Association between Obstructive Sleep Apnea and Glaucoma.

Background: Obstructive sleep apnea (OSA) and glaucoma are major global health challenges. However, the probable association between them is yet to be fully elucidated. This study aimed to investigate the association between OSA and glaucoma. Methods: Data for this cross-sectional study were obtained from the eighth Korea National Health and Nutrition Examination Survey (2019-2021). From among 9,495 individuals who completed the STOP-Bang questionnaire on OSA (for those aged ≥40 years) and provided their glaucoma prevalence/intraocular pressure (IOP) data, 8,741 were selected for glaucoma prevalence analysis. A total of 754 individuals aged 80 years or older or those with missing confounding variable data were excluded. A separate subgroup of 8,627 individuals was selected for IOP analysis after excluding 114 individuals who use glaucoma eye drops. The study employed linear and logistic regression analyses with Stata/MP ver. 17.0 (Stata Corp., USA) to understand the relationship between the risk of OSA assessed using the STOP-Bang score and key glaucoma indicators, adjusted for confounders. Statistical significance was set at a P-value <0.05. Results: The average±standard deviation [SD] age of the glaucoma prevalence study group was 56.59±10.48, and 42.98% were male. Notably, every unit increase in the STOP-Bang score was associated with a greater risk of glaucoma (odds ratio, 1.097; P=0.044). In the IOP subgroup, the average±SD age was 56.49±10.45 years, with 42.88% being males. The linear regression showed a statistically significant relationship between the STOP-Bang score and IOP after adjusting for confounding variables (ß=0.171, P<0.001). Conclusion: Our findings revealed a significant positive association between OSA risk, as measured using the STOP-Bang score, and both the likelihood of glaucoma and high IOP.

Management of Sleep-Disordered Breathing in a Spinal Cord Injury Rehabilitation Center: Model of Care Adaptation and Implementation.

Background: Obstructive sleep apnea (OSA) is highly prevalent and poorly managed in spinal cord injury (SCI). Alternative management models are urgently needed to improve access to care. We previously described the unique models of three SCI rehabilitation centers that independently manage uncomplicated OSA. Objectives: The primary objective was to adapt and implement a similar rehabilitation-led model of managing OSA in an SCI rehabilitation center in Australia. Secondary objectives were to identify the local barriers to implementation and develop and deliver tailored interventions to address them. Methods: A clinical advisory group comprised of rehabilitation clinicians, external respiratory clinicians, and researchers adapted and developed the care model. A theory-informed needs analysis was performed to identify local barriers to implementation. Tailored behavior change interventions were developed to address the barriers and prepare the center for implementation. Results: Pathways for ambulatory assessments and treatments were developed, which included referral for specialist respiratory management of complicated cases. Roles were allocated to the team of rehabilitation doctors, physiotherapists, and nurses. The team initially lacked sufficient knowledge, skills, and confidence to deliver the OSA care model. To address this, comprehensive education and training were provided. Diagnostic and treatment equipment were acquired. The OSA care model was implemented in July 2022. Conclusion: This is the first time a rehabilitation-led model of managing OSA has been implemented in an SCI rehabilitation center in Australia. We describe a theory-informed method of adapting the model of care, assessing the barriers, and delivering interventions to overcome them. Results of the mixed-methods evaluation will be reported separately.

Sleep apnea and sudden death in the non-cardiac population: A systematic review.

