Obstructive Sleep Apnea (OSA)NCT07606898
Fractional Exhaled Nitric Oxide as Possible Non - Invasive Biomarker to Assess Obstructive Sleep Apnea Severity
An observational study of Obstructive Sleep Apnea (OSA), run by Tanta University at 1 site in Egypt.
Trial summary
Aim of work 1. Primary aim: Asses correlation between FeNO level, OSA severity 2. Secondary aim: Clarifying FeNO's role as a biomarker to assess airway inflammation, Cut off value prediction to moderate and severe OSA and its potential significance to improve clinical management strategies for OSA patients. Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Obstructive Sleep Apnea (OSA)
- How many people
- 200 participants
- Where
- 1 siteEgypt
- Study dates
- 25 May 2026to 1 Oct 2026
- How long will I take part?
- 3 Months
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Study Type: prospective observational cross sectional study. Sample Size: This study will be carried out on 200 patients' suspected for obstructive sleep apnea, following approval of medical research ethical committee of Tanta University, Faculty of Medicine. Sample size was calculated using this formula 2SD ^2 × (1.96 + 0.84)^2 /d^2 SD of FeNO 50 at moderate OSA 17.25 d is the difference between both means 21, 13.57 So at power of study 80% CI 95% Least Sample size will be 85 in each group
Who may be able to join
- Ages Eligible for study: 18 years till 70 years old.
- Newly suspected OSA patients with Epworth Sleepiness Scale (ESS) ≥ 10.
Who cannot join
- Current smokers.
- Any chronic Respiratory disorders other than OSA (asthma, COPD, allergic rhinitis, and atopic diseases).
- Younger age than 18 years.
- Recent inhaled or systemic corticosteroids within the pasr 4 weeks.
- Recent respiratory infection less than 4 weeks.
- Uncontrolled diabetes \& any chronic debilitating diseases (liver, renal, collagen diseases) Informed Consent will be taken from the participants before clinical examination.
Trial locations and contacts
1 site in 1 country.
About this study
Aim of work
- Primary aim: Asses correlation between FeNO level, OSA severity
- Secondary aim: Clarifying FeNO's role as a biomarker to assess airway inflammation, Cut off value prediction to moderate and severe OSA and its potential significance to improve clinical management strategies for OSA patients.
Read the detailed description
Obstructive Sleep Apnea is a highly prevalent sleep-related breathing disorder characterized by recurrent episodes of upper airway obstruction during sleep, resulting in intermittent hypoxia, sleep fragmentation, and significant cardiometabolic consequences. The severity of OSA is traditionally assessed using overnight polysomnography (PSG), with the apnea-hypopnea index (AHI) serving as the gold standard metric. However, PSG is resource-intensive, time-consuming, and not readily accessible in many healthcare settings, particularly in resource-limited environments. This has driven increasing interest in identifying reliable, non-invasive biomarkers that could aid in the assessment of disease severity and reduce dependence on PSG.(1) Airway and systemic inflammation play a central role in the pathophysiology of OSA. Recurrent hypoxia-reoxygenation cycles induce oxidative stress and activate inflammatory pathways, leading to endothelial dysfunction and tissue injury.(1) Fractional exhaled nitric oxide (FeNO) is a well-established non-invasive biomarker of airway inflammation, widely used in the assessment of eosinophilic airway diseases such as asthma. Given its ability to reflect inflammatory processes within the respiratory tract, FeNO has been proposed as a potential marker in OSA.(2) Several studies have explored the relationship between FeNO levels and OSA. Some have demonstrated elevated FeNO levels in patients with OSA compared to healthy controls, along with positive correlations between FeNO and indices of disease severity such as AHI and oxygen desaturation index (ODI).(3) In contrast, other studies have reported inconsistent or weak associations, suggesting that the inflammatory profile in OSA (often predominantly neutrophilic rather than eosinophilic) may limit the specificity of FeNO as a biomarker in this context.
Importantly, the current literature is characterized by several limitations. Many studies have small sample sizes, heterogeneous populations, and inadequate control for confounding factors such as smoking, obesity, and coexisting airway diseases. Furthermore, most studies focus primarily on simple correlations with AHI, without evaluating the diagnostic performance of FeNO or its ability to discriminate between different severity categories of OSA. The absence of robust predictive models integrating FeNO with clinical parameters further limits its applicability in routine clinical practice.(4) Therefore, a significant gap remains regarding whether FeNO can serve as a clinically meaningful, non-invasive biomarker for stratifying OSA severity. In particular, there is a need for well-designed studies that not only assess the association between FeNO and polysomnographic parameters, but also evaluate its diagnostic accuracy and potential role within predictive models.
