Objective Obstructive Sleep Apnea Research Articles

Sleep in children and young adults with interstitial and diffuse lung disease

ObjectiveObstructive sleep apnea (OSA) is common in adult patients with interstitial lung disease (ILD). The aim of the study was to evaluate the prevalence of OSA and sleep quality in children and young adults with children's interstitial and diffuse lung disease (chILD). MethodsA polysomnography (PSG) was performed in room air in all consecutive patients followed at a national reference centre between June 2018 and September 2019. Clinical and PSG data were collected. ResultsThe PSG data of 20 patients (12 girls, median age 9 (range 0.5–20) years), were analyzed. Seven (35%) patients had pulmonary alveolar proteinosis (PAP), 5 (25%) a disorder of surfactant metabolism, 3 (15%) diffuse pulmonary hemorrhage, 4 (20%) chILD of unknown etiology and one patient had laryngeal and pulmonary sarcoidosis. The median obstructive apnea-hypnea index (OAHI) was normal at 0 events/hour, with a value > 4 events/hour being observed in 2 young adults: an 18-year-old male with PAP and a vital capacity of 27% predicted who had an OAHI of 10.7 events/hour, and a 20-year-old male with laryngeal and pulmonary sarcoidosis who had positional OSA with an OAHI of 19.5 events/hour. The median total sleep time, sleep efficiency, % of wake after sleep onset, and sleep stages were moderately disturbed. ConclusionsModerate or severe OSA was not observed in children <18 years with chILD. Mild or moderate OSA was observed in 2 young adults with PAP and sarcoidosis. As opposed to adults, OSA seems uncommon in children with chILD.

Does neck circumference predict obstructive sleep apnea in children with obesity?

ObjectivesObstructive sleep apnea (OSA) affects 10–50% of children with obesity, but its identification is challenging and wait times for testing are long. Previous studies suggest that neck circumference (NC) and neck-to-height ratio (NHR) may predict OSA. Our objectives were to 1) evaluate associations of NC and NHR with OSA; 2) model NHR as a predictor of OSA, adjusting for age, sex, and Tanner stage; and 3) identify thresholds of NHR associated with OSA, in children with obesity. MethodsParticipants were aged 8–17 years, with obesity (BMI >95%ile), undergoing polysomnography. Associations between NC and NHR with OSA were evaluated. NHR, age, sex and self-reported Tanner stage (early/late) were included in a negative binomial multiple regression model to predict obstructive apnea hypopnea index (OAHI). Results71 children participated, with median age 14.8 years (IQR 12.6, 16.0), 54% male, median BMI z-score 2.5 (IQR 2.3, 2.7), and 77% late Tanner stage. OSA was severe in 18 children (25.4%), moderate in 12 (16.9%), and mild in 18 (25.4%). In the model, each 0.01 increase in NHR was associated with a 55% increase in OAHI (95% CI: 36%, 80%); boys had a 119% higher OAHI than girls (95% CI: 10%, 337%). Threshold NHR associated with moderate-severe OSA was 0.25 in females and 0.23 in males. ConclusionsNHR and male sex independently predict OSA severity in children with obesity, adjusting for age and Tanner stage. Children with obesity and NHR above identified thresholds are more likely to have moderate-severe OSA, and may benefit from earlier polysomnography.

Airflow dynamics in obese minipigs with obstructive sleep apnea

ObjectivesObstructive sleep apnea (OSA) is associated with anatomical restrictions of pharyngeal airway, but the mechanism of airflow dynamics in OSA is largely unknown. This study utilized computational flow dynamics (CFD) to build a 3D model of the pharynx and to test the hypothesis that an increased restriction in the pharynx in OSA/obese minipigs leads to higher resistance, which in turn creates turbulence to induce temporary blockage of pharyngeal airway patency. DesignOf five 9-11-months-old Yucatan minipigs, 3 were non-obese (BMI<35) and two obese (BMI>51). After natural sleep monitoring using BioRadio system, pigs were sedated to collect MRI images and airflow parameters. The MRI images were processed to create 3D configurations of pharynx. These 3D configurations were meshed to create finite element models (FEM) of CFD. The obtained airflow parameters were input into the configurations to identify turbulent airflow and its location. ResultsHeavy snoring and multiple >5s hypopnea/apnea episodes (AHI = 32–35) were identified in both obese minipigs during sleep. Compared to the non-obese/non-OSA controls, obese/OSA minipigs showed much lower respiratory tidal volumes and inspiratory airflow speed. FEM simulation found that turbulence was not present in the pharynx in either model. However, a 25% increase of airflow velocity was observed at the narrowest part of the nasal pharynx in the obese/OSA minipig model. ConclusionsDespite the narrower pharyngeal airway and the higher velocity of airflow, FEM simulation indicated that turbulence was not produced in the obese/OSA minipigs.

