Effect of Weight Loss on Upper Airway Anatomy and the Apnea-Hypopnea Index. The Importance of Tongue Fat

The Association of Body Mass Index and Adiposity-Estimating Equations with Measures of Obstructive Sleep Apnea Severity: A Cross-Sectional Study

Background and Purpose

Obesity, a risk factor for obstructive sleep apnea (OSA), is usually estimated by body mass index (BMI). However, other adiposity-estimating equations may better capture variations in fat distribution. This study assessed the relationship between OSA severity and 15 adiposity-estimating equations, compared to BMI, with subgroup analyses by sex and age (<50 vs ≥50).

Patients and Methods

We conducted a cross-sectional cohort study using data from 5021 consecutive adults who underwent a Level 1 polysomnography (2015-2017) in a large academic sleep center in Ottawa, Canada. We assessed correlations between adiposity measures and the apnea-hypopnea index (AHI) and examined discriminative ability for moderate-to-severe (AHI ≥15/h) and severe OSA (AHI >30/h) using univariate logistic regressions.

Results

The mean age was 49.5 years, 46.6% were women; the mean BMI was 30.0 kg/m2 and 12.7% had severe OSA. All adiposity equations showed negligible (Pearson r 0.0 to ±0.3) to low (Pearson r ± 0.30 to 0.50) statistically significant correlations with AHI, with many of the equations having a marginally stronger correlation coefficient than BMI, in total and subgroup analysis. Discriminative ability for severe OSA was generally low, with c-indices ranging from 0.52 to 0.67 in the overall sample. However, in females under 50, several equations (eg, Gallagher 2000, Deurenberg 1991 and 1998, ECORE BF) reached excellent discriminative ability (c-indices 0.81), including BMI (c-index 0.80). This pattern was not observed in other subgroups.

Conclusion

In this clinical cohort, BMI was associated poorly with AHI; however, the other equations did not outperform BMI. Moreover, BMI demonstrated poor discriminative ability for moderate/severe and severe OSA, with none of the other equations performing better in this context. Notable subgroup differences-particularly among younger females-suggest that tailoring screening strategies by age and sex may improve risk stratification and support refining obesity-based screening approaches.

Early-to-Midlife Body Mass Index Trajectories and Obstructive Sleep Apnoea Risk 10 Years Later

BACKGROUND AND OBJECTIVE

While short-term weight changes are known to influence obstructive sleep apnoea (OSA), the impact of body mass index (BMI) changes over the life course has been poorly documented. We examined the association between BMI trajectories from childhood to middle age and adult OSA, 10 years later.

METHODS

Five BMI trajectories were previously identified in the population-based cohort Tasmanian Longitudinal Health Study (TAHS), using eight time-point BMI from age 5 to 43 years. The primary outcome was probable OSA at 53 years, defined using STOP-Bang questionnaire, with Berlin and OSA-50 questionnaires used to ensure consistency of findings. Clinically significant diagnosed OSA was defined as self-reported medical diagnosis or mild OSA with symptoms or moderate-to-severe OSA, using type-4 sleep studies. Associations were examined using multivariable logistic regression.

RESULTS

Compared with the average BMI trajectory, the child average-increasing (aOR = 5.28, 95% CI 3.38-8.27) and persistently high trajectories (aOR = 3.73, 2.06-6.74) were associated with increased risk of probable OSA. These associations were consistent when using clinically significant diagnosed OSA (child average-increasing trajectory: aOR = 2.95, 1.30-6.72; high trajectory: aOR = 2.23, 0.82-6.09). Individuals belonging to the low trajectory were less likely than the average trajectory to have OSA. Notably, the child high-decreasing trajectory was not associated with OSA.

CONCLUSION

Physicians and the public should be aware of the potential risk of OSA in middle-aged adults when BMI is high or continuously increasing from childhood to mid-40s. Obese children who subsequently lose weight were not at higher risk of OSA in middle age-a novel and key finding.

Effect of bariatric surgery in the treatment of obstructive sleep apnea in obese patients

PURPOSE

To analyze the success rate of bariatric surgery in the treatment of obstructive sleep apnea (OSA) in obese patients and its related factors.

METHODS

Longitudinal, prospective, single cohort study, with consecutive sampling including OSA patients aged 18-65 years intervened of bariatric surgery. An anamnesis regarding OSA, a complete upper airway (UA) exploration and a cardiorespiratory polygraphy (CRP) pre- and post-surgery were performed.

RESULTS

Fifty-seven patients were included in this study. The overall surgical success and cure rates for bariatric surgery as a treatment for OSA were 61.4% and 52.6%, respectively. Factors predicting success were female sex (OR = 12.54; CI95% = 1.75-89.88, p = 0.012), age below 53 years old (OR = 7.24; CI95% = 1.48-35.51, p = 0.015) and pre-surgical weight below 105 kg (OR = 8.1; CI95% = 1.44-45.62, p = 0.018). Surgical success cases had lower weight and body mass index, greater weight loss, smaller postsurgical neck circumference and less palatal webbing, however these were not independent factors in the multivariate analysis.

CONCLUSIONS

Our results show that bariatric surgery is a feasible option for OSA treatment in obese patients, with a higher success rate in female, younger and thinner patients. Moreover, adipose tissue on the UA has been proven to decrease as a result of weight loss, although not correlated with surgery success in the treatment of OSA.

Predictors for cure of obstructive sleep apnea in bariatric patients

INTRODUCTION

Obstructive sleep apnea (OSA) is common among candidates for bariatric surgery and is often underdiagnosed. Given that obesity and OSA share comorbidities and mutually reinforce each other, it is important to identify factors that predict OSA resolution after bariatric surgery. However, studies on this topic are limited and offer contradictory results. The objective of the study was to identify predictors of OSA resolution one year after bariatric surgery.

METHODS

A prospective study was conducted with bariatric surgery candidates aged 18-65. Patients underwent preoperative cardiorespiratory polygraphy (PR) and an otorhinolaryngological examination. A follow-up PR was performed one year after surgery. A multivariate analysis was conducted, examining anthropometric, metabolic, and upper airway anatomical variables to determine predictors of resolution.

RESULTS

The prevalence of OSA was 75%. Predictors of resolution included preoperative body mass index (BMI), neck circumference and age. Each additional kg/m² in BMI reduced the probability of resolution by 14% (OR = 0.86; P = .037), each additional centimeter of neck circumference reduced the probability by 16% (OR = 0.84; P = .018), and each year of age reduced the probability by 11% (OR = 0.89; P = .009).

CONCLUSIONS

The prevalence of OSA in bariatric patients is high, and BMI, neck circumference, and age are predictive factors of OSA resolution after bariatric surgery.

Endotypic Traits Characterizing Obesity and Sleep-related Hypoventilation in Patients with Obstructive Sleep Apnea

Rationale: Sleep-related hypoventilation disorder (SHD) is common among obese patients with obstructive sleep apnea (OSA), but the pathological endotypes associated with obesity and SHD remain unclear. Objectives: To investigate the relationship between endotypes with body mass index (BMI) among patients with OSA and to explore endotypic traits of patients with comorbid SHD. Methods: We prospectively collected polysomnographic studies of 1,364 patients with OSA and overnight transcutaneous CO2 measurements among 420 obese patients. Endotypic traits were estimated using polysomnographic signals. SHD was determined using transcutaneous CO2 > 55 mm Hg for ⩾10 minutes. We illustrated the nonlinear relationship between BMI and endotypic traits. Differences in endotypic traits between nonobese patients with OSA, obese patients with simple OSA, and obese patients with comorbid OSA and SHD were examined using Kruskal-Wallis tests and multiple regression analysis. Results: A unit increase in BMI was associated with a 1.02%eupnea increase in arousal threshold, 1.16%eupnea increase in collapsibility, 0.01 increase in loop gain, and 0.48%eupnea increase in compensation, with a ceiling effect. SHD was observed in 18-36% of obese patients with OSA, depending on the criteria. Among obese patients with OSA, those with SHD exhibited a 0.06 higher loop gain than those with simple OSA, after adjusting for BMI. Conclusions: A ceiling effect of upper airway compensation function coupled with worse collapsibility and high loop gain characterizes pathological endotypes of obese patients with OSA. Patients with SHD exhibited a more sensitive respiratory pattern, indicated by increased loop gain.

Obesity: pathophysiology and therapeutic interventions

Over the past few decades, obesity has transitioned from a localized health concern to a pressing global public health crisis affecting over 650 million adults globally, as documented by WHO epidemiological surveys. As a chronic metabolic disorder characterized by pathological adipose tissue expansion, chronic inflammation, and neuroendocrine dysregulation that disrupts systemic homeostasis and impairs physiological functions, obesity is rarely an isolated condition; rather, it is frequently complicated by severe comorbidities that collectively elevate mortality risks. Despite advances in nutritional science and public health initiatives, sustained weight management success rates and prevention in obesity remain limited, underscoring its recognition as a multifactorial disease influenced by genetic, environmental, and behavioral determinants. Notably, the escalating prevalence of obesity and its earlier onset in younger populations have intensified the urgency to develop novel therapeutic agents that simultaneously ensure efficacy and safety. This review aims to elucidate the pathophysiological mechanisms underlying obesity, analyze its major complications-including type 2 diabetes mellitus (T2DM), cardiovascular diseases (CVD), non-alcoholic fatty liver disease (NAFLD), obesity-related respiratory disorders, obesity-related nephropathy (ORN), musculoskeletal impairments, malignancies, and psychological comorbidities-and critically evaluate current anti-obesity strategies. Particular emphasis is placed on emerging pharmacological interventions, exemplified by plant-derived natural compounds such as berberine (BBR), with a focus on their molecular mechanisms, clinical efficacy, and therapeutic advantages. By integrating mechanistic insights with clinical evidence, this review seeks to provide innovative perspectives for developing safe, accessible, and effective obesity treatments.

