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Study objectivesUpper airway collapsibility is a key determinant of obstructive sleep apnea (OSA) which can influence the efficacy of certain non-continuous positive airway pressure (CPAP) treatments for OSA. However, there is no simple way to measure this variable clinically. The present study aimed to develop a clinically implementable tool to evaluate the collapsibility of a patient's upper airway.MethodsCollapsibility, as characterized by the passive pharyngeal critical closing pressure (Pcrit), was measured in 46 patients with OSA. Associations were investigated between Pcrit and data extracted from patient history and routine polysomnography, including CPAP titration.ResultsTherapeutic CPAP level, demonstrated the strongest relationship to Pcrit (r2=0.51, p < .001) of all the variables investigated including apnea-hypopnea index, body mass index, sex, and age. Patients with a mildly collapsible upper airway (Pcrit ≤ -2 cmH2O) had a lower therapeutic CPAP level (6.2 ± 0.6 vs. 10.3 ± 0.4 cmH2O, p < .001) compared to patients with more severe collapsibility (Pcrit > -2 cmH2O). A therapeutic CPAP level ≤8.0 cmH2O was sensitive (89%) and specific (84%) for detecting a mildly collapsible upper airway. When applied to the independent validation data set (n = 74), this threshold maintained high specificity (91%) but reduced sensitivity (75%).ConclusionsOur data demonstrate that a patient's therapeutic CPAP requirement shares a strong predictive relationship with their Pcrit and may be used to accurately differentiate OSA patients with mild airway collapsibility from those with moderate-to-severe collapsibility. Although this relationship needs to be confirmed prospectively, our findings may provide clinicians with better understanding of an individual patient's OSA phenotype, which ultimately could assist in determining which patients are most likely to respond to non-CPAP therapies.

Weight loss is one of the first line treatments for people with obstructive sleep apnea (OSA); however, people with OSA may have difficulties losing weight. Few studies have investigated the factors underlying these challenges in people with OSA. The aim of this study was to compare dietary intake, eating behavior and physical activity data in people with OSA and without OSA. Seventy-four patients referred to a sleep disorders clinic for suspected OSA underwent a standard clinical overnight polysomnography and completed questionnaires assessing dietary intake, physical activity and eating behavior prior to treatment. On the Three Factor Eating Questionnaire-R18 patients with OSA (n = 49, AHI 19.5 [13.0–55.4] events/h) had higher levels of uncontrolled eating (adjusted means, 19.7 (0.7) vs 16.1 (1.0): F (1, 69) = 7.103, p = 0.010 partial η2 = 0.093), than those who did not have OSA (n = 25, AHI 3.3 [0.8–4.4] events/h) after adjusting for age, fat mass % and depression. There were no differences between groups in dietary intake measures or physical activity. These results suggest that people with OSA may need specific attention to eating behavior when undergoing weight loss interventions. [ABSTRACT FROM AUTHOR]

Rationale: Unstable ventilatory control (high loop gain) is a causal factor in the development of obstructive sleep apnea. Methods for quantifying loop gain using polysomnography have been developed that predict favorable responses to upper airway surgery. However, this method is reliant on respiratory event scoring and hence may be affected by hypopnea scoring criteria.Objectives: To determine to what extent differences in hypopnea scoring influence loop gain measurement.Methods: We performed a retrospective analysis of 46 polysomnograms before and after upper airway surgery. Polysomnograms were rescored according to three different American Academy of Sleep Medicine hypopnea definitions (2007Alternative, 2012Recommended, and 2012Acceptable criteria). Loop gain and apnea-hypopnea indexes (AHIs) were compared between criteria using linear regression and Bland-Altman limits of agreement (LOA). Responders to surgery were classified by a 50% or greater reduction in AHI and AHIpostsurgery less than 10 events per hour. Responders were determined separately for each American Academy of Sleep Medicine criterion. Receiver operating characteristic curve analysis predicting surgical outcome was performed for each loop gain measurement derived from each criterion.Results: A near-perfect agreement was found between loop gains derived using the 2007Alternative and 2012Recommended criteria (r2 = 0.99; bias = -0.003; LOA, -0.016 to 0.010). Greater variability was found for 2012Acceptable compared to the 2007Alternative (r2 = 0.70; bias = -0.015; LOA, -0.099 to 0.070) and 2012Recommended (r2 = 0.69; bias = +0.018; LOA, -0.068 to 0.104) criteria. Both 2007Alternative and 2012Recommended loop gains significantly predicted surgical response with similar areas under the curve (AUCs; 2007Alternative AUC = 0.86 [95% confidence interval (CI), 0.75-0.97]; 2012Recommended AUC = 0.84 [95% CI, 0.71-0.97]). 2012Acceptable loop gains were a poor predictor of surgical response (AUC = 0.62 [95% CI, 0.43-0.80]).Conclusions: Loop gain measured noninvasively by polysomnography can be influenced by respiratory event scoring. We recommend caution when using the 2012Acceptable criteria with this method, because such findings may not be directly generalizable to other loop gain values derived from other scoring criteria. [ABSTRACT FROM AUTHOR]

