Obstructive Hypopnea Research Articles

Clinical features of sleep-disordered breathing in children with neuromuscular disease

OBJECTIVE To study the clinical features of sleep-disordered breathing (SDB) in children with neuromuscular disease (NMD). METHODS A retrospective analysis was performed on the medical data of 18 children who were diagnosed with NMD and underwent polysomnography (PSG) (NMD group). Eleven children without NMD who had abnormal sleeping habit and normal sleep structure on PSG were enrolled as the control group. The two groups were compared in terms of the daily and nocturnal symptoms of SDB, incidence rate of obstructive sleep apnea (OSA), pulmonary function, end-tidal partial pressure of carbon dioxide (PetCO2), features of sleep structure, and sleep respiratory events. RESULTS In the NMD group, 16 children (89%) had related daily and nocturnal symptoms of SDB, and the youngest age was 1 year at the onset of such symptoms. Compared with the control group, the NMD group had significant reductions in total sleep time and sleep efficiency (P < 0.05), a significant reduction in the proportion of rapid eye movement (REM) sleep (P < 0.05), significant increases in obstructive apnea and hypopnea events (P < 0.05) and oxygen reduction events during REM sleep (P < 0.05), and a significant reduction in blood oxygen saturation during REM sleep (P < 0.05). In the NMD group, 17 children (94%) were diagnosed with OSA, and all children had normal lung function and PetCO2. CONCLUSIONS There is a high proportion of children with SDB among the children with NMD, and SDB can be observed in the early stage of NMD, which results in the damage of sleep structure and the reduction in sleep efficiency. Respiratory events are mainly obstructive events, and oxygen reduction events are mainly observed during REM sleep.

Prevalence, clinical symptoms and polysomnographic findings of REM-related sleep disordered breathing in Japanese population

BackgroundRapid eye movement sleep -predominant sleep-disordered breathing (REM-SDB) is a condition in which sleep apneas or hypopneas predominantly occur during REM sleep. This study aimed to investigate the prevalence, clinical findings including daytime sleepiness or comorbid cardio-metabolic diseases, and detailed polysomnographic features of REM-SDB in Japanese population. MethodsTotal of 1458 patients diagnosed as SDB were selected for this study. Prevalence of REM-SDB was estimated in the groups of mild, moderate and severe SDB. Polysomnographic findings, daytime sleepiness self-measured with Epworth Sleepiness Scale (ESS) and history of comorbid cardio-metabolic diseases were obtained and compared between the groups with REM-SDB and non-stage specific SDB. ResultsPrevalence of REM-SDB according to the criteria #2 was 22.1% in total SDB subjects, 46,1% in mild SDB and 18.9% in moderate SDB. None was found in severe SDB. Patients with REM-SDB showed milder SDB, higher BMI and higher female predominance than those with non-stage specific SDB. They also showed lower arousal index, respiratory arousal index per total AHI, percentage of N1 sleep, total AHI, ODI, and higher sleep efficiency. Meanwhile, maximum event durations of obstructive apnea and hypopnea were significantly longer, and the nadir SpO2 was lower in REM-SDB. The ESS score and percentages of comorbid cardio-metabolic diseases were roughly equivalent between REM-SDB and non-stage specific SDB. ConclusionREM-SDB was associated with high obesity, female gender, and mild severity of SDB. They showed daytime sleepiness and comorbid cardio-metabolic diseases quite equally to patients with non-stage specific SDB in spite of their lower AHI and better sleep quality.