Estimating direct tissue effects versus weight loss effects of incretin-based drugs for obesity on various chronic conditions

The extent to which newer, incretin-based drugs for obesity improve disease outcomes via weight loss versus the direct effects of these drugs is the subject of intense interest. Although reductions in major adverse cardiovascular events appear to be predominantly driven by the direct tissue effects of such drugs, the associated weight loss effects must be relevant to the benefits observed in other major outcomes, albeit to differing extents. In this Personal View, we draw on evidence to support that weight loss is at least partly responsible (albeit to differing extents) for the reported benefits of incretin-based drugs for obesity in people living with heart failure with preserved ejection fraction, hypertension, chronic kidney disease, and type 2 diabetes. Concurrently, we propose that drug-induced weight loss is largely responsible for the reported improvements in osteoarthritis, obstructive sleep apnoea, and metabolic dysfunction-associated steatohepatitis outcomes. However, more evidence is needed to solidify these observations, including, when possible, trials comparing the effects of incretin-based drugs for obesity with calorie-reduced diets on both outcomes and mechanistic pathways. Such evidence has implications for public health and the design of future trials of novel drugs for obesity.

The Effect of Tongue Volume and Adipose Content on Obstructive Sleep Apnea: Meta-analysis & Systematic Review

Objective

Macroglossia is a risk factor for obstructive sleep apnea (OSA) and has been linked to an elevated apnea-hypopnea index (AHI). Obesity may contribute to macroglossia, but its exact relationship is unknown and likely multifactorial, and the degree to which increased adiposity of the tongue affects the development of OSA is not understood. The primary objective of this study was to evaluate how tongue fat and volume relate to the presence and severity of OSA.

Data Sources

Studies reporting the impact of tongue fat or volume were identified using predefined inclusion criteria from September 2002 to 2022.

Review Methods

All studies underwent a 2-stage blinded screening, extraction, and evaluation process. Primary outcomes were the effect of tongue fat and volume on OSA severity and evaluation of study quality. Secondary outcomes included the impact of obesity on tongue fat distribution and OSA severity.

Results

Out of 930 studies, 6 studies with 219 patients and 133 controls were included in meta-analysis. All 6 studies were case-control designs. Included studies showed low (4) and moderate (2) risks of bias. All studies compared tongue volume with an observed significant increase in tongue volume in OSA patients (P < .00001) with a weighted mean difference of 19.00 cm3 [15.53, 22.47]. Two studies compared tongue fat, and there was a significant increase in tongue fat in patients with OSA (P < .00001) with a weighted mean difference of 8.04 cm3 [4.25, 11.82].

Conclusion

This meta-analysis supports increased tongue volume and tongue adipose as important risk factors associated with OSA. Larger studies investigating tongue fat distribution and the effect of weight changes on tongue fat and volume and OSA severity are needed to characterize this relationship better.

Lateral epiglottic collapse in obstructive sleep apnea is associated with laterally directed pharyngeal collapse

STUDY OBJECTIVES

Epiglottic collapse can obstruct the airway in patients with obstructive sleep apnea in an anteroposterior or lateral direction. The present study investigates the concept that lateral or concentric pharyngeal collapse patterns may remodel the epiglottis and predispose it to lateral collapse. To do so, we hypothesized that the presence of-any form of laterally directed pharyngeal collapse, eg, oropharyngeal lateral wall collapse or complete concentric collapse of the soft palate, is associated with increased odds for having concurrent lateral epiglottic collapse (E-lat).

METHODS

We analyzed 582 patients with obstructive sleep apnea from our drug-induced sleep endoscopy cohort. Site of collapse was scored by a single scorer using the VOTE criteria, with patients with epiglottic collapse reviewed by 2 additional independent scorers. Logistic regression evaluated the association between presence of laterally directed pharyngeal collapse and the presence of E-lat.

RESULTS

The overall prevalence of E-lat was 2.6% (n = 15). The presence of any form of laterally directed pharyngeal collapse was associated with 4-fold increased odds (4.4 [1.5-12.6], P = .006) of having concurrent E-lat. Further, the specific presence of either complete oropharyngeal lateral wall collapse or complete concentric collapse of the soft palate was associated with an odds ratio of 3.4 [1.2-9.6] and 8.6 [2.2-33.5], respectively, of having concurrent E-lat.

CONCLUSIONS

Greater prevalence of severe laterally directed pharyngeal collapse, in the form of either complete concentric collapse of the soft palate or oropharyngeal lateral wall collapse in patients with E-lat supports the concept that laterally and concentric pharyngeal collapse patterns may shape the epiglottis and thereby contribute to the pathogenesis of E-lat.

CITATION

Wang T-Y, Huyett P, Yang H, et al. Lateral epiglottic collapse in obstructive sleep apnea is associated with laterally directed pharyngeal collapse. J Clin Sleep Med. 2025;21(4):649-654.

Selective Adipose Cryolysis for Reduction of Lingual Tissue in a Porcine Model

OBJECTIVES

Oropharyngeal fat volume is associated with obstructive sleep apnea (OSA) severity. Selective adipose cryolysis may produce cold-induced adipose cell death while sparing surrounding tissues. This study explored (1) similarities in tongue fat between porcine and human models and (2) the feasibility and potential reduction of lingual fat using selective adipose cryolysis.

STUDY DESIGN

Porcine model.

SETTING

Preclinical research laboratory under IACUC-approved protocols.

METHODS

Anatomical, histological, and biochemical characterizations of tongue tissue from 6 porcine and 4 human cadaver specimens were conducted to establish comparative frameworks. Comparison of fat distribution and composition was conducted via image analysis of histological sections as well as gas chromatography analysis of fatty acid composition. Safety and efficacy of selective adipose cryolysis were evaluated in an additional 16 porcine animals using a prototype cooling system. Histological analysis examined tissue response at 3, 6, 30, and 45 d posttreatment.

RESULTS

Comparative analysis revealed similar fat distribution and composition between human and porcine tongues. Selective adipose cryolysis induced progressive reduction in treated area tongue fat content at all timepoints, from 42% at baseline to 32% (t = 3 d) and 14% (t = 30 d), accompanied by macrophage infiltration, crown-like structure formation, and tissue remodeling.

CONCLUSION

Selective adipose cryolysis holds promise as a targeted therapeutic approach for reducing lingual fat in humans. The porcine model may provide valuable insight into treatment mechanisms and support initial translational work. Further research is warranted to elucidate long-term treatment outcomes and optimize clinical implementation strategies, with the goal of improving management of OSA in humans.

Multimodal Treatment of Sleep Apnea

Obstructive sleep apnea (OSA) is a common condition linked with multiple comorbidities. Continuous positive airway pressure (CPAP) devices, though the gold standard for OSA treatment, often do not address the entirety of the disorder. Various treatment strategies exist to address OSA beyond CPAP, each targeting different OSA aspects. These include managing comorbid sleep disorders, anatomic considerations, endotype-directed therapy, and lifestyle interventions. These comprehensive approaches aim to improve the benefits of treatment, and reduce the complications associated with OSA.

Dynamic behavior of the oropharynx airway during deep breath in patients with obstructive sleep apnoea hypopnoea syndrome observed by ultrasonography

This study aimed to determine whether ultrasonography can be used to assess the oropharyngeal airway in patients with obstructive sleep apnoea hypopnoea syndrome (OSAHS). 104 patients with OSAHS and 104 sex-, body mass index (BMI)-, and age-matched healthy subjects underwent oropharynx airway assessment using ultrasound. The dimensional changes of the oropharynx were monitored, and sonographic measurements of the airway lumen were obtained during deep breathing. Measurements were compared between groups. All suspected patients underwent Polysomnography in the sleep laboratory. OSAHS was defined as apnea-hypopnea index (AHI) > 5 events/h. Adequate visualization of oropharyngeal dimensional changes was obtained in 95.19% of patients with OSAHS and 100% of healthy subjects. The anteroposterior diameter (AP) and lateral diameter (LAT) of the oropharyngeal airway of patients with OSAHS were smaller than those of healthy subjects at the end of deep inspiration and expiration (all P < 0.05). Patients with OSAHS had greater lateral airway dimensional changes than the anterior-posterior dimension changes (P < 0.001). The AP/LAT ratio of OSAHS at the end of deep inspiration was higher than that of healthy subjects (P = 0.012). Ultrasonography can detect the dimensional changes of the oropharyngeal airway in patients with OASHS during deep breathing. Patients with OASHS have a smaller airway size, a more circular configuration, and a more significant change of diameter in oropharynx airway than healthy subjects.

Association of Craniofacial Skeletal and Soft Tissue Characteristics With Severe Obstructive Sleep Apnea in Age-specific and BMI-specific Patient Groups

PURPOSE

To identify the key craniofacial anatomic characteristics associated with the prevalence of severe obstructive sleep apnea (OSA) in patient cohorts stratified by age and body mass index (BMI).

