An interventional study of Sleep Inertia Questionnaire (SIQ) in Obstructive Sleep Apnea, Obesity (BMI>30) and Obesity Hypoventilation Syndrome (OHS), sponsored by Hospices Civils de Lyon. Not yet recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Hospices Civils de Lyon · Not applicable, Interventional, and Diagnostic
Obesity-related sleep hypoventilation represents a continuum ranging from isolated nocturnal hypoventilation to obesity hypoventilation syndrome. Current diagnostic criteria rely mainly on dichotomous thresholds and may not adequately reflect cumulative nocturnal carbon dioxide exposure.
Hypercapnic burden, defined as the cumulative area under the transcutaneous carbon dioxide (PtcCO₂) curve above a predefined threshold, has recently emerged as a novel physiological marker integrating both the intensity and duration of nocturnal hypercapnia.
This prospective observational cohort study aims to evaluate the association between nocturnal hypercapnic burden and obstructive sleep apnea severity, assessed by the apnea-hypopnea index (AHI), in adults with obesity referred for diagnostic polysomnography.
Secondary objectives include evaluating associations between hypercapnic burden and sleep architecture, respiratory events, oxygenation parameters, daytime symptoms, and patient-reported outcomes. In addition, the study will investigate the relationship between nocturnal hypercapnic burden and sleep inertia, assessed using the Sleep Inertia Questionnaire (SIQ), based on the hypothesis that greater nocturnal carbon dioxide exposure immediately before awakening may contribute to impaired alertness upon awakening.
Hypothesis: Increased nocturnal hypercapnic burden is associated with greater obstructive sleep apnea severity and reflects an additional physiological dimension of obesity-related sleep hypoventilation beyond conventional polysomnographic indices. Furthermore, higher nocturnal hypercapnic burden is hypothesized to be associated with greater sleep inertia.
73 studies on the registry are indexed under Obesity Hypoventilation Syndrome; 10 are open to participants now.
This study's planned enrollment of 150 is above the median of 40 across 42 interventional studies indexed under Obesity Hypoventilation Syndrome.
Browse Obesity Hypoventilation Syndrome studies →Hospices Civils de Lyon is the lead sponsor of 1,866 studies on the registry; 448 are open to participants now.
Compared within Obesity Hypoventilation Syndrome, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Sleep Apnea, Obstructive. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults with obesity (body mass index ≥30 kg/m²) referred to the Sleep Medicine Center for routine diagnostic polysomnography because of suspected obstructive sleep apnea
Behavioral: Sleep Inertia Questionnaire (SIQ)
The only research-specific procedure is the completion of the Sleep Inertia Questionnaire (SIQ), a self-administered questionnaire requiring approximately 5 minutes to complete and performed once after the diagnostic sleep study.
Correlation between nocturnal hypercapnic burden and apnea-hypopnea index
Correlation between nocturnal hypercapnic burden above 45 mmHg (HB45), defined as the area under the nocturnal transcutaneous carbon dioxide pressure (PtcCO₂) curve above 45 mmHg and normalized per hour of recording (mmHg·min/hour), and the apnea-hypopnea index derived from diagnostic polysomnography (events/hour). The correlation will be assessed using Pearson's or Spearman's correlation coefficient, according to data distribution.
Time frame: Baseline only (overnight diagnostic polysomnography)
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Obesity Hypoventilation Syndrome →