Accordingly, the present study aims to investigate the role of FeNO in assessing the severity of OSA, to determine its relationship with key polysomnographic indices, and to evaluate its potential utility as a non-invasive tool for disease stratification.
- Conditions
- Obstructive Sleep Apnea (OSA)
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| • Control group AHI less than 5 \ hour - case groups Milld OSA & moderate to severe OSA | All 200 participants will undergo: * History taking including: Age, sex, occupation, residence, education, and special habits e.g., smoking * Plain chest x ray\& PFT to exclude any other chest diseases (asthma\& COPD) * The participants' Blood pressure, height and weight will be measured, and body mass index will be calculated. * Daytime sleepiness will be assessed by the Epworth Sleepiness Scale and a value of 10 or more denoting as excessive daytime sleepiness. * Full laboratory investigation to exclude any chronic diseases. * Full-night PSG in chest department, Tanta university hospital. * FENO level base line at 9 am after PSG night \& interpretation accordin * After PSG result, cases will be divided in 3 groups * Control group AHI less than 5 \ hour * Mild OSA group AHI than 5-15 \ hour * Mod to severe OSA more than 15 \ hour |
What is being measured
The primary outcome is the main question the study is designed to answer.
Asses correlation between FeNO level, OSA severity• through measuring FeNo level in 3 groups which will be divided according to AHI in PSG study -Control group AHI less than 5 \ hour, Mild OSA group AHI than 5-15 \ hour, Moderate to severe OSA group
address the correlation between PSG parameters performed by Somno medics screen including (apnea hypopnea index (event\ hour) oxygen nadir(%), oxygen desaturation index, % of time desaturation below 90% (T90), snoring index) and FeNo level ppb which measured by (Bedfont NIN006187 Nobreath) to Clarify FeNO's role as a biomarker to assess airway inflammation, and OSA severity, address FeNoCut off value as prediction tool to moderate and severe OSA and its potential significance to improve clinical management strategies for OSA patients.
FeNo measurement precaution will be addressed as the participants will be asked to abstain from eating, drinking, and exercise, and avoid exposure to tobacco fumes 60 minutes before testing, so all cases FeNO assay will be hold at 9 am, Ask patients to refrain from Intake of nitrate-containing food like green-leaved vegetables on the day of assessment and then will be interprated according to ATS guidelines
Measured: baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 May 2026
- Study start25 May 2026
- Primary completion1 Sep 2026 (estimated)
- Study completion1 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Obstructive Sleep Apnea (OSA)Studies of the same condition, open and under way.
- More trials run by Tanta UniversityThe sponsor's other registered studies.
- 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
- Target duration
- 3 Months
Sponsor and investigators
- Lead sponsor
- Tanta University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Martina Reda Abdo, Tanta University
- Investigators
- Mohammed Sayed Hantira, professor, Study director, Tanta UniversityAyman Hassan AbdElzaher, professor, Study chair, Tanta UniversityAhmed Gharib Gharib, assistant professor, Study chair, cairo institute for researchMohammed Samy Torky, assistant professor, Study chair, Tanta UniversityMartina Reda Abdo, lecturer, Principal investigator, Tanta UniversityAya Mohammed Rabeah, lecturer, Study chair, Tanta University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07606898
- Sponsor's protocol ID
- FeNo in OSA
- Status last verified
- May 2026
- First submitted
- 12 May 2026
- Last updated
- 25 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Slowik JM, Sankari A, Collen JF. Obstructive Sleep Apnea. 2025 Mar 4. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK459252/
PubMed 29083619Ragnoli B, Radaeli A, Pochetti P, Kette S, Morjaria J, Malerba M. Fractional nitric oxide measurement in exhaled air (FeNO): perspectives in the management of respiratory diseases. Ther Adv Chronic Dis. 2023 Aug 1;14:20406223231190480. doi: 10.1177/20406223231190480. eCollection 2023.
PubMed 37538344Zhu Q, Huang L, Zhu L, Zhang X, Ji H, Niu D, Ji W, Ma Q, Chen R, Shi H, Wang Y, Xu L. Association Between Fractional Exhaled Nitric Oxide (FeNO) and Cognitive Function in Patients with Obstructive Sleep Apnea. Nat Sci Sleep. 2025 Jul 12;17:1603-1614. doi: 10.2147/NSS.S524831. eCollection 2025.
