The Combination of Atomoxetine and Oxybutynin Greatly Reduces Obstructive Sleep Apnea Severity. A Randomized, Placebo-controlled, Double-Blind Crossover Trial

A randomized dose finding study of combination dronabinol and acetazolamide for the treatment of obstructive sleep apnea

STUDY OBJECTIVES

Current treatments for obstructive sleep apnea (OSA) are ineffective or not tolerated in a proportion of patients. Other therapeutic options are needed and pharmaceuticals may provide an alternative. This randomized, double-blind, placebo-controlled, crossover study examined the effect of a combination of acetazolamide and dronabinol (IHL-42X) at low, medium, and high doses on OSA severity.

METHODS

Participants with OSA (apnea-hypopnea index; AHI ≥15 events/hour) received 1 week of IHL-42X at each of three doses and placebo, each separated by a 1-week washout. The change from baseline in AHI, oxygen desaturation index (ODI), Epworth sleepiness score (ESS), and mood (profile of mood states) on the final night of each treatment arm relative to the change from baseline to placebo were the major endpoints. Adverse events (AEs) were monitored throughout.

RESULTS

Ten of 11 participants completed the final night of at least one treatment arm. IHL-42X demonstrated a greater reduction in AHI from baseline compared with placebo (low, -19.7 ± 27.1; medium, -17.5 ± 23.3; high, -16.4 ± 23.8 vs. placebo, -2.8 ± 21.0 events/hour; all p < .05). The change from baseline in ODI3% was greater for the medium IHL-42X dose when compared with placebo (-15.4 ± 19.0 vs. placebo, -2.8 ± 21.0 events/hour; p < .05) but not the low or high doses (low, -15.2 ± 24.8; high, -8.3 ± 13.2 events/hour). IHL-42X did not change ESS or mood. No serious AEs occurred; however, 35 mild-moderate possibly, probably, or treatment-related AEs occurred during IHL-42X dosing and 5 occurred during placebo.

CONCLUSIONS

One week of nightly IHL-42X at low, medium, and high doses was well tolerated, safe, and associated with significant reductions in OSA severity.

Understanding the clinical management of co-occurring sleep-related bruxism and obstructive sleep apnea in adults: A narrative and critical review

Sleep-related bruxism (SRB) is a motor oral behavior characterized by tooth grinding and jaw clenching activity, reported by 8%-12% of the adult general population and 3% of older individuals. The frequency of one of its biomarkers, rhythmic masticatory muscle activity (RMMA), remains elevated across ages. Obstructive sleep apnea (OSA) is associated with the brief and repetitive pause of breathing (apnea) and with transient reduction in oxygen (hypoxia). OSA is observed at all ages and in about 50% of older individuals with a male preponderance. SRB clinical assessment is based on self-reporting of tooth grinding sound, awareness of clenching, jaw pain or headache, and clinical observation of tooth damage. OSA clinical assessment is based on sleepiness and fatigue, snoring, sleep quality, and awareness of breathing cessation, plus clinical examination of anatomical factors (e.g., obesity, retrognathia, large tonsil, macroglossia), age, gender, and body mass. Although the literature does not support association or causality between these two conditions, the co-occurrence is reported in about 30%-50% of adults. To confirm a diagnosis of co-occurring SRB and OSA, home sleep testing (HST) may be indicated. A sleep test is performed using electromyography (EMG) of jaw muscle (masseter or temporalis) and cardio-respiratory variables (e.g., air flow, respiratory effort, oxygen level, heart rate). The management of co-occurring SRB and OSA for individuals with prosthodontic needs is challenging to prevent compromising the oro-pharyngeal space and breathing efficiency. OSA treatment in the presence of SRB includes continuous positive airway pressure (CPAP) use alone or with an occlusal splint or mandibular advancement device (MAD). In addition, the following may be considered: supine sleep correction device, myofuncional therapy, medications, and surgeries. All have limitations and risks. Individual variability suggests that phenotyping is mandatory to select the most efficient and personalized treatment.

Images: Combined positive air way pressure and atomoxetine-oxybutynin for the treatment of severe obstructive sleep apnea

Obstructive sleep apnea is one of the most common sleep disorders. Positive airway pressure therapy is considered the gold standard for treating obstructive sleep apnea. Yet, optimal therapy might not be achieved in some cases of severe obstructive sleep apnea, despite using maximum settings. In this case report, we describe the successful combination of positive airway pressure therapy and atomoxetine-oxybutynin in reducing the apnea-hypopnea index from the severe range to the mild to moderate range. This was also associated with significant improvement in several symptoms including excessive daytime sleepiness and drowsiness while driving.

CITATION

Mitton J, Khan ME, Combs D, Parthasarathy S, Mashaqi S. Images: combined positive air way pressure and atomoxetine-oxybutynin for the treatment of severe obstructive sleep apnea. J Clin Sleep Med. 2025;21(4):743-746.

REM sleep breathing: Insights beyond conventional respiratory metrics

Breathing and sleep state are tightly linked. The traditional approach to evaluation of breathing in rapid eye movement sleep has been to focus on apneas and hypopneas, and associated hypoxia or hypercapnia. However, rapid eye movement sleep breathing offers novel insights into sleep physiology and pathology, secondary to complex interactions of rapid eye movement state and cardiorespiratory biology. In this review, morphological analysis of clinical polysomnogram data to assess respiratory patterns and associations across a range of health and disease is presented. There are several relatively unique insights that may be evident by assessment of breathing during rapid eye movement sleep. These include the original discovery of rapid eye movement sleep and scoring of neonatal sleep, control of breathing in rapid eye movement sleep, rapid eye movement sleep homeostasis, sleep apnea endotyping and pharmacotherapy, rapid eye movement sleep stability, non-electroencephalogram sleep staging, influences on cataplexy, mimics of rapid eye movement behaviour disorder, a reflection of autonomic health, and insights into cardiac arrhythmogenesis. In summary, there is rich clinically actionable information beyond sleep apnea encoded in the respiratory patterns of rapid eye movement sleep.

Multimodal Treatment of Sleep Apnea

Obstructive sleep apnea (OSA) is a common condition linked with multiple comorbidities. Continuous positive airway pressure (CPAP) devices, though the gold standard for OSA treatment, often do not address the entirety of the disorder. Various treatment strategies exist to address OSA beyond CPAP, each targeting different OSA aspects. These include managing comorbid sleep disorders, anatomic considerations, endotype-directed therapy, and lifestyle interventions. These comprehensive approaches aim to improve the benefits of treatment, and reduce the complications associated with OSA.

Combination Drug Therapy with Acetazolamide, Eszopiclone ± Venlafaxine for Obstructive Sleep Apnea (RESCUE-Combo): A Randomized, Double-Blind, Placebo-controlled Clinical Trial

Rationale: Acetazolamide, eszopiclone, and venlafaxine may target different underlying mechanisms of obstructive sleep apnea (OSA) and individually may partially reduce OSA severity in select patients. We tested whether acetazolamide plus eszopiclone (DualRx) reduces OSA severity. We further explored whether the addition of venlafaxine (TripleRx) alleviates OSA in patients who do not fully respond to DualRx. Methods: In this double-blind crossover trial, 20 patients with OSA underwent baseline polysomnography followed by DualRx/placebo phases in random order. Subsequently, 18 patients underwent an open-label TripleRx phase. Each phase lasted 3 days and concluded with polysomnography. The primary outcome was the placebo-adjusted change in apnea-hypopnea index during supine, non-rapid eye movement sleep (AHINREM,supine) from baseline to DualRx. Secondary outcomes included other OSA metrics, sleep parameters, and select clinical outcomes (blood pressure, symptoms, and vigilance). Results: Participants were on average middle aged, overweight, and relatively diverse (20% women, 60% non-White), with severe OSA (median [interquartile range] AHINREM,supine, 32.8 [20 to 48.8] events/h). Compared with placebo, DualRx was well tolerated and improved AHINREM,supine (-13.8 [-24.1 to -5.2] events/h or -45% [-77% to -14%]; PWilcoxon = 0.003), overall AHI, hypoxic burden, and sleep architecture (P < 0.05) but not the selected clinical outcomes. TripleRx did not provide a clear benefit relative to DualRx, although some measures of OSA-related hypoxemia improved more substantially. There were no serious side effects. Conclusions: Short-term use of dual-drug therapy with DualRx substantially reduced OSA severity. Adding venlafaxine did not generally reduce OSA severity but may be beneficial for some patients. Longer term studies are needed to assess effects on clinically important outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT04639193).

