Factors In Obstructive Sleep Apnea Research Articles

Do traditional risk factors for obstructive sleep apnea vary by race among U.S. veterans?

Do traditional risk factors for obstructive sleep apnea vary by race among U.S. veterans?

A first look at childhood abuse in women with obstructive sleep apnea

Study objectivesWomen who experienced childhood sexual abuse have higher rates of obesity, a risk factor for obstructive sleep apnea (OSA). We assessed if prior childhood sexual abuse was more common in women with OSA vs. those in the control group, with possible mediation by obesity.MethodsIn a secondary analysis of a larger project, we studied 21 women with OSA (age mean ± SD 59 ± 12 years, body mass index [BMI] 33 ± 8 kg/m2, respiratory event index [REI] 25 ± 16 events/hour, and Epworth Sleepiness Scale [ESS] score 8 ± 5) and 21 women without OSA (age 53 ± 9 years, BMI 25 ± 5 kg/m2, REI [in 7/21 women] 1 ± 1 events/hour, and ESS score, 5 ± 3). We evaluated four categories of trauma (general, physical, emotional, and sexual abuse) with the Early Trauma Inventory Self-Report–Short Form (ETISR-SF). We assessed group differences in trauma scores with independent samples t-tests and multiple regressions. Parametric Sobel tests were used to model BMI as a mediator for individual trauma scores predicting OSA in women.ResultsEarly childhood sexual abuse reported on the ETISR-SF was 2.4 times more common in women with vs. without OSA (p = 0.02 for group difference). Other trauma scores were not significantly different between women with and without OSA. However, BMI was a significant mediator (p = 0.02) in predicting OSA in women who experienced childhood physical abuse.ConclusionChildhood sexual abuse was more common in women with vs. without OSA. BMI was a mediator for OSA of childhood physical but not sexual abuse. This preliminary hypothesis-generating study suggests that there may be physiological impacts of childhood trauma in women that predispose them to OSA.

Characterization of risk factors for obstructive sleep apnea and its association with absenteeism among nurses.

To characterize risk factors associated with obstructive sleep apnea (OSA) and its relationship with nurses' absenteeism. A cross-sectional study was conducted from 2018 to 2020 at a 1,000-bed academic hospital complex and biomedical research facility in Tehran, Iran. Participants were selected through consecutive sampling after obtaining ethical approval and informed consent. Data on demographics, medical conditions, occupational characteristics, and absenteeism were collected through face-to-face interviews. The STOP-Bang questionnaire was utilized to assess the probability of OSA. Statistical tests included the Mann-Whitney U, t-test, Chi-square, and multivariable regression. In this study involving 304 nurses, the majority were female (81.3%), with an average age of 35. About 27 participants (8.9%) had a high probability of OSA, with male sex, older age, higher body mass index, neck circumference, and diastolic BP identified as the main determinants of OSA. Additionally, shift work and night shifts were associated with increased absenteeism, while sex showed no significant association with absenteeism rates among nurses. Male sex, neck circumference (obesity), night shifts, and diastolic BP can predict OSA risk. However, unauthorized absence from work is not associated with a high risk for OSA (STOP-BANG ≥3) or the individual risk factors of OSA.

Tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig.

Obesity is a common finding and a major pathogenetic factor in obstructive sleep apnea (OSA) in adults. To understand the mechanisms behind this, the present study investigated the tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig model. In 4 verified obese/OSA and 3 non-obese/non-OSA control minipigs, MRI fat-weighted images, ultrasound elastography (USE), and sleep video-fluoroscopy (SVF) were performed to quantify the fat composition, tissue stiffness, and respiratory kinematics of the tongue base and soft palate during sedated sleep. The results indicated that the fat composition gradually increased from the rostral to caudal tongue base, particularly in the posterior 1/3 of the tongue base, regardless of the presence of obesity and OSA. However, this trend was not seen in the soft palate and pharyngeal wall. The pharyngeal wall presented the highest fat composition as compared with the tongue base and soft palate. Overall, obese OSA minipigs showed stiffer tongue tissue than the controls, particularly in the rostral region of the tongue in obese Yucatan minipigs. The respiratory moving ranges of the soft palate were greater in both dorsal-ventral and rostral-caudal directions and during both respiratory and expiratory phases in OSA obese than control minipigs, and the largest moving ranges were seen in OSA obese Panepinto minipigs. The moving range of the tongue base was significantly smaller. These results suggest more fat infiltration in the caudal region of the tongue base regardless of the presence of obesity and/or OSA. The greater tissue stiffness of the tongue in obese OSA minipigs may result from altered neuromuscular drive.

