Sleep-related Breathing Problems Research Articles

O039 A Novel Approach to Quantify Breathing effort in Obstructive Sleep Apnoea

Abstract Introduction Breathing effort is an important component of obstructed breathing and determinant of arousal in obstructive sleep apnoea (OSA). However, relative effects of hypopnoea versus apnoea on effort and work of breathing (WOB) are largely unknown. This study applied a novel modelling approach to quantify breathing effort, WOB and obstruction severity to evaluate differences between hypopnoea and apnoea events in OSA. Methods 1659 apnoea and hypopnea events from six obese males (BMI: 30-41 kg/m2; age: 34-56 years; AHI: 31-114 events/hr) with severe OSA were evaluated using conventional sleep measures and a 3-compartment (nasal, collapsible upper airway and lungs) respiratory mechanics model using mask airflow and pressure, and oesophageal and epiglottic pressures. Attempted airflow and WOB, and WOB loss to obstruction (attempted minus measured WOB), were estimated breath-by-breath via the model for comparisons between hypopnoea and apnoea events and sleep stages. Results The model explained most of the variance in attempted flow (Pearson r= 0.91 [95% CI 0.71 to 0.98]). Compared to hypopnoea events, WOB loss during obstructive apnoeas was 3.5 [95%CI 1.7 to 5.4] times higher. WOB losses were also higher during deep versus N2 sleep. Visualising breath-by-breath WOB loss revealed a significant number of flow- limited breaths not detected using traditional human scoring. Over 30% of breaths not classified as hypopnoeas or apnoeas exhibited WOB loss higher than for hypopnoea events. Conclusions Respiratory mechanics modelling is useful to assess breathing effort and upper airway obstruction severity and could provide novel mechanistic insights into sleep-related breathing problems and treatment outcomes.

The Usefulness of Modified Mallampati Score and CT Upper Airway Volume Measurements in Diagnosing OSA among Patients with Breathing-Related Sleep Disorders

Background: Obstructive sleep apnea (OSA) is a condition causing restriction of the airflow through the upper airways during sleep, despite preserved inspiratory muscle activity. This may lead to the development of secondary hypertension, ischemic heart disease, myocardial infarction, and arrhythmia. Moreover, the prevalence of OSA is on the rise. Methods: Comparison of scores from the Berlin Questionnaire, modified Mallampati scores (MMP), pulse oximetry readings and Upper Airway Volume (UAV) data obtained from CBCT (Cone Beam Computed Tomography). The study group of 129 patients of both sexes reporting sleep-related breathing problems completed the Berlin Questionnaire, had their oxygen saturation (SpO2) measured with a PO40 pulse oximeter, and oropharyngeal tissues assessed according to MMP. CBCT scans were put into 3D Amira TM 3D computer analysisto obtain UAV values. Results: Snoring was associated with significantly higher BMI compared to non-snoring patients. Furthermore, snoring patients had higher heart rate, modified Mallampati score, and lower UAV than the non-snoring group. The multifactorial analysis showed MMP as a useful indicator of the risk of snoring (OR = 7.468 (3863–14, 507, p < 0.001)). Conclusions: The composition of MMP together with UAV and the Berlin questionnaire might be reliable indicators to assess the risk of snoring.

