Upper airway function in the pathogenesis of obstructive sleep apnea: a review of the current literature

Role of Nasal Surgery in Adult Obstructive Sleep Apnea: A Systematic Review

Objective  To perform a systematic review to determine if isolated nasal surgery has any impact on subjective or objective parameters in adult obstructive sleep apnea (OSA) patients. Materials and Methods  From December 2022 to March 2023, we conducted a search on the PubMed, Cochrane, Scopus, and Web of Science databases. Two independent investigators performed a study selection according to the established criteria, as well as data collection, including the study design, the subjective and objective parameters addressed, the type of intervention, and the outcomes, considering the methodological quality and risk of bias. Results  In total, 25 studies met the selection criteria, and they showed that there is a significant improvement in sleep quality, sleepiness, nasal resistance, and snoring after isolated nasal surgery. Still, there is no relevant modification of other polysomnographic parameters. It also reduces the required titration pressures of continuous positive airway pressure (CPAP) and increases the duration of its use. Conclusion  Isolated nasal surgery is not a primary treatment for OSA. Still, it improves the subjective parameters and can lead to CPAP therapy success by enhancing its effectiveness and long-term compliance.

The effect of including dynamic imaging derived airway wall motion in CFD simulations of respiratory airflow in patients with OSA

Obstructive sleep apnea (OSA) is an airway disease caused by periodic collapse of the airway during sleep. Imaging-based subject-specific computational fluid dynamics (CFD) simulations allow non-invasive assessment of clinically relevant metrics such as total pressure loss (TPL) in patients with OSA. However, most of such studies use static airway geometries, which neglect physiological airway motion. This study aims to quantify how much the airway moves during the respiratory cycle, and to determine how much this motion affects CFD pressure loss predictions. Motion of the airway wall was quantified using cine MRI data captured over a single respiratory cycle in three subjects with OSA. Synchronously-measured respiratory airflow was used as the flow boundary condition for all simulations. Simulations were performed for full respiratory cycles with 5 different wall boundary conditions: (1) a moving airway wall, and static airway walls at (2) peak inhalation, (3) end inhalation, (4) peak exhalation, and (5) end exhalation. Geometric analysis exposed significant local airway cross-sectional area (CSA) variability, with local CSA varying as much as 300%. The comparative CFD simulations revealed the discrepancies between dynamic and static wall simulations are subject-specific, with TPL differing by up to 400% between static and dynamic simulations. There is no consistent pattern to which static wall CFD simulations overestimate or underestimate the airway TPL. This variability underscores the complexity of accurately modeling airway physiology and the importance of considering dynamic anatomical factors to predict realistic respiratory airflow dynamics in patients with OSA.

The interaction between neuromuscular forces, aerodynamic forces, and anatomical motion in the upper airway predicts the severity of pediatric OSA

Upper airway neuromuscular response to air pressure during inhalation is an important factor in assessing pediatric subjects with obstructive sleep apnea (OSA). The neuromuscular response's strength, timing, and duration all contribute to the potential for airway collapses and the severity of OSA. This study quantifies these factors at the soft palate, tongue, and epiglottis to assess the relationship between neuromuscular control and OSA severity in 20 pediatric subjects with and without trisomy 21, under dexmedetomidine-induced sedation. The interaction between neuromuscular force and airflow pressure force was assessed based on power transferred between the airway wall and airflow calculated from airway wall motion (from cine magnetic resonance images) and air pressure acting on the airway wall (from computational fluid dynamics simulations). Airway wall motion could be asynchronous with pressure forces due to neuromuscular activation, or synchronous with pressure forces, indicating a passive response to airflow. The obstructive apnea-hypopnea index (oAHI) quantified OSA severity. During inhalation, the normalized work done through asynchronous dilation of the airway at the soft palate, tongue, and epiglottis correlated significantly with oAHI (Spearman's ρ = 0.54, 0.50, 0.64; P = 0.03, 0.03, 0.003). Synchronous collapse at the epiglottis correlated significantly with oAHI (ρ = 0.52; P = 0.02). Temporal order of synchronous and asynchronous epiglottis motion during inhalation predicted the severity of OSA (moderate vs. severe) with 100% sensitivity and 70% specificity. Subjects with severe OSA and/or trisomy 21 have insufficient neuromuscular activation during inhalation, leading to collapse and increased neuromuscular activation. Airflow-driven airway wall motion during late inhalation likely is the main determinant of OSA severity.NEW & NOTEWORTHY This is the first study that combines cine MRI and computational fluid dynamics with in vivo synchronous respiratory flow measurement to quantify the interaction between airway neuromuscular forces, aerodynamic forces, and airway anatomy noninvasively in pediatric patients with obstructive sleep apnea (OSA). The results indicate power transfer predicts OSA severity.

Respiratory Event-Induced Blood Pressure Oscillations Vary by Sleep Stage in Sleep Apnea Patients

Obstructive sleep apnea (OSA) pathologically stresses the cardiovascular system. Apneic events cause significant oscillatory surges in nocturnal blood pressure (BP). Trajectories of these surges vary widely. This variability challenges the quantification, characterization, and mathematical modeling of BP surge dynamics. We present a method of aggregating trajectories of apnea-induced BP surges using a sample-by-sample averaging of continuously recorded BP. We applied the method to recordings of overnight BP (average total sleep time: 4.77 ± 1.64 h) for 10 OSA patients (mean AHI: 63.5 events/h; range: 18.3-105.4). We studied surges in blood pressure due to obstructive respiratory events separated from other such events by at least 30 s (274 total events). These events increased systolic (SBP) and diastolic (DBP) BP by 19 ± 7.1 mmHg (14.8%) and 11 ± 5.6 mmHg (15.5%), respectively, relative to mean values during wakefulness. Further, aggregated SBP and DBP peaks occurred on average 9 s and 9.5 s after apnea events, respectively. Interestingly, the amplitude of the SBP and DBP peaks varied across sleep stages, with mean peak ranging from 128.8 ± 12.4 to 166.1 ± 15.5 mmHg for SBP and from 63.1 ± 8.2 to 84.2 ± 9.4 mmHg for DBP. The aggregation method provides a high level of granularity in quantifying BP oscillations from OSA events and may be useful in modeling autonomic nervous system responses to OSA-induced stresses.

