Sleep Breathing Patterns Research Articles

Ageing-related modification of sleep and breathing in orexin-knockout narcoleptic mice.

Narcolepsy type-1 (NT1) is a lifelong sleep disease, characterised by impairment of the orexinergic system, with a typical onset during adolescence and young adulthood. Since the wake-sleep cycle physiologically changes with ageing, this study aims to compare sleep patterns between orexin-knockout (KO) and wild type (WT) control mice at different ages. Four groups of age-matched female KO and WT mice (16 weeks of age: 8 KO-YO and 9 WT-YO mice; 87 weeks of age: 13 KO-OLD and 12 WT-OLD mice) were implanted with electrodes for discriminating wakefulness, rapid-eye-movement sleep (REMS), and non-REMS (NREMS). Mice were recorded for 48 h in their home cages and for 7 more hours into a plethysmographic chamber to characterise their sleep-breathing pattern. Regardless of orexin deficiency, OLD mice spent less time awake and had fragmentation of this behavioural state showing more bouts of shorter length than YO mice. OLD mice also had more NREMS bouts and less frequent NREMS apneas than YO mice. Regardless of age, KO mice showed cataplexy-like episodes and shorter REMS latency than WT controls and had a faster breathing rate and an increased minute ventilation during REMS. KO mice also had more wakefulness, NREMS and REMS bouts, and a shorter mean length of wakefulness bouts than WT controls. Our experiment indicated that the lack of orexins as well as ageing importantly modulate the sleep and breathing phenotype in mice. The narcoleptic phenotype caused by orexin deficiency in female mice was substantially preserved with ageing.

Sex Differences In The Phenotype Of Sleep-Disordered Breathing In C57BL/6J Mice

Sex differences in sleep-disordered breathing (SDB) are widely recognized. SDB is more prevalent in men, but women appear to exhibit more symptoms at lower levels of SDB severity, including insomnia symptoms. Mechanisms underlying sex differences in SDB are unknown. In this study, we compared the sleep architecture and breathing patterns during sleep between male and female mice and examined the effects of ovariectomy on SDB. We hypothesized that female and male mice differed in sleep and SDB, which are related to differences in carbon dioxide (CO2) chemosensitivity between sexes. Adult male (n=9) and female (n=10) C57BL/6J mice underwent full-polysomnography inside a whole-body plethysmography chamber. Arousals from sleep and apneas were manually scored. Breathing variability was assessed with Poincaré plots of minute ventilation. Hypercapnic ventilatory response (HCVR) was assessed during wakefulness and NREM sleep by acute administration of 8% CO2. In female mice, we performed bilateral ovariectomy and repeated sleep studies after 14 days. We found that arousal index was 55% increased in females compared to males, but sleep fragmentation was mainly attributed to spontaneous arousals in both groups. Surprisingly, apnea severity was significantly increased in female mice compared to males (32.4±6.7 vs 11.8±4.5, P=0.001). Breathing instability was also increased in females. HCVR was positively correlated with apnea index (r=0.55, P=0.05) and was significantly augmented in females compared to males. Ovariectomy did not affect sleep fragmentation, but attenuated CO2 sensitivity and improved breathing stability during sleep. Our results have suggested different SDB phenotypes between male and female C57BL/6J mice. SDB in female mice is associated with a hyperarousal state and increased HCVR compared to males. An exacerbated CO2 responsiveness related to ovarian hormones in females is an important determinant of differences in SDB severity and respiratory patterns between male and female sex. American Heart Association Postdoctoral Fellowship Award 828142 (to L.J.K.), NHLBI grant 2R01 HL133100-05, NIH R01 HL128970, and R01 HL13892 (to V.Y.P.), 1K23HL155730 and American Academy of Sleep Medicine Foundation 238-BS-20 (to L.V.P.). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Pre-sympathetic C1 RVLM neurons drives sleep disordered breathing in heart failure through activation of central chemoreceptors