The Impact of Ankyloglossia Beyond Breastfeeding: A Scoping Review of Potential Symptoms.

The purpose of this study was to evaluate the spectrum of pediatric quality-of-life sequelae associated with ankyloglossia that may affect children who do not undergo tongue-tie release (frenotomy) during infancy. This study contains data from PubMed, Embase, CINAHL, PsycINFO, Web of Science, and Google Scholar (1961-January 2023). The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews reporting guidelines. Experimental and observational studies were eligible if they reported baseline outcomes associated with ankyloglossia in children above a year of age. Two reviewers independently screened studies, extracted data, and assessed quality. Low-quality studies were excluded. Twenty-six of 1,568 screened studies (> 1,228 patients) were included. Six studies were high quality and 20 were medium quality. Studies identified various symptoms that may be partially attributable to ankyloglossia after infancy, including speech/articulation difficulties, eating difficulties, dysphagia, sleep-disordered breathing symptoms, dental malocclusion, and social embarrassment such as oral hygiene issues. Multiple comparative studies found associations between ankyloglossia and risk factors for obstructive sleep apnea; a randomized controlled trial found that frenotomy may attenuate apnea severity. Ankyloglossia may also promote dental crowding. Ankyloglossia may be associated with myriad effects on children's quality of life that extend beyond breastfeeding, but current data regarding the impact are inconclusive. This review provides a map of symptoms that providers may want to evaluate as we continue to debate the decision to proceed with frenotomy or nonsurgical therapies in children with ankyloglossia. A continuing need exists for controlled efficacy research on frenotomy for symptoms in older children and on possible longitudinal benefits of early frenotomy for maxillofacial development. https://doi.org/10.23641/asha.23900199.

Protocol for a pragmatic trial testing a self-directed lifestyle program targeting weight loss among patients with obstructive sleep apnea (POWER Trial)

BackgroundObesity comprises the single greatest reversible risk factor for obstructive sleep apnea (OSA). Despite the potential of lifestyle-based weight loss services to improve OSA severity and symptoms, these programs have limited reach. POWER is a pragmatic trial of a remote self-directed weight loss care among patients with OSA. MethodsPOWER randomizes 696 patients with obesity (BMI 30–45 kg/m2) and recent diagnosis or re-confirmation of OSA 1:1 to either a self-directed weight loss intervention or usual care. POWER tests whether such an intervention improves co-primary outcomes of weight and sleep-related quality of life at 12 months. Secondary outcomes include sleep symptoms, global ratings of change, and cardiovascular risk scores. Finally, consistent with a hybrid type 1 approach, the trial embeds an implementation process evaluation. We will use quantitative and qualitative methods including budget impact analyses and qualitative interviews to assess barriers to implementation. ConclusionsThe results of POWER will inform population health approaches to the delivery of weight loss care. A remote self-directed program has the potential to be disseminated widely with limited health system resources and likely low-cost.

Prevalence and Risk Factors of Obstructive Sleep Apnea among Patients Attending Tertiary Care Teaching Hospital in Odisha, India: A Retrospective Observational Study

Background: Although obstructive sleep apnea is the most common sleep-disordered breathing, there are fewer studies estimating the prevalence of OSA and its risk factors in urban and rural populations in Odisha. Objective: To estimate the prevalence and risk factors of obstructive sleep apnea in a tertiary care teaching hospital in Odisha, India. Method: It is an observational, retrospective study that was conducted in a sleep study lab for a duration of 4 years (January 2016 to December 2019) by the Department of Physiology and Department of Pulmonology of a tertiary care teaching hospital in Odisha. Patients were first screened for high-risk sleep apnea disorder by the Berlin questionnaire, and then they underwent a level 1 sleep study. Results: Total study patients were 1423, of whom 718 and 705 were from urban and rural areas. The mean age of urban and rural patients was 50.81±12.5 years and 51.63±15.3 years, respectively. The prevalence of OSA in urban areas by AHI criteria was 5.9%, and in rural areas it was 4.9%. The mean AHI of urban OSA patients was 37.86±23.46 and that of rural patients was 16.96±13.8. Conclusion: The prevalence of OSA was higher in urban areas than in rural areas. Both BMI and NC were higher for urban patients than for rural patients. The risk factors were mainly diabetes mellitus and hypertension.