Clinical and Cardiorespiratory Polygraphy Profile in Children with Obstructive Sleep Apnoea Syndrome: A Cross-sectional Study

Introduction: Cardiorespiratory Polygraphy (CRP) is a less costly and simplified alternative to time consuming and laborious over night polysomnography for diagnosis of Obstructive Sleep Apnoea Syndrome (OSAS) in children. The Apnoea Hypopnea Index (AHI) is simple and useful index that can be estimated by using CRP. The magnitude of AHI which reflects severity of OSAS is unknown in the paediatric population. Aim: To describe the clinical characteristics and to estimate AHI in a population of children with obstructive sleep apnoea and hypopnea syndrome. Materials and Methods: This cross-sectional observational study was conducted on 1500 children, below 12 years of age, from January 2018 to November 2018. They were screened using Paediatric Sleep Questionnaire (PSQ) in the Outpatient Departments of General Paediatrics and Pulmonology respectively, at the Institute of Child Health and Hospital for Children, Chennai, Tamil Nadu, India. Those children identified to have probable OSAS were made to undergo cardiorespiratory assessment. Children with craniofacial syndromes and congenital heart disease were excluded from the study. Anthropometric parameters, vital signs, and Body Mass Index (BMI) were recorded. AHI and oxyhaemoglobin desaturation index were estimated in CRP. After descriptive analysis, non parametric Mann-Whitney test was used to find out any significant difference in median values of AHI in clinical subgroups. Regression analysis was done between AHI values and BMI. Results: Total 47 children were subjected to cardiorespiratory polygraphy. There was no statistically significant difference in gender distribution and prevalence of adenoid enlargement (p-value=0.1447 and 0.7705, respectively). It was found that maximum occurrence of OSAS was at the age of 6 years (25.5%). Based on AHI score 44.7% children fell in moderate to severe OSAS category. There was a poor correlation between BMI scores and AHI, though no significant difference was observed (r=-0.266, p-value=0.07087). The difference in median AHI between males and females was not statistically significant (p-value=0.5256), while that between children with/without adenoid enlargement was statistically significant (p-value ≤0.001). Conclusion: Children with adenoid hypertrophy have higher AHI than children without adenoid hypertrophy. There is lack of evidence for male predominance in the study. Obesity poorly correlated with AHI score.

Evaluation of Acromegaly patients with sleep disturbance related symptoms.

Background and Objectives:It is known that the prevalence of obstructive sleep apnea (OSA) is increased in acromegaly. Craniofacial anomalies, macroglossia, and thickening of the laryngeal wall caused by the increase in soft tissue in these patients lead to OSA. Also, the increase in growth hormone can trigger central apnea by causing a decrease in respiratory drive. Determining the polysomnographic characteristics of acromegaly patients is important to reveal the effect of these mechanisms.Methods:The demographic and polysomnographic characteristics of 33 acromegaly patients who underwent polysomnography (PSG) with suspicion of sleep disorders between 2011 and 2018 in the sleep laboratory of our hospital were retrospectively analyzed. One of the patients was excluded from the analysis because PSG was performed in the postoperative period. The remaining 32 patients with active acromegaly were grouped according to their gender and the presence of OSA and compared with statistical methods in terms of polysomnographic and clinical features.Results:OSA (AHI>5) was detected in 78.1% of 32 active acromegaly patients (18 females, 14 males) who underwent PSG with suspicion of sleep-disordered breathing. Moderate-severe OSA (62.5%) was found in most patients, and there was no difference between the sexes in terms of OSA detection rate and OSA severity. Respiratory events appear to be predominantly obstructive hypopneas. Also, the polysomnographic features of female and male acromegaly patients with OSA were found to be similar. It is seen that the OSA group is similar to the group with simple snoring in terms of body mass index (BMI), but is statistically significantly older (p=0,007). A positive correlation was found between age and AHI in pairwise correlation analysis (r:0,426 p:0,015, respectively).Conclusion:Considering that the prevalence of OSA in the population is approximately 5%, our results show that the risk of OSA in acromegaly increases, and obstructive pathways are effective in this increase. The probability of OSA occurrence and polysomnographic features between the genders are similar. Although the median BMI of the patients with and without OSA was similar, the median age was higher in the group with OSA, middle-aged acromegaly patients should be evaluated in terms of OSA even if there is no obvious obesity.

Case Report: Parasomnia Overlap Disorder Induced by Obstructive Sleep Hypopnea Apnea Syndrome: A Case Report and Literature Review.