Obstructive Sleep Apnea-induced Endothelial Dysfunction Is Mediated by miR-210

Rationale: Obstructive sleep apnea (OSA)-induced endothelial cell (EC) dysfunction contributes to OSA-related cardiovascular sequelae. The mechanistic basis of endothelial impairment by OSA is unclear. Objectives: The goals of this study were to identify the mechanism of OSA-induced EC dysfunction and explore the potential therapies for OSA-accelerated cardiovascular disease. Methods: The experimental methods include data mining, bioinformatics, EC functional analyses, OSA mouse models, and assessment of OSA human subjects. Measurements and Main Results: Using mined microRNA sequencing data, we found that microRNA 210 (miR-210) conferred the greatest induction by intermittent hypoxia in ECs. Consistently, the serum concentration of miR-210 was higher in individuals with OSA from two independent cohorts. Importantly, miR-210 concentration was positively correlated with the apnea-hypopnea index. RNA sequencing data collected from ECs transfected with miR-210 or treated with OSA serum showed a set of genes commonly altered by miR-210 and OSA serum, which are largely involved in mitochondrion-related pathways. ECs transfected with miR-210 or treated with OSA serum showed reduced [Formula: see text]o2 rate, mitochondrial membrane potential, and DNA abundance. Mechanistically, intermittent hypoxia-induced SREBP2 (sterol regulatory element-binding protein 2) bound to the promoter region of miR-210, which in turn inhibited the iron-sulfur cluster assembly enzyme and led to mitochondrial dysfunction. Moreover, the SREBP2 inhibitor betulin alleviated intermittent hypoxia-increased systolic blood pressure in the OSA mouse model. Conclusions: These results identify an axis involving SREBP2, miR-210, and mitochondrial dysfunction, representing a new mechanistic link between OSA and EC dysfunction that may have important implications for treating and preventing OSA-related cardiovascular sequelae.

TRPM7 channels regulate breathing during sleep in obesity by acting peripherally in the carotid bodies

Sleep-disordered breathing (SDB) affects over 50% of obese individuals. Exaggerated hypoxic chemoreflex is a cardinal trait of SDB in obesity. We have shown that leptin acts in the carotid bodies (CB) to augment chemoreflex and that leptin activates the transient receptor potential melastatin 7 (TRPM7) channel. However, the effect of leptin-TRPM7 signalling in CB on breathing and SDB has not been characterized in diet-induced obesity (DIO). We hypothesized that leptin acts via TRPM7 in the CB to increase chemoreflex leading to SDB in obesity. DIO mice were implanted with EEG/EMG electrodes and transfected with Leprb short hairpin RNA (shRNA) or Trpm7 shRNA vs. control shRNA in the CB area bilaterally. Mice underwent a full-polysomnography and metabolic studies at baseline and after transfection. Ventilatory responses to hypoxia and hypercapnia were assessed during wakefulness. Leprb and Trpm7 were upregulated and their promoters were demethylated in the CB of DIO mice. Leprb knockdown in the CB did not significantly affect ventilation. Trpm7 knockdown in the CB stimulated breathing during sleep in normoxia. These effects were not driven by changes in CB chemosensitivity or metabolism. Under sustained hypoxia, Trpm7 shRNA in the CB augmented ventilation during sleep, but decreased oxyhaemoglobin saturation. We conclude that the suppression of TRPM7 in the CB improved sleep-related hypoventilation and that the respiratory effects of CB TRPM7 channels in obesity are independent of leptin. TRPM7 signalling in the CB could be a therapeutic target for the treatment of obesity-related SDB. KEY POINTS: The leptin-TRPM7 axis in the carotid bodies may play an important role in the pathogenesis of sleep-disordered breathing. TRPM7 channels regulate breathing during sleep by acting peripherally in the carotid bodies. Suppression of TRPM7 signalling in the carotid bodies improves the obesity-induced hypoventilation in mice. Pharmacological blockade of TRPM7 channels in the carotid bodies could be a therapy for sleep-disordered breathing in obesity.

Transoral awake state neuromuscular electrical stimulation therapy for mild obstructive sleep apnea

Introduction

Obstructive sleep apnea (OSA) is a common disorder with major neurocognitive and cardiovascular sequelae. The treatment of symptomatic patients with mild OSA remains controversial given that adherence to positive airway pressure (PAP) has historically been suboptimal. With this notion in mind, we assessed a daily transoral neuromuscular electrical stimulation (NMES) device for individuals with mild OSA.

Methods

The sample represents a subset of participants with a baseline AHI 5–14.9 events/hour, drawn from a parent study which also included participants with primary snoring. Outcome measures for the current study included changes in apnea-hypopnea index (AHI), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and snoring levels before and after use of the NMES. 

Results

Among 65 participants (68% men) with median age of 49 years (range 24 to 79) and median BMI of 27.7 kg/m2 (range 20 to 34), the NMES device was used daily for 6 weeks. We observed a significant improvement in the AHI from 10.2 to 6.8 events/hour among all participants and from 10.4 to 5.0 events/h among responders. Statistically significant improvements in the ESS, PSQI, objectively measured snoring, and bed partner-reported snoring were observed. Adherence among all participants was 85%.

Discussion

This NMES device has the benefit of being a treatment modality of daytime therapy which confers a high level of tolerability and patient acceptance. It alleviates the need for an in situ device during sleep and leads to improvements in OSA severity, snoring, and subjective sleep metrics, potentially crucial in mild OSA. Further studies are needed to define which individuals may benefit most from the device across the wider spectrum of OSA severity and assess long-term therapeutic outcomes.

Trial registration

ClinicalTrials.gov Identifier: NCT03829956.

Associations of the Severity of Obstructive Sleep Apnea With Age-Related Comorbidities: A Population-Based Study

Aging is accompanied by changes in the quantity and quality of sleep. Obstructive sleep apnea (OSA) is also more prevalent in the older population. Although severe OSA has been linked to a higher risk of cardiovascular disease regardless of adult age, clinical consequences of mild-to-moderate OSA in the older adults are still uncertain.

