Clinical Research Directory

Heart and Brain Blood Flow in Obstructive Sleep Apnea

Obstructive sleep apnea causes repeated pauses in breathing during sleep. Breathing efforts against an occluded airway may change how blood flows through the heart and how blood drains from the brain. This study will examine these changes in 25 adults with severe obstructive sleep apnea and 25 adults without sleep apnea, aged 18 to 65 years. Participants will attend a screening visit and one magnetic resonance imaging (MRI) visit. MRI will measure blood flow in major vessels in the chest, neck and brain at rest and during brief, standardized breathing maneuvers. Participants with sleep apnea will also be studied during obstructive apneas while sleeping in the scanner, and during continuous positive airway pressure (CPAP), which keeps the airway open. The main objective is to quantify changes in blood flow rate and peak blood velocity before, during and at the end of obstructive apneas. The study will also compare responses to breathing maneuvers and resting blood flow between groups, and assess changes associated with CPAP in participants with sleep apnea. Secondary brain MRI outcomes are total perivascular space burden, burden in the basal ganglia and centrum semiovale, and the DTI ALPS index. BrainAGE, the difference between estimated brain age and chronological age in years, is an exploratory outcome. These MRI markers are compared between groups at baseline and after CPAP treatment.

Effect of High-flow Nasal Cannula Oxygenation on the Incidence of Hypoxemia During Painless Gastrointestinal Endoscopy in Patients at High Risk for Obstructive Sleep Apnea Syndrome in High-altitude Regions

Patients living in high-altitude areas naturally have lower blood oxygen levels. Those at high risk for Obstructive Sleep Apnea (OSA) face an even greater risk of low oxygen during painless gastrointestinal endoscopy. This multicenter study will randomly assign these patients to receive either High-Flow Nasal Oxygen (HFNC) or standard oxygen therapy during their procedure, aiming to find out if HFNC can safely and effectively reduce the risk of low oxygen events.

The Impact of Technology in Obstructive Sleep Apnea Myofunctional Therapy

This is a study to test if performing airway exercises to improve snoring and sleep apnea using a mobile phone app is better than using a hardcopy guide.

Myofunctional Therapy for Children With OSA

Myofunctional therapy (MFT) has been proposed as an adjunctive therapy for obstructive sleep apnoea (OSA) in children. Some studies have reported improved sleep parameters and reduced oral breathing after MFT. However, the level of evidence in these studies is limited, with most being case series or case-control studies. There have been only a few randomised controlled trials (RCTs), and these studies have had limitations such as low response rate, short follow-up periods, and the existing evidence does not adequately address the potential clinical benefits and the impact on craniofacial structure. Additionally, there is a lack of evidence regarding the effectiveness of additional measures, such as remote guidance and supervision, in improving treatment outcomes in children. Therefore, there is a need for further research to address these gaps and provide more robust evidence on the efficacy of MFT in children with OSA. The objective of this study is to investigate the efficacy of MFT in children with OSA through a multi-centre randomised controlled trial (RCT). 174 children aged 6-12 years old with OSA will be recruited and randomly assigned to either the intervention or control group. All children will undergo standardised evaluation at baseline and follow-up visits. In the intervention arm, a 24-week myofunctional therapy targeting orofacial MFT, breathing, and postural re-education, with incorporation of telemedicine for remote training and monitoring. In the control arm, children will receive standard care without MFT. The primary outcome measure will be obstructive apnoea hypopnoea index measured by polysomnography. Secondary outcome measures will be the oral breathing pattern, OSA-related symptoms, and quality of life. The treatment effect on outcomes will be examined using a mixed-effects model with an intention-to-treat approach. Subgroup analyses will explore potential effect modification by important participant characteristics, such as OSA severity and compliance. This study will generate evidence-based information regarding the efficacy of MFT in children with OSA and will inform clinical practice.

Prevalence of Obstructive Sleep Apnea in HHT and HHT-specific Challenges in OSA-therapy - a Retrospective Cohort Study

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder (prevalence approx. 1:5,000-1:8,000) characterized by recurrent epistaxis, mucocutaneous telangiectasias and visceral vascular malformations. Chronic bleeding frequently leads to anemia and iron deficiency, which is associated with restless legs syndrome. Our earlier work suggested that up to 22% of affected patients may suffer from it. Nocturnal epistaxis, nasal clots, and nasal obstruction may further disturb sleep, and positive airway pressure (PAP) therapy may dry out the nasal mucosa, aggravate bleeding, and cause mask intolerance. The association between obstructive sleep apnea (OSA) and HHT has not yet been adequately studied. This retrospective, exploratory, hypothesis-generating analysis aims to determine the frequency of OSA diagnoses documented in the clinical records of our existing HHT cohort. The primary endpoint is this documented frequency, explicitly interpreted as a minimum frequency rather than a true prevalence, since not all patients were systematically screened. Secondary endpoints include details of OSA diagnostics and treatment course, complications of OSA therapy in HHT patients, OSA-related comorbidities (e.g., arterial hypertension, obesity), medication and potential adverse effects (especially respiratory depression), hypoxia-related laboratory parameters (iron status, anemia), and general patient and disease characteristics (sex, weight, height, Curaçao criteria). The findings are intended to inform a possible subsequent prospective screening phase.