PubMed 40672996Michils A, Akset M, Haccuria A, Perez-Bogerd S, Malinovschi A, Van Muylem A. The Impact of Airway Obstruction on Feno Values in Asthma Patients. J Allergy Clin Immunol Pract. 2024 Jan;12(1):111-117. doi: 10.1016/j.jaip.2023.08.027. Epub 2023 Aug 25.
PubMed 37634805
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Fractional Exhaled Nitric Oxide as Possible Non - Invasive Biomarker to Assess Obstructive Sleep Apnea Severity
- ClinicalTrials.gov ID
- NCT07606898
- Acronym / sponsor ID
- FeNo in OSA
- Conditions
- Obstructive Sleep Apnea (OSA)
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- 25 May 2026 (actual)
- Primary completion
- 1 Sep 2026 (estimated)
- Study completion
- 1 Oct 2026 (estimated)
- First posted
- 26 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Aim of work
- Primary aim: Asses correlation between FeNO level, OSA severity
- Secondary aim: Clarifying FeNO's role as a biomarker to assess airway inflammation, Cut off value prediction to moderate and severe OSA and its potential significance to improve clinical management strategies for OSA patients.
Detailed description
Obstructive Sleep Apnea is a highly prevalent sleep-related breathing disorder characterized by recurrent episodes of upper airway obstruction during sleep, resulting in intermittent hypoxia, sleep fragmentation, and significant cardiometabolic consequences. The severity of OSA is traditionally assessed using overnight polysomnography (PSG), with the apnea-hypopnea index (AHI) serving as the gold standard metric. However, PSG is resource-intensive, time-consuming, and not readily accessible in many healthcare settings, particularly in resource-limited environments. This has driven increasing interest in identifying reliable, non-invasive biomarkers that could aid in the assessment of disease severity and reduce dependence on PSG.(1) Airway and systemic inflammation play a central role in the pathophysiology of OSA. Recurrent hypoxia-reoxygenation cycles induce oxidative stress and activate inflammatory pathways, leading to endothelial dysfunction and tissue injury.(1) Fractional exhaled nitric oxide (FeNO) is a well-established non-invasive biomarker of airway inflammation, widely used in the assessment of eosinophilic airway diseases such as asthma. Given its ability to reflect inflammatory processes within the respiratory tract, FeNO has been proposed as a potential marker in OSA.(2) Several studies have explored the relationship between FeNO levels and OSA. Some have demonstrated elevated FeNO levels in patients with OSA compared to healthy controls, along with positive correlations between FeNO and indices of disease severity such as AHI and oxygen desaturation index (ODI).(3) In contrast, other studies have reported inconsistent or weak associations, suggesting that the inflammatory profile in OSA (often predominantly neutrophilic rather than eosinophilic) may limit the specificity of FeNO as a biomarker in this context.
Importantly, the current literature is characterized by several limitations. Many studies have small sample sizes, heterogeneous populations, and inadequate control for confounding factors such as smoking, obesity, and coexisting airway diseases. Furthermore, most studies focus primarily on simple correlations with AHI, without evaluating the diagnostic performance of FeNO or its ability to discriminate between different severity categories of OSA. The absence of robust predictive models integrating FeNO with clinical parameters further limits its applicability in routine clinical practice.(4) Therefore, a significant gap remains regarding whether FeNO can serve as a clinically meaningful, non-invasive biomarker for stratifying OSA severity. In particular, there is a need for well-designed studies that not only assess the association between FeNO and polysomnographic parameters, but also evaluate its diagnostic accuracy and potential role within predictive models.
