Non-positional Obstructive Sleep Apnea Research Articles

Outcomes and Predictors of Success Following Multilevel Surgery in Positional and Nonpositional Obstructive Sleep Apnea.

To assess the surgical outcomes and identify predictors of surgical success in patients with positional and non-positional obstructive sleep apnea following multilevel airway surgery. Retrospective cohort study. Singe-tertiary medical center. This study included 158 patients with obstructive sleep apnea who underwent multilevel airway surgery. Patients were divided into 2 groups according to position dependency: "positional patients" group (n = 100), and "nonpositional patients" group (n = 58). The characteristics and surgical outcomes of the 2 groups were compared. The nonpositional group included younger and more obese patients in comparison to the positional group. Moreover, the nonpositional group had more severe disease than the positional group. Both groups showed overall improvement after surgery, and the surgical success rate did not differ significantly between the 2 groups (nonpositional, 41.4% vs positional, 48.0%; P = .424). Notably, 69.0% of patients belonging to the non-positional group converted to positional group postoperatively. Logistic regression analysis revealed that larger tonsil size, female sex, and higher mean O2 saturation were associated with higher success rate in the positional group, whereas larger tonsil size was associated with surgical success in the nonpositional group. Both nonpositional and positional groups showed improvements following multilevel airway surgery, and surgery induced a transition from nonpositional to positional group. Given that the factors related to surgical success differed between the two groups, surgeons should consider position dependency and these distinct factors during decision-making.

Effectiveness of Mandibular Advancement Devices in Positional OSA Patients: A Retrospective Analysis of Predictive Variables in a Sample of Adult Patients.

Objectives To evaluate the efficacy of mandibular advancement devices (MADs) in improving apnea-hypopnea index (AHI) in positional obstructive sleep apnea (POSA), compared with a control group of nonpositional OSA (NPOSA) patients, from mild to very severe degree, in order to to find the main variables characterizing the examined group as potential predictors of treatment success. Materials and Methods In the present observational study, we retrospectively collected polysomnographic records of 39 positional adult patients, divided into 30 supine isolated OSA (siOSA) and 9 supine predominant OSA (spOSA) undergoing MADs from 2003 to 2019, and compared with those of a control group of 47 NPOSA patients. Demographics and anthropometrical data, home sleep apnea test (HSAT) records, drug-induced sleep endoscopy (DISE) results, and dental casts evaluation were analyzed pre- and post-treatment with MADs. Results A prevalence of the male sex (86%), mean age of 49,4 ± 14.98 years, and mean body mass index (BMI) of 26.74 ± 4.29 kg/m 2 were found among the OSA patients with significant differences between the three groups for sex and BMI. After MADs, the HSAT revealed significant reduction of AHI in all of the groups, with greater reduction of the supine AHI in POSA and significant reduction of the snore index for NPOSA. The hypopharynx section (H) of the NOHL Index, a fourth degree of hypopharyngeal collapse and an anteroposterior pattern was the most frequent to occur (19.9%) from DISE exam. No significant correlation between the initial total AHI and the dental variables was found, except for a reduced maxillary intermolar distance. Conclusion MADs are effective in reducing AHI in POSA and NPOSA patients from mild to very severe degree. Supine AHI decreased after treatment with MADs mainly in siOSA and spOSA patients compared with the NPOSA group. The snore index decreased significantly after treatment with MADs in all groups, showing the greater reduction in the NPOSA group. The tongue base (H) represented the most frequent anatomic area of collapse and there was a high prevalence of upper maxillary constriction.

Abstract 12619: Positional Obstructive Sleep Apnea and Risk of Atrial Fibrillation