Sleep-disordered breathing is closely linked to heart failure (HF) morbidity and mortality. Recently, we showed that photo-stimulation of pre-sympathetic motor neurons located within the rostro ventrolateral medulla (RVLM) drive sleep-disordered breathing in healthy conditions. However, the neural circuitry required for these effects and whether this pathway is relevant for HF pathophysiology is not known. Accordingly, we aimed to determine: i) if the generation of RVLM-induced altered breathing encompasses the activation of chemoreceptor neurons from the retrotrapezoid nucleus (RTN), and ii) if selective ablation of RVLM neurons improves breathing control and sleep architecture in HF rats. Sprague-Dawley rats received stereotaxic injections of a lenti-viral vector containing a light-sensitive cation channel (Channelrhodopsin2) in the RVLM and a Substance P-saporin toxin conjugate into the RTN. Then, 200 mm fiber optics were implanted for RVLM neurons photo-stimulation. A second group underwent volume overload to induced HF and ablation of RVLM neurons was performed using a DbH-saporin toxin (DbH-SAP). EEG and EMG leads were implanted, and rats allowed to recover before sleep/breathing studies. We found that photo-stimulation of RVLM neurons triggered breathing disorders only in the presence of a functional RTN neurons. Indeed, breathing irregularity score following RVLM photo-stimulation showed a two-fold increase (9±2 vs. 20±3, pre vs. post-stimulation) and this was absent in the presence of Substance P-saporin (10±3 vs. 12±3, pre vs. post-stimulation with Substance P-saporin). Compared to Sham rats, HF animals showed overt signs of disordered breathing and sleep fragmentation and ablation of RVLM neurons using DbH-SAP significantly improves both breathing and sleep function in HF. Our results showed that RVLM drives breathing disorders through activation of the RTN and that selective ablation of RVLM neurons offer salutary benefit for the control of sleep and irregular breathing patterns in the setting of HF. Fondecyt 1220950. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Changes the level of differentiating growth factor - GDF 15 in patients with sleep apnea syndrome after aPAP-therapy: pilot study

Comparative assessment of the level of differentiating growth factor 15 (GDF 15 ) against the background of a 6-month course of respiratory support in the mode of automatic positive pressure in the airways therapy (aPAP therapy) in patients with obstructive sleep apnea syndrome (OSA). 59 men participated in the study, the average age was 51.9±2.4 years. The main group (MG1) consisted of 30 patients with a verified diagnosis of moderate OSA. 29 men of comparable age and body weight made up the control group (CG) without an objectively confirmed diagnosis of OSA. After the stage of introduction into the study, the type of respiratory support with individual pressure settings was selected for patients with MG1. After 6 months of aPAP therapy with high compliance (at least 85%), the same patients who made up MG2 after treatment underwent repeated polysomnography (PSG) and the GDF 15 content was evaluated. Methods: questionnaire, examination, polysomnography, enzyme immunoassay of blood serum to determine the content of GDF 15. A 6-month course of aPAP therapy with a high degree of compliance significantly improved the sleep structure and breathing pattern: the representation of NREM 3 increased from 79.2±15.6 to 102.6±21.6 minutes and the REM phase from 56.9± 13.6 to 115.6±26.8. Episodes of apnea were eliminated - apnea-hypopnea index decreased from 21.1 [17.3; 39.1] to 2.5 [1.8; 4.6] and the average values of SaO2 increased from 85.9% to 91.5%. At the same time, a statistically significant excess of GDF 15 was revealed in MG1 - 20.4 [14.16; 31.71] and MG2 - 17.2 [13.63; 24.44]) in comparison with CG - 13.65 [10.7; 17.09]. Despite the lack of statistical significance, a change in the level of GDF 15 was revealed in the form of a decrease in its concentration after a 6-month course of aPAP therapy. A 6-month course of aPAP therapy made it possible to eliminate intermittent nocturnal hypoxia and improve sleep structure in patients with OSA, as well as reduce the content of GDF 15 protein in blood serum in patients with OSA. However, the tendency to decrease the content of this protein, despite the lack of statistical reliability, confirms the effectiveness of OSA therapy and the possibility of preventing early and pathological aging from the standpoint of somnology and molecular biogerontology.