A Comparative Effectiveness Study of Positive Airway Pressure (PAP) Therapy, Dental Device, and Atomoxetine-Oxybutynin for Treatment of Obstructive Sleep Apnea in Adults

Researchers want to identify which treatments for obstructive sleep apnea (OSA) work best and are easiest for patients to use consistently. Eligible participants will be randomly assigned one of three OSA treatments: traditional PAP therapy, a dental device, or a combination of two FDA-approved medications (atomoxetine and oxybutynin) that are currently approved for other conditions. Over the course of one year, participants will attend two in-person visits and take part in four phone check-ins to complete surveys, report any side effects, and discuss how well they are following their assigned treatment.

Evaluation of the F&P Mask, US, 2026

This clinical investigation is designed to validate and confirm the overall performance, safety, usability, reliability, and acceptability of the F\&P PAP mask in a home environment.

The Effects of Hypoxic Burden on Executive Function (EF) in Preschool Children With Obstructive Sleep Apnea

The goal of this observational study is to study the effect of hypoxic burden on executive function in preschool children aged 2-6 years who have OSA. The main question it aims to answer is Effect of hypoxic burden from OSA to executive function measured by BRIEF-P in preschool children..

DReAMzz- Dronabinol and Acetazolamide Medication for Sleep Apnea (ZZ). Dose Confirmation Crossover Study for IHL-42X in Subjects With Obstructive Sleep Apnea.

The goal of this randomized, double-blind, multi-dose crossover clinical trial is to determine the safety and efficacy of IHL-42X in subjects with obstructive sleep apnea. The primary endpoint is: Change in AHI4 at the end of each treatment period compared to baseline (each treatment period is 28 days). The study will consist of three separate four-way crossover dose-comparison studies each comparing three dose strengths of IHL-42X to placebo. The double-blind four-way crossover will be conducted according to a Williams design. Each of the crossover studies will test different doses of dronabinol in combination with a distinct, set dose of acetazolamide. In total, nine different combinations of dronabinol and acetazolamide formulated as IHL-42X will be tested in the study. The optimal dose strength will be selected based on safety and efficacy over a 4-week treatment period.

Evaluation of F&P Mask, US, 2026

This clinical investigation is designed to validate and confirm the overall performance, safety, usability, reliability, and acceptability of the F\&P mask in a home environment.

Application of the Patient-reported Longitudinal Assessment Tool for OSA (PLATO) Questionnaire in Oral Appliance Therapy for Obstructive Sleep Apnea

Prospective, real-world observational study in a dental sleep practice to assess the feasibility of incorporating the PLATO into a dental sleep practice and applicability for patients who are undergoing oral appliance therapy for the treatment of obstructive sleep apnea(OSA). The PLATO questionnaire was recently developed by the American Academy of Sleep Medicine specifically for use in patients with obstructive sleep apnea.

Overnight Polysomnography and Respiratory Volume Monitor

Sleep disordered breathing; specifically obstructive sleep apnea (OSA) is a disease affecting 8-12% of the general population and often more than 70% of the bariatric surgical population. OSA is characterized by the repetitive collapse of the upper airway, causing a reduction or cessation in airflow and decreases in oxygen saturation. These events are resolved by arousals from sleep, reducing sleep quality and leading to excessive daytime sleepiness. An in-laboratory polysomnography (PSG) is the gold standard for the diagnosis of OSA. Previous studies have established obstructive sleep apnea (OSA) as a potential independent risk factor for postoperative complications, adverse surgical outcomes, and longer hospital stays. Patients with OSA have an increase in postoperative complications, the most frequent being oxygen desaturation, postoperative atelectasis and increased postoperative pain. Despite the clear risks, OSA remains under diagnosed with an estimated 25-30% of patients at a high risk for OSA. It has been suggested that OSA events may be even more frequent post operatively because of the residual effects of anesthesia and the use of potent pain medications such as opioids. Postoperatively apneas often go undetected and untreated. The use of supplemental O2 may mask any desaturations and there is no convenient technology to noninvasively monitor ventilation to detect apnea and hypopnea in post-surgical patients. New advances in technology and digital signal processing have led to the development of an impedance based Respiratory Volume Monitor (RVM). The RVM (ExSpiron™, Respiratory Motion, Inc.; Waltham, MA) has been shown to provide accurate real-time, continuous, non-invasive measurements of tidal volume (TV), minute ventilation (MV) and respiratory rate (RR). Our main hypotheses are that the non-invasive, impedance-based RVM monitor will accurately reflect TV, RR and MV during sleep and will detect apneas and hypopneas accurately.