Introduction: Obstructive sleep apnea (OSA), a common sleep disorder, has been associated with the risk of atrial fibrillation (AF). OSA is a heterogenous condition but is heavily position-dependent. Positional OSA (POSA) is a common form of OSA in which OSA is predominantly manifested in a supine position. The implication of POSA in cardiovascular risks is unclear. This study aimed to examine whether the risk of AF is different between individuals with POSA and those with non-positional OSA (nPOSA). Methods: We identified individuals with OSA (AHI ≥ 5/h) from the Sleep Heart Health Study (SHHS) cohort. POSA was defined if overall AHI ≥ 5/h, supine AHI ≥ 5/h, and supine AHI greater than twice the non-supine AHI based on the SHHS visit 1 sleep study. Incident AF was deemed present if detected on a 12-lead ECG during the SHHS visit 2 or confirmed by the parent cohorts at any time between the baseline PSG and the final follow-up date for AF assessment. Multiple logistic regression analysis was conducted with covariates including age, race, gender, body mass index, smoking status, systolic blood pressure, use of hyperlipidemia medication, use of diabetes medication (oral or insulin), use of hypertension medication, cholesterol, triglyceride, and high-density-lipoprotein, and other sleep characteristics (total sleep duration, sleep efficiency, and sleep onset latency). Results: The study included a total of 1712 participants (females, 45%; mean age, 65 years old) with OSA. Compared with individuals with nPOSA, those with POSA were more likely to be white (p=.002), older (p<.043), have lower AHI (p<.001), lower BMI (p<.001), lower systolic blood pressure (p<.001), and lower triglyceride (p=.029), longer sleep duration (p=.002), and less likely to take hypertension medication (p<.001). After accounting for these differences, the odds of incident AF were about 30% lower in the individuals with POSA compared with those with nPOSA (OR=0.7, p=.037). Conclusions: Individuals with OSA exhibit a lower risk of AF when they have POSA. While it is possible that residual confounding could account for this finding, we conclude that POSA might represent a unique phenotype with distinct cardiovascular implications.

Upper airway morphology in adults with positional obstructive sleep apnea

PurposeTo compare the anatomical balance and shape of the upper airway in the supine position between adults with positional obstructive sleep apnea (POSA) and adults with non-positional OSA (NPOSA).MethodsAdults diagnosed with OSA (apnea-hypopnea index (AHI) > 10 events/h) were assessed for eligibility. POSA was defined as the supine AHI more than twice the AHI in non-supine positions; otherwise, patients were classified as NPOSA. Cone beam computed tomography (CBCT) imaging was performed for every participant while awake in the supine position. The anatomical balance was calculated as the ratio of the tongue size to the maxillomandibular enclosure size. The upper airway shape was calculated as the ratio of the anteroposterior dimension to the lateral dimension at the location of the minimal cross-sectional area of the upper airway (CSAmin-shape).ResultsOf 47 participants (28 males, median age [interquartile range] 56 [46 to 63] years, median AHI 27.8 [15.0 to 33.8]), 34 participants were classified as having POSA (72%). The POSA group tended to have a higher proportion of males and a lower AHI than the NPOSA group (P = 0.07 and 0.07, respectively). After controlling for both sex and AHI, the anatomical balance and CSAmin-shape were not significantly different between both groups (P = 0.18 and 0.73, respectively).ConclusionAdults with POSA and adults with NPOSA have similar anatomical balance and shape of their upper airway in the supine position.Trial registrationThis study was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR Trial ACTRN12611000409976).

0473 Multi-outcome of mandibular advancement device in Obstructive Sleep Apnea with different polysomnographic phenotype

Abstract Introduction The association of mandibular advancement device (MAD) treatment response and polysomnographic phenotype in patients with obstructive sleep apnea (OSA) has not been fully elucidated. We hypothesized MAD response would be associated with two polysomnographic phenotypes, including sleep stage and positional dependency in treatment-naïve patients with moderate-severe obstructive OSA. Methods This retrospective study recruited OSA patients with AHI ≥15/h, aged 20 to 80, treatment naïve, and received MAD treatment for more than three months. Positional phenotype included supine predominant (supine-p) and non-positional OSA. Sleep stage phenotype included REM-predominant (REM-p), NREM-predominant (NREM-p), and stage-independent (SI) OSA. MAD response was defined as criterion 1: residual AHI< 5/h with >50% reduction, and criterion 2: residual AHI< 10/h with >50% reduction. Outcomes included the change in PSG parameters, habitual latency of sleep onset and sleep hour, Epworth sleepiness scale, excessive daytime sleepiness, depression, physical, vitality and mental health domain of SF-36, and in-lab bedtime and wake blood pressure (BP). Results 379 patients with median age of 52.2 years, BMI of 26 kg/m2, 78.1% of men, and AHI of 28.2/h were recruited. Supine-p and REM-p OSA had lower baseline AHI and desaturation. The overall response rate were 34.7% (criterion 1 ) and 56% (Criterion 2). Supine-p OSA had higher response rate than non-positional OSA (criterion 1: 42.2% vs. 20.3%; criterion 2: 64.3% vs. 32.5%), while NREM-p OSA had lower response rate than REM-p and SI (REM-p vs. NREM-p vs. SI: criterion 1: 43.9% vs. 9.7% vs. 34.2%; criterion 2: 54.5% vs. 41.9% vs. 53.3%). Despite the more reduction in AHI, desaturaiotn, and arousal in responders, there was no differences in change of ESS, EDS, sleep pattern, depression, SF 36 domain, and BP between responders and non-responders which remained unchanged after stratified with sleep stage and position phenotypes. Conclusion Non-positional and NREM-predominant OSA had lower responses rate to MAD treatment. There were no differences in non-breathing outcomes between responders and nonresponders regardless of sleep stage and positional phenotype. Support (if any) The work was supported by grants from the National Science and Technology Council, Taiwan (NSTC 111-2314-B-002-293); Ministry of Science and Technology, Taiwan (MOST 109-2314-B-002-252); National Taiwan University Hospital (NTUH 107-19, 111-X0033, 111-S0298)