A nationwide study on the prevalence and contributing factors of obstructive sleep apnea in Iran

Reliable obstructive sleep apnea (OSA) prevalence information in Iran is lacking due to inconsistent local study results. To estimate OSA prevalence and identify clinical phenotypes, we conducted a nationally representative study using multi-stage random cluster sampling. We recruited 3198 individuals and extrapolated the results to the entire Iranian population using complex sample survey analyses. We identified 3 clinical phenotypes as “sleepy,” “insomnia,” and “restless legs syndrome (RLS).” The prevalence of OSA was 28.7% (95%CI: 26.8–30.6). The prevalence of “sleepy,” “insomnia,” and “RLS” phenotypes were 82.3%, 77.8%, and 36.5% in women, and 64.8%, 67.5%, and 17.9% in men, respectively. “Sleepy” and “insomnia” phenotypes overlapped the most. Age (OR: 1.9), male sex (OR: 3.8), BMI (OR: 1.13), neck circumference (OR: 1.3), RLS (OR: 2.0), and insomnia (OR: 2.3) were significant OSA predictors (p-values: 0.001). In men, “sleepy” phenotype was associated with youth and unmarried status but not in women. The “insomnia” phenotype was associated with shorter sleep duration in women; cardiovascular diseases (CVD), urban residency, and shorter sleep duration in men. “RLS” phenotype was associated with shorter sleep duration and CVD in women and older age, lower educational level, CVD, and hypertension in men. The findings point to the need for funding of OSA screening in Iran, for a different assessment of men and women, and for future sleep research to consider overlapping phenotypes.

Association of adiposity with risk of obstructive sleep apnea: a population-based study

BackgroundObesity is a crucial risk factor for obstructive sleep apnea (OSA), but the association between adiposity deposition and OSA risk has not reached a consistent conclusion. This study sought to reveal the association of multiple adiposity indicators with OSA risk.MethodsThis cross-sectional study included 9,733 participants aged 35–74 years, recruited from an ongoing population-based cohort. OSA was assessed by the Berlin Questionnaire. Six adiposity indicators, including neck circumference (NC), body fat percentage (BF%), waist-to-hip ratio (WHR), visceral adiposity index (VAI), lipid accumulation product (LAP), and resting metabolic rate (RMR), were selected. Multivariate logistic regression models were used to examine the association of adiposity indicators with OSA risk.ResultsOne thousand six hundred twenty-six participants (16.71%) were classified into the OSA group. NC, BF%, WHR, VAI, LAP, and RMR were all positively associated with the risk of OSA after adjusting for confounders, regardless of age, sex, and history of dyslipidemia. Every 1-unit increment of NC, BF%, and VAI was associated with a 13%, 9%, and 14% increased risk of OSA, respectively; every 0.01-unit increment of WHR was associated with a 3% increased risk of OSA; every 10-unit increment of LAP and RMR was associated with 2% and 4% increased risk of OSA, respectively.ConclusionsNC, BF%, WHR, VAI, LAP, and RMR were all independently and positively associated with OSA risk, regardless of age, sex, history of dyslipidemia, and menopausal status. Application of these new indicators could help to more comprehensively reflect and predict the risk of OSA in the general population.

Associations of fine particulate matter exposure with sleep disorder indices in adults and mediating effect of body fat