Obstructive sleep apnea detection using discrete wavelet transform-based statistical features

Motivation and objectiveObstructive sleep apnea (OSA) is a sleep disorder identified in nearly 10% of middle-aged people, which deteriorates the normal functioning of human organs, notably that of the heart. Furthermore, untreated OSA is associated with increased hypertension, diabetes, stroke, and cardiovascular diseases, thereby increasing the mortality risk. Therefore, early identification of sleep apnea is of significant interest. MethodIn this paper, an automated approach for OSA diagnosis using a single-lead electrocardiogram (ECG) has been reported. Three sets of features, namely moments of power spectrum density (PSD), waveform complexity measures, and higher-order moments, are extracted from the 1-min segmented ECG subbands obtained from discrete wavelet transform (DWT). Later, correlation-based feature selection with particle swarm optimization (PSO) search strategy is employed for getting an optimum feature vector. This process retained 18 significant features from initially computed 32 features. Finally, the acquired feature set is fed to different classifiers including, linear discriminant analysis, nearest neighbors, support vector machine, and random forest to perform per segment classification. ResultsExperiments on the publicly available physionet single-lead ECG dataset show that the proposed approach using the random forest classifier effectively discriminates normal and OSA ECG signals. Specifically, our method achieved an accuracy of 89% and 90%, with 50-50 hold-out validation and 10-fold cross-validation, respectively. Besides, in both these validation scenarios, our method obtained 96% of the area under ROC. Importantly, our proposed approach provided better performance results than most of the existing methodologies.

Effect of Obstructive Sleep Apnea on Condylar Malformation, Vertebral Column, and Head Posture: A Cephalometric Evaluation.

Aims and objectivesObstructive sleep apnea (OSA) is by far the most common sleep-related breathing disorder, affecting 2–4% of the adult population. The present study aims to compare the descriptive morphology of the cervical column in subjects with normal craniofacial morphology with those having condylar hypoplasia with OSA and to evaluate a positive correlation between the cervical columns, the cranial base angle, and the posture of the head and neck in subjects of condylar hypoplasia.Materials and methodsThe present study comprised of lateral cephalogram of 40 subjects divided into two equal groups—control groups (n = 20) and OSA with condylar hypoplasia (n = 20).Results and observationThe condylar hypoplasia group has fusion anomalies of 65% and 35% has a posterior arch deficiency. The cervical lordosis, inclination of the cervical column is found to have a positive statistically significant correlation in condylar hypoplasia subjects.ConclusionMorphological deviations and deviation pattern of the cervical column occurred significantly more often in subjects with condylar hypoplasia as compared with normal craniofacial morphology which can be verified by the increased cranial base angle, cervical lordosis, the inclination of the upper cervical spine, and cranial base angle were positively correlated with a fusion of cervical column.Clinical significanceSpecific types of craniofacial morphology and head postures such as a reduced posterior airway space, an abnormally long soft palate, a low position of the hyoid bone, and an extended head posture are considered predisposing factors of OSA. As posture of the head and neck is considered to be associated with OSA, OSA may be associated with fusion of the cervical column. Hence, to know the result of malformation in the cervical column prove to be important with regard to phenotypical subdivision, diagnosis, and treatment of OSA.How to cite this articleDivya, Navit P, Singh R, et al. Effect of Obstructive Sleep Apnea on Condylar Malformation, Vertebral Column, and Head Posture: A Cephalometric Evaluation. Int J Clin Pediatr Dent 2020;13(S-1):S64–S68.

Screening for Obstructive Sleep Apnea in a Diverse Bariatric Surgery Population.