The Effects of Barbed Repositioning Pharyngoplasty in Positional and Non-Positional OSA Patients: A Retrospective Analysis.

The aim of our retrospective study is evaluating the effectiveness of barbed repositioning pharyngoplasty (BRP) in a consecutive cohort of patients and assessing its impact on positional indexes in order to potentially identify specific obstructive sleep apnea (OSA) phenotypes for patients who might benefit more significantly from this intervention. A single-center retrospective study with baseline and follow-up type III sleep tests evaluating the Apnea Hypopnea Index (AHI), supine AHI, non-supine AHI, oxygen desaturation index (ODI), mean SaO2, percentage of time spent at SaO2 below 90% (CT90), and lowest oxygen saturation (LOS) were performed. The patients were then divided into groups according to Sher's criteria and Amsterdam Positional OSA Classification (APOC). Parametric and non-parametric tests and univariate and multivariate analyses were conducted. The study finally included 47 patients. The statistical analysis showed significant improvement in AHI, supine AHI, non-supine AHI, and ODI after surgery. The linear regression showed that high values of baseline AHI, AHI supine, and AHI non supine predict more significant postoperative reductions in AHI, AHI supine, and AHI non supine, respectively. Therapeutic success was achieved in 22 patients out of 47. The logistic regression did not find any independent risk factors for success. The most significant reduction in AHI, supine AHI, and non-supine AHI was observed in the APOC 3 group while the APOC 1 patients experience a substantially lower improvement. BRP appears to be an effective surgical procedure for the treatment of OSA. The non-positional patients might benefit more from BRP in comparison with positional patients. Moreover, OSA severity should not be considered an absolute contra-indication for this surgical procedure.

Short-term positive effects of a mandibular advancement device in a selected phenotype of patients with moderate obstructive sleep apnea: a prospective study.

To evaluate (determinants of) treatment success of mandibular advancement device application in a selected phenotype of patients with obstructive sleep apnea (OSA). Ninety nonobese patients with moderate OSA (obstructive apnea-hypopnea index [OAHI] ≥ 15 and < 30 events/h) without comorbidities were prospectively included. Polysomnography was performed at baseline and with a mandibular advancement device. A drug-induced sleep endoscopy with jaw thrust was performed in 83%. OAHI reduction ≥ 50% was observed in 73%, OAHI reduction ≥ 50% with OAHI < 10 events/h in 70%, and complete OSA resolution (OAHI < 5 events/h) in 40%. Patients with nonpositional OSA showed a significantly higher rate of complete OSA resolution: Posttest probability increased to 67%. In patients with total disappearance of collapse at velum level and at all levels during drug-induced sleep endoscopy with jaw thrust, the drop in OAHI was impressive with an infinitively high positive likelihood ratio. However, the proportion of patients having nonpositional OSA or the drug-induced sleep endoscopy characteristics as described above was < 20%. The change in snoring disturbance based on a visual analog scale was 76% (interquartile range 40-89%, P < .001) and a statistically significant amelioration in Epworth Sleepiness Scale (especially in somnolent subjects) was observed. High adherence was reported. In this predefined OSA phenotype, a mandibular advancement device was effective in reduction of OAHI and in amelioration of symptoms. Stratification by nonpositional OSA and findings on drug-induced sleep endoscopy with jaw thrust increased treatment success defined as reduction in OAHI. However, the clinical relevance can be questioned because only a small number of patients demonstrated these characteristics. Buyse B, Nguyen PAH, Leemans J, etal. Short-term positive effects of a mandibular advancement device in a selected phenotype of patients with moderate obstructive sleep apnea: a prospective study. J Clin Sleep Med. 2023;19(1):5-16.

Associations of overnight changes in body composition with positional obstructive sleep apnea.