Obstructive sleep apnea hypopnea syndrome (OSAHS) and parasomnia overlap disorder (POD) are types of sleep disorders. When the symptoms of both conditions coexist, the POD symptoms are most likely caused by OSAHS. In these cases, the symptoms of POD will be relieved when OSAHS is effectively treated. We refer to these cases as symptomatic POD (related to OSAHS), which differs in pathophysiology, complications, and treatment from idiopathic POD. It is important to note that the treatment for idiopathic POD may aggravate the symptoms of OSAHS. In this case, we used video polysomnography (v-PSG) on a POD patient with suspected OSAHS to distinguish idiopathic POD from symptomatic POD, to inform the appropriate treatment course. The video results and clinical features lead us to diagnose symptomatic POD, and we treated the patient with auto-set continuous positive airway pressure to address their OSAHS. This course of treatment resolved all POD-related symptoms. Here, we discuss this case and review the relevant literature. This report highlights the importance of the use of v-PSG in the clinical diagnosis, differential diagnosis, and subsequent treatment of POD.

Detection and Classification of Sleep Apnea and Hypopnea Using PPG and SpO 2 Signals.

In this work, a detection and classification method for sleep apnea and hypopnea, using photopletysmography (PPG) and peripheral oxygen saturation (SpO 2) signals, is proposed. The detector consists of two parts: one that detects reductions in amplitude fluctuation of PPG (DAP)and one that detects oxygen desaturations. To further differentiate among sleep disordered breathing events (SDBE), the pulse rate variability (PRV) was extracted from the PPG signal, and then used to extract features that enhance the sympatho-vagal arousals during apneas and hypopneas. A classification was performed to discriminate between central and obstructive events, apneas and hypopneas. The algorithms were tested on 96 overnight signals recorded at the UZ Leuven hospital, annotated by clinical experts, and from patients without any kind of co-morbidity. An accuracy of 75.1% for the detection of apneas and hypopneas, in one-minute segments,was reached. The classification of the detected events showed 92.6% accuracy in separating central from obstructive apnea, 83.7% for central apnea and central hypopnea and 82.7% for obstructive apnea and obstructive hypopnea. The low implementation cost showed a potential for the proposed method of being used as screening device, in ambulatory scenarios.

Obstructive Sleep Apnoea Syndrome: Continuous Positive Airway Pressure Therapy for Prevention of Cardiovascular Risk.

Obstructive sleep apnoea (OSA) syndrome is characterised by the presence of apnoea or obstructive hypopnoea during sleep, accompanied by hypoxia. It is estimated that the syndrome affects approximately 10% of men and 15% of women. Diagnosis and treatment rates have increased in recent years, but the condition remains undiagnosed in a high percentage of patients. Recent evidence suggests that OSA may increase the risk of cardiovascular disease. The relationship between OSA and cardiovascular disease can be explained, at least in part, by the coexistence of cardiovascular risk factors in the two pathologies, such as age, overweight, smoking and sedentary lifestyle. However, OSA has been independently associated with the risk of developing hypertension, cerebrovascular disease, ischaemic heart disease, heart failure and arrhythmias. Clinical trials that have evaluated the efficacy of continuous positive airway pressure (CPAP) treatment in primary and secondary cardiovascular prevention have not demonstrated a significant reduction in the incidence or recurrence of cardiovascular events. This article analyses the relationship between OSA and cardiovascular risk and discusses recent clinical trials on the efficacy of CPAP in primary and secondary cardiovascular prevention.

Obstructive sleep apnea syndrome in patients with chronic idiopathic urticaria.

Urticaria is a disease which progresses with itchy papules and plaques called urtica, obstructive sleep apnea syndrome (OSAS) is defined as daytime sleepiness and obstructive apnea and hypopnea attacks during sleep. In this study, we aimed to investigate the relationship between urticaria and OSAS. Thirty-one patients with chronic idiopathic urticaria were included in the study. Body mass indexes (BMIs) were calculated and polysomnography findings were recorded. Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index were used to evaluate daytime sleepiness. The prevalence and severity of urticaria were calculated using the urticaria activity score (UAS). Chronic Urticaria Quality of Life Questionnaire was applied to patients. OSAS was detected in 13 (41.9%) of 31 patients. Then, 11 of the 13 patients had mild, 1 had moderate, and 1 had severe OSAS in the patient group. OSAS was not detected in the control group. A positive correlation was found between apnea-hypopnea index and BMI, the UAS scores in the patient group (respectively, r = .537, P = .002, r = .407, P = .023). In this study, we found that the frequency of OSAS in patients with urticaria was more than that in the normal population. Doctors treating urticaria should consider a comorbidity disease such as OSAS and regulate the treatment according to these two diseases.

