended in-lab polysomnography showing an apnea-hypopnea index of >=15 per hour or, alternatively, an apnea-hypopnea index >=5 with excessive daytime sleepiness as defined by an Epworth Sleepiness Scale score >9. Furthermore, co-existing hypoventilation during wakefulness, defined by a PCO2>45mmHg as measured by arterialized capillary blood gas analysis. | Diagnostic Test: Sleep Study<br>* Full-night attended in-lab polysomnography with accompanying transcutaneous capnometry<br>Diagnostic Test: Pulmonary Function Test<br>* Bodyplethysmographic assessment<br>Diagnostic Test: Hypercapnic ventilatory response<br>* Measurement of hypercapnic ventilatory response based on the method described by Read in 1967, using a rebreathing bag<br>Diagnostic Test: Cardiopulmonary Exercise Test<br>* Symptom-limited cardiopulmonary exercise test with a ramp protocol according to the ATS/ACCP and ERS recommendations<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypercapnic ventilatory response |  | Within 48 hours of sleep lab admission | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obstructive Sleep Apnea, Sleep Hypoventilation