Sleep breathing patterns and neurocognitive function in a diverse Hispanic/Latino cohort

AbstractBackgroundSleep disorders are common in patients with Alzheimer’s Disease (AD). Obstructive sleep apnea (OSA), characterized by intermittent cessation of breathing and hypoxemia, has been associated with increased risk of AD and worse cognitive function. However, the interacting effects of neurocognitive function with sleep breathing patterns, independent of the apnea‐hypopnea index, (a measure of OSA severity) have not been carefully studied. We use a novel approach to analyzing home sleep apnea data to examine breathing patterns and their relationships with neurocognitive function.MethodThe Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a prospective multicenter study of diverse Latinos. Around 16,000 diverse Hispanic/Latinos were recruited from four major metropolitan cities. Participants used an ARES unirecorder device for a single night of unsupervised at home recording. We used python package “bycycle” to cannula data (sampled at 10Hz). Bycycle uses a time domain approach to parameterizing rhythmic time‐series data. We extracted breathing rate (breaths per minute), breathing variability (interquartile range of breathing rate) and time spent in inhalation phase (percent time). Participants ages ≥45 (unweighted n = 5,957) were tested in their preferred language using a brief battery including: B‐SEVLT (3‐trials sum) and Delayed Recall (memory), World Fluency (verbal fluency), and Digit Symbol Substitution (executive function). Covariates used in our models are described in Table 1. All presented estimates were weighted for appropriate generalization to the HCHS/SOL target population.ResultIn unadjusted models, all breathing measures were negatively associated with cognitive function, but only breathing rate remained significant after full covariate adjustment (Figure 1). We found significant interactions between breathing rate and sex, as well as age for verbal fluency models. Being female and older age were associated with steeper slopes of cognitive under‐performance for both breathing rate and breathing variability (Figure 2).ConclusionThese results suggest that breathing patterns outside apneas‐hypopneas may be as critical in understanding sleep related changes and cognitive function in an aging population. Given cessation of breathing during an apnea‐hypopnea event, breathing variability may add more precision to account for varying oxygen demands. Further studies should examine whether breathing instability is also associated with cognitive decline, impairment, and dementia.

0458 Cardiovascular and sociocultural factors are associated with sleep breathing differences in a diverse Hispanic/Latino cohort

Abstract Introduction Obesity and or obstructive sleep apnea (OSA) can impact awake breathing patterns, such as increments in the breathing rate. However, little is known about their associations with breathing dysregulations during sleep beyond the apnea-hypopnea events. Understanding this could help elucidate treatment mechanisms or different pathways for disease. Furthermore, there is a strong connection between breathing patterns and cardiovascular disease, thus it is also critical to understand the links between cardiovascular risk factors and disease (CVD) and sleep breathing patterns. Methods The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a prospective multicenter study of diverse Latinos. A total of N=16,415 participants from four major metropolitan areas and six different Hispanic/Latino backgrounds were sampled for appropriate generalization to the target population. Participants were given an ARES unirecorder device (Carlsbad, San Diego) for a single night of unsupervised at home recording (N=12,022). Raw data from cannula channel (sampled at 10Hz) was processed using the python Bycycle package. Bycycle is a cycle-by-cycle approach to analyzing time series data. Bycycle finds all peaks and throughs in cycles and allows users to extract time dependent information of cycles. We extracted breathing rate (breaths per minute), breathing variability (interquartile range of breathing rate) and time spent in inhalation phase (percent time). Results In multivariable models (N=10,175), age was linked to decreased breathing rate, breathing variability, and time spent in inhalation phase. Compared to females, males had higher breathing variability and spent more time in the inhalation phase. Compared to Mexicans and? Central Americans, Cubans, Dominicans, and Puerto Ricans had less time spent in inhalation phase. Dominicans and Puerto Ricans also had increased breathing rate compared to Mexicans. Smoking, body mass index, and moderate to severe OSA were associated with increased breathing rate and variability. Systolic, but not diastolic blood pressure, was associated with increased breathing rate. We found no significant associations with cardiovascular disease. Conclusion Factors commonly linked to OSA were associated with increased breathing rate, a compensatory mechanism for optimal oxygenation, and breathing variability. Given cessation or reduced breathing during an apnea-hypopnea event, breathing variability may add more precision to account for varying oxygen demands. Support (if any)

Impact of sleep posture and breathing pattern on soft palate flutter and pharynx vibration in a pediatric airway using fluid–structure interaction