Study on the Management of COMISA

COMISA, the combination of obstructive sleep apnea (OSA) and insomnia, is a frequent and burdensome condition. Many patients with OSA experience clinically significant insomnia symptoms, and a substantial proportion of individuals with chronic insomnia also meet criteria for OSA. This comorbidity is associated with more severe symptoms, more complex diagnostic pathways, and reduced adherence to continuous positive airway pressure (CPAP) therapy. This study aims to better understand COMISA and evaluate whether adding daridorexant to CPAP treatment can improve treatment adherence and overall patient outcomes.

Patient-Perceived Symptoms at the Center of Obstructive Sleep Apnea (OSA) Management: Validation of the French Version of the Patient-Reported Apnea Questionnaire (PRAQ)

Obstructive sleep apnea (OSA) is a common and disabling sleep disorder in which the assessment and monitoring of symptoms are central to patient management. However, these steps require a shared understanding of the disease's clinical manifestations among patients, caregivers, and healthcare professionals in order to establish common therapeutic goals and meaningful clinical outcomes. Improving symptoms as experienced and reported by patients has become a major public health priority at both the national and international levels. In France, this patient-centered approach has been identified as a strategic priority by the French National Authority for Health (Haute Autorité de Santé, HAS) in its 2019-2024 strategic plan. Its implementation has been supported through the development and use of Patient-Reported Outcome Measures (PROMs). A disease-specific PROM for OSA, the Patient-Reported Apnea Questionnaire (PRAQ), has recently been developed and validated. The primary objective of this study is to validate a French version of the PRAQ. Secondary objectives are to evaluate the relationship between PRAQ scores and subjective sleep parameters, and to develop a shortened version of the questionnaire to facilitate its use in both clinical practice and research.

Early Dental Risk Screening for Pediatric Sleep-Disordered Breathing

This is a prospective, cross-sectional observational study designed to evaluate the Pediatric Sleep Questionnaire (PSQ) as a screening tool for sleep-disordered breathing (SDB) risk in a pediatric dental setting. Children aged 8-13 years will be classified as low- or high-risk for SDB based on PSQ scores and compared using physiologic sleep parameters obtained from a wearable, FDA-cleared home sleep monitoring device, alongside psychosocial assessments and craniofacial measurements derived from lateral cephalometric radiographs. Findings will inform the feasibility and accuracy of incorporating validated SDB screening into routine pediatric dental care.

FIB-4 Index, Sleep Apnea Severity, and Nocturnal Hypoxemia

This retrospective study evaluates whether the Fibrosis-4 (FIB-4) index is associated with the severity of obstructive sleep apnea (OSA) and nighttime oxygen desaturation. Adults who underwent full-night polysomnography were grouped according to apnea-hypopnea index (AHI) as no OSA, mild OSA, moderate OSA, or severe OSA. Routine clinical, laboratory, and sleep-study data were reviewed. The main aim is to compare FIB-4 values across OSA severity groups and to examine whether FIB-4 is related to AHI, oxygen desaturation index (ODI), and minimum oxygen saturation during sleep. The study also evaluates the proportion of patients with FIB-4 values at or above 1.30, a commonly used threshold for identifying individuals who may need further liver fibrosis assessment. FIB-4 is used in this study as a noninvasive liver fibrosis risk marker and not as a diagnosis of liver fibrosis.

Screening for Obstructive Sleep Apnea in High-risk Patients in a Danish Rural Population: A Pilot Feasibility Study

Background: Obstructive sleep apnea (OSA) is a sleep disorder characterized by recurrent collapse of the upper airway during sleep, resulting in intermittent hypoxia and fragmented sleep. The condition is more prevalent among individuals with hypertension, atrial fibrillation, type 2 diabetes, and other chronic diseases compared with the general population. Evidence indicates that untreated OSA is associated with adverse health outcomes, whereas treatment of OSA provides significant clinical benefits. However, a substantial proportion of individuals with OSA remain undiagnosed, highlighting the need to improve detection and reduce underdiagnosis. Devices currently used to diagnose OSA are not suitable for screening; however, newer alternatives may be appropriate. The study: This study is a pilot feasibility study. All participants will undergo an interview and examination at a baseline visit and will subsequently use OSA testing devices at home for three consecutive nights. The study includes a questionnaire assessing participants' experience with the devices and technology in general. The objective of this study is to test the feasibility of conducting a study in which adult participants with type 2 diabetes undergo three different home sleep apnea tests over three nights, including issues to be optimized in a subsequent main/definitive study. The main study aims to assess the diagnostic agreement between the devices and will be registered independently.