Obstructive sleep apnea - risk factors, diagnosis and management

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder that is characterised by obstructive apneas, hypopneas and respiratory effort-related arousals caused by repetitive collapse of the upper airway during sleep. Most pauses in breathing last between 10 and 30 seconds, but some may persist longer.

Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy

BackgroundCurrent guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known. MethodWe diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor. We compared mean, minimum, maximum HR between those with vs without SDB. In a pilot subanalysis of HCM patients with SDB who also underwent subsequent diagnostic polysomnography (PSG), we analyzed RR interval changes coinciding with obstructive sleep apnea and hypopnea episodes. ResultsOf the 230 HCM patients included in this study (age 54 ± 16 years; 138 male; LVOT pressure gradient at rest 45 ± 39 mmHg), 115 (50%) patients had SDB. HCM patients with SDB were recorded to have higher mean HR (71 vs. 67 bpm; p = .002, adjusted p = .001), and this difference was most pronounced during night hours of 10 PM to 5 AM (61 vs. 67 bpm; p < .001). In the pilot analysis of the available PSG data, the release of obstructive sleep apneas and hypopneas coincided with fluctuation of HR. ConclusionsSDB is independently associated with higher mean HR in patients with HCM, and this difference is most significant during sleep. Treatment of SDB, which is readily available, should be tested as a complementary modality to the currently recommended pharmacotherapy aimed at lowering HR in patients with symptomatic HCM.

Use of heated humidified high flow nasal cannula for obstructive sleep apnea in infants

ObjectiveHeated humidified high flow nasal cannula (HHHFNC) has gained popularity in the treatment of children with respiratory distress and bronchiolitis in the past decade. Its efficacy as a mode of non-invasive respiratory support has been demonstrated in both adults and children. However, reports on its use in the treatment of obstructive sleep apnea (OSA) in infants are limited. We aimed to evaluate the efficacy of HHHFNC therapy as treatment in infants with OSA. MethodsA retrospective analysis of OSA infants who had undergone polysomnographic titration between 2015 and 2017 was undertaken. Data about the age, gender, AHI, co-morbid conditions and flow used for each patient were retrieved. ResultsTen infants were included in this study (median age 34 weeks; IQR 27–38 weeks). The median optimal HHHFNC flow rate was 8.0 L/min (IQR 6.7–8.0 L/min). HHHFNC significantly reduced median obstructive apnea–hypopnea index (OAHI) from 9.1 (IQR 5.1–19.3) to 0.9 (IQR 0–1.6; P = 0.005) events/h; median obstructive apnea index (OAI) from 5.8 (IQR 1.1–13.4) to 0 (IQR 0–0.9; P = 0.021) events/h; median obstructive hypopnea index (OHI) from 4.1 (IQR 0.9–6.8) to 0.1 (0–0.9; P = 0.017) events/h; and median oxygen saturation (SpO2) nadir increased from 88% (IQR 83–94%) to 94% (IQR 93–96%; P = 0.040). ConclusionHHHFNC significantly reduced respiratory events and improved oxygenation in infants with OSA.