Obstructive sleep apnea (OSA) is common among bariatric surgery patients and is associated with perioperative risk. Preoperative screening is recommended, but some screening tools lack validation, and their relative performance is unclear in this population. The study objective was to compare the ability of four existing tools (STOP-BANG, NO-OSAS, No-Apnea, and the Epworth Sleepiness Scale [ESS]) to screen for moderate to severe OSA in a diverse bariatric cohort. Data from patients presenting for first-time bariatric surgery who underwent a sleep study within 1 year of the initial encounter were retrospectively reviewed. Performance of the four tools for detecting moderate to severe OSA was compared based on the area under the receiver operating characteristic curves (AUC). Of the included 214 patients (83.2% female, median age 39 years), 45.3% had moderate to severe OSA. Based on AUC, STOP-BANG (0.75 [95% CI: 0.68-0.81], N = 185), NO-OSAS (0.76 [95% CI: 0.69-0.82], N = 185), and No-Apnea (0.69 [95% CI: 0.62-0.76], N = 190) had similar performance (P > 0.16). Compared with STOP-BANG and NO-OSAS, ESS (0.61 [95% CI: 0.54-0.68], N = 198) had a significantly lower AUC (P < 0.01). Hispanic/Latino self-identification, sex, or obesity class did not significantly modify test performance. STOP-BANG and NO-OSAS may be preferable to No-Apnea and ESS when screening bariatric surgery patients for moderate to severe OSA. Efforts to screen bariatric patients for OSA are recommended.

The burden of obstructive sleep apnea in pediatric sickle cell disease: a Kids' inpatient database study.

Obstructive sleep apnea (OSA) is associated with cardiovascular and cerebrovascular morbidity. Patients with sickle cell disease (SCD) are at increased risk for both neurologic complications (NC) and OSA. However, the relationship between OSA and SCD complications is unclear. We hypothesized that there would be an association between OSA diagnosis and SCD complications. Hospital discharge records of patients with SCD aged < 19 years were obtained for the years 1997, 2000, 2003, 2006, 2009, and 2012 from the Kid's Inpatient Database. The primary outcome, NC, a composite of stroke, transient ischemic attack, and seizures. Secondary outcomes included acute chest syndrome (ACS), vaso-occlusive crisis, length of hospital stay, and inflation-adjusted cost of hospitalization. Multivariable regression was conducted to ascertain the association of OSA with primary and secondary outcomes. Analyses were adjusted for the use of noninvasive mechanical ventilation (NIMV) to determine its role as NC risk modifier. There were 203,705 SCD discharges included in the analysis, of which 2,820 (1.4%) and 4,447 (2.2%) also included OSA and NC diagnoses. Multivariable logistic regression indicated that OSA was associated with NC (adjusted odds ratio [OR], 1.50 [95% CI 1.02-2.21], p = 0.039) and ACS (OR, 1.34 [95% CI 1.08-1.67], p = 0.009) in children with SCD. In the multivariable analysis adjusted for NIMV, the significant association between OSA and NC was no longer observed (OR, 1.39 [95% CI 0.94-2.05], p = 0.100). OSA is associated with a 50% increase of odds of NC in children with SCD in this nationwide dataset. The use of NIMV to treat OSA may modify the risk of OSA-associated NC.

The relationship between attachment, treatment compliance and treatment outcomes in patients with obstructive sleep apnea

ObjectiveObstructive sleep apnea (OSA) is a common condition with numerous health and psychological consequences. While treatment with Continuous Positive Airway Pressure (CPAP) is highly effective, it seems to be impacted by interpersonal aspects of the patient. The current study explores the role of two major interpersonal descriptors (attachment and relationship satisfaction) on treatment initiation and compliance with CPAP. The benefit of CPAP treatment on sleep measures and psychological functioning is also examined. MethodsParticipants in stable relationships, diagnosed with OSA following an inpatient polysomnography test (N = 83), were recruited. Participants were appraised on their decision to initiate treatment and completed interpersonal measures (couples' satisfaction, attachment dimensions) as well as sleep measures and mental health measures. Participants were invited to repeat the measures after 3 months (N = 31 agreed). Associations between interpersonal measures and CPAP initiation and compliance as well as the impact of CPAP on sleep and all psychological measures was assessed. ResultsIndividuals with high attachment anxiety pursued OSA treatment based on a mutual decision with the partner, while individuals with lower attachment anxiety made the decision themselves. Couples' satisfaction was positively associated with CPAP compliance over 3 months. CPAP compliance significantly improved sleep measures, mood and anxiety symptoms. ConclusionThe study brings evidence for a positive role of interpersonal factors in the initiation and compliance with OSA treatment as well as longitudinal benefits on sleep, mood and anxiety levels. The results can inform clinical approaches meant to increase treatment engagement and adherence in OSA patients through psychoeducation.