Objectives

To investigate the relationships between severity and metabolic, cognitive, and functional characteristics in community-dwelling older adults from a representative sample of the city of São Paulo.

Methods

In total, 199 participants of the first follow-up of the São Paulo Epidemiologic Sleep Study (EPISONO, São Paulo, Brazil) >60 years were cross-sectionally assessed through questionnaires, physical evaluations, laboratory tests, and full in-lab polysomnography (PSG). Three groups according to the OSA severity were compared according to sociodemographic characteristics, anthropometric measures, PSG parameters, the frequency of comorbidities, and the use of medications.

Results

Participants' age ranged from 60 to 87 years with a mean of 70.02 ± 7.31, 59.8% female. In the univariate analysis, body mass index (BMI, kg/m2) (p = 0.049) and waist circumference (p = 0.005) were significantly higher in the participants with moderate OSA, but not among those with severe OSA. Participants with severe OSA had a higher arousal index (p = 0.007). Multivariate analysis showed that severe OSA was significantly associated with hypertension (p = 0.005), heart diseases (p = 0.025), and the use of two or more medications (p = 0.035).

Conclusion

In a population-based study, severe, but not mild-to-moderate, OSA in older adults was associated with hypertension and the use of more medications. As age advances, anthropometric indicators of obesity may not increase the risk of severe OSA.

Predictors of response to sleep apnea surgery addressing the lateral pharyngeal wall collapse

PURPOSE

To evaluate the predictive factors for surgical success in sleep apnea surgical techniques addressing the lateral pharyngeal wall.

MATERIALS AND METHODS

This is a retrospective review of consecutive cases treated by functional expansion pharyngoplasty for OSA. Collected data included patients demographics, ENT physical examination and somnographic data. Furthermore inter pterygoid distance was assessed by CT scans. To determine predictors of surgical success, physical examination, CT findings, polysomnographic and demographic data were compared between the success and failure group.

RESULTS

Fifty two patients were enrolled. The mean AHI decreased significantly from 44.3 to 17 (p = 0.001). A total of 33 patients (63.5%) met the surgical success criteria. An inter pterygoid distance longer than 34 mm was the only significant predictor of success.

CONCLUSIONS

Inter pterygoid distance seems to be a promising parameter associated with the surgical outcomes that should be further studied to be validated as predictor of success.

Outcomes of multilevel upper airway surgery, including tongue base resection, in patients with torus mandibularis

By affecting the tongue position and oropharyngeal airway volume, torus mandibularis is an anatomical factor associated with obstructive sleep apnea (OSA). This study aimed to investigate the influence of torus mandibularis on the surgical outcomes of multilevel upper airway surgery with tongue base resection (TBR) in patients with OSA. Patients with OSA who underwent palatal surgery and TBR were retrospectively analyzed. The patients were divided into two groups according to the presence or absence of torus mandibularis upon physical examination or on computed tomography images. The anatomical characteristics of the upper airway and pre/postoperative polysomnography were analyzed. The control and torus mandibularis groups comprised 69 and 35 patients, respectively, with all of them showing improved sleep quality after surgery. Apnea-hypopnea index (AHI) scores decreased from 42.1 ± 22.2 preoperatively to 23.9 ± 21.4 postoperatively in the control group (p < 0.001), and from 45.2 ± 19.9 to 22.5 ± 13.5 in the torus mandibularis group (p < 0.001). Comparing the postoperative changes in AHI, the AHI of the torus mandibularis group improved by 22.7 ± 23.4, whereas that of the control group improved by 18.1 ± 19.6 (p = 0.296). Sleep efficiency improved from 90.0 ± 7.5 to 92.8 ± 6.8 in the control group, and from 90.3 ± 8.7 to 93.6 ± 6.5 in the torus mandibularis group; however, there was no statistical difference between the two groups (p = 0.816). The presence of torus mandibularis did not appear to significantly affect the surgical results in OSA patients, but it did elicit significant changes in polysomnographic parameters compared with the control group. Therefore, following the identification of torus mandibularis in OSA patients, TBR should be considered as part of planning, as it may help to predict surgical outcomes.

The Effectiveness of Nasal Airway Stent Therapy for the Treatment of Mild-to-Moderate Obstructive Sleep Apnea Syndrome

BACKGROUND

Patients with obstructive sleep apnea syndrome (OSAS) experience excessive daytime sleepiness and insomnia and they are at risk of developing cardiovascular disease and stroke. Continuous positive airway pressure therapy could improve symptoms and decrease these risks; however, adherence is problematic. Although the oral appliance is another therapeutic option, patient satisfaction is limited and the effect of the nasal airway stent - a new device - remains unclear.

OBJECTIVES

The aim of this study was to evaluate the effect of NAS therapy in patients with mild-to-moderate OSAS in a prospective, single-arm, interventional pilot study.

METHOD

Patients with mild/moderate sleep apnea (n = 71; Apnea-Hypopnea Index [AHI], 5-20 events/h on polysomnography) were recruited. Sleep-associated events were measured using a portable device (WatchPAT200) pre- and immediately post-treatment and at 1 month follow-up. AHI (including supine and non-supine AHI), Oxygen Desaturation Index (ODI), Respiratory Disturbance Index (RDI), percutaneous oxygen saturation, heart rate, and snore volume were evaluated. Symptoms were assessed using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Hospital Anxiety and Depression Scale.

RESULTS

NAS use significantly improved AHI, supine AHI, RD, ODI, and snore volume compared to pre-intervention (r = 0.44, 0.48, 0.3, 0.42, and 0.34; p < 0.001, p < 0.001, p = 0.011, p < 0.001, and p = 0.048, respectively). Additionally, 25 and 10% of patients showed complete and partial response for AHI, respectively; these improvements remained significant 1 month later. Pittsburgh Sleep Quality Index scores improved from 6.0 to 5.3 (r = 0.46, p = 0.022).

CONCLUSIONS

NAS therapy reduced severity and snoring in patients with mild-to-moderate OSAS. Approximately 30% of patients did not tolerate NAS due to side effects.

The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.