Chinese consensus report on the assessment and management of obstructive sleep apnea in patients with cardiovascular disease: 2024 edition

As cardiovascular disease (CVD) incidence and mortality rates continue to rise in China, the importance of identifying and managing CVD risk factors grows. Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder, affecting an estimated 936 million individuals aged 30-69 worldwide, with China leading globally with about 176 million affected. Increasing research indicates a close association between OSA and the onset and progression of various CVD, significantly affecting outcomes. However, OSA has long been underrecognized and undertreated in CVD clinical practice. To address this gap, a multidisciplinary expert panel developed evidence-based recommendations using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology and the Delphi process. This consensus provides 17 recommendations on core clinical issues such as screening, diagnosis, treatment, and follow-up of CVD patients with OSA, aiming to standardize care and improve patient outcomes. The recommendations were informed by current evidence-based research and extensive expert consensus discussions. This approach seeks to support clinical decision-making, improve the quality of care, and address the unique challenges of managing OSA in Chinese CVD patients.

Sleep apnea endotypes and their implications for clinical practise

Obstructive sleep apnea (OSA) is now recognized to be a multifactorial disorder caused by several endotypes that differ between individuals and patient populations. In order to understand the current clinical implications of OSA endotypes, this review aims to examine the current state of play in endotype measurements, endotype modification and their impact on clinical outcomes/prognosis. In summary, the field has developed multiple techniques to measure the endotypes over the last few decades. There is now good proof-of-concept evidence that a priori knowledge of an individual's OSA endotype traits may be useful in helping to guide treatment decisions. However, in order to truly deliver a personalized medicine approach to the treatment of OSA, we need to address critical gaps in: understanding OSA endotype treatment thresholds, and the impact of OSA modification on patient centred outcomes and hard clinical endpoints. Such efforts will benefit from a united, collaborative approach that involve partnerships between academics and consumers (i.e. patients, healthcare providers, industry).

Exploring the link between comorbid insomnia and sleep apnea (COMISA) and erectile dysfunction: implications for male sexual health

INTRODUCTION

This review explores the interplay between comorbid insomnia and sleep apnea (COMISA) and erectile dysfunction (ED), 2 conditions that significantly impact men's health. COMISA, a recently recognized condition characterized by the coexistence of insomnia and obstructive sleep apnea, has been shown to disrupt sleep architecture and cause intermittent hypoxia. These disturbances are increasingly linked to the exacerbation of ED, a prevalent issue among men. Understanding the connection between COMISA and ED is crucial for developing integrated treatment approaches that address both sleep and sexual health.

OBJECTIVES

We aim to explore the epidemiological, physiological, and potential therapeutic intersections of COMISA and ED. This review sets out to develop a better understanding of the relationship between these conditions and to emphasize the need for an integrated diagnostic and therapeutic approach that addresses both sleep and sexual health.

METHODS

Through a comprehensive analysis, including a detailed examination of extant studies, we address the hormonal imbalances and alterations in neural pathways that collectively contribute to the complex pathophysiology of ED and how these are particularly susceptible to the concurrent presence of COMISA.

RESULTS

Our analysis indicates that disruptions in sleep architecture and intermittent hypoxia associated with COMISA can exacerbate ED. Hormonal imbalances, endothelial dysfunction, autonomic imbalance, and increased inflammation and oxidative stress are key mechanisms through which COMISA influences ED. These factors collectively impair vascular health, reduce testosterone levels, disrupt neural control of erections, and contribute to the severity of ED.

CONCLUSIONS

This review underscores the necessity for an integrated approach to diagnosis and therapy that considers both sleep and sexual health to improve overall outcomes. These insights should foster a deeper understanding of the relationship between COMISA and ED, encourage further research in this area, and potentially lead to the development of innovative treatment strategies to manage these closely intertwined health concerns.

Network Medicine-Based Strategy Identifies Maprotiline as a Repurposable Drug by Inhibiting PD-L1 Expression via Targeting SPOP in Cancer

Immune checkpoint inhibitors (ICIs) are drugs that inhibit immune checkpoint (ICP) molecules to restore the antitumor activity of immune cells and eliminate tumor cells. Due to the limitations and certain side effects of current ICIs, such as programmed death protein-1, programmed cell death-ligand 1, and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) antibodies, there is an urgent need to find new drugs with ICP inhibitory effects. In this study, a network-based computational framework called multi-network algorithm-driven drug repositioning targeting ICP (Mnet-DRI) is developed to accurately repurpose novel ICIs from ≈3000 Food and Drug Administration-approved or investigational drugs. By applying Mnet-DRI to PD-L1, maprotiline (MAP), an antidepressant drug is repurposed, as a potential PD-L1 modifier for colorectal and lung cancers. Experimental validation revealed that MAP reduced PD-L1 expression by targeting E3 ubiquitin ligase speckle-type zinc finger structural protein (SPOP), and the combination of MAP and anti-CTLA4 in vivo significantly enhanced the antitumor effect, providing a new alternative for the clinical treatment of colorectal and lung cancer.

Obstructive sleep apnea syndrome, orexin, and sleep-wake cycle: The link with the neurodegeneration

Obstructive sleep apnea syndrome (OSAS) significantly affects the sleep-wake circadian rhythm through intermittent hypoxia and chronic sleep fragmentation. OSAS patients often experience excessive daytime sleepiness, frequent awakenings, and sleep fragmentation, leading to a disrupted circadian rhythm and altered sleep-wake cycle. These disruptions may exacerbate OSAS symptoms and contribute to neurodegenerative processes, particularly through the modulation of clock gene expression such as CLOCK, BMAL1, and PER. Emerging evidence connects OSAS to cognitive impairment and suggests that these changes may contribute to the development of neurodegenerative disorders such as Alzheimer disease, suggesting that OSAS could be a reversible risk factor for these conditions. Biomarkers, including melatonin and orexin, play crucial roles in understanding these mechanisms. In OSAS patients, melatonin, a marker of circadian rhythmicity, often shows altered secretion patterns that are not fully corrected by continuous positive airway pressure therapy. Orexin, which regulates the sleep-wake cycle, exhibits increased cerebrospinal fluid levels in OSAS patients, possibly due to compensatory mechanisms against sleep impairment and daytime sleepiness. These biomarkers highlight the intricate relationship between circadian rhythm disruptions and neurodegenerative risks in OSAS, emphasizing the need for further research and potential therapeutic strategies to mitigate these effects and improve patient outcomes.

Are noradrenergics combined with antimuscarinics the future pharmacologic treatment for obstructive sleep apnea? A systematic review and meta-analysis of randomized controlled trials

PURPOSE

Noradrenergics and antimuscarinics have been proposed as future pharmacotherapy for obstructive sleep apnea (OSA). However, the available randomized controlled trials (RCTs) showed heterogeneous results regarding the safety and efficacy of the combined regimen in OSA. Therefore, we performed this meta-analysis from the published RCTs to clarify this conflicting evidence.

METHODS

A systematic search of four electronic databases was done till December 2023.

RESULTS

Thirteen RCTs (n = 345) were systematically reviewed and meta-analyzed. The combined regimen significantly reduced apnea-hypopnea index (AHI): AHI 3% [events/h; Mean difference (MD): - 6.30; 95% Confidence interval (CI) (- 9.74, - 2.87); P = 0.0003], AHI 4% [events/h; MD: - 6.50; 95% CI (- 8.74, - 4.26 events/h); P < 0.00001]. All gasometric measures significantly improved in the combined regimen group except mean SpO2. No difference was found in total sleep time between the treatment and placebo. However, compared to placebo, the combined regimen altered sleep architecture and decreased sleep efficiency. Regarding OSA endotypes, the combined regimen significantly improved loop gain, pharyngeal muscle compensation, pharyngeal muscle recruitment, and respiratory arousal threshold.

CONCLUSION

The combined regimen effectively reduces AHI and OSA severity with improvement in almost all OSA endotypes. However, this regimen decreased sleep efficiency and altered sleep architecture. Short-term side effects can be confined to increased heart rate, dry mouth and urinary hesitancy. Therefore, noradrenergics and anti-muscarinics is a promising regimen for treating OSA, yet this optimism must be titrated by the lack of long-term effects of the regimen. Future RCTs with focus on the long-term efficacy of the regimen and cardiovascular outcomes is recommended.