Obstructive sleep apnea risk in patients with focal versus generalized epilepsy

ObjectiveObstructive sleep apnea (OSA) is common in patients with epilepsy (PWE), and treatment may improve seizure control. However, OSA is often undiagnosed in PWE, and understanding of the risk profile for OSA is important. In this study, we sought to determine if OSA risk is similar in patients with generalized versus focal epilepsy. MethodsWe recruited 115 patients presenting to the Rutgers-Robert Wood Johnson Epilepsy Clinic with focal or generalized epilepsy. Obstructive sleep apnea risk was assessed using the Sleep Apnea Scale of the Sleep Disorders Questionnaire (SA-SDQ). Sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Demographic and clinical information was gathered from the electronic medical record. Unadjusted and adjusted analyses were carried out to assess differences in the SA-SDQ between patients with generalized versus focal epilepsy. Further analyses were done to assess the relationship between seizure frequency, epilepsy type, and the SA-SDQ. ResultsUnadjusted mean SA-SDQ scores, as well as scores high enough to represent likely OSA, were similar in patients with generalized versus focal epilepsy. However, in adjusted analyses, patients with generalized epilepsy had a significantly higher mean SA-SDQ score. Older age, higher body mass index (BMI), and a history of hypertension (HTN) were also associated with higher SA-SDQ scores. Sleep Apnea Scale of the Sleep Disorders Questionnaire scores were not significantly affected by the presence of a seizure within the prior one month or six months. Average ESS scores and the percentage of scores consistent with an abnormal degree of sleepiness were statistically similar in patients with generalized versus focal epilepsy. SignificanceOur study suggests that patients with generalized epilepsy have a higher risk of OSA. Further studies measuring OSA directly as well as assessing potential benefits of treatment are needed.

Structural assessment of the optic nerve in patients with obstructive sleep apnea syndrome: Case-control study.

Obstructive sleep apnea syndrome has been identified as a possible risk factor for optic nerve pathology such as glaucoma, nonarteritic ischemic optic neuropathy, and optic disk edema. Accordingly, we aimed to evaluate structural changes of the apparently normal optic nerve in obstructive sleep apnea syndrome patients with effects of its severity. In this prospective case-control study, 47 eyes of 47 obstructive sleep apnea syndrome patients diagnosed with polysomnography and 40 eyes of 40 healthy subjects were included. Spectral-domain optical coherence tomography was used to evaluate the peripapillary retinal nerve fiber layer thickness, optic nerve head topographic parameters, and retinal ganglion cell-inner plexiform layer thickness. The average peripapillary nerve fiber layer thickness was lower in obstructive sleep apnea syndrome patients than in controls (90.74±7.98 vs 94.93±6.13μm; p = 0.008). The average cup/disk ratio and the vertical cup/disk ratio in patients with OSAS were significantly higher compared to the controls (both p < 0.001). However, no significant difference in retinal ganglion cell-inner plexiform layer thickness was found. Even if the retinal ganglion cell-inner plexiform layer thicknesses did not significantly differ between the obstructive sleep apnea syndrome and control groups, obstructive sleep apnea syndrome patients showed a decreased peripapillary nerve fiber layer thickness and increased optic nerve head parameters. These findings can be used as an indicator of optic nerve damage in the early diagnosis of obstructive sleep apnea syndrome patients.

Proteomic biomarkers of sleep apnea.