Accordingly, the present study aims to investigate the role of FeNO in assessing the severity of OSA, to determine its relationship with key polysomnographic indices, and to evaluate its potential utility as a non-invasive tool for disease stratification.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 3 Months
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| • Control group AHI less than 5 \ hour - case groups Milld OSA & moderate to severe OSA | – | –All 200 participants will undergo: * History taking including: Age, sex, occupation, residence, education, and special habits e.g., smoking * Plain chest x ray\& PFT to exclude any other chest diseases (asthma\& COPD) * The participants' Blood pressure, height and weight will be measured, and body mass index will be calculated. * Daytime sleepiness will be assessed by the Epworth Sleepiness Scale and a value of 10 or more denoting as excessive daytime sleepiness. * Full laboratory investigation to exclude any chronic diseases. * Full-night PSG in chest department, Tanta university hospital. * FENO level base line at 9 am after PSG night \& interpretation accordin * After PSG result, cases will be divided in 3 groups * Control group AHI less than 5 \ hour * Mild OSA group AHI than 5-15 \ hour * Mod to severe OSA more than 15 \ hour |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Study Type: prospective observational cross sectional study. Sample Size: This study will be carried out on 200 patients' suspected for obstructive sleep apnea, following approval of medical research ethical committee of Tanta University, Faculty of Medicine. Sample size was calculated using this formula 2SD ^2 × (1.96 + 0.84)^2 /d^2 SD of FeNO 50 at moderate OSA 17.25 d is the difference between both means 21, 13.57 So at power of study 80% CI 95% Least Sample size will be 85 in each group
Key inclusion criteria (2 listed)
- Ages Eligible for study: 18 years till 70 years old.
- Newly suspected OSA patients with Epworth Sleepiness Scale (ESS) ≥ 10.
Key exclusion criteria (6 listed)
- Current smokers.
- Any chronic Respiratory disorders other than OSA (asthma, COPD, allergic rhinitis, and atopic diseases).
- Younger age than 18 years.
- Recent inhaled or systemic corticosteroids within the pasr 4 weeks.
- Recent respiratory infection less than 4 weeks.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Asses correlation between FeNO level, OSA severity• through measuring FeNo level in 3 groups which will be divided according to AHI in PSG study -Control group AHI less than 5 \ hour, Mild OSA group AHI than 5-15 \ hour, Moderate to severe OSA group
Time frame: baseline
address the correlation between PSG parameters performed by Somno medics screen including (apnea hypopnea index (event\ hour) oxygen nadir(%), oxygen desaturation index, % of time desaturation below 90% (T90), snoring index) and FeNo level ppb which measured by (Bedfont NIN006187 Nobreath) to Clarify FeNO's role as a biomarker to assess airway inflammation, and OSA severity, address FeNoCut off value as prediction tool to moderate and severe OSA and its potential significance to improve clinical management strategies for OSA patients. FeNo measurement precaution will be addressed as the participants will be asked to abstain from eating, drinking, and exercise, and avoid exposure to tobacco fumes 60 minutes before testing, so all cases FeNO assay will be hold at 9 am, Ask patients to refrain from Intake of nitrate-containing food like green-leaved vegetables on the day of assessment and then will be interprated according to ATS guidelines
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Background: PubMed 29083619Slowik JM, Sankari A, Collen JF. Obstructive Sleep Apnea. 2025 Mar 4. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK459252/
- Background: PubMed 37538344Ragnoli B, Radaeli A, Pochetti P, Kette S, Morjaria J, Malerba M. Fractional nitric oxide measurement in exhaled air (FeNO): perspectives in the management of respiratory diseases. Ther Adv Chronic Dis. 2023 Aug 1;14:20406223231190480. doi: 10.1177/20406223231190480. eCollection 2023.
- Background: PubMed 40672996Zhu Q, Huang L, Zhu L, Zhang X, Ji H, Niu D, Ji W, Ma Q, Chen R, Shi H, Wang Y, Xu L. Association Between Fractional Exhaled Nitric Oxide (FeNO) and Cognitive Function in Patients with Obstructive Sleep Apnea. Nat Sci Sleep. 2025 Jul 12;17:1603-1614. doi: 10.2147/NSS.S524831. eCollection 2025.
- Background: PubMed 37634805Michils A, Akset M, Haccuria A, Perez-Bogerd S, Malinovschi A, Van Muylem A. The Impact of Airway Obstruction on Feno Values in Asthma Patients. J Allergy Clin Immunol Pract. 2024 Jan;12(1):111-117. doi: 10.1016/j.jaip.2023.08.027. Epub 2023 Aug 25.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mohammed Sayed Hantira, professor study director
Tanta University
Ayman Hassan AbdElzaher, professor study chair
Tanta University
Ahmed Gharib Gharib, assistant professor study chair
cairo institute for research
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obstructive Sleep Apnea (OSA), run by Tanta University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Asses correlation between FeNO level, OSA severity• through measuring FeNo level in 3 groups which will be divided according to AHI in PSG study -Control group AHI less than 5 \ hour, Mild OSA group AHI than 5-15 \ hour, Moderate to severe OSA group (time frame: baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07606898, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.