Snoring is a common condition in the general population, and the management of snoring requires a better understanding of its mechanism through a fluid–structure interaction (FSI) perspective. Despite the recent popularity of numerical FSI techniques, outstanding challenges are accurately predicting airway deformation and its vibration during snoring due to complex airway morphology. In addition, there still needs to be more understanding of snoring inhibition when lying on the side, and the possible effect of airflow rates, as well as nose or mouth-nose breathing, on snoring remains to be investigated. In this study, an FSI method verified against in vitro models was introduced to predict upper airway deformation and vibration. The technique was applied to predict airway aerodynamics, soft palate flutter, and airway vibration in four sleep postures (supine, left/right lying, and sitting positions) and four breathing patterns (mouth-nose, nose, mouth, and unilateral nose breathing). It was found that, at given elastic properties of soft tissues, the evaluated flutter frequency of 19.8 Hz in inspiration was in good agreement with the reported frequency of snoring sound in literature. Reduction in flutter and vibrations due to the mouth-nose airflow proportion changes were also noticed when having side-lying and sitting positions. Breathing through the mouth results in larger airway deformation than breathing through the nose or mouth-nose. These results collectively demonstrate the potential of FSI for studying the physics of airway vibration and clarify to some degree the reason for snoring inhibition during sleep postures and breathing patterns.

Subjective HRQoL in Patients with Sleep Apnea Syndrome Who Underwent PAP Therapy in a Rehabilitation Setting: A Longitudinal Study

Obstructive sleep apnea (OSA) is often associated with decreased health-related quality of life (HRQoL). The aims of this study were to evaluate HRQoL, the clinical and psychological profile of suspected or verified OSA patients, and the impact of PAP therapy at 1-year follow-up. At T0, OSA-suspected subjects underwent clinical, HRQoL, and psychological assessment. At T1, OSA patients underwent PAP therapy in a multidisciplinary rehabilitation setting. At 1 year follow-up, OSA patients were evaluated for the second time. At T0, OSA patients (n = 283) and suspected OSA subjects (n = 187) differed for AHI, BMI, and ESS. At T0, the PAP-treatment group (n = 101) showed moderate-severe anxious (18.7%) and depressive (11.9%) symptoms. At 1 year follow-up (n = 59), the sleep breathing pattern had normalized and there was a reduction of ESS scores and anxious symptoms. There was also an improvement in HRQoL (0.6 ± 0.4 vs. 0.7 ± 0.5, p = 0.032; 70.4 ± 19.0 vs. 79.2 ± 20.3, p = 0.001) and in satisfaction with sleep quantity (52.3 ± 31.7 vs. 71.4 ± 26.2, p = 0.001), sleep quality (48.1 ± 29.7 vs. 70.9 ± 27.1, p = 0.001), mood (58.5 ± 24.9 vs. 71.0 ± 25.6, p = 0.001), and physical resistance (61.6 ± 28.4 vs. 67.8 ± 27.4, p = 0.039). Considering the impact of PAP treatment on patients' psychological and HRQoL evaluations that we observed, our data are valuable for unveiling different profiles characterizing this clinical population.

Changes in airway patency and sleep-breathing in healthy skeletal Class II children undergoing functional activator therapy.

Several studies agree that an abnormal maxilla-mandible relationship correlates better as an Obstructive Sleep Apnea (OSA) predictor, rather than obesity. One of the orthodontic therapies recommended for this kind of craniofacial deformity is to advance the mandible forward with an orthodontic activator, therefore, the aim of this study is to determine if healthy children that use this appliance experience a widening of the upper airway as well as an improvement in their sleep-breathing patterns. 39 healthy children, 20 for activator group (10 boys and 10 girls, 4 mean age 10.9 + 0.9; BMI 16.2 + 1.4), 19 for control group (13 boys and 6 girls, mean age 5 9.8 + 1.4; BMI 17.6 + 2.1) participated in this study. They were required to submit 2 lateral cephalometric radiographs both at initial and final stages of evaluation, and finally three at- home sleep-breathing monitoring results for the activator group and one for the control group. After radiographic evaluation, it was found that children in the activator group experienced an increase in all measured variables. After evaluation with the sleep monitor, an improvement of sleep-breathing was found in children from the activator group (p<0.05). The activator not only provides a harmonious occlusion and proper development of the mandible, but it also helps improve the quality of sleep-breathing through widening of the upper airway and reducing the number of disordered breathing events in children that undergo this therapy.