METHODS

This prospective study was conducted at the Beijing Anzhen Hospital Center for Sleep Medicine and Science between December 2023 and March 2024. Patients suspected of having OSA underwent overnight polysomnography, along with computed tomography scans of the head and neck, to evaluate the skeletal and soft tissue characteristics. Multivariable analysis was conducted to explore the independent risk factors associated with the prevalence of severe OSA (apnea hypopnea index ≥30 events/h) after adjusting for age, sex, BMI, and neck circumference.

RESULTS

Among the 118 participants, 75 (63.6%) were diagnosed with severe OSA. Skeletal variables, such as vertical airway length, and soft tissue-related variables, like soft palate length, were independently correlated with the prevalence of severe OSA. Furthermore, subgroup analysis revealed that all skeletal variables and a few soft tissue parameters were associated with severe OSA in patients aged older than 40 years, whereas only a specific soft tissue variable was independently associated with the occurrence of severe OSA in those aged younger than or equal to 40 years. In addition, certain soft tissue-related variables were notably associated with severe OSA in obese patients (BMI >28 kg/m2), whereas only specific skeletal variables were acted independent risk factors for severe OSA in non-obese patients (BMI ≤28 kg/m2).

CONCLUSION

Craniofacial skeletal and soft tissue features play essential roles in the prevalence of severe OSA, with variations observed based on age and BMI.

Soft palate angle and basihyoid depth increase with tongue size and with body condition score in horses

BACKGROUND

Obesity has been associated with human obstructive sleep apnoea and canine brachycephalic obstructive airway syndrome. The effect of body condition score (BCS) on structures of the oropharynx, nasopharynx and upper airway of the horse has not been investigated.

OBJECTIVES

To investigate the effect of BCS on tongue measurements, soft palate angle and basihyoid depth in horses.

STUDY DESIGN

Retrospective, analytical, cross-sectional.

METHODS

Computed tomographic (CT) images of the head of 58 horses were assessed. DICOM viewing software was used to measure head length, basihyoid-skin depth, soft palate angle (SPA), midline tongue area, dorsoventral height (DVH) of the tongue in two locations and head angle. BCS were assigned during CT examinations. Associations between measurements were tested and following initial calculations, further associations with tongue measurements as a ratio of head length were assessed.

RESULTS

For initial measurements, 44 horses met the inclusion criteria. Addition of head length ratios to tongue measurements resulted in 24 of 44 horses meeting the inclusion criteria for the second set of calculations. Increased BCS led to an increased mean SPA (mean difference = 2.56° $$ {}^{{}^{\circ}} $$ ; p = 0.02) and increased median basihyoid depth (mean difference = 0.246 cm; p = 0.006). Following adjustments made for the effect of head length on tongue measures, significant correlation was identified between SPA and tongue area (Spearman's r = 0.544; p = 0.007); SPA and DVH of the tongue at the level of the hard palate (Spearman's r = 0.562; p = 0.004) and SPA and DVH of the tongue at the lingual process of the basihyoid bone (Spearman's r = 0.690; p < 0.001). No significant correlation was identified between variables and sex.

MAIN LIMITATIONS

The sample size was small and the effect of breed on measures was not studied. Measurements were acquired on a single sagittal CT plane. The investigator collecting CT measures was not blinded to BCS. All horses were sedated for the CT procedure which may have affected measures obtained.

CONCLUSIONS

Increased BCS increases SPA and basihyoid bone depth. Increases in tongue size measurements increase SPA. Results from this study warrant further investigation into the clinical significance of the effects of BCS on the upper airways of the horse.

Pharyngeal airway dimensions and adipose distribution in the minipig

Objective

To evaluate the pharyngeal airway dimensions and regional pharyngeal adipose distribution in the young adult minipig model.

Materials and methods

Eight 7-8-months-old Yucatan minipigs, half male and female, were sedated and placed prone to scan the pharyngeal region. Magnetic resonance imaging (MRI) was performed using dynamic turbo-field echo (TFE)-sequence with respiratory gating and adipose-weighted sequence. Respiratory airflow velocity, pressure, and volume were also recorded. The sizes of velopharyngeal and oropharyngeal airway, and retroglossal areas were measured coronally during inspiration and expiration. The airway volumes from the nasal cavity to the retroglossal space were segmented, reconstructed, and evaluated in sagittal views. The adipose distribution in the tongue base, soft palate, pharyngeal wall, tongue body, and masseter muscle (reference) were segmented and measured in sagittal and coronal planes.

Results

The velopharyngeal and oropharyngeal areas were larger in inspiration than in expiration. These areas were also larger than that in the retroglossal space (p < 0.05). The nasal cavity showed a larger volume than that of the pharyngeal regions (p < 0.05). The adipose distribution was larger in the posterior region of the tongue base and anterior soft palate, both larger than the masseter muscle (p < 0.05).

Conclusion

The larger oropharyngeal dimensions and increased adipose distribution in the tongue base contribute to the functional morphology of the pharyngeal airway in the healthy minipig. These data provide the baseline for further analysis in enlarged and reduced tongue base minipig models.

Analysis of Possible Predictors of Moderate and Severe Obstructive Sleep Apnea in Obese Patients

Objectives: To determine if there are clinical or anatomical differences between patients with grade II-IV obesity without obstructive sleep apnea (OSA) or mild OSA and patients with moderate or severe OSA and to assess whether any of these factors are predictive of moderate/severe OSA. Methods: Observational case-control study with consecutive sampling including patients between 18 and 65 years of age with grade II-IV obesity who were candidates for bariatric surgery. An anamnesis regarding OSA symptoms, a physical examination of the upper airway and a cardiorespiratory polygraphy were performed. Results: A total of 124 patients were included in the study, of whom 61.3% did not have OSA or had mild OSA and 38.7% had moderate or severe OSA. Age over 48 years was the only independent factor associated with moderate or severe OSA. Other factors showed a relation with moderate/severe OSA after multivariate analysis: male sex, STOP-BANG questionnaire ≥ 3, weight ≥ 105 kg, thick neck, neck circumference ≥ 41.25 cm, flaccid palate, Mallampati III-IV index, Friedman tongue position III-IV and retropalatal narrowing. Conclusions: The only independent predictive factor related to moderate or severe OSA in patients with morbid obesity was age over 48 years, therefore a sleep study remains essential for its diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04908-0.

Pilot analysis of magnetic resonance imaging-based contributors to patient-centred optimization of mandibular advancement devices in obstructive sleep apnea

Mandibular advancement devices are an effective treatment option for obstructive sleep apnea. While their efficacy depends on the degree of mandibular protrusion, other contributing factors influencing the optimal outcome are not fully understood. This magnetic resonance imaging-based pilot study aimed at investigating whether there are promising planimetric parameters that may be related to the optimal therapeutic position. A second aim was to assess possible sex-specific differences. Planimetric data from magnetic resonance imaging taken in the habitual position and four protrusion grades were collected from 11 female and 14 male patients with obstructive sleep apnea (age 45 ± 13.3 years; body mass index 27.6 ± 4.5 kg m-2). Data were correlated with outcome as substantiated by polygraphic data obtained at the habitual position and at each of two protrusion positions considered to reveal the highest treatment effect. Protrusion degree and lateral widening of the retropalatal region correlated most strongly (R = 0.56, p < 0.001). Relationships between planimetric data and treatment success were most pronounced at the level of the smallest cross-section, expressed, for example, by a correlation between oxygen desaturation index and lateral diameter (R = -0.4, p = 0.012). Female participants appeared to show improved polygraphic values at a lower protrusion degree than males. Data from magnetic resonance imaging allow for a comprehensive analysis combining insights from planimetric velopharyngeal measurements at different individual protrusion grades and correlation with outcome. The results of this pilot work encourage further evaluation in large-scale studies. These should focus on the velopharyngeal region and investigate the influence of sex more closely.

The Association between Obstructive Sleep Apnea and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Despite previous observational studies linking obstructive sleep apnea (OSA) to venous thromboembolism (VTE), these findings remain controversial. This study aimed to explore the association between OSA and VTE, including pulmonary embolism (PE) and deep vein thrombosis (DVT), at a genetic level using a bidirectional two-sample Mendelian randomization (MR) analysis.

METHODS

 Utilizing summary-level data from large-scale genome-wide association studies in European individuals, we designed a bidirectional two-sample MR analysis to comprehensively assess the genetic association between OSA and VTE. The inverse variance weighted was used as the primary method for MR analysis. In addition, MR-Egger, weighted median, and MR pleiotropy residual sum and outlier (MR-PRESSO) were used for complementary analyses. Furthermore, a series of sensitivity analyses were performed to ensure the validity and robustness of the results.

RESULTS

 The initial and validation MR analyses indicated that genetically predicted OSA had no effects on the risk of VTE (including PE and DVT). Likewise, the reverse MR analysis did not find substantial support for a significant association between VTE (including PE and DVT) and OSA. Supplementary MR methods and sensitivity analyses provided additional confirmation of the reliability of the MR results.

CONCLUSION

 Our bidirectional two-sample MR analysis did not find genetic evidence supporting a significant association between OSA and VTE in either direction.

Symptom subtype progression in obstructive sleep apnea over 5 years

STUDY OBJECTIVES

There is limited knowledge regarding the progression or consistency of symptoms in obstructive sleep apnea (OSA) over time. Our objective was to examine the changes in symptom subtypes and identify predictors over a span of 5 years.