Association of Respiratory Mechanic Instability and Respiratory Parameters among Adults with Obstructive Sleep Apnea

OBJECTIVES

Respiratory mechanic instability (RMI) is derived from analysis of paradoxical thoracoabdominal movements during airway obstruction. This study aimed to evaluate RMI parameters in obstructive sleep apnea (OSA) and the correlation between RMI parameters and other parameters in polysomnography.

STUDY DESIGN

Retrospective review.

SETTING

A university hospital.

METHODS

A retrospective chart review was performed, and data from 189 adult patients who underwent an in-laboratory sleep study and were seen in our clinic during the past 8 months. The RMI parameters were measured from thoracoabdominal bands during polysomnography.

RESULTS

Subjects were divided into 2 groups: control (n = 67, apnea-hypopnea index [AHI] <5) and OSA (n = 122, AHI ≥5). The OSA group was divided into 3 subgroups according to AHI: mild, 5 ≤ AHI < 15; moderate, 15 ≤ AHI < 30; severe, AHI ≥30. As AHI increased, all RMI parameters showed a significant rising pattern and difference between control and subgroups. Arousal index, lowest oxygen saturation, and oxygen desaturation index ≥3% were significantly correlated with all RMI parameters. Based on cutoff values, areas under the curves of the RMI index for predicting mild, moderate, and severe OSA were >0.85.

CONCLUSION

All RMI parameters were well related to respiratory parameters of polysomnography, such as arousal index, lowest oxygen saturation, and oxygen desaturation index ≥3%. The areas under the curves of all RMI parameters for predicting OSA and subgroups showed significant diagnostic performance. These parameters may be useful to identify OSA cases from control.

Features of continuous glycemic profile and glycemic variability in patients with obstructive sleep apnea syndrome

AIMS

To investigate glycemic variability (GV) in Obstructive Sleep Apnea Syndrome (OSAS) patients by monitoring continuous blood glucose profile.

METHODS

OSAS group (n=86) and normal control group (n=40) were included. Continuous blood glucose was monitored. The relationship of GV, insulin resistance index (IRI) and the respiratory disturbance index (AHI) were analyzed.

RESULTS

The daily average blood glucose level was significantly higher in the OSAS patients than in the control group (6.31±0.61vs. 4.94±0.78; P<0.01). The postprandial glycemic peaks in the OSAS patients were significantly higher and prolonged. The indicators of GV were all significantly higher in the OSAS patients, including blood glucose fluctuation coefficient (BGFC, 1.93±0.71vs. 1.21±0.38, P<0.05), mean amplitude of glycemic excursions (MAGE, 4.18±0.65vs. 2.18±0.48; P<0.05) and night mean amplitude of glycemic excursions (NMAGE, 2.00±0.53vs. 1.11±0.43; P<0.05). Pearson correlation analysis showed that among the OSAS patients, the severity of OSAS (AHI) was positively correlated with the IRI (r=0.310); and the GV indicators (MAGE and NMAGE) were positively correlated with IRI and AHI (r=0.318 and 0.349, respectively) (P<0.01 or 0.001).

CONCLUSIONS

Continuous glycemic spectrum and GV provide comprehensive glycemic profiles and may reveal important aspects of glucose metabolism abnormality beyond regular examinations, and are therefore of particular significance for glycemic management in OSAS patients.

Personalised medicine in sleep respiratory disorders: focus on obstructive sleep apnoea diagnosis and treatment

In all fields of medicine, major efforts are currently dedicated to improve the clinical, physiological and therapeutic understanding of disease, and obstructive sleep apnoea (OSA) is no exception. The personalised medicine approach is relevant for OSA, given its complex pathophysiology and variable clinical presentation, the interactions with comorbid conditions and its possible contribution to poor outcomes. Treatment with continuous positive airway pressure (CPAP) is effective, but CPAP is poorly tolerated or not accepted in a considerable proportion of OSA patients. This review summarises the available studies on the physiological phenotypes of upper airway response to obstruction during sleep, and the clinical presentations of OSA (phenotypes and clusters) with a special focus on our changing attitudes towards approaches to treatment. Such major efforts are likely to change and expand treatment options for OSA beyond the most common current choices (i.e CPAP, mandibular advancement devices, positional treatment, lifestyle changes or upper airway surgery). More importantly, treatment for OSA may become more effective, being tailored to each patient's need.

Inhibitory effects of 17β-estradiol or a resveratrol dimer on hypoxia-inducible factor-1α in genioglossus myoblasts: Involvement of ERα and its downstream p38 MAPK pathways

Deficiency in the functioning of the genioglossus, which is one of the upper airway dilator muscles, is an important cause of obstructive sleep apnea/hypopnea syndrome (OSAHS). Estrogens have been reported to inhibit hypoxia-inducible factor-1α (HIF-1α) expression in hypoxia, regulating its target genes and exerting protective effects on the genioglossus in chronic intermittent hypoxia (CIH). This study aimed to investigate the role of 17β-estradiol (E2) and a resveratrol dimer (RD) on HIF-1α and the underlying mechanism. Mouse genioglossus myoblasts were isolated and cultured, and the estrogen receptor α (ERα) shRNA lentivirus was used for gene knockdown. Then MTT assay was used to determine the effects of E2 and RD on the viability of the cells. Cells in different groups were treated with different agents (E2, or RD, or E2 and SB203580), incubated under normoxia or hypoxia for 24 h, and then expression levels of HIF-1α, ERα, ERβ, total-p38 MAPK and phospho-p38 MAPK were detected. We observed that both E2 and RD inhibited the overexpression of HIF-1α induced by hypoxia at the mRNA and protein levels, and these effects were eliminated by genetic silencing of ERα by RNAi. In addition, we found that E2 activated p38 MAPK pathways to inhibit HIF-1α expression. On the whole, ERα may be responsible for downregulation of HIF-1α by E2 or RD via activation of downstream p38 MAPK pathways.

A weight-independent association between atypical antipsychotic medications and obstructive sleep apnea

BACKGROUND

With increasing use of atypical antipsychotic (AAP) agents, the concern has been raised about the association between AAP agents and medical complications. Obstructive sleep apnea (OSA) is a common breathing disorder that adversely affects health and quality of life. Because the major risk factors for OSA are weight gain and obesity by altering the upper airway anatomy, an association between AAP and development of OSA is predictable. However, we hypothesized that AAP may promote OSA not only by weight gain but also because of its potential effects on upper airway muscle function. In the present study, we evaluated the possible association between AAP use and the severity of OSA.