Body composition is considered to be associated with obstructive sleep apnea (OSA) severity. This cross-sectional study aimed to examine associations of overnight body composition changes with positional OSA. The body composition of patients diagnosed with non-positional and positional OSA was measured before and after overnight polysomnography. Odds ratios (ORs) of outcome variables between the case (positional OSA) and reference (non-positional OSA) groups were examined for associations with sleep-related parameters and with changes in body composition by a logistic regression analysis. Among 1584 patients with OSA, we used 1056patients with non-positional OSA as the reference group. We found that a1-unit increase in overnight changes of total fat percentage and total fat mass were associated with 1.076-fold increased OR (95% confidence interval (CI): 1.014, 1.142) and 1.096-fold increased OR (95% CI: 1.010, 1.189) of positional OSA, respectively (all p < 0.05). Additionally, a1-unit increase in overnight changes of lower limb fat percentage and upper limb fat mass were associated with 1.043-fold increased OR (95% CI: 1.004, 1.084) and 2.638-fold increased OR (95% CI: 1.313, 5.302) of positional OSA, respectively (all p < 0.05). We observed that a1-unit increase in overnight changes of trunk fat percentage and trunk fat mass were associated with 1.056-fold increased OR (95% CI: 1.008, 1.106) and 1.150-fold increased OR (95% CI: 1.016, 1.301) of positional OSA, respectively (all p < 0.05). Our findings indicated that nocturnal changes in the body's composition, especially total fat mass, total fat percentage, lower limb fat percentage, upper limb fat mass, trunk fat percentage, and trunk fat mass, may be associated with increased odds ratio of positional OSA compared with non-positional OSA.

Comparison of polysomnographic and cephalometric parameters based on positional and rapid eye movement sleep dependency in obstructive sleep apnea

The aim of this study is to investigate the differences in polysomnographic and cephalometric features according to positional and rapid eye movement (REM) sleep dependencies in obstructive sleep apnea patients. Standard polysomnography and cephalometric analyses were performed on 133 OSA patients. The subjects were categorized into positional and non-positional, and REM-related and not-REM-related OSA groups according to positional and REM sleep dependency on severity of sleep apnea. Polysomnographic and cephalometric parameters were compared between groups. Positional and REM-related OSA patients showed significantly lower non-supine apnea–hypopnea index (AHI), non-REM (NREM) AHI and overall AHI and higher NREM oxygen saturation (SpO2) and mean SpO2 compared to non-positional and not-REM-related OSA patients, respectively. Cephalometric features between positional and non-positional OSA patients did not show any significant differences. However, REM-related OSA patients showed significantly larger inferior oral airway space and shorter perpendicular distance between mandibular plane and anterior hyoid bone and the distance between uvula and posterior nasal spine, and narrower maximum width of soft palate than not-REM-related OSA patients. Positional and REM-related OSA patients have lower severity of sleep apnea, suggesting the possibility of lower collapsibility of the upper airway. REM sleep dependency was associated with anatomical factors, while positional dependency did not show such a tendency.