METHODS

Data of 2,643 participants of the Sleep Heart Health Study with complete baseline and 5-year follow-up visits were analyzed. Latent class analysis on 14 symptoms at baseline and follow-up determined symptom subtypes. Individuals without OSA (apnea-hypopnea index < 5) were incorporated as a known class at each time point. Multinomial logistic regression assessed the effect of age, sex, body mass index, and apnea-hypopnea index on specific class transitions.

RESULTS

The sample consisted of 1,408 females (53.8%) and mean (standard deviation) age 62.4 (10.5) years. We identified 4 OSA symptom subtypes at both baseline and follow-up visits: minimally symptomatic, disturbed sleep, moderately sleepy, and excessively sleepy. Nearly half (44.2%) of the sample transitioned to a different subtype; transitions to moderately sleepy were the most common (77% of all transitions). A 5-year older age was associated with a 50% increase in odds to transit from excessively sleepy to moderately sleepy (odds ratio [95% confidence interval]: 1.52 [1.17, 1.97]). Females had 1.97 times higher odds (95% confidence interval: 1.21, 3.18) to transition from moderately sleepy to minimal symptoms. A 5-unit increase in body mass index was associated with 2.39 greater odds (95% confidence interval: 1.30, 4.40) to transition from minimal symptoms to excessively sleepy. Changes in apnea-hypopnea index did not significantly predict any transitions.

CONCLUSIONS

The symptoms of OSA may fluctuate or remain stable over time. Knowledge of symptom progression in OSA may support clinicians with treatment decisions.

CITATION

Morris JL, Scott PW, Magalang U, et al. Symptom subtype progression in obstructive sleep apnea over 5 years. J Clin Sleep Med. 2024;20(11):1773-1783.

Estimating the severity of obstructive sleep apnea during wakefulness using speech: A review

Obstructive sleep apnea (OSA) is a chronic breathing disorder during sleep that affects 10-30% of adults in North America. The gold standard for diagnosing OSA is polysomnography (PSG). However, PSG has several drawbacks, for example, it is a cumbersome and expensive procedure, which can be quite inconvenient for patients. Additionally, patients often have to endure long waitlists before they can undergo PSG. As a result, other alternatives for screening OSA have gained attention. Speech, as an accessible modality, is generated by variations in the pharyngeal airway, vocal tract, and soft tissues in the pharynx, which shares similar anatomical structures that contribute to OSA. Consequently, in this study, we aim to provide a comprehensive review of the existing research on the use of speech for estimating the severity of OSA. In this regard, a total of 851 papers were initially identified from the PubMed database using a specified set of keywords defined by population, intervention, comparison and outcome (PICO) criteria, along with a concatenated graph of the 5 most cited papers in the field extracted from ConnectedPapers platform. Following a rigorous filtering process that considered the preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach, 32 papers were ultimately included in this review. Among these, 28 papers primarily focused on developing methodology, while the remaining 4 papers delved into the clinical perspective of the association between OSA and speech. In the next step, we investigate the physiological similarities between OSA and speech. Subsequently, we highlight the features extracted from speech, the employed feature selection techniques, and the details of the developed models to predict OSA severity. By thoroughly discussing the current findings and limitations of studies in the field, we provide valuable insights into the gaps that need to be addressed in future research directions.

Obstructive sleep apnea hypopnea syndrome and vascular lesions: An update on what we currently know

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is the most prevalent sleep and respiratory disorder. This syndrome can induce severe cardiovascular and cerebrovascular complications, and intermittent hypoxia is a pivotal contributor to this damage. Vascular pathology is closely associated with the impairment of target organs, marking a focal point in current research. Vascular lesions are the fundamental pathophysiological basis of multiorgan ailments and indicate a shared pathogenic mechanism among common cardiovascular and cerebrovascular conditions, suggesting their importance as a public health concern. Increasing evidence shows a strong correlation between OSAHS and vascular lesions. Previous studies predominantly focused on the pathophysiological alterations in OSAHS itself, such as intermittent hypoxia and fragmented sleep, leading to vascular disruptions. This review aims to delve deeper into the vascular lesions affected by OSAHS by examining the microscopic pathophysiological mechanisms involved. Emphasis has been placed on examining how OSAHS induces vascular lesions through disruptions in the endothelial barrier, metabolic dysregulation, cellular phenotype alterations, neuroendocrine irregularities, programmed cell death, vascular inflammation, oxidative stress and epigenetic modifications. This review examines the epidemiology and associated risk factors for OSAHS and vascular diseases and subsequently describes the existing evidence on vascular lesions induced by OSAHS in the cardiovascular, cerebrovascular, retinal, renal and reproductive systems. A detailed account of the current research on the pathophysiological mechanisms mediating vascular lesions caused by OSAHS is provided, culminating in a discussion of research advancements in therapeutic modalities to mitigate OSAHS-related vascular lesions and the implications of these treatment strategies.

Tackling obstructive sleep apnea with pharmacotherapeutics: expert guidance

INTRODUCTION

The efficacy of non-pharmacotherapeutic treatment of obstructive sleep apnea, a highly prevalent condition with serious cardiometabolic and neurocognitive health consequences, is well established. Supplementing traditional treatment strategies with medications can improve symptoms and reduce side effects. Efforts to identify medications that target the causes of sleep apnea have met with mixed success. However, this remains a worthwhile objective for researchers to pursue, given the potential benefit pharmacotherapy could bring to those patients who reject or struggle to adhere to existing treatments.

AREAS COVERED

This article presents the case for obstructive sleep apnea pharmacotherapy including drugs that reduce the occurrence of apnea events, such as weight loss agents, ventilation activators and muscle and nervous system stimulants, drugs that alleviate symptoms, such as wake-promoting agents for excessive daytime sleepiness, and drugs that improve adherence to existing treatments, such as hypnotics. Literature was accessed from PubMed between 1 March 2024 and 18 April 2024.

EXPERT OPINION

Exciting recent advances in both our understanding of obstructive sleep apnea pathology and in the techniques used to identify therapeutic agents and their targets combine to embolden a positive outlook for the expanded use of drugs in tackling this consequential disease.

Obstructive sleep apnoea in obesity: A review

Obstructive sleep apnea is a common comorbidity that occurs in individuals with obesity. It classically manifests with excessive daytime sleepiness, resulting in reduced quality of life, workplace productivity, and an increased risk of motor vehicle accidents. Weight gain plays an important role in its pathogenesis through worsening upper airway collapsibility, and current treatment options are targeted towards mechanically overcoming upper airway obstruction and weight loss. Continuous positive airway pressure therapy remains the most widely prescribed treatment for obstructive sleep apnea but poor tolerance is a common barrier to effective treatment. Sustainable weight loss is an important treatment option but can be difficult to achieve without bariatric surgery. The recent advances in incretin-based pharmacotherapies represent a promising avenue not only in achieving long-term weight loss but also in treating obstructive sleep apnoea and alleviating the burden of its symptoms and comorbidities.

Effect of obesity on sleep apnea pathogenesis differs in women versus men: multiple mediation analyses in the retrospective SNOOzzzE cohort

There are multiple mechanisms underlying obstructive sleep apnea (OSA) development. However, how classic OSA risk factors such as body mass index (BMI) and sex portend to OSA development has not been fully described. Thus we sought to evaluate how obesity leads to OSA and assess how these mechanisms differ between men and women. The San Diego Multi-Outcome OSA Endophenotype (SNOOzzzE) cohort includes 3,319 consecutive adults who underwent a clinical in-laboratory polysomnography at the University of California, San Diego, sleep clinic between January 2017 and December 2019. Using routine polysomnography signals, we determined OSA endotypes. We then performed mediation analyses stratified by sex to determine how BMI influenced the apnea-hypopnea index (AHI) using OSA pathophysiological traits as mediators, adjusting for age, race, and ethnicity. We included 2,146 patients of whom 919 (43%) were women and 1,227 (57%) were obese [body mass index (BMI) > 30 kg/m2]. BMI was significantly associated with AHI in both women and men. In men, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.124), a reduction in circulatory delay (βstandardized = 0.063), and an increase in arousal threshold (βstandardized = 0.029; Pboot-strapped,all < 0.05). In women, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.05) and circulatory delay (βstandardized = 0.037; Pboot-strapped,all < 0.05). BMI-related OSA pathogenesis differs by sex. An increase in upper airway collapsibility is consistent with prior studies. A reduction in circulatory delay may lead to shorter and thus more events per hour (higher AHI), while the relationship between arousal threshold and OSA is likely complex.NEW & NOTEWORTHY Our data provide important insights into obesity-related obstructive sleep apnea (OSA) pathogenesis, thereby validating, and extending, prior research findings. This is the largest sample size study to examine the relationships between obesity and gender on OSA pathogenesis. The influence of obesity on sleep apnea severity is mediated by different mechanistic traits (endotypes).

OSA pathophysiology: a contemporary update

Defined as an elevated frequency of obstructive respiratory events in sleep, obstructive sleep apnoea (OSA) is driven by a combination of four pathophysiologic mechanisms: elevated upper airway collapsibility, unstable ventilatory control, impaired upper airway dilator muscle responsiveness and decreased arousal threshold. Established therapies such as continuous positive airway pressure (CPAP) and oral appliance therapy (OAT) work chiefly through targeting elevated collapsibility, which affects the majority of OSA patients. However, many patients respond poorly or do not tolerate these 'anatomic' therapies. The emerging field of 'precision sleep medicine' seeks to determine if novel treatment approaches specifically targeting the other, 'non-anatomic' mechanisms will improve treatment efficacy and acceptance. In this review, we consider the concepts underlying each pathophysiologic mechanism, the predisposing factors, and the potential implications for established and future OSA treatments.