Sleep disturbances and related disordered breathing after hip replacement surgery: A randomised controlled trial

IntroductionMechanisms of postoperative sleep architecture disturbances and sleep-disordered breathing are uncertain. The authors hypothesised that patients undergoing surgery under regional anaesthesia without opioids used for postoperative analgesia would experience lesser changes in these parameters than patients operated under general anaesthesia with per- and postoperative opioids. Patients and methodsAfter ethical approval and informed consent, patients undergoing total hip replacement were included in a prospective, randomised trial comparing 3 groups of patients: (1) S-LPB group receiving spinal anaesthesia and postoperative analgesia by lumbar plexus block; (2) GA-PCA group receiving general anaesthesia and postoperative analgesia by morphine patient-controlled analgesia; (3) GA-LPB group receiving general anaesthesia and postoperative analgesia by lumbar plexus block. Outcome measurements were polysomnographic parameters of sleep architecture and sleep-disordered breathing. ResultsEighteen patients completed the 5-night study protocol (preoperative night: N-1, postoperative nights: N1 to N4). The percentage of rapid eye movement (REM) sleep decreased by 49% and 47% during N1 in the GA-PCA and GA-LPB groups respectively. A rebound phenomenon of more than 40% in the GA-PCA group and 25% in the GA-LPB group was observed during N2 and N3. Apnoea hypopnoea index (AHI) and the number of arousals per hour were significantly increased during N2 and N3 when compared with N-1 in the GA-groups. No sleep architecture disturbances and no sleep-disordered breathing were measured in the S-LPB group. ConclusionPostoperative sleep architecture and breathing pattern were disturbed in GA groups. Both were preserved under spinal anaesthesia associated with a free opioid postoperative analgesia.

Portable Sleep Apnea Syndrome Screening and Event Detection Using Long Short-Term Memory Recurrent Neural Network.

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is characterized by repeated airflow partial reduction or complete cessation due to upper airway collapse during sleep. OSAHS can induce frequent awake and intermittent hypoxia that is associated with hypertension and cardiovascular events. Full-channel Polysomnography (PSG) is the gold standard for diagnosing OSAHS; however, this PSG evaluation process is unsuitable for home screening. To solve this problem, a measuring module integrating abdominal and thoracic triaxial accelerometers, a pulsed oximeter (SpO2) and an electrocardiogram sensor was devised in this study. Moreover, a long short-term memory recurrent neural network model is proposed to classify four types of sleep breathing patterns, namely obstructive sleep apnea (OSA), central sleep apnea (CSA), hypopnea (HYP) events and normal breathing (NOR). The proposed algorithm not only reports the apnea-hypopnea index (AHI) through the acquired overnight signals but also identifies the occurrences of OSA, CSA, HYP and NOR, which assists in OSAHS diagnosis. In the clinical experiment with 115 participants, the performances of the proposed system and algorithm were compared with those of traditional expert interpretation based on PSG signals. The accuracy of AHI severity group classification was 89.3%, and the AHI difference for PSG expert interpretation was . The overall accuracy of detecting abnormal OSA, CSA and HYP events was 92.3%.

Inhaled Nitric Oxide: In Vitro Analysis of Continuous Flow Noninvasive Delivery via Nasal Cannula.

Inhaled nitric oxide (NO) is most frequently delivered to mechanically ventilated patients in critical care, but it can also be administered noninvasively. The delivered dose and efficiency of continuous flow NO supplied through a nasal cannula has yet to be established. This study aimed to determine the influence of nasal cannula type, supply flow, and breathing pattern on delivered NO using a realistic adult airway replica and lung simulator. Simulated breathing patterns were selected to represent rest, sleep, and light exercise, and were varied to investigate the effects of tidal volume and breathing frequency independently. Supplied gas flows targeted tracheal concentrations at rest of 5 or 20 ppm NO and were supplied with 2 L/min O2. Three different cannulas were tested. Tracheal NO concentrations and NO mass flow past the trachea were evaluated. Cannula type had a minor influence on delivered dose. Tracheal NO concentrations differed significantly based on breathing pattern (P < 0.01); for a target NO concentration of 20 ppm at rest, average inhaled NO concentrations were 23.3 ± 0.5 ppm, 36.5 ± 1.4 ppm, and 17.2 ± 0.3 ppm for the rest, sleep, and light exercise breathing patterns, respectively. For the same test conditions, mass flow of NO past the trachea was less sensitive to breathing pattern: 20.3 ± 0.5 mg/h, 19.9 ± 0.8 mg/h, and 24.3 ± 0.4 mg/h for the rest, sleep, and light exercise breathing patterns, respectively. Mass flow and delivery efficiency increased when minute volume increased. These results indicate that inhaled NO concentration is strongly influenced by breathing pattern, whereas inhaled NO mass flow is not. NO mass flow may therefore be a useful dose metric for continuous flow delivery via nasal cannula.