Secondhand Smoke Exposure and Sleep-Related Breathing Problems in Toddlers

BackgroundAdequate sleep during childhood is an important component of overall health and wellbeing for children. Secondhand smoke (SHS) exposure has been linked to a greater risk of sleep-disordered breathing. ObjectiveOur objective was to investigate relationships between SHS exposure and sleep-related breathing problems in healthy toddlers aged 2 to 5 years. We hypothesized that there is an independent relationship between objectively measured SHS exposure and presence of sleep-related breathing problems by parental report. MethodsA convenience sample of 149 healthy children ages 2 to 5 years was recruited from an academic pediatric primary care center for this cross-sectional study; 138 had complete data that were analyzed. Current SHS exposure was determined by hair nicotine level. Presence of sleep-related breathing problems was assessed by 1 survey item. Inflammation was determined by serum C-reactive protein (CRP) level. Analysis in Stata 15 included a series of multivariate logistic regression models, controlling for individual-level demographics and body mass index z scores according to mediation analysis procedures for dichotomous outcomes. ResultsApproximately 24% of parents reported their child snored, gasped, or had difficulty breathing at night sometimes, most of the time, or almost always. Regression models with mediation analysis indicate that SHS exposure significantly increased the odds of reporting the child had sleep-related breathing problems, and 18% of this relationship is explained by log serum CRP levels. ConclusionsAlthough the cross-sectional nature of this study limits causality, evidence suggests a relationship exists between SHS exposure, as measured by log hair nicotine and sleep-related breathing problems at night.

Gender and Age Differences in Sleep Problems in Children: Person-Oriented Approach With Multigroup Analysis

ABSTRACTObjective/Background: This study aimed to identify subtypes of sleep problems in children and to examine whether these patterns differed between gender and age groups. Participants: There were 3,052 children (951 elementary school boys, 943 elementary school girls, 603 junior high school boys, and 555 junior high school girls) aged 7–16 years from two school-based epidemiological samples. Methods: Sleep problems were measured by the Sleep Habit Questionnaire based on parent reports. Results: Using the latent class modeling, a person-oriented approach, with a multigroup analysis, we identified four classes of sleep problems: moderate to high sleep problems (1.1%–3.1%), sleep-related breathing problems and parasomnias dominant (14.9%–21.1%), insomnias dominant and parasomnias (1.0%–3.1%), and no or low sleep problems (74.7%–81.4%), with varied prevalence rates of sleep problems across gender and age groups. Conclusions: This study identified four classes of sleep problems across gender and age groups but with different prevalence rates of sleep problems, suggesting the complex interaction of gender and age in the subtypes of sleep problems. The gender- and age-specific interventions for sleep problems are suggested. Future studies are warranted to replicate these classes and to identify associated factors with each class.

Distinctive sleep problems in children with perinatal moderate or mild hypoxic-ischemia

Extensive studies focus on the cognitive and motor impairments after perinatal hypoxic-ischemia (HI). Sleep problems, although reported to be associated with cerebral palsy (CP), are often overlooked in non-severe HI patients. Here, by investigating the sleep qualities of children with different degrees of HI, we discovered that sleep initiation and maintenance, sleep-related breathing problems, or circadian rhythmic issues were highly associated with children of moderate or mild HI, respectively. Follow-up MRI studies in 2-year old patients showed that periventricular white matter lesions including periventricular leukomalacia (PVL) were prevalent in moderate, but not mild, HI children. In contrast, the occurrence of pineal cysts had a high risk in children with mild HI. Our study provides novel insights into the mechanisms of distinctive sleep problems associated with children of different degrees of HI, and therefore sheds light on the studies of targeted therapeutic treatments for sleep disorders in children who suffer from HI.

How has our interest in the airway changed over 100 years?

Since the beginning of our specialty, our understanding of the link between function and facial growth and development has progressively improved. Today, we know that children with sleep-related breathing problems will often develop distinctive facial characteristics. In adults, sleep apnea can result in serious morbidity and mortality. Orthodontists can ask sleep-related questions in the health history to help identify sleep breathing disorders. Treating these patients presents unique opportunities for orthodontists to collaborate with other medical specialties to improve a patient's health and treatment outcome. Research presented in our Journal in the next century may shed new light that will help us better identify the problem and aid the specialty in developing more effective evidence-based treatment. Additional efforts are needed to understand the physiology, neurology, and genetics of sleep breathing disorders.