0706 Older Age Is a Strong Risk Factor for Supine-position Dependent Obstructive Sleep Apnea

Abstract Introduction Positional obstructive sleep apnea (p-OSA) is commonly defined as a supine-position dependent OSA with the ratio of apnea hypopnea index while supine (s-AHI) to AHI while non-supine (ns-AHI) being greater than 2. Prevalence of p-OSA amongst OSA patients varies from 20 to 75% depending on the study. Previous studies using this definition showed p-OSA being more likely to be in subjects with lower BMI, smaller neck circumference, and milder OSA compared to patients with non-positional OSA (np-OSA). The primary aim of this study is to assess the prevalence of p-OSA using different cutoffs of s-AHI/ ns-AHI ratio and to evaluate the correlation of p-OSA with age, gender, neck circumference (NC), and medical comorbidities of OSA. Methods 846 participants aged 18 year or older who underwent diagnostic polysomnography at an academic sleep disorders center from July 2011 to June 2012 were recruited for this study. Inclusion criteria were total sleep time greater than 120 minutes, diagnosis of OSA, sleep time in supine position more than 10 minutes, and sleep time in non-supine position more than 10 minutes. We tested supine position dependency using the ratio of supine AHI to non-supine AHI (s-AHI/ns-AHI) and classified the subjects into p-OSA and np-OSA based on the ratio of s-AHI/ns-AHI at 2, 3, 5, and 10 respectively to assess the prevalence of p-OSA using each cut-off. For the multivariable logistic analysis of p-OSA and its association with independent variables, s-AHI/ns-AHI of 10 and ns-AHI of being less than 5 was used to define p-OSA. Multivariate analysis was conducted to explore correlation with age, gender, neck circumference, and OSA comorbidities (COPD, hypertension, diabetes). Age of 60 was used to define older age group. Results Of 356 eligible participants, p-OSA was highly prevalent when conventional s-AHI/ns-AHI ration of 2 was used resulting in p-OSA in 274 subjects (prevalence of 77%). The mean value of s-AHI/ns-AHI in this aggregate group of all 356 subjects was 11.7 (much higher than conventional ratio of 2). Thus, using s-AHI/ns-AHI ratio of 10 as the cut-off for supine-position dependency, 114 subjects were classified to have p-OSA. Logarithmic multivariate analysis demonstrated that there was a statistically significant, correlation between age and s-AHI/ns-AHI after adjusting for gender, NC, diabetes, hypertension, and COPD (p-value &amp;lt; 0.05). In the older group, 44.3% of older patient had s-AHI/ns-AHI &amp;gt; 10 compared to 30% of young patients (p-value &amp;lt; 0.05). 41.8% of the older group met criteria for p-OSA compared to 29.2% of younger group (p-value &amp;lt; 0.05). Being of older age was strong risk factor for p-OSA with odds ratio (OR) of 1.76 (confidence interval 1.01 – 3.09; p&amp;lt; 0.05). This effect of age on p-OSA was further modified by gender and diabetes. Older men had significantly higher OR of 3.23 (CI 1.51-6.89) for p-OSA whereas olde women was with OR of 0.79 (CI 0.33-2.42). Older persons with diabetes showed significantly higher OR than non-diabetic older persons (OR of 6.81 [CI 1.7-26.8] vs OR 1.22 [CI 0.65-2.29] respectively). Conclusion Supine-position dependency of obstructive events is much stronger than the conventional ratio of two. Thus, stricter definition is positional OSA is desired for more clinically meaningful use of this subgroup of OSA. Using stricter definition with higher supine-position dependency, an older age is significantly associated with positional OSA, especially in men or in diabetic patients. Support (If Any)

Prevalence, characteristics, and respiratory arousal threshold of positional obstructive sleep apnea in China: a large scale study from Shanghai Sleep Health Study cohort

PurposeTo evaluate the prevalence, characteristics, and respiratory arousal threshold (ArTH) of Chinese patients with positional obstructive sleep apnea (POSA) according to the Cartwright Classification (CC) and Amsterdam Positional Obstructive Sleep Apnea Classification (APOC).MethodsA large-scale cross-sectional study was conducted in our sleep center from 2007 to 2018 to analyze the clinical and polysomnography (PSG) data of Chinese POSA patients. Low ArTH was defined based on PSG indices.ResultsOf 5,748 OSA patients, 36.80% met the CC criteria, and 42.88% the APOC criteria, for POSA. The prevalence of POSA was significantly higher in women than men (40.21% and 46.52% vs. 36.13% and 42.18% for CC and APOC, respectively). Chinese POSA patients had a lower apnea hypopnea index (AHI) and lower oxygen desaturation index, shorter duration of oxygen saturation (SaO2) < 90%, and a higher mean SaO2 and higher lowest SaO2 value compared to subjects with non-positional OSA (NPOSA). More than 40% of the POSA patients had a low ArTH; the proportion was extremely high in the supine-isolated-POSA (si-POSA) group and APOC I group. In multivariate logistic regression analyses, higher mean SaO2 and lower AHI during sleep were positive predictors of POSA.ConclusionsAccording to the CC and APOC criteria, more than 1/3 of our Chinese subjects with OSA had POSA. Chinese POSA patients had less severe OSA and nocturnal hypoxia. Compared to NPOSA patients, significantly more patients with POSA had a low ArTH. A low ArTH may be an important endotype in the pathogenesis of POSA, especially in patients with si-POSA and APOC I. Further studies are necessary to develop personalized management strategies for POSA patients.Trial registration: Chinese Clinical Trial Registry; URL: http://www.chictr.org.cn; No. ChiCTR1900025714 (retrospectively registered).

The Worsening of Positional Mild Obstructive Sleep Apnea over Time Is Associated with an Increase in Body Weight: Impact on Blood Pressure and Autonomic Nervous System