Obstructive sleep apnea (OSA) is characterized by recurrent partial to complete upper airway obstructions during sleep, leading to repetitive arousals and oxygen desaturations. Although many OSA biomarkers have been reported individually, only a small subset have been validated through both cross-sectional and intervention studies. We sought to profile serum protein biomarkers in OSA in unbiased high throughput assay. A highly multiplexed aptamer array (SomaScan) was used to profile 1300 proteins in serum samples from 713 individuals in the Stanford Sleep Cohort, a patient-based registry. Outcome measures derived from overnight polysomnography included Obstructive Apnea Hypopnea Index (OAHI), Central Apnea Index (CAI), 2% Oxygen Desaturation index, mean and minimum oxygen saturation indices during sleep. Additionally, a separate intervention-based cohort of 16 individuals was used to assess proteomic profiles pre- and post-intervention with positive airway pressure. OAHI was associated with 65 proteins, predominantly pathways of complement, coagulation, cytokine signaling, and hemostasis which were upregulated. CAI was associated with two proteins including Roundabout homolog 3 (ROBO3), a protein involved in bilateral synchronization of the pre-Bötzinger complex and cystatin F. Analysis of pre- and post intervention samples revealed IGFBP-3 protein to be increased while LEAP1 (Hepicidin) to be decreased with intervention. An OAHI machine learning classifier (OAHI >=15 vs OAHI<15) trained on SomaScan protein measures alone performed robustly, achieving 76% accuracy in a validation dataset. Multiplex protein assays offer diagnostic potential and provide new insights into the biological basis of sleep disordered breathing.

Correlations between disease-specific quality of life and polysomnographic findings in children with obstructive sleep apnea

ObjectivesObstructive sleep apnea (OSA) can have a negative impact on quality of life in children. The OSA-18 is a disease-specific quality of life questionnaire for children. The questionnaire has been found to be a poor predictor of OSA diagnosed with polysomnography (PSG), yet OSA-18 scores do markedly improve after adenotonsillectomy. The aim of this study was to examine the correlations between OSA-18 and PSG findings, beyond the apnea hypopnea index (AHI). MethodsThis study was a prospective study of children 2–6 years of age who were referred to an Ear, Nose and Throat department for adenoidectomy and/or tonsillectomy. Prior to surgery, all of the children underwent PSG and a physical examination, and their parent completed the OSA-18 questionnaire. Spearman correlations were used to determine the associations between OSA-18 scores and PSG parameters. ResultsThe sample consisted of 97 children who underwent PSG and their parents who answered the OSA-18 questionnaire. We found positive correlations between the AHI and both the OSA-18 total score (rho = 0.21, p = 0.04) and the sleep disturbance subscale (rho = 0.51, p < 0.01). The only other PSG parameter that significantly correlated with the OSA-18 was the number of awakenings and arousals per hour of sleep (rho = 0.29, p < 0.01). ConclusionWe only found weak correlations between the OSA-18 score and PSG findings, suggesting the two methods are measuring different aspects of pediatric OSA. Clinical trialNCT 02233166.

Effects of an individualized exercise training program on severity markers of obstructive sleep apnea syndrome: a randomised controlled trial

ObjectiveObstructive sleep apnea (OSA) is a high prevalent disorder with severe consequences including sleepiness, metabolic, and cardiovascular disorders. The aim of this study was to assess the effect of an individualized exercise-training (IET) program with educational sessions vs educational sessions alone on severity markers of OSA over an eight-week duration. MethodsThis was a randomised, controlled, parallel-design study. In sum, 64 patients with moderate-to-severe OSA (apnea-hypopnea index AHI 15–45/hour), low physical activity level (Voorrips<9), body-mass index (BMI) <40 kg/m2 were included in intervention group (IG) or control group (CG), and 54 patients finished the study. All underwent polysomnography (PSG), multiple sleep latency test (MSLT), constant workload exercise test, blood samples and fulfilled questionnaires twice. The primary endpoint was the change in apnea-hypopnea (AHI) at eight weeks from baseline. Main secondary endpoints were daytime sleepiness assessed by questionnaire and objective tests. ResultsNo significant between-group differences were found for changes in AHI. A reduction in AHI was found in IG only (p = 0.005). Compared to CG, exercise training leads to a greater decrease in AHI during REM sleep (p = 0.0004), with a significant increase in mean daytime sleep latency (p = 0.02). Between-group differences were significant for weight reduction, severity of fatigue, insomnia and depressive symptoms with trend for sleepiness symptoms. ConclusionsIn adult patients with moderate-to-severe OSA, IET did not decrease AHI compared to the control group but improved markers of severity of OSA, in particular AHI in rapid eye movement (REM) sleep and objective daytime sleepiness. Adding personalized exercise training to the management of patients with OSA should be considered. ClinicalTrials.gov identifierNCT01256307.