Supine related obstructive sleep apnea (OSA) is the most common clinical and physiological phenotype of OSA. This condition is recognizable by patients, their families and through polysomnographic recordings. Commonly used definitions distinguish the presence of supine related OSA when respiratory events occur at twice the frequency when the patient lies in the supine compared to non-supine sleeping positions. Recent physiology studies have demonstrated that airway obstruction arises more commonly in the supine position particularly at the level of the soft palate and epiglottis. Increased airway collapsibility is reliability observed supine relative to lateral position. To a lesser extent, changes in control of breathing favour less stable ventilation when the supine sleeping posture is adopted. Many treatments have been developed and trialled to help patients avoid sleeping on their back. The last 10 years has seen the emergence of vibrotactile warning devices that are worn on the patients' neck or chest. High quality randomized controlled trial data is accumulating on the efficacy and common pitfalls of the application of these treatments. [ABSTRACT FROM AUTHOR]

Despite substantial disease burden, existing evidence on the risk factors for obstructive sleep apnea (OSA) have been derived primarily from cross-sectional studies without determining temporality. Therefore, we aimed to systematically synthesize the literature on longitudinal risk factors for sleep study-assessed OSA and questionnaire-assessed probable OSA from cohort studies in the general adult population settings. We systematically searched Embase and Medline (on OVID) databases. Eleven studies met the inclusion criteria. Meta-analyses were not conducted due to methodological heterogeneity of exposure and outcome measurements. There was consistent evidence that weight gain was associated with incident (n = 2) and greater severity (n = 2) of OSA. One study each observed an association of higher baseline body-mass index, male sex, asthma, a specific genetic polymorphism in rs12415421 , and insulin resistance/hyperglycemia, with incident OSA. Long-term exposure to ambient air pollution (NO 2 , n = 1) was associated with OSA, and menopausal transitions (n = 1) with higher apnea-hypopnea index. There were no eligible studies on long-term smoking or alcohol use. In conclusion, approximately 10% increase in weight, especially in males, might alert clinicians to consider potential or worsening OSA. Large, well-designed longitudinal studies are needed to consolidate knowledge on other associations with OSA development, especially on potentially modifiable risk factors. [ABSTRACT FROM AUTHOR]

This review aimed to determine the effectiveness of positional modification techniques in preventing supine sleep, sleep-disordered breathing and other clinically important outcomes in patients with supine obstructive sleep apnea (OSA). Randomized controlled trials comparing positional modification techniques with any other therapy or placebo were included. Electronic searches of databases including CENTRAL, MEDLINE, CINAHL, Embase, and Web of Science up to April 2016 were performed. Meta-analysis was undertaken where possible. This comprehensive meta-analysis found benefit for positional modification techniques in those with supine OSA in terms of reduction in apnea-hypopnea index (AHI) and time spent supine. Whilst positional modification techniques were effective in terms of a reduction in AHI, continuous positive airway pressure (CPAP) was more effective than these techniques. A reliable diagnosis of supine OSA should be considered, and further research is required on patient-centred outcomes including comfort, barriers to adherence, cost-analysis, and long term outcomes including the effect on cardiovascular disease, the metabolic syndrome, and insulin resistance. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea (OSA) is one of the most common comorbidities in patients with interstitial lung disease (ILD). Growing evidence highlights the significance of sleep disturbance on health outcomes in this population. The relationships between ILD and OSA are complex and possibly bidirectional, with multiple mechanisms postulated for the pathogenic and physiologic links. This review synthesizes current evidence and hypotheses regarding different aspects of the relationships between ILD and OSA, emphasizing the interactions between epidemiology, pathogenesis, and pathophysiology. [ABSTRACT FROM AUTHOR]