INTRODUCTION: Obstructive sleep apnea (OSA) is one of the main risk factors for cardiovascular diseases and is associated with both morbidity and mortality. OSA has also been linked to arrhythmias and sudden death. OBJECTIVE: To assess whether OSA increases the risk of sudden death in the non-cardiac population. METHODS: This is a systematic review of the literature. The descriptors "sudden death" and "sleep apnea" and "tachyarrhythmias" and "sleep apnea" were searched in the PubMed/Medline and SciELO databases. RESULTS: Thirteen articles that addressed the relationship between OSA and the development of tachyarrhythmias and/or sudden death with prevalence data, electrocardiographic findings, and a relationship with other comorbidities were selected. The airway obstruction observed in OSA triggers several systemic repercussions, e.g., changes in intrathoracic pressure, intermittent hypoxia, activation of the sympathetic nervous system and chemoreceptors, and release of catecholamines. These mechanisms would be implicated in the appearance of arrhythmogenic factors, which could result in sudden death. CONCLUSION: There was a cause-effect relationship between OSA and cardiac arrhythmias. In view of the pathophysiology of OSA and its arrhythmogenic role, studies have shown a higher risk of sudden death in individuals who previously had heart disease. On the other hand, there is little evidence about the occurrence of sudden death in individuals with OSA and no heart disease, and OSA is not a risk factor for sudden death in this population.

Digital Care Pathway for Patients With Sleep Apnea in Specialized Care: Mixed Methods Study.

BACKGROUND: Sleep apnea is a significant public health disorder in Finland, with a prevalence of 3.7%. Continuous positive airway pressure (CPAP) therapy is the first-line treatment for moderate or severe sleep apnea. From November 18, 2019, all patients who started their CPAP therapy at Oulu University Hospital were attached to a sleep apnea digital care pathway (SA-DCP) and were instructed on its use. Some patients still did not use the SA-DCP although they had started their CPAP therapy. OBJECTIVE: We aimed to study health care professionals' (HCPs') perspectives on the SA-DCP and its usefulness for their work; whether the main targets of SA-DCP can be reached: shortening the initial guiding sessions of CPAP therapy, reducing patient calls and contact with HCPs, and improving patients' adherence to CPAP therapy; and patients' perspectives on the SA-DCP and its usefulness to them. METHODS: Overall, 6 HCPs were interviewed in May and June 2021. The survey for SA-DCP users (58/91, 64%) and SA-DCP nonusers (33/91, 36%) was conducted in 2 phases: from May to August 2021 and January to June 2022. CPAP device remote monitoring data were collected from SA-DCP users (80/170, 47.1%) and SA-DCP nonusers (90/170, 52.9%) in May 2021. The registered phone call data were collected during 2019, 2020, and 2021. Feedback on the SA-DCP was collected from 446 patients between February and March 2022. RESULTS: According to HCPs, introducing the SA-DCP had not yet significantly improved their workload and work practices, but it had brought more flexibility in some communication situations. A larger proportion of SA-DCP users familiarized themselves with prior information about CPAP therapy before the initial guiding session than nonusers (43/58, 74% vs 16/33, 49%; P=.02). Some patients still had not received prior information about CPAP therapy; therefore, most of the sessions were carried out according to their needs. According to the patient survey and remote monitoring data of CPAP devices, adherence to CPAP therapy was high for both SA-DCP users and nonusers. The number of patients' phone calls to HCPs did not decrease during the study. SA-DCP users perceived their abilities to use information and communications technology to be better than nonusers (mean 4.2, SD 0.8 vs mean 3.2, SD 1.2; P<.001). CONCLUSIONS: According to this study, not all the goals set for the introduction of the SA-DCP have been achieved. Despite using the SA-DCP, some patients still wanted to communicate with HCPs by phone. The most significant factors explaining the nonuse of the SA-DCP were lower digital literacy and older age of the patients. In the future, more attention should be paid to these user groups when designing and introducing upcoming digital care pathways.

Sleep Apnea is Not an Obstacle for Outpatient Hip and Knee Arthroplasty.