Relationship between inflammatory factors and arrhythmia and heart rate variability in OSAS patients.

Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by recurrent upper airway obstruction, apnea, and hypopnea, associated with decreased oxygen saturation and disturbed sleep structure during sleep. It was found that OSAS was associated with a variety of arrhythmia and conduction disorders, but the relationship between multiple types of arrhythmia and the severity of OSAS, and its possible mechanism remain unclear. The purpose of this study was to observe the main types of arrhythmia and the condition of heart rate variability (HRV) in patients with OSAS, to detect the levels of multiple inflammatory factors in serum of OSAS patients, and to observe the correlation between polysomnographic parameters or inflammatory factors, and arrhythmia or HRV, as well as its possible mechanisms. 141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People's Hospital from February 2016 to February 2018. According to the sleep apnea hypopnea index (AHI), they were divided into control group (AHI <5, n = 34), mild-moderate OSAS group (5≤ AHI <30, n = 48), and severe OSAS group (AHI ≥30, n = 59). Clinical data such as gender and age were collected. All patients completed polysomnography (PSG), 24-hour Holter monitoring and blood routine, biochemical indexes and serum hs-CRP, TNF-α, IL-6, and IL-1β testing. The indicators in the three groups were compared, and the correlation between PSG parameters, HRV and inflammatory biomarkers was investigated. Compared with control group, there were significant differences in age, sex ratio, BMI, uric acid, TC, and TG in the mild-moderate OSAS group (p<0.05), and in age, sex ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL in severe OSAS group (p<0.05). There were significant differences in gender ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL between mild-moderate OSAS group and severe OSAS group (p<0.05). Heart rate variability (HRV) parameters include SDNN, SDNN index, RMSSD, PNN50, LF, HF, and LF/HF. SDNN, PNN50, and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group (p<0.05). LF/HF was significantly higher than that of control group (p<0.05). There was a significant difference in PNN50, HF, and LF/HF between severe OSAS group and mild-moderate OSAS group (p<0.05). In terms of inflammation, serum hs-CRP was significantly higher in mild-moderate OSAS group and severe OSAS group than that in control group (p<0.05). Serum IL-1β was significantly higher in mild-moderate OSAS group than that in severe OSAS group (p<0.05). There was no significant difference in other indicators (p>0.05). There was a significant positive correlation between hs-CRP and oxygen reduction index (ODI) (r=0.209, p=0.013) and a significant negative correlation with PNN50 (r=-0.188, p=0.025). There is no significant correlation between other indicators. Systemic inflammatory reactions existed in patients with OSAS. With the increase of OSAS, inflammation was aggravated, especially serum hs-CRP. Hs-CRP was significantly and negatively correlated with PNN50 and positively correlated with ODI. The results suggested that the inflammatory response was involved in the occurrence of heart rate variability in OSAS patients.

Obstructive sleep apnea intensifies stroke severity following middle cerebral artery occlusion

Study objectivesObstructive sleep apnea (OSA) is a sleep disorder caused by transient obstruction of the upper airway and results in intermittent hypoxia, sleep fragmentation, sympathetic nervous system activation, and arousal which can have an adverse effect on cardiovascular disease. It is theorized that OSA might intensify stroke injury. Our goal here was to develop a new model of experimental OSA and test its ability to aggravate behavioral and morphological outcomes following transient brain ischemia/reperfusion. MethodsWe used a 3D printed OSA device to expose C57BL6 mice to 3 h of OSA (obstructive apnea index of 20 events per hour) for three days. These mice were then subjected to ischemia/reperfusion using the middle cerebral artery occlusion model (MCAO) stroke and examined for overall survival, infarct size and neurological scoring. ResultsWe found that OSA transiently decreased respiration and reduced oxygen saturation with bradycardia and tachycardia typical of human responses during apneic events. Brain injury from MCAO was significantly increased by OSA as measured by infarct size and location as well as by intensification of neurological deficits; mortality following MCAO was also increased in OSA animals. ConclusionsOur findings suggest that our new model of OSA alters respiratory and cardiovascular physiological functions and is associated with enhanced ischemia/reperfusion mediated injury in our non-invasive, OSA intensified model of stroke.