Recent evidence suggests that air pollution exposure may be a contributing risk factor for obstructive sleep apnea (OSA), however, current evidence is conflicting. This systematic review aims to determine the association between air pollution and OSA in the general population, and examine for potential effect modification by seasonality, temperature and humidity. Five full-text articles were included in the review out of 905 articles found by systematically searching PubMed, Embase and Scopus databases. The included studies were limited to OSA in adults that were conducted in middle to high-income countries. The results highlight heterogeneity in the diagnostic criteria for OSA and method used to assess air pollution exposure. There is some evidence to support a relationship between air pollution exposure and OSA. However, the duration of exposure to different air pollutants including particulate matter (PM2.5 and PM10) and nitric oxides (NO2) in relation to OSA varied across different seasons, temperatures, and countries. This variability of the pollutants across studies warrants a more robust study design using time-series analysis with multiple follow-ups to strengthen the evidence for this relationship before considering its implications. [ABSTRACT FROM AUTHOR]

Objective: This meta-analysis of randomized controlled trials (RCTs) evaluates if treating sleep disturbances improves cognitive function over at least 12 weeks.Methods: Multiple data sources were searched until November 1, 2021. RCTs were included if they examined the effect of an intervention (behavioral or medical) on sleep and cognition in an adult sample with sleep disturbances and had an intervention duration and follow-up of at least 12 weeks. Two independent reviewers located 3784 studies; 16 satisfied the inclusion criteria. Primary outcomes included the broad cognitive domains of visual processing, short-term memory, long-term storage and retrieval, processing speed, and reaction time.Results: Most trials were conducted in participants with obstructive sleep apnea (OSA; N = 13); the most studied intervention was continuous positive airway pressure (CPAP; N = 10). All RCTs were 12 months in duration or less. The estimates of mean pooled effects were not indicative of significant treatment effect for any primary outcome. Although the interventions reduced daytime sleepiness (Hedge's g, 0.51; 95% confidence interval, 0.29-0.74; p < 0.01), this did not lead to cognitive enhancement.Conclusions: Overall, there was insufficient evidence to suggest that treating sleep dysfunction can improve cognition. Further studies with longer follow-up duration and supporting biomarkers are needed. [ABSTRACT FROM AUTHOR]

Short pauses or “transition-periods” at the end of expiration and prior to subsequent inspiration are commonly observed during sleep in humans. However, the role of transition periods in regulating ventilation during physiological challenges such as partial airway obstruction (PAO) has not been investigated. Twenty-nine obstructive sleep apnea patients and eight controls underwent overnight polysomnography with an epiglottic catheter. Sustained-PAO segments (increased epiglottic pressure over ≥5 breaths without increased peak inspiratory flow) and unobstructed reference segments were manually scored during apnea-free non-REM sleep. Nasal pressure data was computationally segmented into inspiratory (T I , shortest period achieving 95% inspiratory volume), expiratory (T E , shortest period achieving 95% expiratory volume), and inter-breath transition period (T Trans , period between T E and subsequent T I ). Compared with reference segments, sustained-PAO segments had a mean relative reduction in T Trans (−24.7 ± 17.6%, P < 0.001), elevated T I (11.8 ± 10.5%, P < 0.001), and a small reduction in T E (−3.9 ± 8.0, P ≤ 0.05). Compensatory increases in inspiratory period during PAO are primarily explained by reduced transition period and not by reduced expiratory period. [ABSTRACT FROM AUTHOR]