First Description of the Hyperpnea-Hypopnea Periodic Breathing in Patients with Interstitial Lung Disease-Obstructive Sleep Apnea: Treatment Implications in a Real-Life Setting.

There is evidence that hypopneas are more common than apneas in obstructive sleep apnea (OSA) related to idiopathic pulmonary fibrosis (IPF). We investigated the frequency distribution of hypopneas in 100 patients with interstitial lung diseases (ILDs) (mean age 69 yrs ± 7.8; 70% males), including 54 IPF cases, screened for OSA by home sleep testing. Fifty age- and sex-matched pure OSA patients were included as controls. In ILD-OSA patients the sleep breathing pattern was characterized by a high prevalence of hypopneas that were preceded by hyperpnea events configuring a sort of periodic pattern. This finding, we arbitrarily defined hyperpnea–hypopnea periodic breathing (HHPB), was likely reflecting a central event and was completely absent in control OSA. Also, the HHPB was highly responsive to oxygen but not to the continuous positive pressure support. Thirty-three ILD-OSA patients (42%) with a HHPB associated with a hypopnea/apnea ratio ≥3 had the best response to oxygen with a median residual AHI of 2.6 (1.8–5.6) vs. 28.3 (20.7–37.8) at baseline (p < 0.0001). ILD-OSA patients with these characteristics were similarly distributed in IPF (54.5%) and no-IPF cases (45.5%), the most of them being affected by moderate–severe OSA (p = 0.027). Future studies addressing the pathogenesis and therapy management of the HHPB should be encouraged in ILD-OSA patients.

Effects of acute exposure to moderate altitude on blood pressure and sleep breathing patterns

BackgroundAcute exposure to high altitude (>2500 m) is known to induce a rise in blood pressure (BP) and the appearance of sleep related breathing alterations, in particular central sleep apneas and periodic breathing. Little information is available on whether this is the case in humans also for acute exposure to moderate altitude (between 1500 and 2500 m). Aim of this study was to evaluate the effects of acute exposure of healthy volunteers to moderate altitude on conventional and ambulatory BP as well as on the frequency and severity of breathing alterations during sleep. MethodsForty-four healthy lowlanders underwent 24-hour ambulatory BP monitoring and nocturnal cardio-respiratory sleep study at sea level and during acute (1–2 days after arrival) exposure to moderate altitude (2035 m, Sestriere, Italy). The key variables investigated included average systolic and diastolic BP and heart rate over daytime, night-time and 24 h, the frequency of obstructive and central apneas/hypopnoeas and the behaviour of oxygen saturation during sleep. ResultsCompared to sea level, during moderate altitude exposure mean systolic/diastolic BP increased significantly during daytime (respectively from 125.6 ± 10.9 to 130.6 ± 12.3, p = 0.0032 and from 78.8 ± 6.7 to 81.8 ± 7.7 mmHg, p = 0.0048) and during night-time (respectively from 102.4 ± 12.4 to 107.4 ± 12.7, p = 0.0028, and from 62.0 ± 8.2 to 65.8 ± 8.2 mmHg, p = 0.0014), with no change in nocturnal BP dipping. BP increase was more evident in participants aged over 40 years. Apnea-hypopnea index (AHI) increased from 1.60 (0.40–2.90) to 5.4 (2.90–10.60), p < 0.0001), mainly because of increasing frequency of hypopneas and central apneas, in particular in males aged over 40 years. No association was found between size of BP changes and AHI. ConclusionOur results indicate that in healthy subjects even exposure to moderate altitude may induce significant, although mild, changes in ambulatory BP and in respiratory patterns during sleep with gender and age-related differences. Further studies are needed to explore the clinical relevance of these findings.