Baroreflex sensitivity and sleep-related breathing problems

“Sleep-related breathing problems” (SRBPs), as a term, encompasses a range of disorders of breathing during sleep. They are all characterized by airway obstruction and disturbance of normal breathing, and such disorders have been associated with altered autonomic function in adults. In this issue of The Journal, Coverdale et al, from the University of Western Ontario and the University of Waterloo, report a study of 106 adolescents where baroreflex sensitivity, a measure of autonomic function, was measured from blood pressure and ECG recordings. Teenagers with the highest scores for SRBP had the lowest baroreflex sensitivity, and this relationship was particularly noted in those with higher body mass index. These are new observations in this age group.Article page 610▶ “Sleep-related breathing problems” (SRBPs), as a term, encompasses a range of disorders of breathing during sleep. They are all characterized by airway obstruction and disturbance of normal breathing, and such disorders have been associated with altered autonomic function in adults. In this issue of The Journal, Coverdale et al, from the University of Western Ontario and the University of Waterloo, report a study of 106 adolescents where baroreflex sensitivity, a measure of autonomic function, was measured from blood pressure and ECG recordings. Teenagers with the highest scores for SRBP had the lowest baroreflex sensitivity, and this relationship was particularly noted in those with higher body mass index. These are new observations in this age group. Article page 610▶ Baroreflex Sensitivity is Associated with Sleep-Related Breathing Problems in AdolescentsThe Journal of PediatricsVol. 160Issue 4PreviewTo examine the relationship between sleep-related breathing problems (SRBPs) and baroreflex sensitivity (BRS) among adolescents and assesses whether body mass influences this relationship. Full-Text PDF

Baroreflex Sensitivity is Associated with Sleep-Related Breathing Problems in Adolescents

To examine the relationship between sleep-related breathing problems (SRBPs) and baroreflex sensitivity (BRS) among adolescents and assesses whether body mass influences this relationship. SRBPs were assessed in 106 adolescents aged 11-14 years using the Pediatric Sleep Questionnaire. Body mass index (BMI) was calculated, and 5 minutes of continuous beat-to-beat blood pressure (Finapres) and R-R interval were recorded (standard electrocardiogram) after 15 minutes of supine rest. Spectral indices were computed using fast Fourier transform, and transfer function analysis was used to compute BRS. Regression analyses indicate an interaction between BMI and SRBPs (b=-.151, P=.015) on BRS. Graphing the interaction showed that those with higher SRBP scores had lower BRS but that this effect was stronger for those with higher BMI. Adolescents with elevated SRBP scores had lower BRS. In addition, higher BMI amplified the risk of higher SRBP scores on BRS.

A community study of sleep bruxism in Hong Kong children: Association with comorbid sleep disorders and neurobehavioral consequences

The prevalence of childhood sleep bruxism (SB) varied from 5% to 46% among various studies. In addition to local facial and dental adverse consequences, accumulating evidence suggests that childhood SB could be associated with comorbid sleep and systemic neurobehavioral disturbances. This study attempted to investigate the prevalence and clinical correlates of SB in a large community sample. This study was part of an ongoing epidemiologic study about sleep problems among Hong Kong Chinese children. A total of 9172 questionnaires were distributed to children of grades 1-6 from 13 randomly selected primary schools. Parents of the children were asked to complete and return the Hong Kong children sleep questionnaire, which aimed to explore the sleep problems and patterns of their children. Six thousand three hundred and eighty-nine questionnaires with valid answers to SB were received and the response rate was 69.7%. The mean age of the recruited children was 9.2±1.8years (50.6%, boys). The prevalence of SB with teeth grinding frequency more than thrice weekly over the past year was 5.9%. SB was more prevalent among boys with decreasing prevalence across age. SB was associated with chronic medical diseases, sleep-related breathing problem, upper respiratory infection, and other parasomnia features, especially sleep talking (OR (95%CI)=4.07 (2.33-7.11)). Children with SB were more likely noticed by their parents to be hyperactive (OR (95%CI)=1.61 (1.25-2.07)) and bad-tempered (OR (95%CI)=1.69 (1.35-2.12)) and had deterioration in their academic performance (OR (95%CI)=1.22(1.03-1.43)). Almost 6% of Hong Kong primary schoolchildren suffered from frequent SB. The condition was most prevalent among young boys. SB was found to be associated with a variety of medical conditions, neuropsychiatric sequelae, and comorbid sleep conditions, especially sleep talking and sleep related breathing problems. Further prospective studies will need to clarify the longitudinal course of childhood SB and its response to treatment.

The close relationship between life-threatening breathing disorders and urine storage dysfunction in multiple system atrophy

Survival of multiple system atrophy (MSA) depends on whether a variety of sleep-related breathing problems as well as autonomic failure (AF) occur. Since the brainstem lesions that cause respiratory and autonomic dysfunction overlap with each other, these critical manifestations might get worse in parallel. If so, the detection of AF, which is comparatively easy, might be predictive of a latent life-threatening breathing disorder. In 15 patients with MSA, we performed autonomic function tests composed of postural challenges and administered a questionnaire on bladder condition, as well as polysomnography and laryngoscopy during wakefulness and under anesthesia. Polysomnographic variables such as the apnea-hypopnea index (AHI) and oxygen saturation (SpO(2)) and the findings of laryngoscopy were compared with the degree of cardiac and urinary autonomic dysfunction. AHI, mean SpO(2) and the lowest SpO(2) showed significant correlations with urine storage dysfunction. In addition, patients with vocal cord abductor paralysis (VCAP) or central sleep apnea (CSA) contributing to nocturnal sudden death had more severe storage disorders than those without. On the other hand, no significant relationship between polysomnographic variables and orthostatic hypotension was observed except in the case of mean SpO(2). These results indicate that life-threatening breathing disorders have a close relationship with AF, and especially urine storage dysfunction. Therefore, longitudinal assessment of deterioration of the storage function might be useful for predicting the latent progress of VCAP and CSA.

On using the pathophysiology of obstructive sleep apnea as a teaching tool

I read with interest the recent article by Dr. Michael Levitzky on using the pathophysiology of obstructive sleep apnea (OSA) to teach cardiopulmonary integration ([2][1]). With 10 years of experience of teaching courses in both respiratory physiology and sleep at the University of Toronto, I also

Alistair John Gordon

<h3>Purpose</h3> Pulmonary arterial hypertension (PAH) has been reported with several rheumatologic diseases; however, it is not common in adult-onset Still9s disease (ASD). We describe a patient with ASD who developed...

Polysomnographic values in adolescents with ataxia telangiectasia

Most adolescents with ataxia telangiectasia (A-T) develop progressive bulbar muscle weakness and decreased pulmonary reserve. The purpose of this study was to define the patterns of sleep and respiration during sleep, and to identify sleep-related breathing problems in subjects with A-T. To address these issues, overnight polysomnography was performed on 12 adolescents with A-T. Eleven of the 12 subjects completed overnight polysomnography. The median age was 16 years (range, 13-20 years). All subjects in the study were wheelchair-bound and the median forced vital capacity (% predicted of normal) was 44% (range, 16-82%). The mean sleep efficiency was 72.6% with a mean apnea hypopnea index (AHI) of 0.7 events/hr (range, 0-2.2). The majority of apnea/hypopneas were REM related. The mean central apnea index was 0.1 events/hr (range, 0-0.2). The mean oxygen saturation nadir was 92.7% (range, 87-96) and the mean peak end-tidal carbon dioxide ET(CO(2) ) value was 53.8 mm Hg (range, 49-60). Two of 11 subjects had ET(CO(2) ) values >or=50 mm Hg for more than 50% of total sleep time. In this study, the majority of A-T adolescents had infrequent partial or complete upper airway obstructions during sleep and minimal nighttime hypoxemia. They did, however, have decreased sleep efficiency most likely, due in part, to their underlying neurological condition. This decrease in total sleep time may underestimate hypoventilation. Based on these findings, overnight polysomnography should be considered in adolescents with A-T, particularly in those in which there is a clinical suspicion of sleep related breathing abnormalities.

Role of inhibitory amino acids in control of hypoglossal motor outflow to genioglossus muscle in naturally sleeping rats.