Atomoxetine and spironolactone combine to reduce obstructive sleep apnea severity and blood pressure in hypertensive patients

BACKGROUND

Norepinephrine reuptake inhibitors such as atomoxetine (ato) can improve OSA by increasing pharyngeal muscle activity. Mineralocorticoid antagonists such as spironolactone, may potentiate the reduction of OSA severity and reduce blood pressure. We evaluated whether adding spironolactone to atomoxetine (ato-spiro) improved responses in hypertensive OSA patients.

METHODS

Twenty-one patients with an apnea-hypopnea index (AHI) between 10 and 50 events/h and a history of hypertension were recruited and crossed-over in random order to ato 80 mg and ato-spiro 80/50 mg for 1 week after a 3-day low dose run-in period. Two dropped out due to drug related side effects. Polysomnography and 24-hour blood pressure (BP) monitoring were performed at baseline and after each treatment period.

RESULTS

AHI decreased on both ato and ato-spiro from a baseline median(IQR) of 20.3(18.8 to 28.5) to 8.2(7 to 13.1) and 6.2(5.7 to 14.1), respectively (p < 0.001 for both). Systolic BP (mmHg) fell by mean(95%CI) -4.5(-13.8 to 4.8, p = 0.33) on ato and - 10.3(-19.2 to -1.5, p = 0.02) on ato-spiro, and diastolic BP dropped by -3.0(-8.0 to 2.0, p = 0.23) on ato and - 5.0(-9.1 to -0.9; p = 0.02) on ato-spiro. Both ato and ato-spiro led to a significant shift from apnea to hypopnea predominance (p < 0.001), and significant reductions in hypoxic burden (p ≤ 0.001) and REM sleep (p ≤ 0.001).

CONCLUSIONS

Both ato-spiro and ato alone decreased OSA severity similarly, but ato-spiro led to even greater, statistically significant and clinically meaningful falls in systolic and diastolic BP. BP reductions were likely due to ato-related improvements in upper airway patency and hypoxemia, and to spiro-related reduced fluid retention. These findings show promise for ato-spiro as an oral treatment for hypertensive OSA patients. REGISTERED AT CLINICALTRIALS.GOV: NCT04905979.

Sleep Deficiency and Opioid Use Disorder: Trajectory, Mechanisms, and Interventions

Opioid use disorder (OUD) is a chronic and relapsing brain disease characterized by loss of control over opioid use and impairments in cognitive function, mood, pain perception, and autonomic activity. Sleep deficiency, a term that encompasses insufficient or disrupted sleep due to multiple potential causes, including sleep disorders (eg, insomnia, sleep apnea), circadian disruption (eg, delayed sleep phase and social jet lag), and poor sleep quality (eg, sleep fragmentation, impaired sleep architecture), is present in greater than 75% of patients with OUD. This article focuses on highlighting bidirectional mechanisms between OUD and sleep deficiency and points toward promising therapeutic targets.

The Emerging Role of Pharmacotherapy in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a prevalent pathology with current modalities of treatment including continuous positive airway pressure (CPAP), surgery, weight loss, hypoglossal nerve stimulation, and pharmacotherapy. While CPAP is the current standard treatment for OSA, lack of tolerance and side effects necessitate alternative modalities of treatment. Various pharmacologic agents exist with mechanisms that may target OSA. Early trials have demonstrated efficacy of noradrenergic-antimuscarinic combinations to stimulate the airway, promote pharyngeal muscle tone, and prevent airway collapse. These agents, which we discuss in detail, have demonstrated significant reductions in apnea-hypopnea index (AHI) and lowest oxygen saturations based on preliminary studies. Glucagon-like peptide 1 receptor agonists (GLP-1RA), which stimulate endogenous insulin, reducing glucagon release, and decreasing gastric emptying, have shown positive results for OSA patients through weight loss with reductions in AHI. In this narrative review article, we highlight the mechanisms, current data, and future potential for multiple drug classes, including respiratory stimulants and GLP-1RAs.

Cannabinoids for obstructive sleep apnea: A systematic review

Cannabinoids have emerged as a potential treatment for obstructive sleep apnea (OSA). This systematic review aimed to summarize the efficacy and safety of cannabinoids to treat OSA. Databases including Ovid MEDLINE, EMBASE, Scopus, PsycINFO, and International Pharmaceutical Abstracts were searched; experimental and observational studies were eligible for inclusion. One-hundred seventy unique records were screened, and nine studies included: five full-text studies and four published abstracts. The five full-text studies were judged for quality appraisal: two studies deemed at low risk for bias, one study deemed to have some concerns for bias, and two studies deemed to have high risk for bias. Seven of nine total studies were experimental designs and evaluated dronabinol, and the other two studies were observational designs evaluating cannabis. The range of cannabinoid therapy duration spanned from 1 to 6 weeks, and the median duration was 3 weeks. Eight of nine total studies reported statistically significant, positive OSA outcomes due to cannabinoid therapy including reductions in the apnea hypopnea index and improvements in patient-reported daytime sleepiness scales. Between 70% and 80% of study participants reported neuropsychiatric and gastrointestinal adverse events attributable to cannabinoids. The American Academy of Sleep Medicine does not recommend using cannabinoids to treat OSA due to a lack of long-term safety and efficacy data. This systematic review found similar limitations, with the median cannabinoid treatment duration being only 3 weeks. Adequately powered experimental trials over longer time frames are necessary to more completely assess the long-term efficacy and safety of cannabinoids in the treatment of OSA and its effects on common comorbid conditions, such as obesity and cardiovascular disease.

The Role of Oxidative Stress and the Potential Therapeutic Benefits of Aronia melanocarpa Supplementation in Obstructive Sleep Apnea Syndrome: A Comprehensive Literature Review

Obstructive sleep apnea (OSA) is a sleep disorder characterized by repeated episodes of apnea and hypopnea, leading to inflammation and oxidative stress that contribute to numerous health complications, including cardiovascular diseases. Continuous positive airway pressure (CPAP) is a standard for treating OSA and is effective in reducing inflammation and oxidative stress. Aronia melanocarpa (a black chokeberry), a deciduous shrub belonging to the Rosaceae family and native to eastern North America that is rich in polyphenols, has garnered attention for its therapeutic potential due to its ability to neutralize reactive oxygen species (ROS) and modulate inflammatory pathways, such as NF-κB. This review supports the hypothesis that combining CPAP with black chokeberry supplementation might provide a more comprehensive approach to treating OSA, reducing the risk of health complications by further reducing oxidative stress. In conclusion, Aronia melanocarpa has potential benefits as an adjunct therapy in the treatment of OSA, enhancing overall health and well-being. This review compiles the latest scientific findings on the benefits of black chokeberry supplementation, its application in OSA treatment, and its potential use in the treatment of other conditions linked to oxidative stress.

Sleep Apnea and Stroke: A Narrative Review

TOPIC IMPORTANCE

Stroke is the second-leading cause of death worldwide. OSA is an independent risk factor for stroke and is associated with multiple vascular risk factors. Poststroke OSA is prevalent and closely linked with various stroke subtypes, including cardioembolic stroke and cerebral small vessel disease. Observational studies have shown that untreated poststroke OSA is associated with an increased risk of recurrent stroke, mortality, poorer functional recovery, and longer hospitalizations.

REVIEW FINDINGS

Poststroke OSA tends to be underdiagnosed and undertreated, possibly because patients with stroke and OSA present atypically compared with the general population with OSA. Objective testing, such as the use of ambulatory sleep testing or in-laboratory polysomnography, is recommended for diagnosing OSA. The gold standard for treating OSA is CPAP therapy. Randomized controlled trials have shown that treatment of poststroke OSA using CPAP improves nonvascular outcomes such as cognition and neurologic recovery. However, findings from randomized controlled trials that have evaluated the effect of CPAP on recurrent stroke risk and mortality have been largely negative.

SUMMARY

There is a need for high-quality randomized controlled trials in poststroke OSA that may provide evidence to support the utility of CPAP (and/or other treatment modalities) in reducing recurrent vascular events and mortality. This goal may be achieved by examining treatment strategies that have yet to be trialed in poststroke OSA, tailoring interventions according to poststroke OSA endotypes and phenotypes, selecting high-risk populations, and using metrics that reflect the physiologic abnormalities that underlie the harmful effects of OSA on cardiovascular outcomes.