Clinical and polysomnographic features of hypertension in obstructive sleep apnea: A single-center cross-sectional study.

Objective:Obstructive sleep apnea (OSA) is associated with elevated blood pressure (BP) and increases the risk of developing cardiovascular diseases. This study aimed to determine the clinical and polysomnographic features of OSA that are significantly associated with hypertension (HT).Methods:This is a prospective study that enrolled patients diagnosed with OSA in Ankara University Faculty of Medicine from January 2015 to June 2016. The patients were categorized into normotensives (n=125) and hypertensives (n=141). BP was taken at the evening before and the morning after polysomnography (PSG). The polysomnographic findings of normotensive and hypertensive patients were compared, and independent risk factors that are associated with HT were analyzed.Results:Hypertensive patients exhibited older age and higher Epworth sleepiness scale (ESS), apnea–hypopnea index (AHI), mean apnea duration, arousal index, and oxygen desaturation index (ODI) than normotensive patients. Nocturnal oxygen desaturation (NOD) was more frequent and the percentage of the duration of NOD to total sleep time (TST) was higher in hypertensive than normotensive patients. Multivariate analyses revealed that age (OR: 1.095, 95% CI 1.053 to 1.139, p<0.001), ESS (OR: 1.186, 95% CI 1.071 to 1.313, p=0.001), mean apnea duration (OR: 1.072, 95% CI 1.032 to 1.113, p=0.002), ODI (OR: 1.062, 95% CI 1.025 to 1.101, p=0.001), and NOD (OR: 2.439, 95% CI 1.170 to 5.086, p=0.017) were independent risk factors for HT in OSA.Conclusion:This study suggests that age, ESS, parameters of oxygenation, and apnea duration were associated with HT in patients with OSA. Hence, patients with OSA with these findings should be evaluated for HT.

Reduced Coronary Flow Reserve Is Associated with Impaired Ventricular-vascular Interaction in Patients with Obstructive Sleep Apnea.

Background and ObjectivesObstructive sleep apnea (OSA) is associated with cardiac and arterial damage and adverse cardiovascular outcomes. We aimed to determine whether coronary flow reserve (CFR), which represents microvascular dysfunction, might be associated with the ventricular-vascular coupling index (VVI), which represents the afterload-adjusted contractility in patients with OSA.MethodsWe enrolled 281 patients (257 males; mean age, 43±11 years) with newly diagnosed OSA. Transthoracic echocardiography was performed, and adenosine-associated CFR was measured in the left anterior descending coronary artery. We evaluated the differences between the patients with normal CFR ≥2.5 and reduced CFR <2.5. VVI was calculated using the effective arterial elastance (Ea) and left ventricular (LV) end-systolic elastance (Ees) as follows: 10×Ea/Ees.ResultsThe normal CFR group (n=214) showed increased Ees (7.28±2.31 vs. 8.14±2.33 mmHg/mL, p=0.016) and preserved VVI (3.17±1.53 vs. 2.78±1.20, p=0.044) compared with the reduced CFR group (n=67). There were no differences in LV dimension, LV ejection fraction, left atrial-volume index, E/e′, left atrial strain and LV global longitudinal strain between the 2 groups (all p>0.05). CFR was significantly correlated to Ees (r=0.139; p=0.023) and VVI (r=−0.137; p=0.025).ConclusionsReduced CFR is associated with decreased Ees and impaired VVI in OSA patients. It suggests the necessity of more intensive observation in OSA patients with reduced CFR to improve cardiovascular outcomes.