Tirzepatide for the treatment of obstructive sleep apnea: Rationale, design, and sample baseline characteristics of the SURMOUNT -OSA phase 3 trial

BACKGROUND

Weight reduction is a standard recommendation for obstructive sleep apnea (OSA) treatment in people with obesity or overweight; however, weight loss can be challenging to achieve and maintain without bariatric surgery. Currently, no approved anti-obesity medication has demonstrated effectiveness in OSA management. This study is evaluating the efficacy and safety of tirzepatide for treatment of moderate to severe OSA in people with obesity.

METHODS

SURMOUNT-OSA, a randomized, placebo -controlled, 52-week phase 3 trial, is investigating the efficacy and safety of tirzepatide for treatment of moderate to severe OSA (apnea hypopnea- index ≥15 events/h) in participants with obesity (body mass index ≥30 kg/m2) and an established OSA diagnosis. SURMOUNT-OSA is made of 2 intervention-specific appendices (ISAs): ISA-1 includes participants with no current OSA treatment, and ISA-2 includes participants using positive airway pressure therapy. Overall, 469 participants have been randomized 1:1 to receive tirzepatide or placebo across the master protocol (ISA-1, n = 234; ISA-2, n = 235). All participants are also receiving lifestyle intervention for weight reduction.

RESULTS

The primary endpoint for the individual ISAs is the difference in apnea hypopnea- index response, as measured by polysomnography, between tirzepatide and placebo arms at week 52. Secondary endpoints include sleep apnea-specific hypoxic burden, functional outcomes, and cardiometabolic biomarkers. The trial employs digital wearables, including home sleep testing to capture time to improvement and accelerometry for daily physical activity assessment, to evaluate exploratory outcomes.

CONCLUSION

SURMOUNT-OSA brings a novel design to investigate if tirzepatide provides clinically meaningful improvement in obesity-related OSA by targeting the underlying etiology.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05412004.

The Association of Upper Airway Anatomy with Brain Structure: The Multi-Ethnic Study of Atherosclerosis

Sleep apnea, affecting an estimated 1 in 4 American adults, has been reported to be associated with both brain structural abnormality and impaired cognitive function. Obstructive sleep apnea is known to be affected by upper airway anatomy. To better understand the contribution of upper airway anatomy to pathways linking sleep apnea with impaired cognitive function, we investigated the association of upper airway anatomy with structural brain abnormalities. Based in the Multi-Ethnic Study of Atherosclerosis, a longitudinal cohort study of community-dwelling adults, a comprehensive sleep study and an MRI of the upper airway and brain were performed on 578 participants. Machine learning models were used to select from 74 upper airway measures those measures most associated with selected regional brain volumes and white matter hyperintensity volume. Linear regression assessed associations between the selected upper airway measures, sleep measures, and brain structure. Maxillary divergence was positively associated with hippocampus volume, and mandible length was negatively associated with total white and gray matter volume. Both coefficients were small (coefficients per standard deviation 0.063 mL, p = 0.04, and - 7.0 mL, p < 0.001 respectively), and not affected by adjustment for sleep study measures. Self-reported snoring >2 times per week was associated with larger hippocampus volume (coefficient 0.164 mL, p = 0.007), and higher percentage of time in the N3 sleep stage was associated with larger total white and gray matter volume (4.8 mL, p = 0.004). Despite associations of two upper airway anatomy measures with brain volume, the evidence did not suggest that these upper airway and brain structure associations were acting primarily through the pathway of sleep disturbance.

Effects of the antipsychotic quetiapine on sleep and breathing: a review of clinical findings and potential mechanisms

Quetiapine is an antipsychotic medication indicated for schizophrenia and bipolar disorder. However, quetiapine also has hypnotic properties and as such is increasingly being prescribed at low doses 'off-label' in people with insomnia symptoms. Pharmacologically, in addition to its dopaminergic properties, quetiapine also modulates multiple other transmitter systems involved in sleep/wake modulation and potentially breathing. However, very little is known about the impact of quetiapine on obstructive sleep apnoea (OSA), OSA endotypes including chemosensitivity, and control of breathing. Given that many people with insomnia also have undiagnosed OSA, it is important to understand the effects of quetiapine on OSA and its mechanisms. Accordingly, this concise review covers the existing knowledge on the effects of quetiapine on sleep and breathing. Further, we highlight the pharmacodynamics of quetiapine and its potential to alter key OSA endotypes to provide potential mechanistic insight. Finally, an agenda for future research priorities is proposed to fill the current key knowledge gaps.

Potential Therapeutic Targets in Obesity, Sleep Apnea, Diabetes, and Fatty Liver Disease

Obesity and metabolic syndrome affect the majority of the US population. Patients with obesity are at increased risk of developing type 2 diabetes (T2DM), obstructive sleep apnea (OSA), and metabolic dysfunction-associated steatotic liver disease (MASLD), each of which carry the risk of further complications if left untreated and lead to adverse outcomes. The rising prevalence of obesity and its comorbidities has led to increased mortality, decreased quality of life, and rising healthcare expenditures. This phenomenon has resulted in the intensive investigation of exciting therapies for obesity over the past decade, including more treatments that are still in the pipeline. In our present report, we aim to solidify the relationships among obesity, T2DM, OSA, and MASLD through a comprehensive review of current research. We also provide an overview of the surgical and pharmacologic treatment classes that target these relationships, namely bariatric surgery, the glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon receptor agonists.

Changes of Serum Adiponectin Level in Patients with Obstructive Sleep Apnea Hypopnea Syndrome and Its Relationship with Sleep Monitoring Indexes

Objective

To observe the changes of serum adiponectin (AP) levels in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and explore the correlation between serum AP and polysomnography (PSG) parameters in patients with OSAHS.

Methods

The data of subjects who underwent PSG at the hospital between January 2021 and December 2022 were collected retrospectively and divided into simple snoring group (AHI < 5 times/h, n = 45), mild OSAHS group (5 ≤ AHI < 15 times/h, n = 63), moderate OSAHS group (15 ≤ AHI ≤ 30 times/h, n = 52), and severe OSAHS group (AHI > 30 times/h, n = 60). The general data, PSG indices, and serological indices of the subjects were collected and compared between groups. Pearson correlation analysis and partial correlation analysis were employed to examine the correlation between serum AP level and PSG parameters. Ordered logistic regression was employed to analyze the risk factors influencing the severity of OSAHS. The predictive capability of the serum AP level in determining the occurrence of OSAHS was assessed using ROC. The serum AP levels of subjects with different subtypes of PSG indicators were compared.

Results

In the simple snoring group, mild OSAHS group, moderate OSAHS group, and severe OSAHS group, there were statistically significant differences in microarousal count, MAI, AHI, times of blood oxygen decreased by ≥ 3%, L-SaO2, and TS90% among the 4 groups (P < 0.05). The level of serum AP was positively correlated with L-SaO2 and negatively correlated with the proportion of REM, microarousal count, MAI, AHI, times of blood oxygen decreased by ≥ 3%, TS90%, and LP (P < 0.05). High AHI was a risk factor affecting the severity of OSAHS (95% CI: 1.446-4.170). The AUC of serum AP level in diagnosing OSAHS was 0.906 (95% CI: 0.8601-0.9521), and when the Youden Index was 0.678, the sensitivity was 88.9%, and the specificity was 78.9% (P < 0.0001). In the population with a high microarousal count, high AHI, and high times of blood oxygen decreased by ≥ 3% and high TS90%, the serum AP level was lower than that in the low-level population (P < 0.05). In the population with high L-SaO2, the serum AP level was higher than that in low-level population (P < 0.05).

Conclusion

The level of serum AP decreased with the increase of the disease severity of patients with OSAHS and demonstrates a significant predictive capability for the occurrence of OSAHS. Monitoring the level of serum AP can effectively forecast the risk of OSAHS. Furthermore, alterations in serum AP levels are associated with both hypoxemia and a heightened frequency of arousal in patients with OSAHS.

Effects of different treatments on metabolic syndrome in patients with obstructive sleep apnea: a meta-analysis

Background

Obstructive sleep apnea (OSA) and metabolic syndrome (MetS) often coexist, and the causal relationship between them is not yet clear; treatments for OSA include continuous positive airway pressure (CPAP), mandibular advancement device (MAD), surgery, and lifestyle intervention and so on. However, the effects of different treatments on metabolic syndrome in OSA patients are still under debate.

Objectives

Review the effects of different treatments on metabolic syndrome in OSA patients by meta-analysis.

Methods

we searched articles in PubMed, Embase, Cochrane Library, CNKI, CBM, and Wanfang data from database construction to Feb. 2024.RevMan5.4 and Stata software were used to conduct a meta-analysis of 22 articles.