Treatment of OSA and its Impact on Cardiovascular Disease, Part 2: JACC State-of-the-Art Review

Many studies have shown an association of obstructive sleep apnea (OSA) with incident cardiovascular diseases, particularly when comorbid with insomnia, excessive sleepiness, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease. Randomized controlled trials (RCTs) have demonstrated that treatment of OSA with positive airway pressure devices (CPAP) improves systemic hypertension, particularly in those with resistant hypertension who are adherent to CPAP. However, large RCTs have not shown long-term benefits of CPAP on hard cardiovascular outcomes, but post hoc analyses of these RCTs have demonstrated improved hard outcomes in those who use CPAP adequately. In theory, low CPAP adherence and patient selection may have contributed to neutral results in intention-to-treat analyses. Only by further research into clinical, translational, and basic underlying mechanisms is major progress likely to continue. This review highlights the various treatment approaches for sleep disorders, particularly OSA comorbid with various other disorders, the potential reasons for null results of RCTs treating OSA with CPAP, and suggested approaches for future trials.

Advances in Sleep-Disordered Breathing in Children

Pediatric sleep-disordered breathing disorders are a group of common conditions, from habitual snoring to obstructive sleep apnea (OSA) syndrome, affecting a significant proportion of children. The present article summarizes the current knowledge on diagnosis and treatment of pediatric OSA focusing on therapeutic and surgical advancements in the field in recent years. Advancements in OSA such as biomarkers, improving continuous pressure therapy adherence, novel pharmacotherapies, and advanced surgeries are discussed.

Non-CPAP Therapies for Obstructive Sleep Apnea in Adults

Obstructive sleep apnea (OSA) is a widespread sleep disorder characterized by repeated collapse of the upper airway during sleep, resulting in disruption of sleep. This condition is linked to a host of symptoms, including excessive daytime sleepiness, cardiovascular disorders, and a variety of other comorbidities. Continuous positive airway pressure (CPAP) is, by far, the most common treatment for OSA, and has long served as the standard treatment for most patients. However, CPAP therapy has a variety of limitations, including low adherence, and the heterogenous presentation of OSA. Thus, there exists an increasing need for alternative therapies for OSA. Some of these include lifestyle modifications, positional therapy, mandibular advancement devices, upper airway surgery, pharmacological therapies, and hypoglossal nerve stimulation. Because OSA presents heterogeneously, effective treatment for most patients would likely include a combination of these treatments.

Effect of norepinephrine reuptake inhibitors combined with antimuscarinic agents vs monotherapy for OSA: a systematic review and meta-analysis

STUDY OBJECTIVES

Randomized controlled trials have shown that combining norepinephrine reuptake inhibitors and antimuscarinics can ameliorate the severity of obstructive sleep apnea. This article explores whether the effectiveness and safety of combining norepinephrine reuptake inhibitors with antimuscarinic agents surpass monotherapy for treating obstructive sleep apnea.

METHODS

We searched randomized controlled trials including adult patients with obstructive sleep apnea who received combination therapy and monotherapy in 8 databases from inception until April 5, 2023 and evaluated the studies' quality and conducted a meta-analysis and systematic review. The primary outcome was the apnea-hypopnea index. Secondary outcome measures included loop gain, hypoxic burden, oxygen desaturation index, and ventilation at low ventilatory drive, among other indicators. We assessed the quality of the studies using Cochrane Methods criteria.

RESULTS

We identified 4 randomized controlled trials for systematic review and 2 for meta-analysis. The results of the meta-analysis showed that norepinephrine reuptake inhibitors combined with antimuscarinic agents in patients with obstructive sleep apnea prolonged total sleep time by a mean of 28.20 minutes [95% confidence interval (5.78, 50.61), P = .01] and increased sleep efficiency by 4.73% [95% confidence interval (0.50, 8.97), P = .03] compared with norepinephrine reuptake inhibitors alone. Other indices and adverse events were of no statistical significance. The systematic reviews revealed that norepinephrine reuptake inhibitors combined with antimuscarinics may be superior to monotherapy in improving apnea-hypopnea index and endotypic traits.

CONCLUSIONS

This evaluation demonstrated the potential advantages of combining norepinephrine reuptake inhibitors plus antimuscarinics for treating OSA compared with norepinephrine reuptake inhibitors alone and revealed no statistically significant difference in drug safety.

CITATION

Wang J, Ye Y, Shang Z, et al. Effect of norepinephrine reuptake inhibitors combined with antimuscarinic agents vs monotherapy for OSA: a systematic review and meta-analysis. J Clin Sleep Med. 2024;20(8):1363-1372.

Prevalences of sleep-related breathing disorders and severity factors in chronic spinal cord injury and abled-bodied individuals undergoing rehabilitation: a comparative study

STUDY OBJECTIVES

The objective of this study was to discern distinguishing characteristics of sleep-related breathing disorders in individuals with chronic spinal cord injury (CSCI) compared with participants without CSCI. Additionally, the study investigated factors associated with sleep-related breathing disorder severity.

METHODS

This is a cross-sectional analysis of 123 individuals without CSCI, 40 tetraplegics, and 48 paraplegics who underwent attended or partially supervised full polysomnography for suspected sleep-related breathing disorders in a rehabilitation center. Polysomnographic, transcutaneous capnography, and clinical data were collected and compared between the groups.

RESULTS

Among tetraplegics, apnea-hypopnea index ≥ 30 events/h (67.5%, P = .003), central apnea (17.5%, P = .007), and higher oxygen desaturation index (80.0%, P = .01) prevailed. Sleep-related hypoventilation was present in 15.4% of tetraplegics and 15.8% of paraplegics, compared with 3.2% in participants without CSCI (P = .05). In the group without CSCI and the paraplegic group, snoring and neck circumference were positively correlated with obstructive sleep apnea (OSA) severity. A positive correlation between waist circumference and OSA severity was identified in all groups, and multivariate logistic regression analysis showed that loud snoring and waist circumference had the greatest impact on OSA severity.

CONCLUSIONS

Severe OSA and central sleep apnea prevailed in tetraplegic participants. Sleep-related hypoventilation was more common in tetraplegics and paraplegics than in participants without CSCI. Loud snoring and waist circumference had an impact on OSA severity in all groups. We recommend the routine implementation of transcutaneous capnography in individuals with CSCI. We underscore the significance of conducting a comprehensive sleep assessment in the rehabilitation process for individuals with CSCI.

CITATION

Souza Bastos P, Amaral TLD, Yehia HC, Tavares A. Prevalences of sleep-related breathing disorders and severity factors in chronic spinal cord injury and abled-bodied individuals undergoing rehabilitation: a comparative study. J Clin Sleep Med. 2024;20(7):1119-1129.

Comparison of oximetry event desaturation transient area-based methods in predicting cardiovascular disease mortality outcomes

Desaturation area-based parameters derived from oximetry have recently emerged as novel predictors of cardiovascular disease (CVD) mortality in the context of obstructive sleep apnoea (OSA). Various published calculation methods exist for event desaturation transient area calculation. The published methods differ in how they calculate the sampling window, and how they calculate the baseline. This study aims to evaluate the six possible combinations of baseline (event-specific, record-specific, or fixed) and sampling window (record-specific or fixed) to find an easy-to-calculate yet effective method area for predicting CVD mortality. The Sleep Heart Health Study data and corresponding CVD mortality outcomes were utilized. The predictive performance of each method was assessed by Cox proportional hazard regression analysis with adjustment for relevant covariates. Results show that an area method using a record-specific baseline and a fixed sampling window and an area method using a record-specific baseline and sampling window performed the best.

Orexin receptor 2 agonist activates diaphragm and genioglossus muscle through stimulating inspiratory neurons in the pre-Bötzinger complex, and phrenic and hypoglossal motoneurons in rodents

Orexin-mediated stimulation of orexin receptors 1/2 (OX[1/2]R) may stimulate the diaphragm and genioglossus muscle via activation of inspiratory neurons in the pre-Bötzinger complex, which are critical for the generation of inspiratory rhythm, and phrenic and hypoglossal motoneurons. Herein, we assessed the effects of OX2R-selective agonists TAK-925 (danavorexton) and OX-201 on respiratory function. In in vitro electrophysiologic analyses using rat medullary slices, danavorexton and OX-201 showed tendency and significant effect, respectively, in increasing the frequency of inspiratory synaptic currents of inspiratory neurons in the pre-Bötzinger complex. In rat medullary slices, both danavorexton and OX-201 significantly increased the frequency of inspiratory synaptic currents of hypoglossal motoneurons. Danavorexton and OX-201 also showed significant effect and tendency, respectively, in increasing the frequency of burst activity recorded from the cervical (C3-C5) ventral root, which contains axons of phrenic motoneurons, in in vitro electrophysiologic analyses from rat isolated brainstem-spinal cord preparations. Electromyogram recordings revealed that intravenous administration of OX-201 increased burst frequency of the diaphragm and burst amplitude of the genioglossus muscle in isoflurane- and urethane-anesthetized rats, respectively. In whole-body plethysmography analyses, oral administration of OX-201 increased respiratory activity in free-moving mice. Overall, these results suggest that OX2R-selective agonists enhance respiratory function via activation of the diaphragm and genioglossus muscle through stimulation of inspiratory neurons in the pre-Bötzinger complex, and phrenic and hypoglossal motoneurons. OX2R-selective agonists could be promising drugs for various conditions with respiratory dysfunction.