BACKGROUND: Up to 25% of patients requiring hip or knee arthroplasty have sleep apnea (SA), and these patients have historically been excluded from outpatient programs. The objectives of this study were to evaluate same-day discharge failure as well as 30-day complications, readmissions, and unexpected visits. METHODS: A retrospective case-control study comparing patients who have and do not have SA matched for age, sex and arthroplasty type (total hip arthroplasty, total knee arthroplasty, unicompartimental knee arthroplasty) who underwent primary outpatient surgery between February 2019 and December 2022 in 2 academic hospitals was conducted. Cases with mild SA, moderate SA with a body mass index (BMI) <35, and SA of all severity treated by continuous positive airway pressure machines were eligible. There were 156 patients included (78 cases). Complications were assessed according to the Clavien-Dindo Classification and the Comprehensive Complication Index. Continuous variables were evaluated by Student's T or Mann-Whitney tests, while categorical data were analyzed by Chi-square or Fisher tests. Univariate analyses were performed to determine discharge failure risk factors. RESULTS: There were 6 cases (7.7%) and 5 controls (6.4%) who failed to be discharged on surgery day (P = .754), with postoperative hypoxemia (6, [3.8%]) and apnea periods (3, [1.9%]) being the most common causes. Higher BMI (odds ratio = 1.19, P = .013) and general anesthesia (odds ratio = 11.97, P = .004) were found to be risk factors for discharge failure. No difference was observed on 30-day readmissions (P = .497), unexpected visits (P = 1.000), and complications on the Clavien-Dindo Classification (P > .269) and Comprehensive Complication Index (P > .334) scales. CONCLUSIONS: Selected patients who have SA can safely undergo outpatient hip or knee arthroplasty. Higher BMI and general anesthesia increased the odds of same-day discharge failure. LEVEL OF EVIDENCE: Level III, Case-control Study.

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 is to discern distinguishing characteristics of sleep-related breathing disorders (SRBD) in individuals with chronic spinal cord injury (CSCI) compared to able-bodied participants (non-CSCI). Additionally, the study investigates factors associated with SRBD severity. METHODS: This is a cross-sectional analysis of 123 able-bodied individuals, 40 tetraplegics, and 48 paraplegics, who underwent attended or partially supervised full polysomnography, for suspected SRBD, in a rehabilitation center. Polysomnographic, transcutaneous capnography, and clinical data were collected and compared between the groups. RESULTS: Among tetraplegics prevailed apnea-hypopnea index ≥ 30 (67.5%, p=0.003), central apnea (17.5%, p=0.007), and higher oxygen-desaturation index (80.0%, p=0.01). Sleep-related hypoventilation was present in 15,4% of tetraplegics and 15,8% of paraplegics, compared to 3,2% in able-bodied participants (p=0.05). In the able-bodied and paraplegic groups, 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 compared to able-bodied participants. 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 of individuals with CSCI.

Trajectories of self-reported daytime sleepiness post-ischemic stroke and transient ischemic attack: A propensity score matching study versus non-stroke patients.

INTRODUCTION: Severe sleep apnea (SA) affects one-third of stroke patients. Sleepiness, one of the cardinal symptoms of SA, negatively impacts functional stroke outcomes. The impact of continuous positive airway pressure (CPAP) on post-stroke sleepiness is poorly described. We aimed to compare through a propensity score matching the trajectories of self-reported sleepiness post-stroke with matched individuals including SA patients adherent or not to CPAP. PATIENTS AND METHODS: Sixty five (80.2%) ischemic stroke and 16 (19.8%) TIA patients (median [Q1;Q3] age = 67.0 [58.0;74.0] years, 70.4% male, body mass index [BMI] = 26.1 [24.5;29.8] kg·m-2, admission NIHSS = 3.0 [1.0;5.0]), with polysomnography and an Epworth Sleepiness Scale (ESS) performed within 1 year following stroke and with a follow-up ESS (delay = 236 [147;399] days) were included in the analysis. A 2:1 propensity score matching based on age, gender, BMI, and the apnea-hypopnea index was performed to identify 162 matched individuals referred for SA suspicion, free of stroke or TIA. Multivariable negative binomial regression models were performed to identify the determinants of sleepiness trajectories post-stroke. RESULTS: Baseline ESS was comparable between stroke/TIA and matched individuals (median [Q1; Q3] ESS = 7 [4;10] versus 6 [4;10], p = 0.86). The range of improvement in ESS was higher in stroke patients compared to controls (∆ESS = -2 [-4;1] vs -1 [-3;2], p = 0.03). In multivariable analysis, comorbid SA and CPAP treatment did not influence trajectories of sleepiness post-stroke. DISCUSSION AND CONCLUSION: Sleepiness improvement was unexpectedly higher in stroke patients compared to matched individuals, with no significant influence of comorbid SA and CPAP on its trajectory. Sleepiness may not be primarily indicative of SA in stroke or TIA patients.