Association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone

IntroductionThe association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone is still scarcely addressed in the literature. ObjectiveTo evaluate whether the intensity of obstructive sleep apnea is associated with craniofacial alterations and the position of the hyoid bone in children with mixed dentition. Methods76 children aged 7 to 10 years old were examined by otorhinolaryngological evaluation, polysomnography, and orthodontic assessment, including cephalometry. The participants were divided in 3 groups: primary snoring, mild obstructive sleep apnea and moderate to severe obstructive sleep apnea. Cephalometric measures of the face and hyoid bone were assessed. These measures were compared among the different groups by unpaired Student's t test. Moreover, these measures were correlated with the patient's obstructive apnea and hypopnea index variable using Pearson's correlation test. ResultsOf the 76 children, 14 belonged to group 1, with primary snoring; 46 to group 2, with mild obstructive sleep apnea; and 16 to group 3, with moderate-severe obstructive sleep apnea. There was no difference between the groups regarding the craniofacial variables. Children with obstructive sleep apnea showed a longer distance from the hyoid bone to the mandibular plane when compared to the primary snoring group (p<0.05). Between the two obstructive sleep apnea subgroups, patients with moderate or severe disease showed significantly shorter horizontal distance between the hyoid bone and the posterior pharyngeal wall (p<0.05), when compared to the groups with mild obstructive sleep apnea. We also observed a significant positive correlation between obstructive apnea and hypopnea index and the distance from the hyoid to the mandibular plane (p<0.05) as well as a significant negative association between obstructive apnea and hypopnea index and the horizontal distance from the hyoid to the posterior pharyngeal wall (p<0.01). ConclusionWe did not observe any association between obstructive sleep apnea and linear lateral alterations of the face. In contrast, there is a direct association between obstructive sleep apnea severity and the inferior and posterior position of the hyoid bone in children aged 7 to 10 years old.

Cardiovascular and somatic comorbidities and sleep measures using three hypopnea criteria in mild obstructive sleep-disordered breathing: sex, age, and body mass index differences in a retrospective sleep clinic cohort.

To describe sex, age, and body mass index (BMI) differences in comorbidities and polysomnography measures, categorized using 3 different apnea-hypopnea index (AHI) criteria in sleep clinic patients with mild obstructive sleep-disordered breathing. A retrospective cohort of 305 (64% female) adult sleep clinic patients who underwent full-night in-laboratory polysomnography having been diagnosed with mild sleep-disordered breathing and prescribed positive airway pressure. Effects of sex, age, and BMI on comorbidities and polysomnography measures, including rates of AHI defined by ≥ 3% desaturations (AHI3%), with arousals (AHI3%A), by ≥ 4% desaturations (AHI4%), and by respiratory disturbance index, were evaluated. Sixty-nine (23%), 116 (38%), 258 (85%), and 267 (88%) patients had AHI4%, AHI3%, AHI3%A, and respiratory disturbance index ≥ 5 events/h, respectively. Ninety-day positive airway pressure adherence rates were 45.9% overall and higher in women > 50-years-old (51.2%, P = 0.013) and men (54.5%, P = 0.024) with no difference whether AHI4% or AHI3%A was < 5 or ≥ 5 events/h. Men and women had similar rates of daytime sleepiness (43.3%), anxiety (44.9%), and hypertension (44.9%). Women were more likely to have obesity, anemia, asthma, depression, diabetes, fibromyalgia, hypothyroidism, migraine, and lower rates of coronary artery disease. More patients with AHI4% < 5 events/h had depression, migraines, and anemia, and more patients with AHI4% ≥ 5 events/h had congestive heart failure. Women were more likely to have higher sleep maintenance and efficiency, shorter average obstructive apnea and hypopnea durations, and less supine-dominant pattern. Average obstructive apnea and hypopnea duration decreased with increasing BMI, and average hypopnea duration increased with age. Obstructive apnea duration and obstructive hypopnea with arousal duration decreased with increasing BMI. More women had AHI4% < 5 (81.5% vs 69.1%), AHI3% < 5 (68.7% vs 49.1%), and AHI3%A < 5 events/h (18.5% vs 10.0%). Greater age and higher BMI were associated with higher AHI. Current AHI criteria do not predict comorbidities or adherence in mild sleep-disordered breathing patients. In this hypothesis-generating descriptive analysis, sex, BMI, and age may all be factors that should be accounted for in future research of mild sleep-disordered breathing patients. Different sleep study measures may weigh differently in calculations of risk for cardiovascular versus somatic comorbidities.