Results

A total of 22 articles were finally included. The results showed that CPAP treatment could reduce the prevalence of metabolic syndrome in OSA patients in randomized controlled trials (RCTs) (RR = 0.82 [95% CI, 0.75 to 0.90]; p < 0.01) and single-arm studies (RR = 0.73 [95% CI, 0.63 to 0.84]; p < 0.01). As for metabolic syndrome components, CPAP treatment reduces blood pressure, fasting glucose (FG), triglycerides (TG), and waist circumference (WC) but can't affect high-density lipoprotein cholesterol (HDL-C) levels. Lifestyle intervention could significantly reduce the prevalence of metabolic syndrome in OSA patients (RR = 0.60 [95% CI, 0.48 to 0.74]; p < 0.01) and can lower blood pressure, fasting glucose, and waist circumference but can't affect the lipid metabolism of OSA patients. Upper airway surgery can only reduce TG levels in OSA patients (MD = -0.74 [95% CI, -1.35 to -0.13]; p = 0.02) and does not affect other components of metabolic syndrome. There is currently no report on the impact of upper airway surgery on the prevalence of metabolic syndrome. No study has reported the effect of MAD on metabolic syndrome in OSA patients.

Conclusion

We confirmed that both CPAP and lifestyle intervention can reduce the prevalence of MetS in OSA patients. CPAP treatment can lower blood pressure, fasting glucose, waist circumference, and triglyceride levels in OSA patients. Lifestyle intervention can lower blood pressure, fasting glucose, and waist circumference in OSA patients. Upper airway surgery can only reduce TG levels in OSA patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022326857.

Evaluation of risk factors for sleep-disordered breathing in dogs

BACKGROUND

Brachycephalic dogs display sleep-disordered breathing (SDB). The risk factors for SDB remain unknown.

OBJECTIVES

To identify risk factors for SDB. We hypothesized that brachycephaly, increasing severity of brachycephalic obstructive airway syndrome (BOAS), excess weight, and aging predispose to SDB.

ANIMALS

Sixty-three privately owned pet dogs were prospectively recruited: 28 brachycephalic and 35 normocephalic (mesaticephalic or dolicocephalic) dogs.

METHODS

Prospective observational cross-sectional study with convenience sampling. Recording with the neckband was done over 1 night at each dog's home. The primary outcome measure was the obstructive respiratory event index (OREI). Body condition score (BCS) was assessed, and BOAS severity was graded for brachycephalic dogs.

RESULTS

Brachycephaly was a significant risk factor for high OREI value (ratio of the geometric means 5.6, 95% confidence interval [CI] 3.2-9.9; P < .001) but aging was not (1.1, 95% CI 1.0-1.2; P = .2). Excess weight, defined as a BCS of over 5/9, (3.5, 95% CI 1.8-6.7; P < .001) was a significant risk factor. In brachycephalic dogs, BOAS-positive class (moderate or severe BOAS signs) was a significant risk factor (2.5, 95% CI 1.1-5.6; P = .03).

CONCLUSIONS AND CLINICAL IMPORTANCE

Brachycephaly decreases welfare in a multitude of ways, including disrupting sleep. Brachycephaly, increasing severity of BOAS and excess weight are risk factors for obstructive SDB.

Key genes involved in nonalcoholic steatohepatitis improvement after bariatric surgery

Background

Nonalcoholic steatohepatitis (NASH) is the advanced stage of nonalcoholic fatty liver disease (NAFLD), one of the most prevalent chronic liver diseases. The effectiveness of bariatric surgery in treating NASH and preventing or even reversing liver fibrosis has been demonstrated in numerous clinical studies, but the underlying mechanisms and crucial variables remain unknown.

Methods

Using the GSE135251 dataset, we examined the gene expression levels of NASH and healthy livers. Then, the differentially expressed genes (DEGs) of patients with NASH, at baseline and one year after bariatric surgery, were identified in GSE83452. We overlapped the hub genes performed by protein-protein interaction (PPI) networks and DEGs with different expression trends in both datasets to obtain key genes. Genomic enrichment analysis (GSEA) and genomic variation analysis (GSVA) were performed to search for signaling pathways of key genes. Meanwhile, key molecules that regulate the key genes are found through the construction of the ceRNA network. NASH mice were induced by a high-fat diet (HFD) and underwent sleeve gastrectomy (SG). We then cross-linked the DEGs in clinical and animal samples using quantitative polymerase chain reaction (qPCR) and validated the key genes.

Results

Seven key genes (FASN, SCD, CD68, HMGCS1, SQLE, CXCL10, IGF1) with different expression trends in GSE135251 and GSE83452 were obtained with the top 30 hub genes selected by PPI. The expression of seven key genes in mice after SG was validated by qPCR. Combined with the qPCR results from NASH mice, the four genes FASN, SCD, HMGCS1, and CXCL10 are consistent with the biological analysis. The GSEA results showed that the 'cholesterol homeostasis' pathway was enriched in the FASN, SCD, HMGCS1, and SQLE high-expression groups. The high-expression groups of CD68 and CXCL10 were extremely enriched in inflammation-related pathways. The construction of the ceRNA network obtained microRNAs and ceRNAs that can regulate seven key genes expression.

Conclusion

In summary, this study contributes to our understanding of the mechanisms by which bariatric surgery improves NASH, and to the development of potential biomarkers for the treatment of NASH.

Development and Validation of a Nomogram for Predicting Obstructive Sleep Apnea Severity in Children

Purpose

The clinical presentation of Obstructive Sleep Apnea (OSA) in children is insidious and harmful. Early identification of children with OSA, particularly those at a higher risk for severe symptoms, is essential for making informed clinical decisions and improving long-term outcomes. Therefore, we developed and validated a risk prediction model for severity in Chinese children with OSA to effectively identify children with moderate-to-severe OSA in a clinical setting.

Patients and Methods

From June 2023 to September 2023, we retrospectively analyzed the medical records of 367 Children diagnosed with OSA through portable bedside polysomnography (PSG). Predictor variables were screened using the least absolute shrinkage and selection operator (LASSO) and logistic regression techniques to construct nomogram to predict the severity of OSA. Receiver operating characteristic curve (ROC), calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were used to determine the discrimination, calibration, and clinical usefulness of the nomogram.

Results

A total of 367 children with a median age of 84 months were included in this study. Neck circumference, ANB, gender, learning problem, and level of obstruction were identified as independent risk factors for moderate-severe OSA. The consistency indices of the nomogram in the training and validation cohorts were 0.841 and 0.75, respectively. The nomogram demonstrated a strong concordance between the predicted probabilities and the observed probabilities for children diagnosed with moderate-severe OSA. With threshold probabilities ranging from 0.1 to 1.0, the predictive model demonstrated strong predictive efficacy and yielded improved net benefit for clinical decision-making. ROC analysis was employed to classify the children into high and low-risk groups, utilizing the Optimal Cutoff value of 0.39.

Conclusion

A predictive model using LASSO regression was developed and validated for children with varying levels of OSA. This model identifies children at risk of developing OSA at an early stage.

Recommended assessment and management of sleep disordered breathing in patients with atrial fibrillation, hypertension and heart failure: Taiwan Society of Cardiology/Taiwan Society of sleep Medicine/Taiwan Society of pulmonary and Critical Care Medicine joint consensus statement

Sleep disordered breathing (SDB) is highly prevalent and may be linked to cardiovascular disease in a bidirectional manner. The Taiwan Society of Cardiology, Taiwan Society of Sleep Medicine and Taiwan Society of Pulmonary and Critical Care Medicine established a task force of experts to evaluate the evidence regarding the assessment and management of SDB in patients with atrial fibrillation (AF), hypertension and heart failure with reduced ejection fraction (HFrEF). The GRADE process was used to assess the evidence associated with 15 formulated questions. The task force developed recommendations and determined strength (Strong, Weak) and direction (For, Against) based on the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use. The resulting 11 recommendations are intended to guide clinicians in determining which the specific patient-care strategy should be utilized by clinicians based on the needs of individual patients.

Risk of Sleep Apnea Is Associated with Abdominal Obesity Among Asian Americans: Comparing Waist-to-Hip Ratio and Body Mass Index

OBJECTIVE

This study examines associations between the risk of sleep apnea and abdominal obesity (assessed by waist-to-hip ratio (WHR)) and general obesity (assessed by body mass index (BMI)) in a sample of Chinese and Korean American immigrants.

METHODS

The dataset included Chinese and Korean participants aged 50-75 who were recruited from primary care physicians' clinics from April 2018 to June 2020 in the Baltimore-Washington D.C. Metropolitan area (n = 394). Abdominal obesity was determined if WHR ≥ 0.9 in men and WHR ≥ 0.85 in women. General obesity was determined if BMI ≥ 30. The risk of sleep apnea was determined by using the Berlin questionnaire. Poisson regression models examined associations between sleep apnea risk and obesity. Models controlled for socio-demographic risk factors.

RESULTS

Twelve percent of the study participants were classified as a high risk for sleep apnea, and 75% had abdominal obesity whereas 6.4% had general obesity. High risk of sleep apnea was positively associated with abdominal obesity (PR = 1.31, 95% CI: 1.17-1.47) and general obesity (PR = 2.19, 95% CI: 0.90-5.32), marginally significant at p < 0.1).

CONCLUSIONS

Chinese and Korean immigrants living in the USA who are at high risk of sleep apnea have higher abdominal obesity, even after accounting for sociodemographic characteristics. Abdominal obesity may be a better indicator than general obesity when examining the risk of sleep apnea among Asian Americans.