Impact of Sleep Disorders and Disturbed Sleep on Brain Health: A Scientific Statement From the American Heart Association.

Accumulating evidence supports a link between sleep disorders, disturbed sleep, and adverse brain health, ranging from stroke to subclinical cerebrovascular disease to cognitive outcomes, including the development of Alzheimer disease and Alzheimer disease-related dementias. Sleep disorders such as sleep-disordered breathing (eg, obstructive sleep apnea), and other sleep disturbances, as well, some of which are also considered sleep disorders (eg, insomnia, sleep fragmentation, circadian rhythm disorders, and extreme sleep duration), have been associated with adverse brain health. Understanding the causal role of sleep disorders and disturbances in the development of adverse brain health is complicated by the common development of sleep disorders among individuals with neurodegenerative disease. In addition to the role of sleep disorders in stroke and cerebrovascular injury, mechanistic hypotheses linking sleep with brain health and biomarker data (blood-based, cerebrospinal fluid-based, and imaging) suggest direct links to Alzheimer disease-specific pathology. These potential mechanisms and the increasing understanding of the "glymphatic system," and the recognition of the importance of sleep in poststroke recovery, as well, support a biological basis for the indirect (through the worsening of vascular disease) and direct (through specific effects on neuropathology) connections between sleep disorders and brain health. Given promising evidence for the benefits of treatment and prevention, sleep disorders and disturbances represent potential targets for early treatment that may improve brain health more broadly. In this scientific statement, we discuss the evidence supporting an association between sleep disorders and disturbances and poor brain health ranging from stroke to dementia and opportunities for prevention and early treatment.

Obstructive Sleep Apnea: a risk for uncontrolled and more severe asthma in adults that we should keep an eye on.

Summary: Background. Asthma control can be influenced by several factors, including obstructive sleep apnea (OSA). The literature reports variable prevalence and magnitude of OSA impact on asthma outcomes. The aim of our study is to analyze the frequency of high-risk for OSA in asthma patients and its impact on disease severity and control. Methods. We conducted a cross-sectional study at an Allergy Department with adult asthma patients recruited while undergoing routine lung function tests. Data on sex, age, body mass index, allergen sensitization, smoking habits, risk of OSA (using the Berlin questionnaire), rhinitis control (through CARAT), asthma severity (based on GINA 2023), asthma control (using the ACT), adherence to asthma treatment (through Treatment Adherence Measure) and pulmonary function test results were collected. Results. We included 216 patients, predominantly women (70.4%), with a median (P25-P75) age of 29.0 (21.0-45.0) years, of whom 28.2% were on GINA treatment levels 4-5. In 75.5% of cases asthma was controlled. High-risk for OSA was identified in 21.8% of patients. Asthma patients with high-risk for OSA were more likely to have uncontrolled [(47.8%; n = 22) vs (15.8%; n = 26); p less than 0.001] and more severe disease [(44.7%; n = 21) vs (23.7%; n = 40), p = 0.006]. In multivariable analysis, high-risk for OSA (OR 2.81 [95%CI 1.1.28-6.17], p = 0.010), sex (women) (OR 5.21 [95% CI 1.70-15.96], p = 0.004), uncontrolled rhinitis (OR 3.65 [95%CI 1.38-9.64], p = 0.009) and GINA asthma treatment steps 4-5 (OR 2.46 [95%CI 1.15-5.26], p = 0.020) were associated with uncontrolled asthma. Conclusions. It is crucial to actively investigate OSA, especially in patients with uncontrolled and more severe forms of asthma.