Exposure to particulate matter (PM) may be a risk factor for obstructive sleep apnea (OSA) and obesity. However, whether body fat accumulation exerts mediating effects on the association between air pollutant exposure and OSA aggravation remains unclear.This study retroactively acquired the polysomnographic data (sleep variables) and body composition information from 2893 patients in a northern Taiwan sleep center. The levels of exposure to various air pollutants were estimated using an adjusted method based on data from governmental air quality monitoring stations near registered residential addresses instead of only referencing the nearest station. The sleep disorder indices and body fat metrics, which served as the outcomes of interest, were transformed using the Box-Cox transformation. Multiple linear regression models and causal mediation analysis were employed to investigate the associations between the analyzed parameters and the estimated air pollutant exposure at various time scales (1-, 6-, and 12-month).Significant associations were observed between the increased interquartile range (IQR) of short-term (1-month) exposure to PM ≤ 10 μm (PM10), PM ≤ 2.5 μm (PM2.5), and the apnea–hypopnea index (AHI), oxygen desaturation index (ODI), and arousal index (ArI). Short-term (1-month) exposure to PM10 and PM2.5 was significantly associated with increased trunk fat percentage. Causal mediation analysis revealed that short-term (1-month) exposure to PM10 and PM2.5 affected trunk fat percentage, thereby partially meditating the elevations in AHI, ODI, and ArI.PM exposure may directly increase sleep disorder indices and alter body fat, thereby mediating the worsening of OSA manifestations (i.e., increased AHI, ODI, and ArI).

Associations between air pollution, intracellular-to-extracellular water distribution, and obstructive sleep apnea manifestations.

Exposure to air pollution may be a risk factor for obstructive sleep apnea (OSA) because air pollution may alter body water distribution and aggravate OSA manifestations. This study aimed to investigate the mediating effects of air pollution on the exacerbation of OSA severity through body water distribution. This retrospective study analyzed body composition and polysomnographic data collected from a sleep center in Northern Taiwan. Air pollution exposure was estimated using an adjusted nearest method, registered residential addresses, and data from the databases of government air quality motioning stations. Next, regression models were employed to determine the associations between estimated air pollution exposure levels (exposure for 1, 3, 6, and 12 months), OSA manifestations (sleep-disordered breathing indices and respiratory event duration), and body fluid parameters (total body water and body water distribution). The association between air pollution and OSA risk was determined. Significant associations between OSA manifestations and short-term (1 month) exposure to PM2.5 and PM10 were identified. Similarly, significant associations were identified among total body water and body water distribution (intracellular-to-extracellular body water distribution), short-term (1 month) exposure to PM2.5 and PM10, and medium-term (3 months) exposure to PM10. Body water distribution might be a mediator that aggravates OSA manifestations, and short-term exposure to PM2.5 and PM10 may be a risk factor for OSA. Because exposure to PM2.5 and PM10 may be a risk factor for OSA that exacerbates OSA manifestations and exposure to particulate pollutants may affect OSA manifestations or alter body water distribution to affect OSA manifestations, mitigating exposure to particulate pollutants may improve OSA manifestations and reduce the risk of OSA. Furthermore, this study elucidated the potential mechanisms underlying the relationship between air pollution, body fluid parameters, and OSA severity.

Impact of Obstructive Sleep Apnea on Health-Related Quality of Life in Patients With Partial Laryngectomy for Laryngeal Cancer.

Objectives: To evaluate the possible risk factors of obstructive sleep apnea (OSA) and its impact on the health-related quality of life (HRQoL) in patients with partial laryngectomy for laryngeal cancer. Methods: A cross-sectional method was used to carry out this study. Patients who underwent partial laryngectomy for laryngeal cancer completed overnight polygraphy (PG) home sleep tests and quality of life questionnaires. The Medical Outcome Study 36-item Short-Form Health Survey (SF-36) questionnaire was used to investigate the factors influencing HRQoL. Results: A total of 59 patients completed the PG tests and quality of life questionnaires, with 74.6% demonstrating evidence of OSA. There were significant differences in tumor area and neck dissection between OSA group and non-OSA groups. Based on sleep-related parameters, patients were divided into cluster 1 (n = 14) and cluster 2 (n = 45) using principal component analysis combined with K-means clustering. Two clusters had significantly different scores of body pain, general health, and health transition in SF-36 domains. Independent factors associated with general health were identified as tobacco use (OR = 4.716), alcohol use (OR = 3.193), and OSA-related condition (OR = 11.336). Conclusions: Larger tumor area and neck dissection might be associated with an increased risk for developing OSA in patients with partial laryngectomy for laryngeal cancer. OSA partially mediated the effect on physical health, including body pain, general health, and health transition. It is important to be aware of the potential impact of OSA on diminished HRQoL of these patients.