Hypoglossal Nerve Stimulation Therapy in a Belgian Cohort of Obstructive Sleep Apnea Patients

Hypoglossal nerve stimulation (HGNS) has emerged as a widespread and innovative treatment option for selected moderate-to-severe obstructive sleep apnea (OSA) patients who cannot be treated effectively with traditional treatment modalities. In this observational cohort study, the objective and subjective outcomes of Belgian OSA patients treated with HGNS therapy were analyzed at 6 and 12 months post-implantation. Thirty-nine patients implanted with a respiration-synchronized HGNS device at the Antwerp University Hospital w ere included in this study. Patients underwent baseline in-laboratory polysomnography and a follow-up sleep study 6 and 12 months post-implantation. Questionnaires on patient experience and daytime sleepiness were filled out and data on objective therapy usage were collected. All 39 patients completed the 6-month follow-up and 21 patients (54%) completed the 12-month follow-up. Median AHI decreased from 33.8 [26.1;45.0] to 10.2 [4.8;16.4] at the 6-month follow-up, and to 9.6 [4.1;16.4] at the 12-month follow-up (p < 0.001). The surgical success rate, according to the Sher20 criteria, was 80% and 76% at the 6- and 12-month follow-ups, respectively. Median ESS improved from 12.0 [7.0;18.0] at baseline to 6.0 [2.5;11.0] at 6 months (p < 0.001) and to 6.5 [2.8;11.5] at 12 months (p = 0.012). Objective therapy usage was 7.4 [6.6;8.0] and 7.0 [5.9:8.2] h/night at the 6- and 12-month follow-ups, respectively. A high overall clinical effectiveness of HGNS therapy, as shown by a mean disease alleviation of 58%, was demonstrated at 12 months post-implantation. Overall, HGNS therapy using respiration-synchronized neurostimulation of the XII cranial nerve resulted in a significant improvement in both objective and subjective OSA outcomes, with a high level of patient satisfaction and high treatment adherence.

Tackling obstructive sleep apnea with pharmacotherapeutics: expert guidance

INTRODUCTION

The efficacy of non-pharmacotherapeutic treatment of obstructive sleep apnea, a highly prevalent condition with serious cardiometabolic and neurocognitive health consequences, is well established. Supplementing traditional treatment strategies with medications can improve symptoms and reduce side effects. Efforts to identify medications that target the causes of sleep apnea have met with mixed success. However, this remains a worthwhile objective for researchers to pursue, given the potential benefit pharmacotherapy could bring to those patients who reject or struggle to adhere to existing treatments.

AREAS COVERED

This article presents the case for obstructive sleep apnea pharmacotherapy including drugs that reduce the occurrence of apnea events, such as weight loss agents, ventilation activators and muscle and nervous system stimulants, drugs that alleviate symptoms, such as wake-promoting agents for excessive daytime sleepiness, and drugs that improve adherence to existing treatments, such as hypnotics. Literature was accessed from PubMed between 1 March 2024 and 18 April 2024.

EXPERT OPINION

Exciting recent advances in both our understanding of obstructive sleep apnea pathology and in the techniques used to identify therapeutic agents and their targets combine to embolden a positive outlook for the expanded use of drugs in tackling this consequential disease.

Polysomnographic airflow shapes and site of collapse during drug-induced sleep endoscopy

BACKGROUND

Differences in the pharyngeal site of collapse influence efficacy of non-continuous positive airway pressure therapies for obstructive sleep apnoea (OSA). Notably, complete concentric collapse at the level of the palate (CCCp) during drug-induced sleep endoscopy (DISE) is associated with reduced efficacy of hypoglossal nerve stimulation, but CCCp is currently not recognisable using polysomnography. Here we develop a means to estimate DISE-based site of collapse using overnight polysomnography.

METHODS

182 OSA patients provided DISE and polysomnography data. Six polysomnographic flow shape characteristics (mean during hypopnoeas) were identified as candidate predictors of CCCp (primary outcome variable, n=44/182), including inspiratory skewness and inspiratory scoopiness. Multivariable logistic regression combined the six characteristics to predict clear presence (n=22) versus absence (n=128) of CCCp (partial collapse and concurrent tongue base collapse excluded). Odds ratios for actual CCCp between predicted subgroups were quantified after cross-validation. Secondary analyses examined complete lateral wall, tongue base or epiglottis collapse. External validation was performed on a separate dataset (ntotal=466).

RESULTS

CCCp was characterised by greater scoopiness (β=1.5±0.6 per 2sd, multivariable estimate±se) and skewness (β=11.4±2.4) compared with non-CCCp. The odds ratio for CCCp in predicted positive versus negative subgroups was 5.0 (95% CI 1.9-13.1). The same characteristics provided significant cross-validated prediction of lateral wall (OR 6.3, 95% CI 2.4-16.5), tongue base (OR 3.2, 95% CI 1.4-7.3) and epiglottis (OR 4.4, 95% CI 1.5-12.4) collapse. CCCp and lateral wall collapse shared similar characteristics (skewed, scoopy), diametrically opposed to tongue base and epiglottis collapse characteristics. External validation confirmed model prediction.

CONCLUSIONS

The current study provides a means to recognise patients with likely CCCp or other DISE-based site of collapse categories using routine polysomnography. Since site of collapse influences therapeutic responses, polysomnographic airflow shape analysis could facilitate precision site-specific OSA interventions.

[Use of murine models for the study of obstructive sleep apnea syndrome in Down syndrome]

Down syndrome (DS), or trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21, leading to various characteristic physical features as well as developmental and cognitive delays. Obstructive sleep apnea syndrome (OSAS) is a common disorder in both adult and pediatric patients with DS. Several characteristics of DS may contribute to the development or worsening of OSAS. Numerous murine models of DS exist. A number of studies have explored apneas and the risk of upper airway obstruction in these models, but up until now, only in adulthood.

The Present and Future of the Clinical Use of Physiological Traits for the Treatment of Patients with OSA: A Narrative Review

People with obstructive sleep apnea (OSA) are a heterogeneous group. While many succeed in the treatment of their OSA, many others struggle with therapy. Herein, we discuss how anatomical and physiological factors that cause sleep apnea (OSA traits) impact treatment response and may offer an avenue for more precise care. These OSA traits, including anatomical (upper-airway collapsibility) and physiological (loop gain, airway muscle responsiveness, and arousal threshold) factors, may help determine who can succeed with continuous positive airway pressure, oral appliances, hypoglossal nerve stimulation, or pharmacotherapy. In the future, identifying OSA traits before initiating treatment may help guide the selection of the most effective and tolerable therapy modalities for each individual.

ERS International Congress 2023: highlights from the Sleep Disordered Breathing Assembly

The topic of sleep-related breathing disorders is always evolving, and during the European Respiratory Society (ERS) International Congress 2023 in Milan, Italy, the latest research and clinical topics in respiratory medicine were presented. The most interesting issues included new diagnostic tools, such as cardiovascular parameters and artificial intelligence, pathophysiological traits of sleep disordered breathing from routine polysomnography or polygraphy signals, and new biomarkers and the diagnostic approach in patients with excessive daytime sleepiness. This article summarises the most relevant studies and topics presented at the ERS International Congress 2023. Each section has been written by early career members of ERS Assembly 4.