METHODS

A sample of patients using AAP for treatment of paradoxical insomnia was evaluated before and at least 8 weeks after AAP use. Patients were divided based on type of AAP use to olanzapine, risperidone, and quetiapine groups. Patients used olanzapine (5-10 mg), risperidone (2-4 mg), or quetiapine (100-200 mg) 2 h before bedtime. Before and after treatment, respiratory variables were recorded using polysomnography. BMI, neck circumference (NC), and waist circumference (WC) were measured before and after treatment period.

RESULTS

There was no significant difference between pre- and post-treatment apnea index (0.2 ± 0.6 vs. 2.6 ± 4.3; p = 0.094) in olanzapine group. However, significant differences in hypopnea index (5.1 ± 5 vs. 30 ± 10.8; p < 0.0001) and AHI (5.3 ± 4.9 vs. 32.6 ± 9.6; p < 0.0001) were observed. Similar results were found in quetiapine and risperidone groups, except that in quetiapine group, apnea index was significantly increased after treatment period (0.7 ± 1.2 in pre-treatment vs. 3.1 ± 2.4 in post-treatment; p = 0.007). There were no significant changes in BMI, NC, and WC during treatment period in all three groups.

CONCLUSION

While AAP medications are known cause of weight gain as a main risk factor of OSA, our finding demonstrated a weight-independent association between AAP medications and worsening respiration during sleep.

Understanding Phenotypes of Obstructive Sleep Apnea: Applications in Anesthesia, Surgery, and Perioperative Medicine

Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing with potential long-term major neurocognitive and cardiovascular sequelae. The pathophysiology of OSA varies between individuals and is composed of different underlying mechanisms. Several components including the upper airway anatomy, effectiveness of the upper airway dilator muscles such as the genioglossus, arousal threshold of the individual, and inherent stability of the respiratory control system determine the pathogenesis of OSA. Their recognition may have implications for the perioperative health care team. For example, OSA patients with a high arousal threshold are likely to be sensitive to sedatives and narcotics with a higher risk of respiratory arrest in the perioperative period. Supplemental oxygen therapy can help to stabilize breathing in OSA patients with inherent respiratory instability. Avoidance of supine position can minimize airway obstruction in patients with a predisposition to upper airway collapse in this posture. In this review, the clinically relevant endotypes and phenotypes of OSA are described. Continuous positive airway pressure (CPAP) therapy is the treatment of choice for most patients with OSA but tolerance and adherence can be a problem. Patient-centered individualized approaches to OSA management will be the focus of future research into developing potential treatment options that will help decrease the disease burden and improve treatment effectiveness.

Measurement of exhaled nitric oxide concentration in patients with obstructive sleep apnea: A meta-analysis

BACKGROUND

Exhaled nitric oxide (eNO) has been proposed as a noninvasive measure of airway inflammation. However, its value in patients with obstructive sleep apnea (OSA) is still controversial. The authors aim to assess the difference in eNO levels between patients with OSA and controls by a meta-analysis.

METHODS

A systematic search was performed in the PubMed, EMBASE, the Cochrane Library, and MEDLINE databases to collect relevant studies published from 1996 to 2016. Eligible studies that reported eNO levels in patients with OSA were included. STATA (version 12.0) was used for data analysis.

RESULTS

Two hundred eighty-four studies were reviewed for inclusion, with 16 studies pooled for analysis (16 studies for fractional exhaled nitric oxide [FENO], 5 for alveolar nitric oxide [CANO], and 4 for the maximum airway wall flux of nitric oxide [J'awNO]). The FENO levels were significantly higher in patients with OSA compared with that in the control groups (6.32 ppb, 95% confidence interval [CI] 4.46-8.33, P < 0.001). Furthermore, FENO was significantly increased (4.00 ppb, 95% CI 1.74-6.27, P = 0.001) after overnight sleep in patients with OSA, but not in healthy controls. Additionally, long-term continuous positive airway pressure (CPAP) therapy reduced FENO levels (-5.82 ppb, 95% CI -9.6 to -2.01, P < 0.001). However, the CANO (-0.01 ppb, 95% CI -1.66 to 1.64, P = 0.989) and J'awNO levels (220.32 pl/s, 95% CI -49.31 to 489.94, P = 0.109) were not significantly different between the OSA groups and non-OSA groups.

CONCLUSION

The results of the meta-analysis suggest that OSA is significantly associated with airway inflammation and elevated FENO levels can be modified by long-term CPAP therapy. J'awNO and CANO levels were not significantly different between the OSA groups and control groups.

Hidden Markov modelling of intra-snore episode behavior of acoustic characteristics of obstructive sleep apnea patients

Obstructive sleep apnea (OSA) is a breathing disorder that can cause serious medical consequences. It is caused by full (apnea) or partial (hypopnea) obstructions of the upper airway during sleep. The gold standard for diagnosis of OSA is the polysomnography (PSG). The main measure for OSA diagnosis is the apnea-hypopnea index (AHI). However, the AHI is a time averaged summary measure of vast amounts of information gathered in an overnight PSG study. It cannot capture the dynamic characteristics associated with apnea/hypopnea events and their overnight distribution. The dynamic characteristics of apnea/hypopnea events are affected by the structural and functional characteristics of the upper airway. The upper airway characteristics also affect the upper airway collapsibility. These effects are manifested in snoring sounds generated from the vibrations of upper airway structures which are then modified by the upper airway geometric and physical characteristics. Hence, it is highly likely that the acoustical behavior of snoring is affected by the upper airway structural and functional characteristics. In the current work, we propose a novel method to model the intra-snore episode behavior of the acoustic characteristics of snoring sounds which can indirectly describe the instantaneous and temporal dynamics of the upper airway. We model the intra-snore episode acoustical behavior by using hidden Markov models (HMMs) with Mel frequency cepstral coefficients. Assuming significant differences in the anatomical and physiological upper airway configurations between low-AHI and high-AHI subjects, we defined different snorer groups with respect to AHI thresholds 15 and 30 and also developed HMM-based classifiers to classify snore episodes into those groups. We also define a measure called instantaneous apneaness score (IAS) in terms of the log-likelihoods produced by respective HMMs. IAS indicates the degree of class membership of each episode to one of the predefined groups as well as the instantaneous OSA severity. We then assigned each patient to an overall AHI band based on the majority vote of each episode of snoring. The proposed method has a diagnostic sensitivity and specificity between 87-91%.