Background: Most patients with mild obstructive sleep apnea (OSA) are positional dependent. Although mild OSA worsens over time, no study has assessed the natural course of positional mild OSA. Objectives: The aim of this study was to evaluate the natural course of positional mild OSA, its most valuable progression predictor, and its impact on blood pressure (BP) and the autonomic nervous system (ANS). Methods: This retrospective observational cohort study enrolled 86 patients with positional mild OSA and 26 patients with nonpositional mild OSA, with a follow-up duration of 32.0 ± 27.6 months and 37.6 ± 27.8 months, respectively. Polysomnographic variables, BP, and ANS functions were compared between groups at baseline and after follow-up. Results: In patients with positional mild OSA after follow-up, the apnea/hypopnea index (AHI) increased (9.1 ± 3.3/h vs. 22.0 ± 13.2/h, p = 0.000), as did the morning systolic BP (126.4 ± 13.3 mm Hg vs. 130.4 ± 15.9 mm Hg, p = 0.011), and the sympathetic activity (49.4 ± 12.3% vs. 55.3 ± 13.1%, p = 0.000), while the parasympathetic activity decreased (50.6 ± 12.3% vs. 44.7 ± 13.1%, p = 0.000). The body mass index changes were the most important factor associated with AHI changes among patients with positional mild OSA (Beta = 0.259, adjust R² = 0.056, p = 0.016, 95% confidence interval 0.425 and 3.990). The positional dependency disappeared over time in 66.3% of patients with positional mild OSA while 69.2% of patients with nonpositional mild OSA retained nonpositional. Conclusions: In patients with positional mild OSA, disease severity, BP, and ANS regulation worse over time. Increased weight was the best predictor for its progression and the loss of positional dependency. Better treatments addressing weight control and consistent follow-up are needed for positional mild OSA.

Risk factors for non-positional obstructive sleep apnea-hypopnea syndrome.

To explore the main risk factors for non-positional obstructive sleep apnea (NPOSA). A total of 560 patients withobstructive sleep apnea-hypopnea syndrome (OSAHS) were divided into non-positional obstructive sleep apnea (NPOSA) and positional obstructive sleep apnea (POSA) groups. All patients were assessed by the Friedman staging system and anthropometry before overnight polysomnography. Blood tests were performed to determine the fasting blood glucose level and lipid profile. Forward logistic regression analysis was performed to evaluate the effects of all parameters on positional dependency. The study sample consisted of 318 NPOSA patients and 242 POSA patients (88% and 85% were men, respectively). The mean apnea-hypopnea index (AHI) was 57.0 events/h in the NPOSA group, compared with 25.7 events/h in the POSA group. The POSA group had a significantly smaller neck circumference (NC), waist circumference (WC), hip circumference (HC), lower body mass index (BMI), AHI, fasting blood glucose, and apolipoprotein-B (apoB) levels than did the NPOSA group (all, P < 0.01). The minimal nocturnal oxyhemoglobin saturation (minSpO2) and apoB/apoA ratio were higher in the POSA group than in the NPOSA group (both, P < 0.001). The AHI, minSpO2, WC, and fasting blood glucose level were included in the logistic regression models. The AHI, WC, minSpO2, and fasting blood glucose level are the main independent risk factors for NPOSA.

449 The Effects of Positional and Sleep Stage Dependency on Mandibular Advancement Device Treatment Outcome in Obstructive Sleep Apnea

Abstract Introduction Mandibular advancement device (MAD) responder phenotype are not well understood in patients with obstructive sleep apnea (OSA). Recent studies have reported the association between MAD treatment response and polysomnographic phenotypes using positional and sleep stage dependency, but with inconsistent findings. Thus, the study aims to investigate the relationship between the two phenotypes and MAD response. Methods This retrospective study recruited patients with OSA (apnea-hypopnea index [AHI] &amp;gt;10/h), who were 20 to 80 years old, treatment naïve, and received MAD treatment for more than three months from 2009 to 2017. AHIsupine/AHInon-supine ≥2 and &amp;lt;2 meant supine predominant (supine-p) and non-positional OSA, respectively. REM-AHI/NREM-AHI ≥2, ≤0.5, and between 0.5 to 2 indicated REM-predominant (REM-p), NREM-predominant (NREM-p), and stage-independent (SI) OSA, respectively. Three criteria defined successful MAD treatment (i.e., criterion 1: residual AHI &amp;lt;5/h with &amp;gt;50% reduction; criterion 2: residual AHI 50% reduction; criterion 3: reduction &amp;gt;50%). The association between the two phenotypes and the three treatment criteria was identified using multivariable logistic regression. Results A total of 218 patients with a median age of 52.5 years, body mass index (BMI) of 25.4 kg/m2, and AHI of 28.2/h were recruited. Supine-p OSA had lower waist circumferences than non-positional OSA. The REM-p group had lower AHI and more female than the NREM-p and SI group. Supine-p OSA had better response than non-positional OSA (criterion 1: 43.2% vs 34.1%; criterion 2: 63.6% vs 34.1%; criterion 3: 77.3% vs 51.2%). NREM-p OSA had lower response across all three criteria (REM-p vs NREM-p vs SI: criterion 1: 57.6% vs 0% vs 42.0%; criterion 2: 75.8% vs 16.7% vs 56.5%; criterion 3: 75.8% vs 33.3% vs 77.1%). The odds of MAD response for supine-p OSA was 3.78 (95% CI = 1.44–9.93) to 3.98 (95% CI = 1.58–9.99)-fold than non-positional OSA while the odds for NREM-p OSA were 0.06 (95% CI = 0.01–0.58) to 0.15 (95% CI = 0.03–0.67)-fold than SI OSA after adjusting demographics and clinical features affecting MAD response. Conclusion Positional and sleep stage dependency were associated with MAD response and could be indicators for personal-tailored OSA treatment. Support (if any) The Ministry of Science and Technology, Taiwan (MOST 109-2314-B-002-252)

Real-time prediction of upcoming respiratory events via machine learning using snoring sound signal.

The aim of the study was to inspect the acoustic properties and sleep characteristics of a preapneic snoring sound. The feasibility of forecasting upcoming respiratory events by snoring sound was also investigated. Participants with habitual snoring or a heavy breathing sound during sleep were recruited consecutively. Polysomnography was conducted, and snoring-related breathing sound was recorded simultaneously. Acoustic features and sleep features were extracted from 30-second samples, and a machine learning algorithm was used to establish 2 prediction models. A total of 74 eligible participants were included. Model 1, tested by 5-fold cross-validation, achieved an accuracy of 0.92 and an area under the curve of 0.94 for respiratory event prediction. Model 2, with acoustic features and sleep information tested by Leave-One-Out cross-validation, had an accuracy of 0.78 and an area under the curve of 0.80. Sleep position was found to be the most important among all sleep features contributing to the performance of the 2 models. Preapneic sound presented unique acoustic characteristics, and snoring-related breathing sound could be deployed as a real-time apneic event predictor. The models, combined with sleep information, serve as a promising tool for an early warning system to forecast apneic events. Wang B, Yi X, Gao J, etal. Real-time prediction of upcoming respiratory events via machine learning using snoring sound signal. J Clin Sleep Med. 2021;17(9):1777-1784.

Effect of oral appliance in positional and nonpositional obstructive sleep apnea patients

Effect of oral appliance in positional and nonpositional obstructive sleep apnea patients

Role of drug-induced sleep endoscopy in evaluation of positional vs non-positional OSA

BackgroundThe study aimed to evaluate the anatomical differences between positional and non-positional OSA, and to identify the potential predictors for distinguishing between these two types of OSA.MethodsA cross-sectional study of 230 consecutive patients with OSA undergoing DISE (Drug-induced Sleep Endoscopy) was carried out at a tertiary academic medical center. The factors correlating with positional and non-positional OSA were analyzed, including clinical characteristics, polysomnography data, and DISE findings.ResultsUnivariate analysis revealed that non-positional dependency was correlated with a higher BMI (p < 0.001), neck circumference (p < 0.001), modified Mallampati score (p = 0.003), AHI (p < 0.001), degree of velum concentric collapse (p = 0.004), degree of oropharyngeal lateral wall collapse (p < 0.001), and degree of tongue base anteroposterior collapse (p = 0.004). Multivariate analysis revealed that oropharyngeal lateral wall collapse (OR = 1.90, p = 0.027) was the only anatomical factor significantly predicted non-positional dependency in OSA patients. AHI (OR = 1.04, p < 0.001), although significant, made only a marginal contribution to the prediction of non-positional dependency.ConclusionsOropharyngeal lateral wall collapse was identified as the only anatomical predictor for non-positional dependency in OSA patients. Therefore, further treatment modalities should address the distinct anatomical trait between positional and non-positional OSA.Graphical abstract

0567 Hypoxic Burden and Apnea-Hypopnea Duration in Patients with Positional Obstructive Sleep Apnea

Abstract Introduction Recently, the measurement of the hypoxic burden and apnea-hypopnea duration has been shown to correlate with mortality in patients with obstructive sleep apnea (OSA). We hypothesized that in patients with mild positional OSA (apnea-hypopnea index [AHI] &amp;lt; 5 events/hr in the non-supine position) the hypoxic burden would be increased and apnea-hypopnea duration shortened and similar to patients with non-positional OSA. Methods Fourteen patients with positional OSA and 24 patients non-positional OSA with similar severity of OSA based on the respiratory event index (REI) were included. All patients had a home sleep apnea test for suspected OSA. The hypoxic burden was calculated by the multiplication of REI and the mean area under the desaturation curves. Results Thirty-eight patients [12 (35%) males, 50±12 yrs, BMI 35±7 kg/m2, Epworth Sleepiness Scale (ESS) 11±8, REI 10±3 events/hr, apnea-hypopnea duration 19±4 sec, mean SaO2 94±2%, lowest SaO2 79±8%, % total sleep time (TST) SaO2 &amp;lt; 90% 11±16%, hypoxic burden 30±17 %min/hr] completed the study. Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 &amp;lt; 90% 4±6%] had positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) and 24 patients had non-positional OSA [3 (13%) males, 52±10 yrs, BMI 38±7 kg/m2, ESS 12±9, REI 10±3 events/hr, mean SaO2 94±2%, lowest SaO2 77±9%, %TST SaO2 &amp;lt; 90% 14±19%]. The hypoxic burden was elevated in both the positional and non-positional OSA patients with no difference between the groups (26±19 %min/hr and 32±15 %min/hr, respectively, p=0.13). The apnea-hypopnea duration was similar in positional and non-positional OSA patients (20±3 sec and 18±4 sec, respectively, p=0.08 sec). Conclusion In patients with mild positional OSA the hypoxic burden, which has been associated with cardiovascular mortality, is elevated and similar to patients with non-positional OSA. Support None

1048 Prevalence Of Positional Obstructive Sleep Apnea (OSA) In Patients With OSA-COPD Overlap Syndrome

Abstract Introduction Positional OSA (non-supine apnea-hypopnea index [AHI] &amp;lt; 5 events/hr) is present in 30% of patients with OSA. We demonstrated that in patients with OSA- COPD overlap syndrome the AHI inversely correlated with the degree of gas trapping, suggesting a stabilizing effect on the upper airway. We hypothesized that sleep position would be less important, resulting in a lower prevalence of positional OSA. Methods Patients underwent a polysomnogram that demonstrated OSA (AHI &amp;gt; 5 events/hr). To confirm COPD, patients had spirometry performed and a chest computed tomography for measurements of percent gas trapping. Results Sixteen patients [6 (38%) males, 55±7 years/old, FEV1 1.2±0.5 L, FEV1 % Predicted 45±19%, FVC 2.3±0.8 L, FVC % Predicted 69±20%, FEV1/FVC 51±12%, BMI 33±9 kg/m2)] were diagnosed with OSA (AHI 15±12 events/hour). Four patients (25%) had positional OSA (AHI 13±6 events/hr, non-supine AHI 1±1 event/hr) compared to 12 patients who were non-positional [AHI 16±13 events/hr (p=0.95)]. There was no difference in age [52±8 and 56±7 yrs (p=0.3)] or severity of obstruction in those with and without positional OSA [FEV1 1.4±4 L and 1.1±0.5 L, (p=0.3), FEV1 % predicted 50±17% and 44±20%, (p=0.7), FVC 2.9±0.8 L and 2.1±0.8 L (p=0.1), FVC % predicted 78±21% and 66±20%, (p=0.3), and FEV1/FVC 50±11% and 51±12%, (p=0.8), respectively]. However, patients with positional OSA were less heavy than those with non-positional OSA [BMI 23±3 and 37±8 kg/m2, respectively (p=0.005)]. Finally, there was no difference in the CT-Derived % Gas Trapping in those with and without positional OSA [48±37% and 36±25%, (p=0.6), respectively]. Conclusion The prevalence of positional OSA in patients with OSA-COPD overlap is similar to OSA patients without COPD. Despite the presence of obstructive disease and gas trapping that may affect upper airway stability, other factors including body position and BMI remain important determinants for developing OSA in patients with COPD. Support R01-HL089856, R01-HL089897

Effects of sleep position on the treatment response of oral appliance for obstructive sleep apnea

ABSTRACT Objective: This retrospective study aimed to clarify the characteristics of positional obstructive sleep apnea (P-OSA) patients and to examine the relationship between sleep position and the efficacy of oral appliance (OA) therapy. Methods: Seventy-three patients who underwent polysomnography before and after OA therapy were divided into P-OSA or non-positional OSA (NP-OSA) and examined. Results: Forty-seven patients had P-OSA and 26 had NP-OSA. P-OSA was characterized by a relatively high ratio of supine to lateral apnea hypopnea index (AHI) because the lateral AHI of P-OSA was significantly lower than that of NP-OSA. OA therapy was more effective for P-OSA than NP-OSA. Younger age and the presence of P-OSA are useful as predictors of OA therapy efficacy. Discussion: Even for relatively severe OSA, in the case of younger age and/or P-OSA, the application of simple, cost-effective OA therapy might be recommended over other treatment modalities.