The hypoglossal motor nucleus innervates the genioglossus (GG) muscle of the tongue, a muscle that helps maintain an open airway for effective breathing. Rapid-eye-movement (REM) sleep, however, recruits powerful neural mechanisms that can abolish GG activity even during strong reflex stimulation such as by hypercapnia, effects that can predispose to sleep-related breathing problems in humans. We have developed an animal model to chronically manipulate neurotransmission at the hypoglossal motor nucleus using in vivo microdialysis in freely behaving rats. This study tests the hypothesis that glycine receptor antagonism at the hypoglossal motor nucleus, either alone or in combination with GABAA receptor antagonism, will prevent suppression of GG activity in natural REM sleep during room air and CO2-stimulated breathing. Rats were implanted with electroencephalogram and neck muscle electrodes to record sleep-wake states, and GG and diaphragm electrodes for respiratory muscle recording. Microdialysis probes were implanted into the hypoglossal motor nucleus for perfusion of artificial cerebrospinal fluid (ACSF) and strychnine (glycine receptor antagonist, 0.1 mM) either alone or combined with bicuculline (GABAA antagonist, 0.1 mM) during room air and CO2-stimulated breathing. Compared to ACSF controls, glycine receptor antagonism at the hypoglossal motor nucleus increased respiratory-related GG activity in room air (P = 0.010) but not hypercapnia (P = 0.221). This stimulating effect of strychnine in room air did not depend on the prevailing sleep-wake state (P = 0.625) indicating removal of a non-specific background inhibitory glycinergic tone. Nevertheless, GG activity remained minimal in those REM sleep periods without phasic twitches in GG muscle, with GG suppression from non-REM (NREM) sleep being > 85 % whether ACSF or strychnine was at the hypoglossal motor nucleus or the inspired gas was room air or 7 % CO2. While GG activity was minimal in these REM sleep periods, there was a small but measurable increase in GG activity after strychnine (P < 0.05). GG activity was also minimal, and effectively abolished, in the REM sleep periods without GG twitches with combined glycine and GABAA receptor antagonism at the hypoglossal motor nucleus. We conclude that these data in freely behaving rats confirm that inhibitory glycine and GABAA receptor mechanisms are present at the hypoglossal motor nucleus and are tonically active, but that such inhibitory mechanisms make only a small contribution to the marked suppression of GG activity and reflex responses observed in periods of natural REM sleep.

Sleep Abnormalities Associated with Neuromuscular Disease: Pathophysiology and Evaluation

The development of respiratory failure is common in patients with neuromuscular disorders that involve the respiratory muscles. However, the high incidence of sleep-related breathing problems in this population is less well known. In patients with neuromuscular disease, nocturnal breathing abnormalities frequently precede respiratory failure during wakefulness by months or even years. These nocturnal breathing problems are caused by multiple factors, including diaphragm and upper airway muscle weakness, scoliosis, obesity, and central respiratory control problems. Advances in the understanding of the links between sleep-disordered breathing and the development of daytime dysfunction and respiratory failure has revolutionized the management of these individuals. Mask positive pressure therapy is now available to improve both quality of life and longevity for these individuals. The lack of correlation between daytime testing and the severity of nocturnal breathing abnormalities makes it difficult to predict the presence of sleep-disordered breathing. Further, patients may not always be aware of symptoms associated with sleep-disordered breathing, even if specifically questioned. However, simple bedside measurements of vital capacity and inspiratory muscle strength can provide useful guides for when nocturnal respiratory monitoring is indicated.

Sleep disorders: a risk factor for pseudotumor cerebri?