Chronic sustained hypoxia-induced redox remodeling causes contractile dysfunction in mouse sternohyoid muscle

Chronic sustained hypoxia (CH) induces structural and functional adaptations in respiratory muscles of animal models, however the underlying molecular mechanisms are unclear. This study explores the putative role of CH-induced redox remodeling in a translational mouse model, with a focus on the sternohyoid—a representative upper airway dilator muscle involved in the control of pharyngeal airway caliber. We hypothesized that exposure to CH induces redox disturbance in mouse sternohyoid muscle in a time-dependent manner affecting metabolic capacity and contractile performance. C57Bl6/J mice were exposed to normoxia or normobaric CH (FiO₂ = 0.1) for 1, 3, or 6 weeks. A second cohort of animals was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine in the drinking water). Following CH exposure, we performed 2D redox proteomics with mass spectrometry, metabolic enzyme activity assays, and cell-signaling assays. Additionally, we assessed isotonic contractile and endurance properties ex vivo. Temporal changes in protein oxidation and glycolytic enzyme activities were observed. Redox modulation of sternohyoid muscle proteins key to contraction, metabolism and cellular homeostasis was identified. There was no change in redox-sensitive proteasome activity or HIF-1α content, but CH decreased phospho-JNK content independent of antioxidant supplementation. CH was detrimental to sternohyoid force- and power-generating capacity and this was prevented by chronic antioxidant supplementation. We conclude that CH causes upper airway dilator muscle dysfunction due to redox modulation of proteins key to function and homeostasis. Such changes could serve to further disrupt respiratory homeostasis in diseases characterized by CH such as chronic obstructive pulmonary disease. Antioxidants may have potential use as an adjunctive therapy in hypoxic respiratory disease.

Investigating the association between obstructive sleep apnea and periodontitis

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep disorder characterized by disruptions of normal sleep architecture. Chronic periodontitis is a chronic disease of the periodontium that elicits a general inflammatory response to local dental plaque. It has been suggested that periodontal disease may increase in severity with increasingly severe OSA because both disease entities share common inflammatory pathways, acting synergistically to alter the host response. The aim of this study is to analyze the association between severity of OSA and the prevalence/severity of periodontitis.

METHODS

One hundred patients from a large veterans administration sleep study center (n = 26 normal, n = 21 mild, n = 19 moderate, n = 34 severe) diagnosed with an overnight polysomnogram underwent a comprehensive periodontal examination. Periodontal parameters measured included the following: 1) mean periodontal probing depth (PD); 2) clinical attachment level (CAL); 3) gingival recession; and 4) percentage of sites with bleeding on probing, plaque, PD ≥5 mm, and CAL ≥3 mm.

RESULTS

Seventy-three percent of the sampled population had moderate/severe periodontal disease. χ(2) analyses revealed no significant differences in the prevalence of periodontal disease between the apnea-hypopnea index (AHI) groups, with a negligible Spearman correlation coefficient of 0.246 between AHI severity and periodontal disease severity categories. Analysis of covariance indicated a significant association between AHI severity categories and percentage of sites with plaque, after adjusting for age. Multivariable logistic regression analysis predicting moderate/severe periodontitis with AHI score, age, and smoking status indicated a significant association with age (P = 0.028) but no significant association with the other two predictors.

CONCLUSION

OSA was not significantly associated with the prevalence of moderate/severe periodontitis and the periodontal parameters examined, except percentage plaque.

Mechanical properties of the upper airway

The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions.

Upper Airway Anatomical Changes after Velopharyngeal Surgery in Obstructive Sleep Apnea Patients with Small Tonsils

Objective

To evaluate the relationships between anatomical changes and treatment outcomes after velopharyngeal surgery in obstructive sleep apnea (OSA) patients with small tonsils (grade 0-2 on the Brodsky scale).

Study Design

Case series with planned data collection.

Setting

University medical center.

Subjects and Methods

Thirty-six OSA patients with small tonsils underwent velopharyngeal surgery including revised uvulopalatopharyngoplasty with uvula preservation and transpalatal advancement pharyngoplasty. Pre- and postoperative upper airway 3-dimensional computed tomography and polysomnography findings were obtained for comparison and analysis.

Results

The overall apnea hypopnea index (AHI) decreased from 56.8 (interquartile range, 37.5-70.1) preoperatively to 16.1 (10.8-33.5) postoperatively ( P < .001). The change in minimal cross-sectional area of the velopharynx (VmCSA) was independently associated with the change in AHI ( P = .001, R2 = 0.271). Preoperative VmCSA was the only preoperative anatomical variable that was an independent predictor of change in VmCSA ( P = .009, R2 = 0.184). Postoperative VmCSA was independently associated with postoperative AHI ( P < .001, R2 = 0.341).

Conclusion

In patients with small tonsils, an adequate increase in VmCSA is associated with a successful outcome after surgery. Patients with a relatively small preoperative VmCSA are more likely to have favorable anatomical changes after surgery.

Obesity and craniofacial structure as risk factors for obstructive sleep apnoea: impact of ethnicity

OSA is the result of structural and functional abnormalities that promote the repetitive collapse of the upper airway during sleep. This common disorder is estimated to occur in approximately 4% of men and 2% of women, with prevalence studies from North America, Australia, Europe and Asia indicating that occurrence is relatively similar across the globe. Anatomical factors, such as obesity and craniofacial morphology, are key determinants of the predisposition to airway collapse; however, their relative importance for OSA risk likely varies between ethnicities. Direct inter-ethnic studies comparing craniofacial phenotypes in OSA are limited. However, available data suggest that Asian OSA populations primarily display features of craniofacial skeletal restriction, African Americans display more obesity and enlarged upper airway soft tissues, while Caucasians show evidence of both bony and soft tissue abnormalities. Our recent comparison of Chinese and Caucasian OSA patients found for the same degree of OSA severity. Caucasians were more obese, and Chinese had more skeletal restriction. However, the ratio of obesity to craniofacial bony size (or anatomical balance, an important determinant of upper airway volume and OSA risk) was similar between Caucasians and Chinese OSA patients. Ethnicity appears to influence OSA craniofacial phenotype but furthermore the relative contribution of the anatomical factors underlying OSA risk. The skeletal restriction craniofacial phenotype may be particularly vulnerable to increasing obesity rates. Better understanding of craniofacial phenotypes encompassing ethnicity may help improve OSA recognition and treatment; however, further studies are needed to elucidate ethnic differences in OSA anatomical risk factors.