A novel TASK channel antagonist nasal spray reduces sleep apnea severity in physiological responders: a randomized, blinded, trial

Preclinical and human physiological studies indicate that topical, selective TASK 1/3 K+ channel antagonism increases upper airway dilator muscle activity and reduces pharyngeal collapsibility during anesthesia and nasal breathing during sleep. The primary aim of this study was to determine the effects of BAY2586116 nasal spray on obstructive sleep apnea (OSA) severity and whether individual responses vary according to differences in physiological responses and route of breathing. Ten people (5 females) with OSA [apnea-hypopnea index (AHI) = 47 ± 26 events/h (means ± SD)] who completed previous sleep physiology studies with BAY2586116 were invited to return for three polysomnography studies to quantify OSA severity. In random order, participants received either placebo nasal spray (saline), BAY2586116 nasal spray (160 µg), or BAY2586116 nasal spray (160 µg) restricted to nasal breathing (chinstrap or mouth tape). Physiological responders were defined a priori as those who had improved upper airway collapsibility (critical closing pressure ≥2 cmH2O) with BAY2586116 nasal spray (NCT04236440). There was no systematic change in apnea-hypopnea index (AHI3) from placebo versus BAY2586116 with either unrestricted or nasal-only breathing versus placebo (47 ± 26 vs. 43 ± 27 vs. 53 ± 33 events/h, P = 0.15). However, BAY2586116 (unrestricted breathing) reduced OSA severity in physiological responders compared with placebo (e.g., AHI3 = 28 ± 11 vs. 36 ± 12 events/h, P = 0.03 and ODI3 = 18 ± 10 vs. 28 ± 12 events/h, P = 0.02). Morning blood pressure was also lower in physiological responders after BAY2586116 versus placebo (e.g., systolic blood pressure = 137 ± 24 vs. 147 ± 21 mmHg, P < 0.01). In conclusion, BAY2586116 reduces OSA severity during sleep in people who demonstrate physiological improvement in upper airway collapsibility. These findings highlight the therapeutic potential of this novel pharmacotherapy target in selected individuals.NEW & NOTEWORTHY Preclinical findings in pigs and humans indicate that blocking potassium channels in the upper airway with topical nasal application increases pharyngeal dilator muscle activity and reduces upper airway collapsibility. In this study, BAY2586116 nasal spray (potassium channel blocker) reduced sleep apnea severity in those who had physiological improvement in upper airway collapsibility. BAY2586116 lowered the next morning's blood pressure. These findings highlight the potential for this novel therapeutic approach to improve sleep apnea in certain people.

Pharmacological interventions for the treatment of obstructive sleep apnea syndrome

Obstructive Sleep Apnea Syndrome (OSAS) affects 13-33% of males and 6-9% of females globally and poses significant treatment challenges, including poor adherence to Continuous Positive Airway Pressure (CPAP) and residual excessive sleepiness (RES). This review aims to elucidate the emerging interest in pharmacological treatments for OSAS, focusing on recent advancements in this area. A thorough analysis of extensive clinical trials involving various drugs, including selective dopamine reuptake inhibitors, selective norepinephrine inhibitors, combined antimuscarinic agents, and orexin agonists, was conducted. These trials focused on ameliorating respiratory metrics and enhancing sleep quality in individuals affected by OSAS. The studied pharmacological agents showed potential in improving primary outcomes, notably the apnea-hypopnea index (AHI) and the Epworth sleepiness scale (ESS). These improvements suggest enhanced sleep quality and symptom management in OSAS patients. With a deeper understanding of OSAS, pharmacological interventions are emerging as a promising direction for its effective management. This review provides a comprehensive overview of the current state of drug research in OSAS, highlighting the potential of these treatments in addressing the disorder's complex challenges.

Combination pharmacological therapy targeting multiple mechanisms of sleep apnoea: a randomised controlled cross-over trial

RATIONALE

Acetazolamide and atomoxetine-plus-oxybutynin ('AtoOxy') can improve obstructive sleep apnoea (OSA) by stabilising ventilatory control and improving dilator muscle responsiveness respectively. Given the different pathophysiological mechanisms targeted by each intervention, we tested whether AtoOxy-plus-acetazolamide would be more efficacious than AtoOxy alone.

METHODS

In a multicentre randomised crossover trial, 19 patients with moderate-to-severe OSA received AtoOxy (80/5 mg), acetazolamide (500 mg), combined AtoOxy-plus-acetazolamide or placebo at bedtime for three nights (half doses on first night) with a 4-day washout between conditions. Outcomes were assessed at baseline and night 3 of each treatment period. Mixed model analysis compared the reduction in Apnoea-Hypopnoea Index (AHI) from baseline between AtoOxy-plus-acetazolamide and AtoOxy (primary outcome). Secondary outcomes included hypoxic burden and arousal index.

RESULTS

Although AtoOxy lowered AHI by 49 (33, 62)%baseline (estimate (95% CI)) vs placebo, and acetazolamide lowered AHI by+34 (14, 50)%baseline vs placebo, AtoOxy-plus-acetazolamide was not superior to AtoOxy alone (difference: -2 (-18, 11)%baseline, primary outcome p=0.8). Likewise, the hypoxic burden was lowered with AtoOxy (+58 (37, 71)%baseline) and acetazolamide (+37 (5, 58)%baseline), but no added benefit versus AtoOxy occurred when combined (difference: -13 (-5, 39)%baseline). Arousal index was also modestly reduced with each intervention (11%baseline-16%baseline). Mechanistic analyses revealed that similar traits (ie, higher baseline compensation, lower loop gain) were associated with both AtoOxy and acetazolamide efficacy.

CONCLUSIONS

While AtoOxy halved AHI, and acetazolamide lowered AHI by a third, the combination of these leading experimental interventions provided no greater efficacy than AtoOxy alone. Failure of acetazolamide to further increase efficacy suggests overlapping physiological mechanisms.

TRIAL REGISTRATION NUMBER

NCT03892772.

Pharmacological treatment for obstructive sleep apnea: A systematic review and meta-analysis

OBJECTIVE

Summarize the evidence on drug therapies for obstructive sleep apnea.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. PubMed, Embase, Scopus, Web of Science, SciELO, LILACS, Scopus, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched on February 17th, 2023. A search strategy retrieved randomized clinical trials comparing the Apnea-Hypopnea Index (AHI) in pharmacotherapies. Studies were selected and data was extracted by two authors independently. The risk of bias was assessed using the Cochrane Risk of Bias tool. RevMan 5.4. was used for data synthesis.

RESULTS

4930 articles were obtained, 68 met inclusion criteria, and 29 studies (involving 11 drugs) were combined in a meta-analysis. Atomoxetine plus oxybutynin vs placebo in AHI mean difference of -7.71 (-10.59, -4.83) [Fixed, 95 % CI, I2 = 50 %, overall effect: Z = 5.25, p < 0.001]. Donepezil vs placebo in AHI mean difference of -8.56 (-15.78, -1.33) [Fixed, 95 % CI, I2 = 21 %, overall effect: Z = 2.32, p = 0.02]. Sodium oxybate vs placebo in AHI mean difference of -5.50 (-9.28, -1.73) [Fixed, 95 % CI, I2 = 32 %, overall effect: Z = 2.86, p = 0.004]. Trazodone vs placebo in AHI mean difference of -12.75 (-21.30, -4.19) [Fixed, 95 % CI, I2 = 0 %, overall effect: Z = 2.92, p = 0.003].

CONCLUSION

The combination of noradrenergic and antimuscarinic drugs shows promising results. Identifying endotypes may be the key to future drug therapies for obstructive sleep apnea. Moreover, studies with longer follow-up assessing the safety and sustained effects of these treatments are needed.

PROSPERO REGISTRATION NUMBER

CRD42022362639.

Obstructive sleep apnea heterogeneity and autonomic function: a role for heart rate variability in therapy selection and efficacy monitoring

Obstructive sleep apnea is a highly prevalent sleep-related breathing disorder, resulting in a disturbed breathing pattern, changes in blood gases, abnormal autonomic regulation, metabolic fluctuation, poor neurocognitive performance, and increased cardiovascular risk. With broad inter-individual differences recognised in risk factors, clinical symptoms, gene expression, physiological characteristics, and health outcomes, various obstructive sleep apnea subtypes have been identified. Therapeutic efficacy and its impact on outcomes, particularly for cardiovascular consequences, may also vary depending on these features in obstructive sleep apnea. A number of interventions such as positive airway pressure therapies, oral appliance, surgical treatment, and pharmaceutical options are available in clinical practice. Selecting an effective obstructive sleep apnea treatment and therapy is a challenging medical decision due to obstructive sleep apnea heterogeneity and numerous treatment modalities. Thus, an objective marker for clinical evaluation is warranted to estimate the treatment response in patients with obstructive sleep apnea. Currently, while the Apnea-Hypopnea Index is used for severity assessment of obstructive sleep apnea and still considered a major guide to diagnosis and managements of obstructive sleep apnea, the Apnea-Hypopnea Index is not a robust marker of symptoms, function, or outcome improvement. Abnormal cardiac autonomic modulation can provide additional insight to better understand obstructive sleep apnea phenotyping. Heart rate variability is a reliable neurocardiac tool to assess altered autonomic function and can also provide cardiovascular information in obstructive sleep apnea. Beyond the Apnea-Hypopnea Index, this review aims to discuss the role of heart rate variability as an indicator and predictor of therapeutic efficacy to different modalities in order to optimise tailored treatment for obstructive sleep apnea.