INFORMATION ON CLINICAL TRIAL

Name: Screening To Prevent ColoRectal Cancer (STOP CRC) among At-Risk Asian American Primary Care Patients NCT Number: NCT03481296; Date of registration: March 29, 2018 URL: https://clinicaltrials.gov/ct2/show/NCT03481296?term=Sunmin+Lee&draw=2&rank=1.

Use of Ultrasound to Verify the Impact of Telemedicine Myofunctional Therapy on Sleep Apnea Syndrome: Study Protocol Proposal

The anatomy of the upper airways influences the risk of obstructive sleep apnea (OSA). The size of soft tissue structures, such as the tongue, soft palate, and lateral walls of the pharynx, contributes to the pathogenesis of OSA. New lines of treatment for sleep apnea, such as myofunctional therapy (MT), aim to strengthen the oropharyngeal musculature to improve the defining parameters of apnea. The present protocol uses ultrasound imaging to measure the size of the lingual musculature non-invasively and cost-effectively and evaluates the changes in its morphology. Eligible patients include those with OSA who have undergone submental cervical ultrasound and drug-induced sleep endoscopy before starting MT with the AirwayGym app. Follow-up evaluations are conducted at 3 months after beginning treatment. Patients diagnosed with OSA via questionnaires and polysomnography or respiratory polygraphy are evaluated anatomically and functionally using the Iowa Oral Performance Instrument, a tongue digital spoon, somnoscopy, and submental cervical ultrasound to assess their responses to the AirwayGym app. The lingual thickness (mm) and volume (cm3) and the distance between both lingual arteries (mm) are measured. The AirwayGym app helps users and therapists monitor the patient performance of MT. Incorporating submental ultrasound can be a useful non-invasive tool to evaluate OSA and MT.

Effect of Weight Loss on the Apnea Hypopnea Index is Related to Waist Circumference in Chinese Adults with Overweight and Obesity

Purpose

The present study aimed to evaluate the efficiency of traditional anthropometric and body composition parameters in predicting apnea hypopnea index (AHI) change after weight loss.

Patients and Methods

Chinese adults with overweight and obesity were included into this study containing two parts. A cross-sectional study was conducted in 137 individuals using the baseline data from two weight loss intervention trials. The second part was the weight-loss intervention study conducted in 60 overweight and obese patients with obstructive sleep apnea (OSA). All participants underwent physical examination, bioelectrical impedance analysis and overnight polysomnography. Multivariate linear regression models were used to identify the most accurate parameters to predict AHI and the mediation analysis to evaluate the mediators between weight loss and AHI reduction.

Results

Waist circumference (WC), body mass index and fat mass were positively associated with AHI after adjusting multiple collinearities in the cross-sectional study. After weight-loss intervention, body weight decreased from 94.6 ± 15.3 to 88.0 ± 13.9 kg, and AHI decreased from 41.9 (13.0,66.9) to 20.7 (8.7,51.2) events/h. Among these parameters, only percentage changes in WC and AHI across the intervention were positively intercorrelated after controlling for covariates (adjusted r = 0.271, P = 0.041). The mediation analysis supported WC as a mediator between weight loss and AHI reduction (standardized indirect effect [95% CI] = 4.272[0.936,7.999]).

Conclusion

Both general and abdominal obesity are of high prognostic value for OSA. WC as an easily accessible parameter mediates the effects of weight loss in decreasing OSA severity.

The role of the tongue in post-stroke dysphagia and obstructive sleep apnea: Correlation with sonography measurement

OBJECTIVE

Obstructive sleep apnea (OSA) is a common risk factor for stroke, and dysphagia and pneumonia are both well-known complications of stroke. The development of these conditions is related to the oropharyngeal structures. We investigated whether specific structural features of the tongue may lead to the development of these complications.

METHODS

Patients with ischemic stroke who required admission and community-dwelling elderly controls were enrolled. The participants underwent tongue measurements by received hand-held ultrasound, and received questionnaires to evaluate sleep quality and daytime sleepiness. The patient group also underwent objective sleep measurement by actigraphy and the 3-Step Swallowing Test (3-SSS). Sleep parameters and outcomes were analyzed.

RESULTS

Patient with ischemic stroke had significantly thicker tongue than controls (6.53 cm v. 6.05 cm, p = 0.002). Multiple logistic regression analysis revealed that the anatomical parameters of the tongue in patients with stroke were significantly correlated with parameters of OSA, and the thickness of the tongue was positively correlated with the development of OSA (p = 0.024) and pneumonia (p = 0.048).

CONCLUSIONS

A thicker-than average tongue may be a risk factor for OSA and pneumonia in patient with stroke. Hand-held ultrasound can be used to identify these anatomical features. Further studies are warranted to clarify the role of the tongue in these post-stroke complications.

The effect of obstructive sleep apnea severity on PTSD symptoms during the course of esketamine treatment: a retrospective clinical study

STUDY OBJECTIVES

Intranasal administration of esketamine is Food and Drug Administration-approved for treatment-resistant depression. In a recent retrospective case series, we show that it has promise in reducing symptoms of posttraumatic stress disorder (PTSD) as well. Untreated obstructive sleep apnea (OSA) is prevalent among veterans with PTSD and has been shown to interfere with other PTSD treatments. In the current study, we examined whether OSA impacts esketamine's effectiveness in reducing symptoms of PTSD or depression.

METHODS

Participants were 60 veterans with a diagnosis of major depressive disorder and PTSD who received intranasal esketamine treatment at the San Diego Veterans Affairs (VA) Medical Center. We used growth-curve modeling to examine changes in depression and PTSD symptoms following esketamine treatments and, in the subset of individuals screened for OSA (n = 24, all prescribed positive airway pressure therapy), examined the impacts of OSA severity on these trajectories.

RESULTS

We first showed that both PTSD and depressive symptoms significantly decreased over the course of esketamine treatment. In the subset of veterans screened for OSA, individuals with lower OSA severity reported the greatest reduction in PTSD symptoms, while veterans with the most severe OSA reported the least reduction in PTSD symptoms. Depression response was not affected by severity of OSA in this analysis.

CONCLUSIONS

Veterans with PTSD and depression tend to benefit from esketamine treatment, but OSA may interfere with esketamine effectiveness. Comorbid OSA should be assessed for and treated to maximize esketamine's benefits in PTSD.

CITATION

Titone MK, Hunt C, Bismark A, et al. The effect of obstructive sleep apnea severity on PTSD symptoms during the course of esketamine treatment: a retrospective clinical study. J Clin Sleep Med. 2023;19(12):2043-2051.

The association of upper airway anatomy with cognitive test performance: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Numerous upper airway anatomy characteristics are risk factors for sleep apnea, which affects 26% of older Americans, and more severe sleep apnea is associated with cognitive impairment. This study explores the pathophysiology and links between upper airway anatomy, sleep, and cognition.

METHODS

Participants in the Multi-Ethnic Study of Atherosclerosis underwent an upper airway MRI, polysomnography to assess sleep measures including the apnea-hypopnea index (AHI) and completed the Cognitive Abilities Screening Instrument (CASI). Two model selection techniques selected from among 67 upper airway measures those that are most strongly associated with CASI score. The associations of selected upper airway measures with AHI, AHI with CASI score, and selected upper airway anatomy measures with CASI score, both alone and after adjustment for AHI, were assessed using linear regression.

RESULTS

Soft palate volume, maxillary divergence, and upper facial height were significantly positively associated with higher CASI score, indicating better cognition. The coefficients were small, with a 1 standard deviation (SD) increase in these variables being associated with a 0.83, 0.75, and 0.70 point higher CASI score, respectively. Additional adjustment for AHI very slightly attenuated these associations. Larger soft palate volume was significantly associated with higher AHI (15% higher AHI (95% CI 2%,28%) per SD). Higher AHI was marginally associated with higher CASI score (0.43 (95% CI 0.01,0.85) per AHI doubling).

CONCLUSIONS

Three upper airway measures were weakly but significantly associated with higher global cognitive test performance. Sleep apnea did not appear to be the mechanism through which these upper airway and cognition associations were acting. Further research on the selected upper airway measures is recommended.

Body composition changes and their relationship with obstructive sleep apnoea symptoms, severity: The Sleeping Well Trial

BACKGROUND & AIMS

Obstructive sleep apnoea (OSA) and obesity share a complex bi-directional relationship as location of body fat and changes in regional body composition may be more important for OSA improvement than changes in total body weight only. The aim of this study was to evaluate the impact of a 6-month weight loss intervention for adults newly diagnosed with moderate-severe OSA and obesity on regional body composition. The secondary aims evaluated the relationship between changes in OSA symptoms and severity and anthropometry and regional body composition during the first 12-months after commencing CPAP and explored differences in outcomes between males and females.

METHODS

Participants (n = 59) received CPAP overnight at home alongside a 6-month modified fasting intervention with 12-months follow up. Regional body composition was measured by Dual X-ray absorptiometry, (DXA) and anthropometry before and after the lifestyle intervention. OSA severity was measured using the apnoea hypopnea index via overnight polysomnography and OSA symptoms were measured using the Epworth Sleepiness scale.