Hallucinations in patients with obstructive sleep apnea-hypopnea syndrome: report of 3 cases.

Hallucinations are false sensory perceptions that occur in the absence of an external stimulus. Three cases of hallucinations related to obstructive sleep apnea-hypopnea syndrome are reported, 2 of which improved with the initiation of continuous positive airway pressure therapy. So far there are no published reports in the literature that account for this relationship in the absence of primary or structural mental pathology. All 3 reported patients had visual hallucinations that were uncomfortable and frightening. Polysomnography showed moderate-to-severe obstructive sleep apnea-hypopnea syndrome with severe oxygen desaturation. Initiation of continuous positive airway pressure therapy achieved control of hallucinations in 2 patients during follow-up. Very little information is available on the coexistence of obstructive sleep apnea-hypopnea syndrome and hallucinations. Observational and experimental studies are required to clarify whether there is a causal relationship between the 2 pathologies as well as the therapeutic role that continuous positive airway pressure may have. CITATION: Venegas MA, Montoya JS. Hallucinations in patients with obstructive sleep apnea-hypopnea syndrome: report of 3 cases. J Clin Sleep Med. 2024;20(1):165-167.

Computational fluid dynamics study in children with obstructive sleep apnea.

OBJECTIVES: This study aims to identify characteristics in image-based computational fluid dynamics (CFD) in children with obstructive sleep apnea (OSA). DESIGN: Diagnostic study. SETTING: Hospital-based cohort. PARTICIPANTS: Children with symptoms suggestive of OSA were recruited and underwent polysomnography. MAIN OUTCOME MEASURES: Three-dimensional models of computational fluid dynamics were derived from cone-beam computed tomography. RESULTS: A total of 68 children participated in the study (44 boys; mean age: 7.8 years), including 34 participants having moderate-to-severe OSA (apnea-hypopnea index [AHI] greater than 5 events/h), and 34 age, gender, and body mass index percentile matched participants having primary snoring (AHI less than 1). Children with moderate-to-severe OSA had a significantly higher total airway pressure (166.3 vs. 39.1 Pa, p = .009), total airway resistance (9851 vs. 2060 Newton-metre, p = .004) and velocity at a minimal cross-sectional area (65.7 vs. 8.8 metre per second, p = .017) than those with primary snoring. The optimal cut-off points for moderate-to-severe OSA were 46.2 Pa in the total airway pressure (area under the curve [AUC] = 73.2%), 2373 Newton-metre in the total airway resistance (AUC = 72.5%) and 12.6 metres per second in the velocity at a minimal cross-sectional area (AUC = 70.5%). The conditional logistic regression model revealed that total airway pressure, total airway resistance and velocity at minimal cross-sectional area were significantly associated with an increased risk of moderate-to-severe OSA. CONCLUSIONS: This study demonstrates that CFD could be a useful tool for evaluating upper airway patency in children with OSA.

The Clinical Relevance of Autonomic Dysfunction, Cerebral Hemodynamics, and Sleep Interactions in Individuals Living With SCI.

A myriad of physiological impairments is seen in individuals after a spinal cord injury (SCI). These include altered autonomic function, cerebral hemodynamics, and sleep. These physiological systems are interconnected and likely insidiously interact leading to secondary complications. These impairments negatively influence quality of life. A comprehensive review of these systems, and their interplay, may improve clinical treatment and the rehabilitation plan of individuals living with SCI. Thus, these physiological measures should receive more clinical consideration. This special communication introduces the under investigated autonomic dysfunction, cerebral hemodynamics, and sleep disorders in people with SCI to stakeholders involved in SCI rehabilitation. We also discuss the linkage between autonomic dysfunction, cerebral hemodynamics, and sleep disorders and some secondary outcomes are discussed. Recent evidence is synthesized to make clinical recommendations on the assessment and potential management of important autonomic, cerebral hemodynamics, and sleep-related dysfunction in people with SCI. Finally, a few recommendations for clinicians and researchers are provided.