Drug therapies for obstructive sleep apnoea: a systematic review and meta-analysis protocol

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common disorder that can affect the quality of life and increase the risk for psychiatric, neurological and cardiometabolic diseases. Despite the significant burden, it poses on health and well-being, there is a lack of evidence regarding the use of drug therapies in these patients. This work aims to evaluate the efficacy and safety of pharmacological treatment alternatives for patients with OSA.

METHODS AND ANALYSIS

Databases, including PubMed, Embase, Web of Science, SciELO, LILACS, Scopus, Cochrane Register of Controlled Trials and ClinicalTrials.gov, will be used for the search. A search strategy was developed to retrieve clinical trials that have evaluated polysomnographic primary outcome (Apnoea-Hypopnoea index) and secondary outcomes (eg, daytime sleepiness, adverse events) of any drug therapy used for OSA. No date or language restrictions will be applied. Two authors will independently select the studies meeting the inclusion criteria by screening the title, abstract and full text. Data will be extracted, and the risk of bias will be evaluated using the Cochrane Risk of Bias Tool. Review Manager V.5.4.1 will be used for data synthesis. The Grading of Recommendation Assessment, Development and Evaluation will be used to assess the strength of the evidence.

ETHICS AND DISSEMINATION

As a review of published data, it is not necessary to obtain ethical approval. The findings of this systematic review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022362639.

The effects of atomoxetine and trazodone combination on obstructive sleep apnea and sleep microstructure: A double-blind randomized clinical trial study

STUDY OBJECTIVES

we aimed to compare the effects of atomoxetine and trazodone (A-T) in combination with placebo in patients with obstructive sleep apnea (OSA).

METHODS

This randomized, placebo-controlled, double-blind, crossover trial study was conducted in adults with OSA referred to a Sleep Clinic. Participants with eligibility criteria were recruited. Patients were studied on two separate nights with one-week intervals, once treated with trazodone (50 mg) and atomoxetine (80 mg) combination and then with a placebo and the following polysomnography tests.

RESULTS

A total of 18 patients with OSA completed the study protocol, 9(50%) were male, the mean age was 47.5 years (SD = 9.8) and the mean Body mass index of participants was 28.4 kg/m2 (SD = 3.4). Compared with the placebo, the A-T combination resulted in significant differences in AHI (28.3(A-T) vs. 42.7 (placebo), p = 0.025), duration of the REM stage (1.3%TST (A-T) vs. 13.1%TST (placebo), p = 0.001), and the number of REM cycles (0.8 (A-T) vs. 4.7 (placebo), p = 0.001), number of apneas (38.3 (A-T) vs. 79.3 (placebo), p = 0.011), number of obstructive apneas (37.2 (A-T) vs. 75.2 (placebo), p = 0.011), oxygen desaturation index (29.5 (A-T) vs. 42.3 (placebo), p = 0.022) and number of respiratory arousals (43.2 (A-T) vs. 68.5 (placebo), p = 0.048). This decrement effect did not change among those with a low-arousal phenotype of OSA.

CONCLUSIONS

The A-T combination significantly improved respiratory events' indices compared with placebo in patients with OSA. This combination is recommended to be assessed in a large trial. It could be an alternative for those who do not adhere to the standard available treatments for OSA.

The Combination of Aroxybutynin and Atomoxetine in the Treatment of Obstructive Sleep Apnea (MARIPOSA): A Randomized Controlled Trial

Rationale: Obstructive sleep apnea (OSA) is a common sleep disorder for which the principal treatment option, continuous positive airway pressure, is often poorly tolerated. There is currently no approved pharmacotherapy for OSA. However, recent studies have demonstrated improvement in OSA with combined antimuscarinic and noradrenergic drugs. Objectives: The aim of this study was to evaluate the efficacy and safety of AD109, a combination of the novel antimuscarinic agent aroxybutynin and the norepinephrine reuptake inhibitor atomoxetine, in the treatment of OSA. Methods: Phase II randomized, double-blind, placebo-controlled, parallel-group, 4-week trial comparing AD109 2.5/75 mg, AD109 5/75 mg, atomoxetine 75 mg alone, and placebo (www.clinicaltrials.gov identifier NCT05071612). Measurements and Main Results: Of 211 randomized patients, 181 were included in the prespecified efficacy analyses. Sleep was assessed by two baseline and two treatment polysomnograms. Apnea-hypopnea index with a 4% desaturation criterion (primary outcome) was reduced from a median (IQR) of 20.5 (12.3-27.2) to 10.8 (5.6-18.5) in the AD109 2.5/75 mg arm (-47.1%), from 19.4 (13.7-26.4) to 9.5 (6.1-19.3) in the AD109 5/75 mg arm (-42.9%; both P < 0.0001 vs. placebo), and from 19.0 (11.8-28.8) to 11.8 (5.5-21.5) with atomoxetine alone (-38.8%; P < 0.01 vs. placebo). Apnea-hypopnea index with a 4% desaturation criterion decreased from 20.1 (11.9-25.9) to 16.3 (11.1-28.9) in the placebo arm. Subjectively, there was improvement in fatigue with AD109 2.5/75 mg (P < 0.05 vs. placebo and atomoxetine). Atomoxetine taken alone decreased total sleep time (P < 0.05 vs. AD109 and placebo). The most common adverse events were dry mouth, insomnia, and urinary hesitancy. Conclusions: AD109 showed clinically meaningful improvement in OSA, suggesting that further development of the compound is warranted. Clinical trial registered with www.clinicaltrials.gov (NCT05071612).

The combination of atomoxetine and oxybutynin for the treatment of obstructive sleep apnea in children with Down syndrome

STUDY OBJECTIVES

Children with Down syndrome (DS) are at very high risk for obstructive sleep apnea (OSA). Current OSA treatments have limited effectiveness in this population. We evaluated the effectiveness of atomoxetine and oxybutynin (ato-oxy) to treat OSA in children with Down syndrome.

METHODS

Children ages 6-7 years old with Down syndrome and OSA participated in a double-blind crossover clinical trial evaluating two dose regimens of ato-oxy. Participants received low-dose ato-oxy (0.5 mg/kg atomoxetine and 5 mg oxybutynin) and high-dose ato-oxy (1.2 mg/kg atomoxetine and 5 mg oxybutynin) for 1 month in random order. The primary study outcome was change in obstructive apnea-hypopnea index. Health-related quality of life as measured by the OSA-18 as well as changes in sleep architecture were secondary outcomes.

RESULTS

Fifteen participants qualified for randomization and 11 participants had complete data at all points. Baseline obstructive apnea-hypopnea index was 7.4 ± 3.7 (mean ± standard deviation), obstructive apnea-hypopnea index with low-dose ato-oxy was 3.6 ± 3.3 (P = .001 vs baseline), and obstructive apnea-hypopnea index with high-dose ato-oxy was 3.9 ± 2.8 (P = .003 vs baseline). No significant sleep architecture differences were present with ato-oxy. No significant difference in OSA-18 score was present. OSA-18 total score was 51 ± 19 at baseline, 45 ± 17 (P = .09) at the end of 4 weeks of low-dose ato-oxy, and 45 ± 16 (P = .37) at the end of high-dose ato-oxy therapy. The most common adverse effects were irritability and fatigue, and these were generally mild.

CONCLUSIONS

Ato-oxy is a promising treatment for OSA in children with Down syndrome.

CLINICAL TRIAL REGISTRATION

Registry: Clinicaltrials.gov; Name: Medications for Obstructive Sleep Apnea In Children With Down Syndrome (MOSAIC); URL: https://clinicaltrials.gov/ct2/show/NCT04115878; Identifier: NCT04115878.

CITATION

Combs D, Edgin J, Hsu C-H, et al. The combination of atomoxetine and oxybutynin for the treatment of obstructive sleep apnea in children with Down syndrome. J Clin Sleep Med. 2023;19(12):2065-2073.