Parents’ Perceptions of Breathing Pattern Changes, Sleep Quality, and Fatigue in Children after Rapid Maxillary Expansion: A Survey and Case Series Study

Background: Rapid Maxillary Expansion (RME) aims to re-establish balance between the widths of the jaws. It is mainly utilized to treat skeletal and dental manifestations associated with transverse maxillary constriction and to improve facial structures involving the nasal cavity. Objectives: This study aimed to investigate parents’ perceptions of breathing pattern changes after their child had undergone RME and the associated effects on sleep quality and fatigue. We also evaluated nasal cavity changes in three dimensions in six randomly selected patients. Methods: Ninety-one children aged 5-13 years with transverse maxillary deficiency and no major systemic diseases or syndromes were recruited. Their parents completed a 16-item questionnaire pre-treatment and 6 months post-treatment. The questionnaire included items pertaining to changes in (1) sleep apnea and breathing patterns, (2) sleep quality and fatigue, and (3) behavior. The cone beam computed tomography scans from six randomly chosen patients were also subjected to stereolithographic reconstruction of the midface pre-RME and post-RME. Results: Responses in the three domains exhibited good reliability. Significant improvements were observed in 59% of the items post vs. pre-RME. The overall rates of dry mouth in the morning, snoring half of the time, and heavy breathing decreased by ≥30%. The percentage change in headache in the morning, snoring loudly, and snoring half of the time was &gt;80%. In addition, in the series of six cases, the mean difference in nasal cavity area post-RME was 4.1 mm2. Conclusion: Post-RME, parents perceived that their children exhibited improved behavior and were less fatigued during the day. Enhanced sleep quality and breathing patterns were also observed, but to a lesser extent.

Respiratory Polysomnographic Findings in Patients Treated Primarily for Unilateral Cleft Lip and Palate.

Cleft lip and palate (CLP) is the most common congenital craniofacial abnormality. Obstructive sleep apnea syndrome (OSAS) is a highly prevalent but underdiagnosed disease and is frequently associated with craniofacial anomalies. There are few studies describing the sleep breathing pattern of children with CLP. This study sought to characterize the respiratory profile of 23 children with unilateral cleft lip and palate, aged 7-12 years, who had undergone cleft lip and nasal repair at age 3-4 months and palatoplasty at 12-15 months, with a particular focus on evaluating the presence of OSAS in children with CLP. Polysomnography was performed and findings were analyzed descriptively. We found a mean and median for apnea/hypopnea index (AHI) of 1.11/h (SD = 0.78) and 0.9/h, respectively. The mean obstructive apnea index (OAI) was 0.27/h (SD = 0.38) and the median, 0.1/h. Nearly 30% of patients had an AHI above 1.4 events/h. There was no significant oxyhemoglobin desaturation in the study group. In this group, the prevalence of OSAS was higher than in noncleft populations when compared to the normality values adopted. This sample of patients with unilateral cleft lip and palate exhibited an increased prevalence of OSAS during the mixed dentition stage. Although the results showed that OSAS was mild, we advise closer observation of these patients. Polysomnography is recommended for the assessment of children with airway abnormalities, to individualize the extent of treatment.

Evaluation of changes in sleep breathing patterns after primary palatoplasty in cleft children

Introduction: There is a need to more clearly understand the characteristics of breathing patterns in children with cleft palate inthe first year of life, as there is little data available to guide current practice. Pierre Robin patients are known to have a higher incidence, however we hypothesised sleep breathing disturbance is not confined to this sub-group of cleft patient.Methods: We conducted a prospective observational study of sleep disordered breathing patterns in a cohort of infants with oronasal clefts (cleft palate with or without cleft lip) to describe the spectrum of sleep breathing patterns both pre and post palate repair. Sleep breathing studies were performed pre- and post-operatively in sequential infants referred to a regional cleft lip andpalate unit. Results of sleep breathing studies were analysed according to American Academy of Sleep Medicine scoring guidelines and correlated with clinical history and details of peri-operative respiratory compromise. The degree of sleep disordered breathingwas characterised using desaturation indices (number of desaturations from baseline SpO2 of &gt;=4%, per hour).Results: Thirty-nine infants were included in this study, twenty-five female and fourteen male. Twelve had isolated Cleft Palate aspart of an associated syndrome. Patients were categorised into Isolated Cleft Palate, Isolated Cleft Palate in the context of Pierre Robin Sequence, and those with Cleft Lip and Palate. All groups demonstrated some degree of sleep breathing abnormality. Not unsurprisingly the eight infants with Pierre Robin Sequence had a significantly higher desaturation index before surgicalintervention (p=0.043), and were more likely to require a pre-operative airway intervention (p=0.009). Palate repair in this group did not alter the relative distribution of patients in each severity category of sleep disorder breathing. Surgical repair ofthe secondary palate in the remaining children was associated with some improvement but by no means complete resolution of their sleep disordered breathing patterns.Conclusions: We conclude that sleep breathing disturbance is not confined to Pierre Robin patients alone and all cleft palate patients should undergo pre-operative and post-operative sleep breathing analysis.