Insomnia and sleep-disordered breathing in FKRP-related limb-girdle muscular dystrophy R9. The Norwegian LGMDR9 cohort study (2020).

Limb-girdle muscular dystrophy R9 (LGMDR9) is a progressive and disabling genetic muscle disease. Sleep is relevant in the patient care as it impacts on health, functioning, and well-being. LGMDR9 may potentially affect sleep by physical or emotional symptoms, myalgia, or sleep-disordered breathing (SDB) through cardiorespiratory involvement. The objective was to investigate the occurrence of insomnia and unrecognized or untreated SDB in LGMDR9, associated factors, and relationships with fatigue and health-related quality of life (HRQoL). All 90 adults in a Norwegian LGMDR9 cohort received questionnaires on sleep, fatigue, and HRQoL. Forty-nine of them underwent clinical assessments and 26 without mask-based therapy for respiration disorders additionally underwent polysomnography (PSG) and capnometry. Among 77 questionnaire respondents, 31% received mask-based therapy. The prevalence of insomnia was 32% of both those with and without such therapy but was significantly increased in fatigued respondents (54% vs 21%). Insomnia levels correlated inversely with mental HRQoL. Among 26 PSG candidates, an apnea-hypopnea index (AHI) ≥ 5/h was observed in 16/26 subjects (≥ 15/h in 8/26) with median 6.8 obstructive apneas and 0.2 central apneas per hour of sleep. The AHI was related to advancing age and an ejection fraction < 50%. Sleep-related hypoventilation was detected in one subject. Fatigue severity did not correlate with motor function or nocturnal metrics of respiration or sleep but with Maximal Inspiratory Pressure (r = - 0.46). The results indicate that insomnia and SDB are underrecognized comorbidities in LGMDR9 and associated with HRQoL impairment and heart failure, respectively. We propose an increased attention to insomnia and SDB in the interdisciplinary care of LGMDR9. Insomnia and pulmonary function should be examined in fatigued patients.

Analysing the impact of body position shift on sleep architecture and stage transition: A comprehensive multidimensional study using event-synchronised polysomnography data.

Although understanding the physiological mechanisms of obstructive sleep apnea (OSA) is important for treating OSA, limited studies have examined OSA patients' sleep architecture at the epoch-by-epoch level and analysed the impact of sleep position and stage on OSA pathogenesis. The epoch-labelled polysomnogram was analysed multidimensionally to investigate the effect of sleep position on the sleep architecture and risk factors of apnea in patients with OSA. This retrospective multicentric case-control study reviewed full-night diagnostic polysomnography of 6983 participants. The difference in the proportion of time spent supine during non-rapid eye movement (NREM) and REM stages, and the mean duration of respiratory events per body position were evaluated. The frequency of sleep stage transition per body position shift type was computed. Further subgroup analysis was performed based on OSA severity and positional dependency. Supine time in patients with OSA varied across sleep stages, with lower proportions in N3 and REM, and shorter durations with severity. Patients with OSA spent less time in supine positions during N3 and REM, and experienced longer apnea events in both positions compared to the control group. The frequency of all sleep stage transitions increased with OSA severity and was higher among non-positional OSA than positional OSA and the control group, regardless of body position shift type. The sleep stage transition from N3 and REM to wakefulness was notably heightened during position shift. Understanding the sleep architecture of patients with OSA requires analysing various sleep characteristics including sleep position simultaneously, with future studies focusing on position detection to predict sleep stages and respiratory events.

Predictors of Initial CPAP Prescription and Subsequent Course with CPAP in Patients with Central Sleep Apneas at a Single Center.