Sympathetic and catecholaminergic alterations in sleep apnea with particular emphasis on children

Sleep is involved in the regulation of major organ functions in the human body, and disruption of sleep potentially can elicit organ dysfunction. Obstructive sleep apnea (OSA) is the most prevalent sleep disorder of breathing in adults and children, and its manifestations reflect the interactions between intermittent hypoxia, intermittent hypercapnia, increased intra-thoracic pressure swings, and sleep fragmentation, as elicited by the episodic changes in upper airway resistance during sleep. The sympathetic nervous system is an important modulator of the cardiovascular, immune, endocrine and metabolic systems, and alterations in autonomic activity may lead to metabolic imbalance and organ dysfunction. Here we review how OSA and its constitutive components can lead to perturbation of the autonomic nervous system in general, and to altered regulation of catecholamines, both of which then playing an important role in some of the mechanisms underlying OSA-induced morbidities.

Oxidative stress and quality of life in elderly patients with obstructive sleep apnea syndrome: are there differences after six months of Continuous Positive Airway Pressure treatment?

OBJECTIVES

This study evaluated the effect of Continuous Positive Airway Pressure treatment on oxidative stress parameters and the quality of life of elderly patients with obstructive sleep apnea syndrome.

METHODS

In total, 30 obstructive sleep apnea syndrome patients and 27 subjects without obstructive sleep apnea syndrome were included in this study. Both groups underwent quality of life and oxidative stress evaluations at baseline and after six months. Polysomnography was performed in both groups at baseline and a second time in the obstructive sleep apnea syndrome group after six months of Continuous Positive Airway Pressure treatment. All of the variables were compared between the control and obstructive sleep apnea syndrome groups in this prospective case-control study.

RESULTS

The baseline concentrations of the antioxidant enzyme catalase were higher in the obstructive sleep apnea syndrome group than the control group. After Continuous Positive Airway Pressure treatment, the obstructive sleep apnea syndrome group exhibited a reduction in the level of oxidative stress, as indicated by a decrease in the level of lipid peroxidation measured by the malondialdehyde (MDA) concentration [pre: 2.7 nmol malondialdehyde/mL (95% 1.6-3.7) vs. post: 1.3 nmol MDA/mL (0.7-1.9), p<0.01]. Additionally, improvements were observed in two domains covered by the SF-36 questionnaire: functional capacity [pre: 77.4 (69.2-85.5) vs. post: 83.4 (76.9-89.9), p = 0.002] and pain [pre: 65.4 (52.8-78.1) vs. post: 77.8 (67.2-88.3), p = 0.004].

CONCLUSION

Our study demonstrated that the use of Continuous Positive Airway Pressure to treat obstructive sleep apnea syndrome in elderly patients reduced oxidative stress and improved the quality of life.

Down-regulation of hypoxia inducible factor-1alpha: a possible explanation for the protective effects of estrogen on genioglossus fatigue resistance

Patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) often exhibit fatigued or inefficient upper airway dilator muscle activity. It has been shown that estrogen may have some impact on upper airway contractility under normoxic conditions. Chronic intermittent hypoxia (CIH) is a frequent feature of OSAHS, and it may alter muscle susceptibility to oxidative stress, a characteristic of a fatigable nature. Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is responsible for the regulation of oxygen homeostasis under hypoxic conditions. We examined the effects of estrogen on the contractility of the genioglossus by exposing rats to alternating cycles of 6-8% O(2) every 15 s for a total duration of 35 d. The results showed that muscle fatigue resistance was significantly decreased after CIH but was partially reversed after estrogen treatment. Compared with the control group, real-time reverse transcription-polymerase chain reaction and western blotting showed higher levels of HIF-1alpha messenger RNA and protein in the CIH group, but estrogen treatment reduced, in a dose-independent manner, the levels of HIF-1alpha messenger RNA and protein in rats exposed to CIH. We conclude that CIH induced the expression of HIF-1alpha in the genioglossus and altered the physical properties towards a more fatigable phenotype, whereas estrogen inhibited the over-expression of HIF-1alpha, and this may account for the improvement of upper airway muscle endurance in CIH rats.

What is central sleep apnea?

Central sleep apnea (CSA) describes a group of conditions in which cessations in air flow occur without respiratory effort. In contrast, obstructive sleep apnea patients have ongoing respiratory effort during respiratory events. However, considerable overlap exists in the pathogenesis and clinical presentation of obstructive sleep apnea and CSA. A good working knowledge of the mechanisms underlying CSA is important for optimal clinical care. In general, CSA can be classified into those with excessive drive (eg, Cheyne-Stokes breathing) versus those with inadequate drive (eg, sleep hypoventilation syndrome). One critical factor contributing to the cessation of air flow during sleep is the concept of the apnea threshold, such that a P(aCO(2)) value below a certain level will lead to cessations in breathing. P(aCO(2)) can fall below the chemical apnea threshold when drive is excessive (eg, robust chemosensitivity) or when hyperventilation is occurring (eg, following arousal). Another important factor is the loss of the so-called wakefulness drive to breathe, such that some rise in P(aCO(2)) is likely to occur at the onset of sleep. A variety of factors contribute to this rise, including upper-airway collapse and diminished chemosensitivity (particularly during rapid-eye-movement sleep). In patients with low central drive, this further loss of drive at sleep onset can lead to marked hypercapnia in some cases. The treatment of CSA is also reviewed in some detail, including a role for positive airway pressure (eg, bi-level positive airway pressure in hypoventilation patients) and optimization of medical therapy (eg, in Cheyne-Stokes breathing). A paucity of research exists in this area, emphasizing the opportunities for young investigators who are interested in this field.