P29: Snore Vibro-acoustic Platelet Activation: A Thrombotic Risk Factor in Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is a common disease state with prevalence in the U.S. of near 25%. of the population, characterized by snoring and apnea. Beyond intermittent hypoxemia, OSA imparts increased risk of myocardial infarction (MI) and stroke (CVA), both driven by thrombosis and thromboembolism. Central in thrombosis is platelet activation, traditionally felt to driven by biochemical agonists. We explored the possibility that mechanical vibration generated by OSA snore is also a driver of platelet activation. We hypothesized that OSA snore frequency components induce vibration capable of platelet activation. Here we characterized 1. the frequency content of OSA snore and 2. the effect of specific frequencies ranges on platelet activation, and 3. the optoacoustic vibration pattern generated by snore frequency components. Methods: Snore from OSA patients was recorded in a sleep lab. A snore emulator device (speaker platform) was constructed allowing exposure of human gel filtered platelets to snore via placement on a stage transmitting sound and associated vibration, at clinical sound intensity. Snore was analyzed as to sound frequency content. Gel filtered platelet were exposed to snore sound bandwidths (100 – 1000 Hz.) for 40 min (identical intensities) with activation assessed by thrombin generation (PAS assay). Snore vibration was characterized via assessment of optoacoustic fluid wave patterns generated. Results: OSA snore vibration led to definitive platelet activation. Notably, low frequency snore bandwidths induced greater degrees of activation than high frequency exposure - 53.26% activation at 300 hz vs. 13.44% at 900 hz. (Fig. 1a). Low frequency bandwidths induced noticeably greater fluid oscillation than high frequency bandwidth exposure. (Fig. 1b). Conclusion: OSA snore is capable of inducing vibrations which impart adequate mechanical energy to fluid to induce platelet activation. Within snore, specific frequency bandwidths, i.e. low frequencies, appear to be more activating than others. Correlating with platelet activation is detectable visual fluid disturbance which may be characterized via opto-acoustic patterns. Modulation of sound and vibration associated with OSA snore may offer opportunity as a means of limiting thrombotic consequences and adverse events associated with OSA.

0568 Trends in OSA Disease Severity Over Nearly Two Decades: Update on the VA San Diego Experience

Abstract Introduction The Veterans Health Administration (VA) is one of the largest integrated healthcare systems in the United States. Key risk factors for obstructive sleep apnea (OSA) include aging, weight, and male gender, all of which are highly prevalent in the VA population and help to explain the higher rates of OSA in the VA. The Pulmonary Sleep Program at the VA San Diego Healthcare System (VASDHS) started a patient database over twenty years ago for its home sleep apnea testing (HSAT) program. An analysis of ten years of diagnostic HSAT data was reported on over 12,500 patients in 2014. This analysis focuses on an update on the last four years and a comparison to 2014. Methods A retrospective review of the local clinical database of HSAT diagnostic testing was conducted. The database contained 8,928 sleep studies from 2018 to 2022. Invalid studies were removed. Only initial diagnostic studies were included. Results Of the 8,928 diagnostic studies, 2,564 tested negative for OSA (28.7%). Of the 6,364 positive cases, 43.3% were mild, 28.8% were moderate, and 27.9% were severe. The percentages of each OSA severity level were stable across these years (mild: 42%-45%; moderate: 27%-32%; and severe: 26%-29%). The mean AHI did not significantly change from 2018 (24.1+/-20.6) to 2022 (25.1+/-21.2) (overall mean 24.4+/-20.3; range: 5-140). Conclusion Based on this extensive retrospective review of diagnostic testing at a single, high-volume HSAT program, it appears that OSA severity levels have stabilized over these past five years, with the highest percentage of mild OSA cases (~43%) followed by moderate (~29%) and severe (~28%). Our facility saw a significant decrease in severe cases (60% to 30%) and increase in mild OSA (7% to 35%) from 2004 to 2013. Today, over 4 out of every 10 new OSA diagnoses are mild, which has significant treatment implications given that adherence to the two primary medical device options is suboptimal. Identifying patient-centered treatment options for these patients is a priority. Support (if any) VA RR&D D2651-R and the Sleep Medicine Section of the VA San Diego Healthcare System supported this project.