PURPOSE: Guidelines recommend considering an initial trial of continuous positive airway pressure (CPAP) to treat central sleep apnea (CSA). However, practice patterns vary widely. This study investigated predictors for an initial trial of CPAP in patients with central apneas and whether those factors predict adequate treatment response in patients receiving an initial CPAP trial. METHODS: Charts of patients receiving a diagnostic code for CSA following a sleep study during 2016-2018 at a single center were reviewed. Patient factors, initial treatment prescriptions, and subsequent changes to therapy were extracted from electronic health records. Regression models were used to estimate factors associated with an initial CPAP prescription and the likelihood of an adequate CPAP response (no subsequent therapy change and no discontinuation of therapy) among patients prescribed CPAP. RESULTS: 429/588 (73%) patients with central apneas received an initial trial of CPAP. Younger age, diagnosis by home sleep testing, non-opiate etiology of central apneas, and a lower proportion of central apneas at diagnosis were independently associated with a higher likelihood of an initial CPAP trial. A lower proportion of central apneas was associated with a higher probability of adequate response, while current smoking and opiate-related central apneas predicted an unsuccessful CPAP trial. A new finding was that older age predicted a lower likelihood of an initial CPAP prescription but did not predict an unsatisfactory response to CPAP. CONCLUSION: Clinicians may incorrectly weigh certain clinical and sleep study characteristics when deciding whether to trial CPAP for patients with central apneas.

Innate Sleep Apnea in Spontaneously Hypertensive Rats Is Associated With Microvascular Rarefaction and Neuronal Loss in the preBötzinger Complex.

BACKGROUND: Sleep apnea (SA) is a major threat to physical health and carries a significant economic burden. These impacts are worsened by its interaction with, and induction of, its comorbidities. SA holds a bidirectional relationship with hypertension, which drives atherosclerosis/arteriolosclerosis, ultimately culminating in vascular dementia. METHODS: To enable a better understanding of these sequelae of events, we investigated innate SA and its effects on cognition in adult-aged spontaneously hypertensive rats, which have a range of cardiovascular disorders: plethysmography and electroencephalographic/electromyographic recordings were used to assess sleep-wake state, breathing parameters, and sleep-disordered breathing; immunocytochemistry was used to assess vascular and neural health; the forced alteration Y maze and Barnes maze were used to assess short- and long-term memories, respectively; and an anesthetized preparation was used to assess baroreflex sensitivity. RESULTS: Spontaneously hypertensive rats displayed a higher degree of sleep-disordered breathing, which emanates from poor vascular health leading to a loss of preBötzinger Complex neurons. These rats also display small vessel white matter disease, a form of vascular dementia, which may be exacerbated by the SA-induced neuroinflammation in the hippocampus to worsen the related deficits in both long- and short-term memories. CONCLUSIONS: Therefore, we postulate that hypertension induces SA through vascular damage in the respiratory column, culminating in neuronal loss in the inspiratory oscillator. This induction of SA, which, in turn, will independently exacerbate hypertension and neural inflammation, increases the rate of vascular dementia.

Sleep disordered breathing in infants identified through newborn screening with spinal muscular atrophy.

BACKGROUND: Spinal muscular atrophy (SMA) is a genetic disorder that may result in neuromuscular weakness and respiratory insufficiency. Gene replacement therapy has changed the trajectory of this condition, but long-term outcomes related to sleep disordered breathing are not known. METHODS: This was a retrospective review of infants with SMA identified via newborn screening who subsequently received onasemnogene abeparvovec at the Hospital for Sick Children (Ontario, Canada). Polysomnograms were conducted at the time of confirmed diagnosis as well as regularly thereafter. RESULTS: Eleven children (4 female) were identified via newborn screen (7 with 2 copies of the SMN2 gene and 4 with 3 copies of the SMN2 gene) and received onasemnogene abeparvovec at a median age of 3.6 weeks. All eleven infants met criteria for sleep disordered breathing based on their first completed polysomnograms but improved over time. Three infants required respiratory technology, including a premature infant who was prescribed nocturnal supplemental oxygen therapy for central sleep apnea and two symptomatic infants with neuromuscular weakness who required nocturnal noninvasive ventilation. We did not find a correlation between motor scores and polysomnogram parameters. CONCLUSION: Children treated with onasemnogene abeparvovec have reduced sleep disordered breathing over time. Polysomnograms revealed abnormal parameters in all children, but the clinical significance of these findings was unclear for children who were asymptomatic for sleep disordered breathing or neuromuscular weakness. These results highlight the need to evaluate both motor scores and respiratory symptoms to ensure a holistic evaluation of clinical status.