Relationship between Oral Flow Patterns, Nasal Obstruction, and Respiratory Events during Sleep.

Sleep breathing patterns are altered by nasal obstruction and respiratory events. This study aimed to describe the relationships between specific sleep oral flow (OF) patterns, nasal airway obstruction, and respiratory events. Nasal flow and OF were measured simultaneously by polysomnography in 85 adults during sleep. OF was measured 2 cm in front of the lips using a pressure sensor. OF could be classified into three patterns: postrespiratory event OF (postevent OF), during-respiratory event OF (during-event OF), and spontaneous arousal-related OF (SpAr-related OF). Postevent OFs begin at the end of airflow reduction, are preceded by respiratory arousal, and are accompanied by postapneic hyperventilation; during-event OFs occur during nasal flow reduction; and SpAr-related OFs to OF begin during stable breathing, and are preceded by spontaneous arousal but are rarely accompanied by apnea/hypopnea. Multivariate regression showed that nasal obstruction was predictive of SpAr-related OF. The relative frequency of SpAr-related OF events was negatively correlated with the apnea-hypopnea index. The fraction of SpAr-related OF duration relative to total OF duration was significantly greater in patients with nasal obstruction than in those without. SpAr-related OF was associated with nasal obstruction, but not respiratory events. This pattern thus functions as a "nasal obstruction bypass", mainly in normal subjects and patients with mild sleep disordered breathing (SDB). By contrast, the other two types were related to respiratory events and were typical patterns seen in patients with moderate and severe SDB.

Characterization of sleep breathing pattern in patients with type 2 diabetes: sweet sleep study.

BackgroundAlthough sleep apnea-hypopnea syndrome (SAHS) is highly prevalent in patients with type 2 diabetes (T2D), it is unknown whether or not subjects with and without T2D share the same sleep breathing pattern.Methodology/Principal findingsA cross-sectional study in patients with SAHS according to the presence (n = 132) or not (n = 264) of T2D. Both groups were matched by age, gender, BMI, and waist and neck circumferences. A subgroup of 125 subjects was also matched by AHI. The exclusion criteria included chronic respiratory disease, alcohol abuse, use of sedatives, and heart failure. A higher apnea hypopnea index (AHI) was observed in T2D patients [32.2 (10.2–114.0) vs. 25.6 (10.2–123.4) events/hours; p = 0.002). When sleep events were evaluated separately, patients with T2D showed a significant increase in apnea events [8.4 (0.1–87.7) vs. 6.3 (0.0–105.6) e/h; p = 0.044), as well as a two-fold increase in the percentage of time spent with oxygen saturation <90% [15.7 (0.0–97.0) vs. 7.9 (0.0–95.6) %; <0.001)], higher rates of oxygen desaturation events, and also higher daily sleepiness [7.0 (0.0–21.0) vs. 5.0 (0.0–21.0); p = 0.006)] than subjects without T2D. Significant positive correlations between fasting plasma glucose and AHI, the apnea events, and CT90 were observed. Finally, multiple linear regression analyses showed that T2D was independently associated with AHI (R2 = 0.217), the apnea index (R2 = 0.194), CT90 (R2 = 0.222), and desaturation events.Conclusions/significanceT2D patients present a different pattern of sleep breathing than subject without diabetes. The most important differences are the severity of hypoxemia and the number of apneas whereas the incidence of hypopnea episodes is similar.

Researchers Work to Define Phenotypes of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a complex disease that is characterized by the collapse of the pharyngeal airway, resulting in recurrent episodes of airway closure, oxygen desaturation, and disrupted sleep. In recent studies, researchers have sought to define multiple phenotypes on the basis of local and distant anatomy, sleep breathing and arousal patterns, and response to treatment. In this article, experts in sleep-disordered breathing discussed the spectrum of OSA phenotypes and their implications for therapy.