Prevalence and Risk Factors of Obstructive Sleep Apnea Among Hypertensive Sudanese Patients Attending Selected Hospital in Khartoum State, Sudan Between February - April 2022

Prevalence and Risk Factors of Obstructive Sleep Apnea Among Hypertensive Sudanese Patients Attending Selected Hospital in Khartoum State, Sudan Between February - April 2022

Effect of yoga-based lifestyle and dietary modification in overweight individuals with sleep apnea: A randomized controlled trial (ELISA)

BackgroundObesity is recognised as an important risk factor for obstructive sleep apnea (OSA), with obese individuals at a four times higher risk of being diagnosed with the syndrome. Treating obesity with lifestyle modification is associated with a reduction in the severity of obstructive sleep apnea. Yoga comprises lifestyle modification that includes asana (postures), pranayama (breathing techniques), dhyana (meditation) and guideline principles for healthy living (Yama and Niyama). There is a scarcity of data to evaluate the effect of yoga on OSA. This study was conducted to evaluate the efficacy of Yoga based lifestyle modification on OSA. MethodsConsenting obese patients (BMI >23) diagnosed with obstructive sleep apnea (OSA) (AHI>5) on Polysomnography (PSG) were enrolled. Eligible patients were randomized into two groups. The control group received counselling for dietary modification (staple Indian) with regular exercise and the active intervention group received Yoga intervention as treatment (OSA module) in addition to similar dietary modification and regular exercise counselling. Polysomnography (PSG) was conducted at baseline and one year follow-up. All patients were evaluated at baseline, six months, and one year for compliance and anthropometric parameters. Additional assessment with Hamilton scales for depression and anxiety, SF-36, and the Pittsburgh sleep quality index was also conducted. ResultsA total of 37 eligible patients (19 in the control group and 18 in the yoga group) were recruited for the study. The age [45.73 ± 10.71 vs. 46.22 ± 9.39 years, p = 0.88] and gender [15(78.95%) vs. 12(66.67%), p = 0.48 (males)] distribution was similar in both groups. After adjusting for age and gender, the percentage reduction in weight between the two groups did not reach statistical significance at one year. There was no significant difference in mean AHI between the two groups at one year. However, the number of patients with more than 40% AHI reduction [2/19 (10.52%) vs 8/18 (44.44%), p = 0.02] was significantly higher in the yoga group. Additionally, within the groups, the mean AHI at one year was significantly reduced in the yoga group [51.2 ± 28.0 to 36.8 ± 21.0/hour, p = 0.003], while no significant change was found in the control group [47.2 ± 23 to 38.8 ± 19.9/hour, p = 0.08]. ConclusionsLifestyle alteration using Yoga intervention and modification of staple Indian diet may be effective in reducing OSA severity among obese patients. CTRI numberCTRI/2017/05/008462.

Worldwide prevalence and associated risk factors of obstructive sleep apnea: a meta-analysis and meta-regression.

This study aimed to identify the prevalence of obstructive sleep apnea (OSA) and associated risk factors globally. Six databases and registrations and three grey databases were explored for observational field research. Independently and impartially paired reviewers selected research, gathered data, and evaluated the methodological quality. Heterogeneity was investigated using subgroup analysis and meta-regression following the moderating variable in a meta-analysis of proportions with a random-effects model. The critical appraisal instrument developed by the Joanna Briggs Institute was used to evaluate the listed studies' methodology. The certainty of the evidence was evaluated using the GRADE tool. A total of 8236 articles were collected during the databasesearch, resulting in 99 articles included for qualitative synthesis, and 98 articles were included for the meta-analysis. The estimated combined prevalence of OSAwas 54% [CI 95% = 46-62%; I2 = 100%]. Mean age, percentage of moderate-severe cases, and the sample's body mass index (BMI) did not affect the heterogeneity that was already present when meta-regressed (p > 0.05). Ninety-one studies were deemed to have a low risk of bias, while eight were deemed to have a moderate risk. For OSA prevalence outcomes, the GRADE criteria were considered very low. Approximately half of the people worldwidehave OSA. High BMI, increasing age, and male gender are described as risk factors in the literature, but these covariates do not affect pre-existing heterogeneity.

Associations Between Systemic Inflammatory Markers Based on Blood Cells and Polysomnographic Factors in Obstructive Sleep Apnea.