0698 A Comparison Of Two Visual Hypopnea Classification Methods

Abstract Introduction The rules for classifying apneas as either obstructive or central using usual polysomnography (PSG) channels are well established, but classification of hypopneas is less straightforward without special sensors. Visual scoring methods have been proposed by the American Academy of Sleep Medicine (AASM) and by Randerath, et al. These two scoring methods have never been compared. We evaluated these two scoring methods for clinical use. Methods We selected 50 hypopnea segments from patient’s PSGs with very clear obstructive physiology (average total AHI 48.6, central AI 0), assumed to be obstructive hypopneas, and from patient’s PSGs with very clear central physiologies (average total AHI 34.3, obstructive AI 0.3), assumed to be central hypopneas. These 100 hypopnea-containing PSG segments (HCPS) were deidentified, placed in randomized order, and sent to two groups of 6 PSG scorers (2 RPSGTs, 2 sleep medicine fellows, 2 sleep medicine specialists). One group scored using the AASM criteria and the other used the Randerath algorithm. After a washout period, re-randomized HCPS were sent to be scored using the alternative method. We used Fleiss’ kappa to determine inter-rater reliability—i.e., how consistently multiple scorers came to the same conclusion about a given hypopnea segment using each method, and accuracy—how often the scorers rated the HCPS in a manner consistent with the assumed physiology. We also recorded the time it took to score. Results Overall accuracy of both methods was 68%. Among 12 scorers, Fleiss’ Kappa coefficient was 0.32 and 0.27 for the AASM and Randerath scoring methods, respectively. Average scoring time (24.3 minutes for AASM and 26.2 minutes for Randerath) was similar (p=0.79). Conclusion Inter-rater agreement was only fair using these methods, and accuracy was only 68%. More work is needed to discover a convenient, non-invasive way to reproducibly and accurately characterize hypopneas. Support This project does not have any funding support.

Is cellular energy monitoring more responsive to hypoxia than pulse oximetry?

PurposePulse oximetry is the current standard for detecting drops in arterial blood oxygen saturation (SpO2) associated with obstructive sleep apnea and hypopnea events in polysomnographic (PSG) testing. However, cellular energy monitoring (CE monitoring), a measure related to cellular hypoxia in the skin, is likely to be more responsive to inadequate breathing during sleep because during hypoxic challenge, such as occurs during apneic events, regulatory mechanisms restrict blood flow to the skin to preferentially maintain SpO2 for more vital organs. We carried out initial proof of concept testing to determine if CE monitoring has promise for being more responsive to hypoxic challenge occurring during sleep-disordered breathing (SDB) than pulse oximetry.MethodsWe assessed both CE monitoring and pulse oximetry in a series of conditions which affect oxygen supply: (1) breathing nitrogen or 100% oxygen, (2) physical exertion, and (3) studying a night of sleep in an individual known to be a loud snorer. We also present the results of a preliminary study comparing CE monitoring to pulse oximetry in eight individuals undergoing standard clinical overnight polysomnography for suspected SDB.ResultsCE monitoring is responsive to changes in cellular oxygen supply to the skin and detects hypoxia during SDB events that is not detected by pulse oximetry.ConclusionCE monitoring is a promising tool for identifying pathology at the mild end of the SDB spectrum.

The effect of gradually increased mandibular advancement on the efficacy of an oral appliance in the treatment of obstructive sleep apnea.