Obstructive sleep apnea in children with Down syndrome: contribution of upper airway and chemosensitivity

BACKGROUND

The high prevalence of obstructive sleep apnea syndrome (OSAS) in children with Down syndrome (DS) has been attributed to a reduced upper airway size, while the role of ventilatory control is unclear. The objectives of our case-control study were to evaluate the upper airway reduction in children with DS and moderate to severe OSAS as compared to typically developing (TD) children with similar OSAS severity and to evaluate the degree of chemical loop gain modifications including its components: controller and plant gains (CG, PG).

METHODS

Thirteen children with DS were matched for age, sex, OSAS severity and ethnicity with 26 TD children. They had undergone acoustic rhinometry and pharyngometry, chemical LG obtained during awake tidal breathing measurement and hypercapnic-hyperoxic ventilatory response testing.

RESULTS

As compared to TD, children with DS depicted reduced oropharyngeal dimensions, significantly lower CG and LG and no different PG. Their hypercapnic ventilatory response slopes were not different.

CONCLUSIONS

We concluded that the decreased CG in DS was related to decreased peripheral chemoreceptor sensitivity, and while central chemosensitivity was normal, the former explained the increased end-tidal PCO2 observed in children with DS as compared to TD. Pharyngeal dimensions are reduced in children with DS and OSAS.

IMPACT

Reduced upper airway size and nocturnal alveolar hypoventilation in children with Down syndrome (DS) have been previously reported. We confirmed that children with DS and moderate-to-severe OSA have reduced oropharyngeal size as compared to typically developing children with similar OSAS severity and demonstrated decreased peripheral chemosensitivity explaining the alveolar hypoventilation observed in children with DS. Central chemosensitivity appears to be intact in children with DS and moderate to severe OSAS Our results support growing evidence that Down syndrome is associated with autonomic nervous system dysfunction.

A Narrative Review of the Clinical Trials in Sleep-Related Breathing Disorders from 2022 to Present

Sleep-related breathing disorders (SRBD) comprise obstructive sleep apnea (OSA), central sleep apnea (CSA), obesity-hypoventilation syndrome (OHS), as well as isolated sleep-related hypoxemia (ISRH), according to the recent International Classification of Sleep Disorders 3. During the last decades, there have been cumulative research reports indicating an association between the SRBD and increased cardiometabolic illness and death, as well as decreased quality of life. Notwithstanding, the results have been inconclusive, and the evidence level was not high regarding the effect of treatment for the SRBD on adverse outcomes. In the current work, we aim to give a comprehensive review of the clinical trials published from January 2022 to August 31, 2023. We highlight the heterogeneity of cardiometabolic disorders among adults with SRBD and particularly emphasize OSA management, drug therapy for OSA, positive airway pressure (PAP) therapy and cardiovascular outcomes, other effects of PAP in pregnancy and neurocognitive function, as well as the effects of surgical treatment and oral appliances. We also underline future directions in OSA management, telemonitoring, and druginduced sleep endoscopy in managing the SRBD, especially OSA. We ascertain that more studies are needed within the CSA, OHS, and ISRH research fields.

A muscarinic, GIRK channel-mediated inhibition of inspiratory-related XII nerve motor output emerges in early postnatal development in mice

In neonatal rhythmic medullary slices, muscarinic acetylcholine receptor (mAChR) activation of hypoglossal (XII) motoneurons that innervate the tongue has a net excitatory effect on XII inspiratory motor output. Conversely, during rapid eye movement sleep in adult rodents, XII motoneurons experience a loss of excitability partly due to activation of mAChRs. This may be mediated by activation of G-protein-coupled inwardly rectifying potassium (GIRK) channels. Therefore, this study was designed to evaluate whether muscarinic modulation of XII inspiratory motor output in mouse rhythmic medullary slices includes GIRK channel-mediated inhibition and, if so, when this inhibitory mechanism emerges. Local pressure injection of the mAChR agonist muscarine potentiated inspiratory bursting by 150 ± 28% in postnatal day (P)0-P5 rhythmic medullary slice preparations. In the absence of muscarine, pharmacological GIRK channel block by Tertiapin-Q did not affect inspiratory burst parameters, whereas activation with ML297 decreased inspiratory burst area. Blocking GIRK channels by local preapplication of Tertiapin-Q revealed a developmental change in muscarinic modulation of inspiratory bursting. In P0-P2 rhythmic medullary slices, Tertiapin-Q preapplication had no significant effect on muscarinic potentiation of inspiratory bursting (a negligible 6% decrease). However, preapplication of Tertiapin-Q to P3-P5 rhythmic medullary slices caused a 19% increase in muscarinic potentiation of XII inspiratory burst amplitude. Immunofluorescence experiments revealed expression of GIRK 1 and 2 subunits and M1, M2, M3, and M5 mAChRs from P0 to P5. Overall, these data support that mechanisms underlying muscarinic modulation of inspiratory burst activity change postnatally and that potent GIRK-mediated inhibition described in adults emerges early in postnatal life.NEW & NOTEWORTHY Muscarinic modulation of inspiratory bursting at hypoglossal motoneurons has a net excitatory effect in neonatal rhythmic medullary slice preparations and a net inhibitory effect in adult animals. We demonstrate that muscarinic modulation of inspiratory bursting undergoes maturational changes from postnatal days 0 to 5 that include emergence of an inhibitory component mediated by G-protein-coupled inwardly rectifying potassium channels after postnatal day 3 in neonatal mouse rhythmic medullary slice preparations.

A Review of Novel Oximetry Parameters for the Prediction of Cardiovascular Disease in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a sleep disorder with repetitive collapse of the upper airway during sleep, which leads to intermittent hypoxic events overnight, adverse neurocognitive, metabolic complications, and ultimately an increased risk of cardiovascular disease (CVD). The standard diagnostic parameter for OSA, apnoea-hypopnoea index (AHI), is inadequate to predict CVD morbidity and mortality, because it focuses only on the frequency of apnoea and hypopnoea events, and fails to reveal other physiological information for the prediction of CVD events. Novel parameters have been introduced to compensate for the deficiencies of AHI. However, the calculation methods and criteria for these parameters are unclear, hindering their use in cross-study analysis and studies. This review aims to discuss novel parameters for predicting CVD events from oximetry signals and to summarise the corresponding computational methods.

Sleep disorder and apnea events detection framework with high performance using two-tier learning model design

Sleep apnea is defined as a breathing disorder that affects sleep. Early detection of sleep apnea helps doctors to take intervention for patients to prevent sleep apnea. Manually making this determination is a time-consuming and subjectivity problem. Therefore, many different methods based on polysomnography (PSG) have been proposed and applied to detect this disorder. In this study, a unique two-layer method is proposed, in which there are four different deep learning models in the deep neural network (DNN), gated recurrent unit (GRU), recurrent neural network (RNN), RNN-based-long term short term memory (LSTM) architecture in the first layer, and a machine learning-based meta-learner (decision-layer) in the second layer. The strategy of making a preliminary decision in the first layer and verifying/correcting the results in the second layer is adopted. In the training of this architecture, a vector consisting of 23 features consisting of snore, oxygen saturation, arousal and sleep score data is used together with PSG data. A dataset consisting of 50 patients, both children and adults, is prepared. A number of pre-processing and under-sampling applications have been made to eliminate the problem of unbalanced classes. Proposed method has an accuracy of 95.74% and 99.4% in accuracy of apnea detection (apnea, hypopnea and normal) and apnea types detection (central, mixed and obstructive), respectively. Experimental results demonstrate that patient-independent consistent results can be produced with high accuracy. This robust model can be considered as a system that will help in the decisions of sleep clinics where it is expected to detect sleep disorders in detail with high performance.

Summary of drug therapy to treat cognitive impairment-induced obstructive sleep apnea

Obstructive sleep apnea (OSA) is a severe sleep disorder associated with intermittent hypoxia and sleep fragmentation. Cognitive impairment is a signifi- cant and common OSA complication often described in such patients. The most commonly utilized methods in clinical OSA treatment are oral appliances and continuous positive airway pressure (CPAP). However, the current therapeutic methods for improving cognitive function could not achieve the expected efficacy in same patients. Therefore, further understanding the molecular mechanism behind cognitive dysfunction in OSA disease will provide new treatment methods and targets. This review briefly summarized the clinical manifestations of cognitive impairment in OSA disease. Moreover, the pathophysiological molecular mechanism of OSA was outlined. Our study concluded that both SF and IH could induce cognitive impairment by multiple signaling pathways, such as oxidative stress activation, inflammation, and apoptosis. However, there is a lack of effective drug therapy for cognitive impairment in OSA. Finally, the therapeutic potential of some novel compounds and herbal medicine was evaluated on attenuating cognitive impairment based on certain preclinical studies.