Atypical antipsychotic medications are independently associated with severe obstructive sleep apnea

BACKGROUND

Atypical antipsychotic (AA) medications are widely prescribed for their Food and Drug Administration-approved uses (acute mania, bipolar mania, psychotic agitation, bipolar maintenance, etc) and off-label indications. Although AA medications are associated with substantial weight gain, their tranquilizing effects may independently contribute to risk of obstructive sleep apnea (OSA) perhaps, by a reduction in activity of hypoglossal or recurrent activity of laryngeal nerve on the upper motor airway musculature.

METHODS

We hypothesized that AA medications are associated with more severe OSA independent of weight and neck circumference. Medical intake data and polysomnographic studies of patients referred to community hospital sleep disorders center were analyzed retrospectively.

RESULTS

Mean age of patients was 49.1 years, 55.1% were male, and mean body mass index (BMI) was 33.8 kg/m. Sixty-eight patients (8.1%) were taking AA at the time of polysomnography. There were no differences in age, sex, neck circumference and BMI of AA versus non-AA patients. The mean (SE) apnea-hypopnea index values were 29.2 (3.5)/h in AA patients and 21.3 (0.8)/h in non-AA patients (P = 0.03). Thirty-four percent of AA patients had severe OSA (apnea-hypopnea index > 30/h) compared with 23% of non-AA patients (P = 0.04). When adjusted for BMI, sex, and use of benzodiazepines and sleeping aids, the odds ratios of severe OSA in AA patients were 1.9 times in non-AA patients (95% confidence interval, 1.1-3.3).

CONCLUSIONS

Atypical antipsychotic medication use may increase the risk of more severe OSA independent of weight and neck circumference.

Sleep-disordered breathing and obesity: pathophysiology, complications, and treatment

Sleep-disordered breathing (SDB) is a medical condition that has increasingly recognized adverse health effects. Obesity is the primary risk factor for the development of SDB and contributes to cardiovascular and metabolic abnormalities in this population. However, accumulating evidence suggests that SDB may be related to the development of these abnormalities independent of obesity. Periodic apneas and hypopneas during sleep result in intermittent hypoxemia, arousals, and sleep disturbances. These pathophysiologic characteristics of SDB are likely mechanisms underlying cardiovascular and metabolic abnormalities including hypertension and other cardiovascular diseases, altered adipokines, inflammatory cytokines, insulin resistance, and glucose intolerance. Treatment of SDB with continuous positive airway pressure reverses some but not all of these abnormalities; however, studies to date have demonstrated inconsistent findings. Weight loss strategies, including diet, exercise, medications, and bariatric surgery, have been evaluated as a treatment strategy for SDB. In preliminary studies, dietary intervention and exercise reduced severity of SDB. One study demonstrated improvements in SDB severity using the weight-reducing medication sibutramine. In morbidly obese subjects, bariatric surgery effectively induces weight loss and improvement in SDB severity and symptoms, but long-term benefits remain uncertain. Large randomized trials are required to determine the utility of these strategies as long-term approaches to improving SDB and reducing associated complications.

17beta-Estradiol accentuates contractility of rat genioglossal muscle via regulation of estrogen receptor alpha

OBJECTIVE

This study in rat genioglossus muscle (GG) was designed to test the hypothesis that the effects of estrogen are at least in part, meditated directly by the estrogen receptors (ERs) of muscle.

DESIGN

Eighty-eight-week-old female Sprague-Dawley rats were randomly assigned to five groups: (1) normal animals (Normal); (2) sham operation animals (Sham); (3) ovariectomized animals without estrogen replacement (OVX); (4) ovariectomized animals with olive oil replacement (OVX+O); (5) ovariectomized animals with 17beta-estradiol replacement (OVX+E2). Six weeks later, GG was assessed in vivo for contractile properties and further analysis for ERs expression was carried out including real-time quantitative RT-PCR, immunohistochemistry and Western blotting.

RESULTS

The maximal twitch tension, 70%-decay time and fatigue index of GG decreased significantly in OVX group when compared with Normal group (P<0.05, P<0.05, P<0.05). However, all the three parameters reversed in OVX+E2 group especially fatigue index. Further analysis showed a clear expression of ERalpha and ERbeta in rat GG. The expression of both ERalpha protein and ERalpha mRNA was both significantly decreased in OVX group (P<0.05) and recovered back to previous level after receiving 17beta-estradiol replacement (P<0.05). But neither ERbeta protein nor ERbeta mRNA was regulated by estrogen deprivation and replacement.

CONCLUSION

The results demonstrated that the contractility of GG was accentuated by estrogen. Moreover, these effects were at least in part, meditated directly via regulation of the expression of ERalpha. It might contribute to the protective effects of estrogen on the patency of upper airway and the pathogenesis of obstructive sleep apnea hypopnoea syndrome.

Evaluation of the upper airway in children and adolescents with cystic fibrosis and obstructive sleep apnea syndrome

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) in cystic fibrosis (CF) patients may be associated with the presence of upper airway obstruction caused by chronic infection and nasal polyposis that may also contribute to OSAS severity. Our objective was to identify the profile of findings in CF and OSAS patients by performing upper airway examinations.

METHODOLOGY

Observational, cross-sectional study involving 63 children and adolescents between the ages of 2 and 14 with CF. All patients answered a questionnaire and underwent a standard otolaryngology examination, including an endoscopic nasal and nocturnal polysomnography. OSAS diagnosis was confirmed if the obstructive apnea index was >or=1.

RESULTS

OSAS was identified in 35 (55.6%) patients. The upper airway findings were evaluated using multiple correspondence factorial analysis. The OSAS group presented with overjet >2mm, enlarged pharyngeal pillars, palatine tonsils and pharyngeal tonsils hypertrophy, ogival hard palates and characteristics of chronic rhinosinusitis.

CONCLUSION

Bone and soft tissue structural alterations of the upper airway and chronic rhinosinusitis were associated with the OSAS group patients.