To determine whether sleep-related breathing disorders are common in patients with idiopathic intracranial hypertension. Medical records of 53 patients with idiopathic intracranial hypertension from a tertiary center neuroophthalmology practice were reviewed. Thirty-seven patients were identified who had a history of snoring, difficulty sleeping, or daytime somnolence. The data from polysomnograms were tabulated to determine the frequency of apneas, hypopneas, and arousals. Fourteen of 37 patients with idiopathic intracranial hypertension and symptoms of sleep disturbance underwent polysomnography. There were two men and 12 women varying in age from 24 to 58 years (mean, 39.4 +/- 11.9). These patients were obese with body mass indexes varying from 33.0 to 63.2 (mean, 46.0 +/- 9.5). A diagnosis of sleep apnea was made in six and upper airway resistance syndrome in seven patients. Sleep-related breathing problems were common in our patients with idiopathic intracranial hypertension. Obesity was common in these patients and may be playing a causative role in sleep apnea and idiopathic intracranial hypertension. It is suggested that idiopathic intracranial hypertension patients who have symptoms of sleep disturbance should be further evaluated for the presence of sleep-related breathing problems.

Nocturnal problems in postpolio syndrome: sleep apnea symptoms and nocturia.

Nocturia, generally accepted as an inevitable consequence of aging, is also a symptom of a potentially lethal condition--obstructive sleep apnea (OSA). The descriptive study reported in this article examined nocturia and sleep-related breathing problems in persons with postpolio syndrome (PPS) and tested the Sleep Disordered Breathing--Nocturia Model. This model describes the cascade of events that results in polyuria in persons with sleep-related breathing disorders. Data were analyzed with descriptive and inferential statistics. A 34-item questionnaire was published in the newsletter of a national polio support group, and the 584 respondents constituted a convenience sample. The results showed statistically significant associations between OSA symptoms, nocturia, poor sleep quality, daytime sleepiness, lower urinary tract symptoms, naps, and decreased self-rated health. Study limitations were the use of a convenience sample and possible self-selection of persons with more severe sleep and bladder problems. The results support the model and document how nocturia and sleep disturbances negatively impact persons with PPS.

A questionnaire survey of sleep and night-time behaviour in a community-based sample of adults with intellectual disability.

Two hundred and five people with intellectual disability, aged 18 years or over, and living in health- or social-services-managed community housing, completed sleep and behaviour questionnaires. An 85.7% return rate was achieved. Settling problems were present in 26.8% and night waking in 55.6% of the subjects. Parasomnias were present in 14% of subjects and 15% of the sample showed some features associated with sleep-related breathing problems. Factors associated with sleep-related problems included gender, aetiology of intellectual disability, epilepsy, treatment with antiepileptic medication, evening caffeine consumption, nocturnal urinary incontinence and ability to communicate. Significant sleep-related problems were demonstrated in this population; some of these problems might be avoided by simple measures.

SLEEP AND DEGENERATIVE NEUROLOGIC DISORDERS

This article summarizes sleep disturbances in a variety of neuro-degenerative diseases, including Parkinson's disease, multiple system atrophy, and amyotrophic lateral sclerosis. Sleep complaints in these conditions include insomnia, hypersomnia, abnormal motor activity and behavior during sleep, sleep-related breathing problems, and circadian rhythm sleep disturbances. Clinical examination followed in selected cases by polysomnographic, multiple sleep latency, and other laboratory tests is essential for correct diagnosis and treatment of these sleep disturbances.

Posttraumatic excessive daytime sleepiness: a review of 20 patients.

Twenty patients complaining of excessive daytime somnolence (EDS) secondary to significant head trauma were studied objectively. Several polygraphic recording protocols were performed over the 12-year study period. Eighteen of the 20 patients were objectively sleepy, 8 of them presented mixed sleep apnea syndrome that fragmented their sleep, 5 patients' sleep-related breathing problems improved over time, 9 patients presented daytime somnolence, and 1 reported abrupt bouts of muscle weakness and had two sleep onset rapid eye movement (REM) periods during daytime testing. Cerebrospinal fluid analysis for specific neurotransmitter metabolites' evaluation, pre- and postprobenecid, did not differentiate posttraumatic EDS patients from narcoleptics or other patients with EDS. Two patients (one with organic brain syndrome, the other depressed) reported subjective sleepiness, not confirmed by objective data. Objective testing in posttraumatic sleepiness is recommended because of the plurality of problems and medicolegal implications.