RESULTS

Forty-seven adults (74% male) had complete measures available with a mean age of 50.0 y (SD 11.0) and BMI 34.1 kg/m2 (SD 5.0). Following the intervention average fat mass changed by -5.27 kg (5.36), p < 0.001) and visceral adipose tissue (-0.63 kg (0.67), p < 0.001) significantly decreased in males only with a maintenance of fat-free mass (mean -0.41 kg (1.80), p = 0.18). Females (n = 12) had significant decreases in waist circumference (mean -3.36 cm (3.18) p < 0.01), android lean (-0.12 kg (0.04), p < 0.05) and android total mass (-0.28 kg (0.39), p < 0.05) only. Regional body composition changes in males were positively associated with improvements in OSA severity (p < 0.01) but not OSA symptoms.

CONCLUSION

Improvements in regional body composition were seen in males only which were related to improvements in OSA severity but not OSA symptoms. Females may exhibit different OSA pathophysiology and may require different treatment approaches.

TRIAL REGISTRATION

https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=369975&isReview=trueAACTRN12616000203459 ACTRN12616000203459.

Relationship between Symptom Profiles and Endotypes among Patients with Obstructive Sleep Apnea: A Latent Class Analysis

Rationale: Obstructive sleep apnea (OSA) is a heterogeneous syndrome with various endotypic traits and symptoms. A link among symptoms, endotypes, and disease prognosis has been proposed but remains unsupported by empirical data. Objectives: To link symptom profiles and endotypes by clustering endotypic traits estimated using polysomnographic signals. Methods: We recruited 509 patients with moderate to severe OSA from a single sleep center. Polysomnographic data were collected between May 2020 and January 2022. Endotypic traits, namely arousal threshold, upper airway collapsibility, loop gain, and upper airway muscle compensation, were retrieved using polysomnographic signals during non-rapid eye movement periods. We used latent class analysis to group participants into endotype clusters. Demographic and polysomnographic parameter differences were compared between clusters, and associations between endotype clusters and symptom profiles were examined using logistic regression analyses. Results: Three endotype clusters were identified, characterized by high collapsibility/loop gain, low arousal threshold, and low compensation, respectively. Patients in each cluster exhibited similar demographic characteristics, but those in the high collapsibility/loop gain cluster had the highest proportion of obesity and severe oxygen desaturation observed in polysomnographic studies. The low compensation cluster was characterized by fewer sleepy symptoms and exhibited a lower rate of diabetes mellitus. Compared with the excessively sleepy group, disturbed sleep symptoms were associated with the low arousal threshold cluster (odds ratio, 1.89; 95% confidence interval, 1.16-3.10). Excessively sleepy symptoms were associated with the high collapsibility/loop gain cluster (odds ratio, 2.16; 95% confidence interval, 1.39-3.37) compared with the minimally symptomatic group. Conclusions: Three pathological endotype clusters were identified among patients with moderate to severe OSA, each exhibiting distinct polysomnographic characteristics and clinical symptom profiles.

The relationship of tongue fat content and efficacy of uvulopalatopharyngoplasty in Chinese patients with obstructive sleep apnea

BACKGROUND

To investigate the relationship between tongue fat content and severity of obstructive sleep apnea (OSA) and its effects on the efficacy of uvulopalatopharyngoplasty (UPPP) in the Chinese group.

METHOD

Fifty-two participants concluded to this study were diagnosed as OSA by performing polysomnography (PSG) then they were divided into moderate group and severe group according to apnea hypopnea index (AHI). All of them were also collected a series of data including age, BMI, height, weight, neck circumference, abdominal circumference, magnetic resonance imaging (MRI) of upper airway and the score of Epworth Sleepiness Scale (ESS) on the morning after they completed PSG. The relationship between tongue fat content and severity of OSA as well as the association between tongue fat content in pre-operation and surgical efficacy were analyzed.Participants underwent UPPP and followed up at 3rd month after surgery, and they were divided into two groups according to the surgical efficacy.

RESULTS

There were 7 patients in the moderate OSA group and 45 patients in the severe OSA group. The tongue volume was significantly larger in the severe OSA group than that in the moderate OSA group. There was no difference in tongue fat volume and tongue fat rate between the two groups. There was no association among tongue fat content, AHI, obstructive apnea hypopnea index, obstructive apnea index and Epworth sleepiness scale (all P > 0.05), but tongue fat content was related to the lowest oxygen saturation (r=-0.335, P < 0.05). There was no significantly difference in pre-operative tongue fat content in two different surgical efficacy groups.

CONCLUSIONS

This study didn't show an association between tongue fat content and the severity of OSA in the Chinese group, but it suggested a negative correlation between tongue fat content and the lowest oxygen saturation (LSaO2). Tongue fat content didn't influence surgical efficacy of UPPP in Chinese OSA patients.

TRIAL REGISTRATION

This study didn't report on a clinical trial, it was retrospectively registered.

The effect of surgical weight loss on upper airway fat in obstructive sleep apnoea

PURPOSE

Obesity is a reversible risk factor for obstructive sleep apnoea (OSA). Weight loss can potentially improve OSA by reducing fat around and within tissues surrounding the upper airway, but imaging studies are limited. Our aim was to study the effects of large amounts of weight loss on the upper airway and volume and fat content of multiple surrounding soft tissues.

METHODS

Participants undergoing bariatric surgery were recruited. Magnetic resonance imaging (MRI) was performed at baseline and six-months after surgery. Volumetric analysis of the airway space, tongue, pharyngeal lateral walls, and soft palate were performed as well as calculation of intra-tissue fat content from Dixon imaging sequences.

RESULTS

Among 18 participants (89% women), the group experienced 27.4 ± 4.7% reduction in body weight. Velopharyngeal airway volume increased (large effect; Cohen's d [95% CI], 0.8 [0.1, 1.4]) and tongue (large effect; Cohen's d [95% CI], - 1.4 [- 2.1, - 0.7]) and pharyngeal lateral wall (Cohen's d [95% CI], - 0.7 [- 1.2, - 0.1]) volumes decreased. Intra-tissue fat decreased following weight loss in the tongue, tongue base, lateral walls, and soft palate. There was a greater effect of weight loss on intra-tissue fat than parapharyngeal fat pad volume (medium effect; Cohen's d [95% CI], - 0.5 [- 1.2, 0.1], p = 0.083).

CONCLUSION

The study showed an increase in velopharyngeal volume, reduction in tongue volume, and reduced intra-tissue fat in multiple upper airway soft tissues following weight loss in OSA. Further studies are needed to assess the effect of these anatomical changes on upper airway function and its relationship to OSA improvement.

Obstructive Sleep Apnea and Cardiovascular Disease: Where Do We Stand?

Obstructive sleep apnea is common in adults with cardiovascular disease. Accumulating evidence suggests an association between obstructive sleep apnea and cardiovascular disease independent of the traditionally recognized cardiovascular disease risk factors. Observational studies indicate that obstructive sleep apnea is a risk factor for development of cardiovascular disease and that alleviation of obstructive events with positive airway pressure may improve cardiovascular disease outcomes. However, recent randomized controlled trials have not supported the beneficial effect of positive airway pressure in cardiac populations with concomitant obstructive sleep apnea. Some evidence suggests that the relationship between obstructive sleep apnea and traditionally recognized cardiovascular disease risk factors is bidirectional, suggesting that patients with cardiovascular disease may also develop obstructive sleep apnea and that efficient treatment of cardiovascular disease may improve obstructive sleep apnea. Recent data also indicate that the apnea-hypopnea index, which is commonly used as a diagnostic measure of obstructive sleep apnea severity, has limited value as a prognostic measure for cardiovascular disease outcomes. Novel markers of obstructive sleep apnea-associated hypoxic burden and cardiac autonomic response seem to be strong predictors of adverse cardiovascular disease outcomes and response to treatment of obstructive sleep apnea. This narrative review and position paper from the Turkish Collaboration of Sleep Apnea Cardiovascular Trialists aims to update the current evidence about the relationship between obstructive sleep apnea and cardiovascular disease and, consequently, raise awareness for health professionals who deal with cardiovascular and respiratory diseases to improve the ability to direct resources at patients most likely to benefit from treatment of obstructive sleep apnea and optimize treatment of the coexisting cardiovascular diseases. Moreover, the Turkish Collaboration of Sleep Apnea Cardiovascular Trialists aims to contribute to strengthening the efforts of the International Collaboration of Sleep Apnea Cardiovascular Trialists in this context.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Pharmacotherapy for obstructive sleep apnea: targeting specific pathophysiological traits

INTRODUCTION

The pathophysiology of obstructive sleep apnea (OSA) is multi-factorial and complex. Varying OSA's pathophysiological traits have been identified, including pharyngeal collapsibility, upper airway muscle reactivity, arousal threshold, and regulation of the ventilatory drive. Being CPAP of difficult tolerance and other interventions reserved to specific subpopulations new pharmacological treatments for OSA might be resolutive.

AREAS COVERED

Several existing and newly developed pharmacological drugs can impact one or more endotypes and could therefore be proposed as treatment options for sleep disordered breathing. With this review we will explore different pathophysiological traits as new targets for OSA therapy. This review will summarize the most promising pharmacological treatment for OSA accordingly with their mechanisms of action on upper airway collapsibility, muscle responsiveness, arousal threshold, and loop gain.

EXPERT OPINION

Only understanding the pathophysiological traits causing OSA in each patient and placing the disease in the framework of patient comorbidities, we will be able to evolve interventions toward OSA. The development of new drug's combinations will permit different approaches and different choices beside conventional treatments. In the next future, we hope that sleep specialists will select the treatment for a specific patient on the base of its pathophysiology, defining a precision medicine for OSA.