To analyze the effect of gradual increments of mandibular advancement on the treatment efficacy of mandibular advancement devices and identify determinants of effective and target protrusion for OSA. Patients were prospectively recruited. The mandible was titrated from 0 mm with a stepwise increment of 0.5 mm until the AHI was reduced to the lowest level. Rhinospirometry, rhinomanometry, and magnetic resonance imaging were used to observe the change of respiratory function and upper airway morphology. Forty-two patients aged 41.5 ± 9.0 years participated. There was a dose-dependent relationship between mandibular protrusion and the AHI improvement rate, the success rate, and the normalization rate; the changing curves plateaued after approximately 70% of maximal mandibular protrusion was achieved. The correlation between AHI and mandibular protrusion became stronger as the severity of OSA increased. The target protrusion for patients with mild, moderate, and severe OSA was 3.5 ± 1.8 mm (38.6 ± 19.4% maximal mandibular protrusion), 5.8 ± 1.9 mm (62.9 ± 18.8% maximal mandibular protrusion), and 5.9 ± 2.2 mm (68.8 ± 15.6% maximal mandibular protrusion), respectively. Regression analysis revealed that the factors influencing effective and target protrusion included change of maximal lateral dimension of the total upper airway with mandibular advancement devices, mean lateral dimension of the oropharynx, and soft palate length. Further protrusion brought more lateral expansion of the velopharynx, whereas the change in nasal ventilation was not significant. The dose-dependent effect of mandibular protrusion on reduction of AHI by mandibular advancement devices was nonlinear and became more pronounced with increased severity of OSA. The mandibular protrusion should be more personalized to each patient. Registry: Chinese Clinical Trial Registry; Name: Study of the Onset Point of Oral Appliance Treatment in Obstructive Sleep Apnea and Hypopnea Syndrome; URL: http://www.chictr.org.cn/showproj.aspx?proj=22291; Identifier: ChiCTR-IND-17013232.

Association between central sleep apnea and atrial fibrillation/flutter in Japanese-American men: The Kuakini Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS)

IntroductionWhile several studies have indicated that central sleep apnea (CSA) is associated with atrial fibrillation and atrial flutter (AF) in older populations, few studies have focused on older Asian populations. MethodsWe conducted a cross- sectional analysis using data from the 1999–2000, 7th exam cycle of the Kuakini Honolulu-Asia Aging Study. Participants were 718 Japanese-American men between 79 and 97 years old, who had overnight polysomnography. Obstructive Apnea-Hypopnea Index (OAHI) was the measure of the number of obstructive apneas and hypopneas with >4% oxygen desaturation. Additionally, the Central Apnea Index (CAI) was the measure of the number of central apneas. Obstructive sleep apnea (OSA) was categorized as none (OAHI <5), mild (OAHI 5–14), moderate (OAHI 15–29) and severe (OAHI ≥30). CSA was defined by CAI of 5 or more. Cheyne-Stokes Breathing (CSB) was defined as a minimum consecutive 5-minute period of a crescendo-decrescendo respiratory pattern associated with CSA. ResultsAF prevalence was 5.5% (39 of 709). The prevalence proportions of severe OSA, CSA, and CSB were 20.2% (143 of 709), 6.4% (43 of 673) and 3.2% (22 of 673), respectively. In multivariable-adjusted logistic regression models, CSA and CSB were significantly associated with AF prevalence: odds ratio (OR) 5.15, 95% confidential interval (CI), 2.21–12.52 and OR 6.26, 95% CI, 2.05–19.14, respectively. However, OSA was not significantly associated with AF prevalence. ConclusionAF prevalence is associated with CSA and CSB but not OSA in older Japanese-American men. This information could help target AF prevention strategies in this population.

Serum adropin level is associated with endothelial dysfunction in patients with obstructive sleep apnea and hypopnea syndrome.

Adropin is a recently discovered peptide hormone that plays a vital role in metabolism and cardiovascular-cerebrovascular function. The purpose of this study is to investigate the role of circulating adropin levels in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and further determine the relationship between serum adropin concentration and endothelial dysfunction in patients with OSAHS. Forty polysomnography-diagnosed patients with OSAHS and 21 age and sex-matched healthy controls were enrolled in the current study. Serum adropin level, endothelial function parameters including flow-mediated dilatation (FMD) of brachial artery, endothelin-1 (ET-1), and nitric oxide (NO) were measured in all participants. Serum adropin levels were significantly lower in patients with OSAHS compared to the control subjects. FMD was lower and serum ET-1 levels were higher in patients with OSAHS compared to control subjects. No significant difference was seen in serum NO levels between the two groups. Multivariate linear regression analysis revealed that serum adropin level was positively associated with FMD and negatively correlated with AHI. Additionally, serum adropin levels were lower in patients with OSAHS who had endothelial dysfunction compared with those patients without endothelial dysfunction. The receiver operating characteristic (ROC) analysis showed that area under the curve (AUC) for serum adropin in predicting endothelial dysfunction status in patients with OSAHS was 0.815 (95% CI 0.680-0.951, p = 0.001). The cutoff value of serum adropin level was less than 235.0 pg/mL, which provided the sensitivity and specificity of 81% and 75%, respectively, for the detection of endothelial dysfunction in patients with OSAHS. Lower circulating adropin levels are closely associated with endothelial dysfunction in patients with OSAHS. Circulating adropin level may serve as an early biomarker to predict the development of endothelial dysfunction before the emergence of clinical symptoms in patients with OSAHS.