Systemic inflammation plays a key role in the pathogenesis of obstructive sleep apnea (OSA); however, easy-to-use methods to evaluate the severity of systemic inflammation have yet to be developed. This study investigated the association between systemic inflammation markers that could be derived from the complete blood count (CBC) profile and sleep parameters in a large number of patients with OSA. Patients who visited our hospital's Otorhinolaryngology Sleep Clinic between January 2017 and April 2022 underwent polysomnography and routine laboratory tests, including a CBC. Associations between three systemic inflammatory markers-the systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR)-and polysomnographic and demographic factors including age, sex, body mass index, the apnea-hypopnea index (AHI), the hypopnea index (HI), lowest oxygen saturation (%), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, and percentages of non-rapid eye movement (REM) sleep stage 3, REM sleep, and snoring time were analyzed. The inflammation markers were compared among OSA subgroups, and associations were also analyzed in subgroups with different OSA severities. In total, 1,102 patients (968 men and 134 women) were included, and their mean AHI was 33.0±24.3. PSQI was significantly associated with SII (P=0.027). No independent significant factors were identified for the NLR or PLR. Within the simple snoring and mild OSA subgroups, no significant association was found between sleep parameters and the SII. In the severe OSA subgroup, the AHI (P=0.004) and PSQI (P=0.012) were independently associated with the SII. Our study analyzed systemic inflammatory markers based on the CBC, a simple, relatively cost-effective test, and showed that the AHI and SII were significantly correlated only in the severe OSA subgroup.

Pro: can physiological risk factors for obstructive sleep apnea be determined by analysis of data obtained from routine polysomnography?

This article is a written debate between the author(s) of this article and the author(s) of the opposing argument [1]. The following argument was prepared in response to the question without the knowledge of the contents of the opposing argument. Obstructive sleep apnea (OSA) is a highly prevalent disorder characterized by heterogeneous underlying mechanisms and heterogeneous adverse outcomes. Over the last 20 years, investigators have described how OSA is manifest as a combination of several established physiological risk factors or “endotypic traits”: greater pharyngeal collapsibility, dampened pharyngeal dilator muscle compensation, hyper-responsive ventilatory control (elevated loop gain), and a low arousal threshold (increased arousability from sleep). Evidence for important roles of each pathophysiological pathway are extensive. Profoundly improving pharyngeal collapsibility with CPAP is highly efficacious for resolving OSA, and individuals without a collapsible pharynx (critical collapsing pressure <5 cmH2O) very rarely exhibit OSA [2, 3]; thus, a level of pharyngeal mechanical vulnerability is considered a requirement for OSA. Yet measures of collapsibility alone do not accurately predict the presence/absence of OSA, that is, for the same level of collapsibility some patients exhibit severe OSA and others do not. The two leading endotypic traits responsible for modifying OSA risk are reduced muscle compensation and elevated loop gain. Notably, obese individuals without OSA typically exhibit augmented muscle responses [4], and loop gain is elevated in OSA patients with less-severe collapsibility [5]. A lower arousal threshold is considered to contribute to more severe OSA within participants in lighter non-REM and REM [6].

Con: can physiological risk factors for obstructive sleep apnea be determined by analysis of data obtained from routine polysomnography?

The following argument was prepared in response to the question without the knowledge of the contents of the opposing argument. The answer is CLEARLY NO. The mechanisms of ventilatory instability in obstructive sleep apnea (OSA) are complex [1, 2], and defining them with confidence requires interventions that are not practical in routine polysomnography [3–5]. If it is not possible to measure instability traits from routine polysomnograms (PSGs), how is it that since 2015 papers and reviews are being published at an impressive rate in top-rated journals using an approach that claims to estimate all the stability factors from standard clinical PSGs? All these papers are based on a method proposed by Terrill et al. in 2015 to measure loop gain (LG) [6], and subsequently “improved” to provide more and more traits [7]. The basic approach is to measure ventilation in the hyperpneic phase between obstructive events (Vdrive). Without arousal, Vdrive is assumed to reflect chemical drive at the end of apnea. Arousal, if present, is assumed to contribute a fraction of Vdrive. A model with four variables (LG, time constant of chemical responses, circulatory delay, and the arousal contribution) is used to partition Vdrive into the components related to arousal (a constant predicted from the model; Varousal) and that related to the chemical drive (Vchem). The model is then used to estimate the time course of the chemical drive during the obstructed phase. From this LG, the chemical drive preceding arousal (arousal threshold), airway collapsibility, and pharyngeal muscle compensation are derived [8]. In our view, this model is based on untenable assumptions and does not identify the traits that are truly relevant to ventilatory instability in OSA: