non-REM Apnea-hypopnea Index Research Articles

Are there any differences at gray matter sites between severe obstructive sleep apnea patients and healthy controls?

ObjectivesObstructive sleep apnea (OSA) is a disease that may cause many medical conditions. Neurocognitive disorders may be triggered by OSA. In recent studies, selectively decreased gray matter tissue was observed in patients with OSA. We aimed to determine if there was a substantial difference in patients with extreme OSA by comparing the microstructural changes in different gray matter sub-areas with healthy controls using diffusion-weighted imaging methods. MethodsWe studied 15 diagnosed severe OSA subjects before any treatment and 32 healthy control subjects. High resolution Magnetic Resonance Imaging (MRI) T1 and T2-weighted scans were visually examined to assess any major brain lesions. ResultsThere were no statistically significant differences of age and gender between the groups.The left and right globus pallidus, putamen and thalamus values did not differ significantly between OSA and control subjects. Right putamen values was negatively correlated with Apnea Hypopnea Index (AHI), supine AHI and non-REM AHI in OSA subjects, but no correlations appeared with left putamen values. The other gray matter parameters did not show any correlations with PSG parameters. AHI, Supine AHI, Non-Supine AHI, REM and NON-REM AHI values was not show any correlation with Right and Left Putamen volume sizes. ConclusionsWe made a morphological comparison of various gray matter areas of OSA patients and healthy volunteers in our study. We observed a significant decrease in right putamen gray matter volumes in patients with higher AHI values. Decreased cognitive functions are found in patients with OSA. In order to demonstrate this cognitive loss in patients with morphologically there is a need for further prospective studies with larger sample sizes.

Association of sleep disorders with clinical symptoms and age in Chinese older adult patients with and without cognitive decline.

To investigate correlation between cognitive function, age, and sleep disturbances. This retrospective clinical study enrolled 78 patients with sleep disorders who were divided into three groups: a group of 24 patients with sleep disorders accompanied by cognitive decline (SD-CD); 54 patients with sleep disorders and no cognitive decline (SD-nCD) was divided into two groups, one of 30 patients aged between 60 and 70 years and another of 24 patients aged >70 years. Polysomnography was used to record patients' sleep indicators throughout night; these included total sleep duration, sleep efficiency (SE), sleep latency, sleep structure and percentage of N1, N2, and N3 stages, rapid eye movement (REM) stage, as well as apnea hypopnea index (AHI), and oxygen saturation (OS). Analysis of variance (ANOVA) for continuous variables and chi-square test for categorical variables were used to analyze variables between different groups. Pearson's correlation was used to analyze correlation between sleep parameters and mini-mental state examination (MMSE). Blood samples were used to determine their Aβ, Aβ40, Aβ42, total tau, phosphorylated tau protein (ptau), ptau181, ptau217, the inflammatory factor IL-1β, vitamin B12 (VB12), and melatonin levels. In the SD-CD group, there was a significant decrease in SE and an increase in N1 stage sleep in older patients and a significant increase in AHI, REM stage AHI, and non-REM stage AHI. In patients with SD-nCD, the minimum OS, minimum OS in the REM period, and minimum OS in the non-REM period were significantly reduced. OS was significantly correlated with cognitive level, as evaluated by the MMSE. The addition of sleep parameters can significantly improve the accuracy of dementia diagnosis. Dementia biomarkers of Aβ and tau proteins in blood showed cognition-related differences, while ptau181 was associated with both cognition and age-related differences. Regression models revealed that age was related to higher levels of cognitive decline before (β = -0.43, P < 0.001) and after (β = -0.38, P < 0.001) adjustment of gender, BMI, and education level. There was a significant mediation effect of relationship between aging and cognitive function by sleep efficiency and N1 stage sleep. Sleep disorders and low OS are associated with a higher incidence of cognitive decline and dementia.

0525 Effect of Body Position and Sleep State on Obstructive Respiratory Events Distribution in Children with Down syndrome

Abstract Introduction The influence of body position and sleep state on obstructive respiratory events distribution in children with Down syndrome (DS) need further studies. Methods This was a single center, retrospective study that included children younger than 18 years old with DS who were evaluated for suspected sleep disordered breathing and underwent a full overnight polysomnography in an academic sleep disorders center over a period of 10 years. DS children with Obstructive apnea hypopnea index (OAHI) ≥ 1.5 were included in this study. Total OAHI, apnea hypopnea index (AHI) in different body positions and in different sleep stages including rapid eye movement (REM) and Non-REM (NREM) sleep were collected. Results A total of 158 children with DS met the inclusion criteria. The median age was 5 years (IQR 8.0---), 53.2% were male with a median BMI z-score of 1.2. Median times (%) spent in REM and NREM sleep were 17 % and 83% respectively. Median times (minutes) spent in different body positions were supine 194.1, left side 53.5, right side 39 and prone 32. The overall median OAHI was 7.6, respiratory obstructive events were more common in REM sleep and in supine position. The median REM obstructive AHI was 20 events per hour (IQR: 10.1-34.5), whereas the median NREM AHI was 5.2 events per hour (IQR: 2.4-15 p &amp;lt; 0.0001). Similarly, supine obstructive AHI was 9.4 (IQR-4.15 – 24.1) and off supine AHI was 2.4 (IQR 0-8.9 p &amp;lt; 0.0001). Only 24 out of 158 subjects had NREM predominant OSA. Age was a significant predictor of NREM predominant OSA (P= 0.012) compared to other factors such as gender, race, BMI, tonsillar grade, hypothyroidism and congenital heart disease. For every one year increase in age, the odds of having NREM predominant OSA was 14% higher than having REM predominant OSA. Conclusion Obstructive respiratory events in children with DS occur predominantly in REM sleep and in supine position. Non-REM predominant distribution of respiratory events was seen in older children with DS. Support (if any)

0526 Effect of Body Position and Sleep State on Sleep Disordered Breathing Distribution in Infants Ages 6 to 12 months

Abstract Introduction The effect of body position and sleep state on events distribution in infants ages 6 to 12 months needs further study. We aimed to study this distribution and determine the difference of body position in infants with and without sleep disordered breathing. Methods This was a single center, retrospective study that included infants ages 6 to 12 months who were evaluated for suspected sleep disordered breathing and underwent a full overnight polysomnography in an academic sleep disorders center over a period of 10 years. Infants with ages 6 to 12 months with obstructive sleep apnea hypopnea index (OAHI) and central apnea index (CAI) ≥ 1 (sleep disordered breathing [SDB] group) were compared with infants with normal AHI who represented the control group (CG). Total OAHI, CAI, apnea hypopnea index (AHI) in different body positions, rapid eye movement (REM), and Non-REM sleep were collected. Results A total of 36 infants had SDB and 18 infants had normal AHI. The median age was not significantly different between both groups with a median age of 10 months (IQR 7.75-11) in SDB group and 8.5 months in CG (IQR 7.25- 10.00) (p=0.258). Male sex was predominant in both groups (58.3% in SDB group and 61.1% in CG). There were no significant differences between both groups in the BMI, median total sleep time, REM% sleep time, and Non-REM% sleep time. The supine sleep time in the SDB group [258.90 minutes (IQR 149.35-381.25)] was significantly higher than the supine sleep time in the CG [165.90 minutes (IQR 54.55 to 285.05)] (p=0.035). In the SDB group, REM AHI [8.55 (IQR 5.02 – 15.25] was significantly higher than Non-REM AHI [0.50 (IQR 0.30-1.20)] (p&amp;lt; 0.001). In the SDB group, there were no significant differences in the supine vs. off-supine distribution of respiratory events. Conclusion Obstructive and central respiratory events in infants ages 6 to 12 months occurred predominantly in REM sleep compared to Non-REM sleep. Infants with SDB significantly spent more time in supine position when compared to infants without SDB but the respiratory events distribution in infants with SDB did not have a significant positional distribution. Support (if any)

Polysomnography findings in children with spinal muscular atrophy after onasemnogene-abeparvovec

BackgroundSleep disordered breathing (SDB) is common in patients with neuromuscular diseases, including spinal muscular atrophy (SMA). While polysomnography (PSG) findings have been described in natural history studies of patients with SMA, reports regarding PSG in treated children are limited to nusinersen. We aim to describe the sleep characteristics in a cohort of children treated with Onasemnogene-abeparvovec. MethodsWe conducted a cross-sectional cohort study of children with SMA followed at the University of Florida Center for neuromuscular and rare diseases and had a diagnostic or split night PSG after SMA treatment. ResultsEight children were included in the cohort (four female), aged 5–250 days at diagnosis. Five children had two survival motor neuron 2 (SMN2) copies, two had three SMN2 copies and one subject had four SMN2 copies. Median age at the time of treatment was 46.5 days (range 20–257). All children received onasemnogene-abeparvovec (OA) before their PSG; in addition to OA, one received nusinersen and one received risdiplam. Apnea hypopnea index (AHI) ranged from 3.6 to 24.1/h. REM AHI was higher than NREM AHI. Median Children's Hospital of Philadelphia Infant test of neuromuscular disorders (CHOP-Intend) score at the time of PSG was 55 (range 33–64). There was no correlation between age at treatment, CHOP-Intend score and AHI. ConclusionSDB is common in treated children with SMA, regardless of age at diagnosis, treatment and neuromotor scores. While AHI may not be the only indicator of SDB in this population, indications, timing of PSG in this cohort remain unknown.

P040 Obstructive sleep apnea during REM sleep: Effects on morning and evening blood pressure

Abstract Study Objectives Obstructive sleep apnea (OSA) is linked to the emergence and progression of cardiovascular complications including hypertension, stroke, arrhythmias, coronary artery disease and heart failure. Epidemiological studies have reported that hypertension is associated with respiratory events during REM sleep. We examined the relationship between respiratory events during REM and morning and evening hypertension in a clinical sleep population. Methods This study included data from in-laboratory diagnostic polysomnographic studies (n=797) from adults attending for investigation of OSA. Hypertension was defined using blood pressure measurements taken in the evening before and morning after polysomnography, and use of anti-hypertensive medication. Regression modelling was undertaken to examine the probability of evening and morning hypertension according to REM apnea hypopnea index (AHI), NREM AHI, gender, age, body mass index (BMI), alcohol use, total sleep time (TST), sleep time SpO2 &amp;lt;90%, smoking and waist-to-hip ratio. Results The probability of morning hypertension was significantly independently associated with age (p&amp;lt;0.001), BMI (p&amp;lt;0.001) and REM AHI (p=0.012). No significant effect was found for male gender, NREM AHI, alcohol use, TST, sleep time SpO2 &amp;lt;90%, smoking or waist-to-hip ratio (p&amp;gt;0.05 for all). The probability of evening hypertension was only significantly associated with age (p&amp;lt;0.001), BMI (p&amp;lt;0.001) and TST (p=0.029). Conclusions Respiratory events during REM sleep are significantly associated with morning hypertension. Future research is needed to determine whether treatment of these events can prevent or reverse morning hypertension.

Comparison of clinical features and surgical outcomes between hypopnea- and apnea-predominant obstructive sleep apnea.

This study is aimed to investigate the differences in the clinical features and surgical outcomes between hypopnea- and apnea-predominant obstructive sleep apnea (OSA). Cohort study. Single tertiary care centre. This study included 190 patients with OSA who underwent multilevel upper airway surgery between September 2012 and September 2021. The patients were divided into two groups according to the proportion of each respiratory event: hypopnea-predominant (n=102) and apnea-predominant (n=88). The primary outcome measure was the percentage improvement in the apnea-hypopnea index (AHI) from baseline AHI after surgery. The apnea-predominant group included more male patients and had higher AHI, respiratory disturbance index (RDI) and oxygen desaturation index (ODI) than the hypopnea-predominant group. Both groups showed significant improvements in AHI, apnea index, RDI, supine AHI, REM AHI, non-REM AHI, ODI, lowest O2 saturation and Epworth Sleepiness Scale scores following the surgery. Notably, hypopnea index increased after surgery in the apnea-predominant OSA group. Although the improvement in the absolute value of AHI by surgery was significantly greater in the apnea-predominant group than in the hypopnea-predominant group, the two groups showed no significant difference in the percentage improvement in AHI from baseline AHI. Patients with apnea-predominant OSA had more severe disease than those with hypopnea-predominant OSA; however, surgical outcomes, as evaluated by percentage AHI improvement, were comparable between the two groups. In addition, multilevel upper airway surgery may induce the transition from apnea to hypopnea in patients with apnea-predominant OSA.

Obstructive sleep apnea during REM sleep: effects on morning and evening blood pressure.

Obstructive sleep apnea (OSA) is linked to the emergence and progression of cardiovascular complications including hypertension, stroke, arrhythmias, coronary artery disease, and heart failure. Epidemiological studies have reported that hypertension is associated with respiratory events during REM sleep. We examined the relationship between respiratory events during REM and morning and evening hypertensive blood pressure (BP) levels in a clinical sleep population. This study included data from in-laboratory diagnostic polysomnographic studies (n = 797) from adults attending for investigation of OSA. Hypertensive BP levels were defined using BP measurements taken in the evening before and morning after polysomnography, and the use of antihypertensive medication. Regression modeling was undertaken to examine the probability of evening and morning hypertensive BP levels according to REM apnea-hypopnea index (AHI), NREM AHI, gender, age, body mass index (BMI), alcohol use, total sleep time (TST), sleep time SpO2 <90%, and smoking status. The probability of morning hypertensive BP levels was significantly independently associated with age (p < .001), BMI (p < .001), and REM AHI (p < .001). No significant effect was found for the male gender, NREM AHI, alcohol use, TST, sleep time SpO2 <90%, or smoking (p > .05 for all). The probability of evening hypertensive BP levels was only significantly associated with age (p < .001), male gender (p = .012), BMI (p < .001), and TST (p = .032). Respiratory events during REM sleep are significantly associated with morning hypertensive BP levels. Future research is needed to determine whether treatment of these events can prevent or reverse morning hypertensive BP levels.

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.

A clue for obstructive sleep apnea hidden in tomographic images of idiopathic pulmonary fibrosis patients

Objectives: The most common opinion about apnea/hypopnea formation in restrictive pulmonary diseases is based on decreased lung volumes causing upper airway collapse. This study targets to reveal some evidence for this pathophysiological pathway in patients with idiopathic pulmonary fibrosis (IPF) and obstructive sleep apnea (OSA). Methods: The clinical, demographical, and polysomnographic characteristics of 19 patients with OSA and IPF who underwent all-night polysomnography (PSG) were retrospectively evaluated for investigating the correlations between lung volumes calculated on the images of high-resolution computed tomography (HRCT) and polysomnographic findings. Supine HRCT images performed at the time of diagnosis of IPF were used for the calculation of total lung volume and low attenuation areas of the lung (LAA). The results were compared with the results of the PSG and pulmonary function tests (PFT). Results: The study group comprised 19 patients (3 female, 16 male) with a median apnea-hypopnea index (AHI) of 23.5/h. AHI in this IPF cohort was not correlated with body-mass index, neck circumference, age, or PFT. However, overall AHI and non-rapid eye movement (non-REM) AHI had a trend of positive correlation with LAA. We also showed a positive correlation between the LAA and forced vital capacity (FVC) (r=0.682 and, p = 0.003). Conclusions: The severity of OSAS in IPF patients is well correlated with LAA. This result supports the gravitational and the volumetric effect of the lung in apnea-hypopnea formation.

Changes in Sleep Parameters in Different Age Groups between Genders

Aim: To examine the changes in sleep parameters related to sex between the patients over 65 years old and younger group. Method:A total of 293 patients who applied to the sleep clinic with complaints such as snoring, cessation of breathing during sleep, and excessive daytime sleepiness (GAUH) and whose Polysomnography (PSG) were taken were included in the study. Of these patients, 71 people were in the group over 65 (Male: 43, Female: 28) and 222 people (Male: 139, Female: 83) were in the group between the ages of 45-60. The medical histories of the patients were retrospectively scanned from the patient files. Among the PSG parameters, Total Sleep Time, Sleep Efficiency (%), REM sleep rate (%), NREM sleep rate (%), AHI (Apnea Hypopnea index), REM AHI, NREM AHI, minimum oxygen saturation (min O2 hours), mean oxygen saturation (mean O2 hours), oxygen desaturation time (min) and oxygen desaturation index (ODI) were recorded. Results: When sleep parameter changes between age groups were examined, regardless of gender, it was observed that sleep efficiency (the ratio of total sleep time to length of stay in bed) was significantly decreased in the 65+ age group compared to the younger group (73.69±17.49 and 79.44±14.65 p: 0.014). When the total sleep duration (244.38±97.44 and 284.51±93.40) and sleep efficiency data (73.55±16.16 and 82.19±14.13 p:0.002 ) of PSG parameters in male patients were examined, it was seen that the data of the over 65 age group were lower than the young group. When the minimum and mean oxygen saturation in female patients was examined, it was observed that the group over 65 years had lower levels (minimum oxygen saturation: 71.14±13.52 and 77.97±11.01 p:0.021, mean oxygen saturation: 89.78±4.52 and 91.93±3.70 p:0.030). Desaturation (%) was found to be lower in the elderly group also.(30.52±33.71 and 12.22±18.97 p:0.012) Conclusion: In this study, decreases in total sleep duration, sleep efficiency, minimum oxygen saturation, average oxygen saturation and desaturation (%) were detected in sleep parameters in advanced age compared to younger ages. Further studies with larger participation and younger patients are needed to support the results and for the new results.

411 REM predominance of OSA: Associated with supine position, but not with CPAP adherence

Abstract Introduction Obstructive sleep apnea (OSA) is a heterogeneous disease dependent on many factors including the sleep stage and the body position. OSA is often more severe during the rapid eye movement (REM) sleep stage, a phenomenon known as REM predominance. Prior studies suggested associations of higher REM predominance of OSA with younger age, higher obesity, and lower adherence to continuous positive airway pressure (CPAP) therapy, but these studies had small cohort sizes. Here we leverage home-based sleep tests (HST) that estimate REM sleep and measure body position to study REM predominance in a larger cohort of OSA patients. Methods We retrospectively reviewed patients who took HST at our clinic using devices based on peripheral arterial tonometry (WatchPAT, Itamar Medical). The HST results included estimated REM sleep periods and measured body positions. Auto-titrating CPAP therapy was prescribed for the majority of OSA patients diagnosed by the HST. Our inclusion criteria were: apnea-hypopnea index (AHI) above 5 /hour, estimated REM sleep time above 30 minutes, oxygen saturation below 90% (T90) for less than 10 minutes, and successful retrieval of CPAP usage data. CPAP adherence was defined as the percentage of nights with CPAP usage above four hours, and REM predominance as the ratio between REM AHI and non-REM AHI. Additionally, the percentage of estimated sleep time in supine position was calculated. Results Among 292 consecutive patients whose HST were reviewed, 113 patients met the inclusion criteria. The 25th-75th percentile ranges of age, body mass index (BMI), AHI, REM predominance, CPAP adherence and supine sleep percentage were 36–56 years, 28.1–38.4 kg/m2, 8.9–25.9 /hour, 1.27–2.89, 40%-97% and 28%-72%, respectively. REM predominance was not associated with CPAP adherence (P &amp;gt; 0.05), but was significantly associated with lower age, higher BMI, and higher supine sleep percentage (all P &amp;lt; 0.01). Conclusion We found that REM-predominant OSA is relatively more prevalent not only in young and obese patients, but in patients who sleep relatively more in the supine position. This association of REM predominance with body position is a novel finding to our knowledge. Contrary to prior studies, we did not find association of REM predominance with adherence to CPAP therapy. Support (if any):

Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing.

Night-to-night variability of obstructive sleep apnea severity is considerable and may depend on the diagnostic modality used. We investigated the night-to-night variability using peripheral arterial tonometry (PAT). Home sleep apnea testing was performed in 51 patients during 3 consecutive nights using PAT. Patients referred to our sleep clinic were screened and prospectively recruited for this study. All recordings were automatically and manually scored according to the PAT scoring guidelines. No systematic differences in PAT-derived apnea-hypopnea index (pAHI) were found between the nights. The night-to-night variability was comparable between manually and automatically scored data. pAHI varied in 35% of patients more than 10 events/h between the nights. The obstructive sleep apnea severity of 24% of patients was misclassified when using 1 night compared to the average of all nights. On average, pAHI varied by 57% from night to night. The variability of pAHI could partially be explained by the variability of time spent in the supine position with more time supine leading to a higher pAHI. On measuring a subsequent night, 12-14% of patients spontaneously fulfilled the commonly accepted criteria for treatment success without any intervention. With repeated recordings of PAT, we found no first night effect. However, there is considerable night-to-night variability similar to values found for polysomnography, which can partially be explained by the variability of time spent in the supine position. Obstructive sleep apnea severity was frequently misclassified due to the night-to-night variability. Our findings make a strong case for multiple testing in the diagnostic work-up of obstructive sleep apnea patients. Tschopp S, Wimmer W, Caversaccio M, Borner U, Tschopp K. Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing. J Clin Sleep Med. 2021;17(9):1751-1758.

Obstructive sleep apnea and sudden unexpected death in epilepsy in unselected patients with epilepsy: are they associated?

We aimed to determine (1) the frequency of high-risk sudden unexpected death in epilepsy (SUDEP) in patients with epilepsy who have had obstructive sleep apnea (OSA) in different stages of sleep using the revised SUDEP risk inventory (rSUDEP-7) score instrument and (2) the factors associated with high risk SUDEP in patients with epilepsy who have had OSA. We conducted a cross-sectional study of consecutive subjects who are more than 15 years old without known sleep disorders, recruited from a single epilepsy clinic in a tertiary care facility. Participants underwent polysomnography. Scoring was performed by two blinded board-certified sleep physicians. The relationships between rSUDEP-7 scores and OSA measures were evaluated using Wilcoxon rank-sum test, chi-squared test, and quantile regression. Our study population consisted of 95 participants. Overall median (IQR) apnea-hypopnea index (AHI) of our populations was 2.3 (0.7,7.5) events rate per hour; 12 (75%) patients had moderate OSA and 4 (25%) patients had severe OSA. Nine patients had a rSUDEP-7 score of 5 to 7. There was no significant difference between total rSUDEP-7 score or rSUDEP-7 score of > 5 or < 5 and total AHI, supine AHI, non-supine AHI, NREM AHI, or REM AHI; similarly, (2) there was no significant difference in total rSUDEP-7 score between AHI of < 15 or > 15. Our study reveals no association between AHI score, OSA, and total rSUDEP-7 score or rSUDEP-7 score of > 5. The pathophysiology underlying SUDEP appears complex. We need further studies on SUDEP to help elucidate the cardiorespiratory mechanisms and predisposing factors.

Relevance of obstructive sleep apnea and smoking: Obstructive sleep apnea and smoking.

The data concerning the association of smoking and obstructive sleep apnea (OSA) are limited. The effects of cigarette smoking on OSA still remain obscure. To reveal the impact of smoking on obstructive sleep apnea. About 384 patients with the diagnosis of OSA through full night polysomnographic (PSG) examination were included to the study. The demographic data (age, sex and BMI), complaints and medical history, status of smoking as non-smokers and smokers, smoking frequency (cigarettes/day), polysomnograhic data comprising apnea hypopnea index (AHI), non-REM sleep AHI (NREM AHI), REM sleep AHI (REM AHI), minimum oxygen saturation (min SaO2) were recorded for all the subjects. Non-smokers and smokers were compared in terms of severity of OSA. The study population consisted of 384 subjects, 253 males and 131 females. Smoking frequency was not found correlated with OSA severity. Among smokers, males had higher severe OSA rate (P = 0.002, P < 0.05). In subjects with BMI < 30, severe OSA rate was higher in smokers (34.44% versus 21%) (P = 0.027, P < 0.05). Our study detected higher rate of severe OSA in male smokers and smokers with BMI < 30. PSG data did not yield statistically significant difference in non-smokers and smokers. OSA severity was not found correlated with smoking frequency. Along with the study results, the impact of smoking on OSA is still controversial. Prospective studies with larger sample size may be contributive to further evaluation of the association of OSA with smoking.

Gender Differences in the Clinical and Polysomnographic Characteristics Among Australian Aboriginal Patients with Obstructive Sleep Apnea.

BackgroundIn this study, we assessed the clinical and polysomnographic (PSG) characteristics according to gender among Australian Aboriginal men and woman diagnosed to have obstructive sleep apnea (OSA).MethodsIn this retrospective study, all adult Aboriginal patients over 18 years of age diagnosed to have OSA with an apnea hypopnea index (AHI) > 5/hour over a 5 year period were included.ResultsOf the 337 patients (168 females and 169 males), who underwent a diagnostic PSG, 297 (88%) were diagnosed to have OSA (AHI) >5/hour), 154/297 males (52%) and 143/297 females (48%). Amongst male and female patients with OSA, 63% and 37% were in the severe spectrum (AHI>30/hour). The male cohort had higher stage N1 NREM sleep (P<0.001), reduced N3 NREM sleep (P<0.001), higher AHI severity (P<0.001), higher NREM AHI (P<0.001), and high arousal index (P<0.005). REM sleep-related AHI was higher among female patients with all severity of OSA, along with severe oxygen desaturation during REM sleep. Among patients with severe OSA, the female cohort were younger (age 46 years vs 49 years, P=0.030) and had higher BMI with all severity of OSA, while males had larger neck circumference compared to females. Hypertension increased the odds of severe OSA versus the combined odds of mild and moderate OSA for both genders.ConclusionThis study highlights some important differences in the way sleep apnea manifests in Australian Aboriginal males and females and further studies are warranted to explore avenues to look for a physiological basis for these observations and targeted interventions.

0911 Association Between Chromosomal Abnormality And Sleep Disordered Breathing Characteristics In Children With Prader Willi Syndrome

Abstract Introduction Prader-Willi Syndrome (PWS) is a genetic disorder caused by lack of expression of paternal genes from the chromosomal region 15 q11.2-q13. PWS is associated with excessive daytime sleepiness, sleep-disordered breathing (SDB), hypoventilation and circadian rhythm disturbance. Chromosomal deletion and uniparental disomy (UPD) are the two most common genetic etiologies of PWS. Differences in clinical features between these groups are recognized; however, limited literature exists regarding sleep characteristics. Methods The objective was to evaluate sleep characteristics of children with PWS between those with 15q11.2-q13 chromosomal deletion and those with other genetic etiologies. A retrospective chart review of in-laboratory polysomnograms (PSG) in children with PWS prior to growth hormone treatment was performed. The apnea hypopnea index (AHI), REM AHI, NREM AHI, Obstructive Apnea Index (OAI), Central Apnea Index (CAI), hypopnea index, arousal index, presence of hypoventilation, and positional AHI were assessed. Results Overall 33 PWS children were identified. Mean age was 5.9 ± 5.19 (range 1-16 years), 57% were male and 85% had SDB. Almost half (42%) had a 15q11.2-q13 chromosomal deletion. Of those without deletion, 30% had UPD. Sleep variables were similar in PWS with and without deletion: AHI (5.9±5.7 vs. 8.54±7.1; p=0.27), NREM AHI (3.3±4.6 vs. 6.2±6.3; p=0.16), CAI (1.1±1.5 vs. 1.9±3.8; p=0.43) SpO2 nadir 82.7±9.9% vs. 85.3±5.7%; p=0.36) and arousal index (10.3±7.8 vs. 15.4±7.8; p=0.09). Conclusion Sleep characteristics do not appear to clearly differ between genetic etiologies of PWS. Larger sample sizes are needed to support these findings. Support

1139 Sleep Disturbances In Chronic Stroke Patients: Emotional And Cognitive Impact

Abstract Introduction The objective was to investigate the impact of sleep-wake disturbances (SWD) on cognition and quality of life in the post-acute phase of stroke. Methods Adult stroke (n=92) patients were assessed for SWD via overnight polysomnography. The mean age was 52 ± 1 years and mean latency from injury was 117 ± 10 days. Sleep measures included total sleep time (TST), sleep and REM latency, percent time in sleep stages, apnea/hypopnea index (AHI), wake after sleep onset (WASO), and arousal index. The primary cognitive/outcome measures were: Montreal Cognitive Assessment (MoCA), California Verbal Learning Test (CVLT-II), Neuro-QoL and Mayo Portland Adaptability Inventory (MPAI). Results Women had lower AHI (F(1,88)=9.360, p&amp;lt;.01), fewer arousals (F(1,90)=4.53, p&amp;lt;.05), and spent significantly more time in SWS (F(1,90)=11.525, p&amp;lt;.001) than men; however, SWS was reduced in both sexes. SWS made up &amp;lt; 3% of TST in 60% of patients and was not correlated with higher AHI. SWDs negatively impacted subjective quality of life (NeuroQOL). Longer latencies to sleep were associated with increased depression (p&amp;lt;.05) and decreased positive affect (p&amp;lt;.01). Increased sleep efficiency led to improved positive affect (p&amp;lt;.05) and decreases in emotional/behavioral dyscontrol (p&amp;lt;.05). Increased time in REM sleep decreased emotional/behavioral dyscontrol (p&amp;lt;.05), while increasing satisfaction with social roles and activities(p&amp;lt;.01). SWDs also negatively impacted cognitive/outcome scores. Increased TST and sleep efficiency led to higher scores on CVLT-II list B and long delay free recall (p&amp;lt;.05), while higher AHI led to poorer performance on long delay and forced choice recognition trials (p&amp;lt;.01). Additionally, non-REM AHI negatively impacted MPAI adjustment scores (F(1,69)=4.036, p&amp;lt;.05). Conclusion Male stroke patients displayed significantly more arousals and spent less time in SWS than females. For both sexes, better sleep indicated improved quality of life. Sleep measures were correlated with cognitive/outcome measures. Non-REM AHI significantly predicted outcome at discharge from rehabilitation facility. Support

Natural History of Sleep-disordered Breathing during Rapid Eye Movement Sleep. Relevance for Incident Cardiovascular Disease.

Rationale: Sleep-disordered breathing (SDB) occurring primarily during rapid eye movement (REM) sleep is a common clinical problem. The natural history of REM-related SDB and the associated cardiovascular sequelae of disease progression remain to be determined.Objectives: The objective of the current study was to describe the natural history of REM-related SDB, ascertain predictors of progression, and determine whether the evolution of REM-related SDB into non-REM (NREM) sleep is associated with incident cardiovascular events.Methods: Participants from the Sleep Heart Health Study with a baseline NREM apnea-hypopnea index (NREM-AHI) of <5 events/h and data from a follow-up sleep study along with information on incident cardiovascular disease were included in the study. Bivariate logistic regression was used to jointly model the predictors of disease progression based on the presence or absence of SDB during NREM and REM sleep using a cut-point of 5 events/h. Explanatory variables such as age, race, body mass index (BMI), change in BMI, and baseline REM-AHI were considered. Proportional hazards regression was then used to establish whether the development of SDB during NREM sleep was associated with incident cardiovascular disease.Results: The majority of the 1,908 participants included in the study did not develop SDB during NREM sleep. The likelihood of progression of SDB into NREM sleep did increase with higher baseline REM-AHI. BMI and an increase in BMI predicted progression of SDB in both NREM and REM sleep in men but not in women. There was a strong interdependence between developing a NREM-AHI of ≥5 events/h and worsening REM-AHI at follow-up with odds ratios of 6.01 and 4.47, in women and men, respectively. Moreover, the relative risk for incident cardiovascular events among those who developed a NREM-AHI of ≥5 events/h at the follow-up visit was elevated only in women with REM-related SDB at baseline.Conclusions: SDB during REM sleep is a relatively stable condition and does not progress in the majority of individuals. Progression of SDB into NREM sleep is associated with sex, weight, and age. SDB during REM and NREM sleep tends to develop concurrently. Finally, the development of SDB during NREM sleep is associated with incident cardiovascular events, but only in women with REM-related SDB at baseline.

Moderate to severe obstructive sleep apnea during REM sleep as a predictor of metabolic syndrome in a Korean population.

Metabolic syndrome is a cluster of metabolic abnormalities including obesity, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hyperglycemia. Obstructive sleep apnea (OSA) is known to be associated with metabolic syndrome. However, it remains uncertain which sleep parameters of OSA are associated with metabolic syndrome. We aimed to clarify the relationship between sleep variables and the presence of metabolic syndrome in patients with OSA. We prospectively recruited patients who visited the institute for the evaluation of sleep-disordered breathing. All patients underwent overnight polysomnography and sleep questionnaires. They were diagnosed with metabolic syndrome according to the 2007 consensus definition by the International Diabetes Federation. We applied multivariate logistic regression models to predict the presence of metabolic syndrome with variables related to sleep parameters. A total of 85 patients (43 men) were enrolled. The mean age (± standard deviation) was 52.0 ± 14.3 years. Metabolic syndrome was diagnosed in 39 (46%) patients. Patients with metabolic syndrome had a significantly higher apnea-hypopnea index (AHI) compared with patients without metabolic syndrome. An AHI greater than 15/h during REM sleep was a significant independent predictor of metabolic syndrome (adjusted OR, 7.08; 95% CI, 1.60-31.41; p = 0.010) after adjusting for age, body mass index, and non-REM AHI ≥ 15/h. In partial correlation analysis, REM AHI was significantly associated with the presence of metabolic syndrome after adjusting for age and BMI (r = 0.229, p = 0.042). Korean patients with OSA frequently had comorbid metabolic syndrome. Moderate to severe OSA during REM sleep may be a predictor of metabolic syndrome.