Weekly Phone Calls Versus Brief Patient Education to Improve CPAP (Continuous Positive Airway Pressure) Compliance

The purpose of this study is to compare the effects of three interventions on CPAP adherence.

Automated Manual Lymphatic Drainage Therapy to Improve Glymphatic Function in OSA Patients

The purpose of this research is to investigate whether enhancing systemic lymphatic drainage improves glymphatic function in patients with obstructive sleep apnea (OSA).

Low-Tech Treatments for Obstructive Sleep Apnea

The overall purpose of this study is to compare changes in sleep outcomes in people with obstructive sleep apnea (OSA) depending on their participation in one of two behavioral interventions; both involve drinking water and breathing. A second purpose is to compare outcomes between people who have sustained a traumatic brain injury (TBI) and those with no history of TBI. The main questions it aims to answer are whether sleep quality improves after 3-months of high-resistance versus low-resistance exercises, and whether people have different outcomes depending on their history of TBI.

C-LIFT Efficacy in Patients With Obstructive Sleep Apnea

The goal of this clinical trial is to evaluate the efficacy of the C-Lift Device as a non-invasive treatment for Sleep Disordered Breathing (SDB) within the population of adults diagnosed with moderate to severe Obstructive Sleep Apnea (OSA), who are not currently being treated with a Continuous Positive Airway Pressure (CPAP) device or other intervention. This study aims to answer 2 main questions: "Will C-Lift demonstrate a qualitative improvement in a participant's perception/description of their sleep-quality?" And, "Will wearing the C-Lift Device overnight show a quantitative improvement in a participant's oxygen saturation?"

Endotype DIrected Treatment for OSA in Down Syndrome

Down syndrome is the most common genetic cause of intellectual disability. People with Down syndrome often have obstructive sleep apnea (OSA), a condition where people have difficulties with breathing while asleep. OSA can lead to poor sleep, worse quality of life, behavior problems and more difficulties with thinking ("cognitive impairment"). Current treatments for OSA in people with Down syndrome are not very effective or require surgery. The combination of 2 medications, atomoxetine and oxybutynin ("ato-oxy") is a promising treatment for OSA in people with Down syndrome, but ato-oxy does not work for everyone with Down syndrome. Similarly, oxygen is effective for OSA in some people, but does not work for everyone. This study will evaluate the use a precision medicine approach to increase the effectiveness of OSA treatment in people with Down syndrome. The study will compare two groups. In the first group, everyone will be treated with ato-oxy. In the second group, a precision medicine approach will be used to assign participants to either ato-oxy or oxygen therapy, based on the specific reasons they have OSA. The research team will enroll 200 children (age 6-17 years old) and adults with Down syndrome and OSA from five sites across the country. Half of participants will randomly receive ato-oxy while the other will receive either oxygen or ato-oxy dependent upon which treatment would be expected to work better for them. The research team will measure OSA severity, quality of life, behavior and cognition at the start of the study and after 12 months of treatment for every participant. The study will also track any treatment side effects for each treatment group.

Sleep Apnea Biomarkers and Adherence to Continuous Positive Airway Pressure

Obstructive sleep apnea (OSA) is commonly assessed using the apnea-hypopnea index, although this measure does not fully reflect cardiovascular risk or the physiological impact of the disease. Emerging biomarkers, including sleep apnea-specific hypoxic burden, pulse wave amplitude drop index, and heart rate response, may provide additional information on cardiovascular vulnerability. This prospective multicenter observational study will investigate the association between these biomarkers, measured from the diagnostic sleep study, and adherence to continuous positive airway pressure (CPAP) therapy after three months. Symptoms, quality of life, clinical characteristics, and changes in biomarkers under continuous positive airway pressure will also be evaluated.

The Improving Sleep in African American Couples Study (ISAAC)

The goal of this randomized study is to compare a combined behavioral intervention (remote tele-monitoring and feedback, virtual cognitive behavioral couple therapy, and couple-oriented peer support) on continuous positive airway pressure (CPAP) adherence, quality of sleep, functional status, and quality of life among patients with obstructive sleep apnea (OSA) and their bed partners.