The role of sleep laboratory polygraphy in the evaluation of obstructive sleep apnea syndrome in Robin infants

Objective/backgroundCurrently, obstructive sleep apnea syndrome (OSAS) management in Robin sequence (RS) infants has not been standardized. Sleep laboratory polysomnography (PSG) is the gold standard for OSAS diagnosis, however, access is restricted. This study aimed to compare the respiratory indexes measured in a sleep laboratory using PSG as well as a possible alternative, polygraphy (PG). Patients/methodsThis retrospective study was conducted between 2015 and 2017 in a tertiary hospital. PSG performed in RS infants in the sleep laboratory was analysed by a single reviewer. After sleep data removal, anonymized raw data were analysed to obtain only PG data. Respiratory indexes were compared for (i) PSG and PG and (ii) patients with or without OSAS clinical signs. ResultsAmong the 20 RS (median [IQR] age: 43 [25–114] days at evaluation), 70% of the patients had OSAS clinical signs but all of them had severe OSAS. The median mixed obstructive apnea hypopnea index was not significantly different between PSG and PG (27/h [18–38] versus 26/h [18–56], p = 0.43). The median obstructive apnea index was higher with no significant difference between PG and PSG (19/h [15–31] versus 7/h [4–25], p = 0.05). The median obstructive hypopnea index was significantly lower on PG than on PSG (2/h [0–3] versus 8/h [8–19], p = 0.01). No difference on PSG or PG was observed for patients with and without clinical signs of OSAS. ConclusionAlthough PSG remains the gold standard for OSA evaluation, a PG seems to be a useful alternative to measure OSA in RS infants because of their OSAS severity. This evaluation should be recommended in all RS infants, even in the absence of OSAS clinical signs. Clinical trial registrationNot applicable.

Obstructive sleep apnea and hypopnea syndrome in patients admitted in a tertiary hospital in Cameroon: Prevalence and associated factors.

Obstructive sleep apnea and hypopnea syndrome (OSAHS) is poorly documented in Sub-Saharan Africa, especially in the hospital setting. The aim of this study was to determine its prevalence and to investigate the associated factors in patients admitted in a tertiary referral hospital in Cameroon. In this cross-sectional study conducted in the Cardiology, Endocrinology and Neurology departments of the Yaounde Central Hospital; all patients aged 21 and older were included consecutively. A sample of randomly selected patients was recorded using a portable sleep monitoring device (PMD). OSAHS was defined as apnea-hypopnea index (AHI) ≥ 5/hour (with > 50% of events being obstructive) and moderate to severe OSAHS as an AHI > 15/hour. Logistic regression was used to identify factors associated to OSAHS. Of the 359 patients included, 202 (56.3%) patients were women. The mean age (standard deviation) was 58 (16) years. The prevalence of OSAHS assessed by PMD (95% CI) was 57.7% (48.5-66.9%), 53.8% in men and 62.7% in women (p = 0.44). The median (25th-75th percentiles) AHI, body mass index and Epworth Sleepiness Scale score of OSAHS patients were 17 (10.6-26.9)/hour, 27.4 (24.7-31.6) kg/m2 and 7 (5-9) respectively. The only factor associated to moderate to severe OSAHS was hypertension [odds ratio (95% CI)]: 3.24 (1.08-9.72), p = 0.036. OSAHS is a common condition in patients in this health care centre of Cameroon. In the hospital setting, screening for OSAHS in patients with hypertension is recommended.