The predictive values of BOAH and No-apnea score for screening obstructive sleep apnea in rotating shift worker drivers.

Objective: To evaluate the BOAH (Body mass index, Observed apnea, Age, and Hypertension) and No-apnea score's diagnostic values for detecting obstructive sleep apnea (OSA) risk in shift workers. Methods: Cross-sectional study with male rotating shift workers and drivers of heavy off-road machinery. The BOAH score is based on body mass index, witnessed apneas during sleep, age, and hypertension. The No-apnea score is based on neck circumference and age. Based on the apnea-hypopnea index (AHI), the severity of OSA was categorized as least mild OSA (AHI ≥5/h), moderate to severe OSA (AHI ≥15/h), and severe OSA (AHI ≥30/h). Sensitivity, specificity, positive predictive value, negative predictive value, and areas under the curve (AUC) were calculated. Results: Among 119 workers evaluated, 84.0% had AHI ≥5, 46.2% had AHI ≥15, and 14.3% had AHI ≥30. BOAH score with 2 points for AHI ≥5, the AUC was 0.679, and sensitivity and specificity were 41.0% and 94.7%, respectively. No-apnea score with 3 points AHI ≥5, the AUC was 0.692, and sensitivity and specificity were 70.0% and 68.4%, respectively. Furthermore, using at least one of the positive scores, the AUC was higher when compared to the single tests for AHI ≥5 (AUC = 0.727). And when both scores were positive, the AUC was higher for AHI ≥30 (AUC = 0.706). Conclusion: In rotating shift workers and drivers of heavy off-road machinery, BOAH, and No-apnea scores can be helpful tools in identifying individuals at risk for sleep apnea. In addition, matching the scores may increase the prediction of OSA.

Prevalence of central sleep apnea in people with tetraplegic spinal cord injury: a retrospective analysis of research and clinical data.

STUDY OBJECTIVES: Over 80% of people with tetraplegia have sleep-disordered breathing (SDB), but whether this is predominantly obstructive or central is unclear. This study aimed to estimate the prevalence of central sleep apnea (CSA) in tetraplegia and the contributions of central, obstructive, and hypopnea respiratory events to SDB summary indices in tetraplegia. METHODS: Research and clinical data from 606 individuals with tetraplegia and full overnight polysomnography were collated. The proportions of different respiratory event types were calculated; overall and for mild, moderate, and severe disease. The prevalence of Predominant CSA (Central Apnea Index [CAI] ≥ 5 and more central than obstructive apneas) and Any CSA (CAI ≥ 5) was estimated. Prevalence of sleep-related hypoventilation (SRH) was estimated in a clinical sub-cohort. RESULTS: Respiratory events were primarily hypopneas (71%), followed by obstructive (23%), central (4%), and mixed apneas (2%). As severity increased, the relative contribution of hypopneas and central apneas decreased, while that of obstructive apneas increased. The prevalence of Predominant CSA and Any CSA were 4.3% (26/606) and 8.4% (51/606) respectively. Being male, on opiates and having a high tetraplegic spinal cord injury were associated with CSA. SRH was identified in 26% (26/113) of the clinical sub-cohort. CONCLUSIONS: This is the largest study to characterize SDB in tetraplegia. It provides strong evidence that obstructive sleep apnea is the predominant SDB type; 9-18 times more prevalent than CSA. The prevalence of CSA was estimated to be 4%-8%, significantly lower than previously reported.