The Effect Of Acute Hypoxia On Audition;An Experimental Study

OBJECTIVE:Obstructive sleep apnea syndrome (OSAS) is a health problem that has increasing importance in society. In the literature, many studies about an audition in patients with OSAS are present. In this study, the effects of hypoxia on an audition that develop during the apnea attacks in OSAS were investigated experimentally.METHODS:This study was conducted in Inonu University Audiology Laboratory after the approval of Inonu University Faculty of Medicine Experimental Animal Research Ethics Committee (Protocol Number: 2011/A-102). In this study, 15 Wistar albino rats with a weight of 250–300 g were used. Anesthesia was performed by 40 mg/kg Ketamine and 5 mg/kg Xylazine through intramuscular administration. The processes were applied in the silence. This study involved 15 rats with normal auditory functions. Only tracheotomy was performed in the control group. Auditory assays were administered with otoacoustic emission (DP gram) before and after the process. In hypoxia group, hypoxia was created by making apnea attacks that lasted at least 10 seconds after the tracheotomy process. Auditory assays using DP gram were performed before tracheotomy and during hypoxia in the hypoxia group.RESULTS:In the control group, statistically significant values were not found. In the hypoxia group, statistically significant differences were detected in high frequencies.CONCLUSION:In conclusion, cochlear reply decreased in high frequencies during hypoxia that was created by apnea attacks.

Pulmonary Function and Effects of Body Position in Patients with Obstructive Sleep Apnea

Objective Obstructive sleep apnea (OSA) is known to be associated with upper airway collapse during sleep. However, OSA has also been suggested to have effects on the lower airway. This study examined the association between pulmonary function test (PFT) results during daytime and OSA according to the severity of OSA and presence of obesity. Changes in PFT results with body position (sitting vs. supine) were also analyzed. Methods A total of 46 patients who were diagnosed with OSA were included in this study. Patients were grouped according to the severity of OSA and presence of obesity. Results Obese, severe OSA patients tended to show poorer pulmonary function than non-obese, mild-to-moderate OSA patients. Forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC; sitting), peak expiratory flow (PEF; sitting), and forced expiratory flow during the middle half of the FVC (FEF25-75; supine) were significantly lower in the severe OSA group than the mild-to-moderate OSA group (p=0.020, p=0.044, and p=0.042, respectively). Positional change from sitting to the supine position significantly reduced pulmonary function in the total OSA patient population. The effect of body position on PFT results was greater in non-obese, mild-to-moderate OSA patients. FEF25-75 in the sitting position was still significantly related to the apnea-hypopnea index in OSA patients after adjusting for other factors (p=0.048). Conclusion This study indicated that relationships exist between lower airway function, body position, and OSA. The PFT is a simple test that can provide useful information about the upper and lower airways in OSA patients. Keywords: Pulmonary function test; Body position; Spirometry; Obstructive sleep apnea; Obesity

Does Neck Circumference Predict Obstructive Sleep Apnea In Children With Obesity?

Abstract Objectives Obstructive sleep apnea (OSA) affects 10–50% of children with obesity, but its identification is challenging and wait times for testing are long. Previous studies suggest that neck circumference (NC) and neck-to-height ratio (NHR) may predict OSA. Our objectives were to 1) evaluate associations of NC and NHR with OSA; 2) model NHR as a predictor of OSA, adjusting for age, sex, and Tanner stage; and 3) identify thresholds of NHR associated with OSA, in children with obesity. Methods Participants were aged 8–17 years, with obesity (BMI >95%ile), undergoing polysomnography. Associations between NC and NHR with OSA were evaluated. NHR, age, sex and self-reported Tanner stage (early/late) were included in a negative binomial multiple regression model to predict obstructive apnea hypopnea index (OAHI). Results 71 children participated, with median age 14.8 years (IQR 12.6, 16.0), 54% male, median BMI z-score 2.5 (IQR 2.3, 2.7), and 77% late Tanner stage. OSA was severe in 18 children (25.4%), moderate in 12 (16.9%), and mild in 18 (25.4%). In the model, each 0.01 increase in NHR was associated with a 55% increase in OAHI (95% CI: 36%, 80%); boys had a 119% higher OAHI than girls (95% CI: 10%, 337%). Threshold NHR associated with moderate-severe OSA was 0.25 in females and 0.23 in males. Conclusions NHR and male sex independently predict OSA severity in children with obesity, adjusting for age and Tanner stage. Children with obesity and NHR above identified thresholds are more likely to have moderate-severe OSA, and may benefit from earlier polysomnography.