International Consensus Document on Obstructive Sleep Apnea. / Documento internacional de consenso sobre apnea obstructiva del sueño.

The main aim of this international consensus document on obstructive sleep apnea is to provide guidelines based on a critical analysis of the latest literature to help health professionals make the best decisions in the care of adult patients with this disease. The expert working group was formed primarily of 17 scientific societies and 56 specialists from a wide geographical area (including the participation of 4 international societies), an expert in methodology, and a documentalist from the Iberoamerican Cochrane Center. The document consists of a main section containing the most significant innovations and a series of online manuscripts that report the systematic literature searches performed for each section of the international consensus document. This document does not discuss pediatric patients or the management of patients receiving chronic non-invasive mechanical ventilation (these topics will be addressed in separate consensus documents).

Telemedicine Strategy to Rescue CPAP Therapy in Sleep Apnea Patients with Low Treatment Adherence: A Pilot Study.

Patients with sleep apnea are usually treated with continuous positive airway pressure (CPAP). This therapy is very effective if the patient's adherence is satisfactory. However, although CPAP adherence is usually acceptable during the first months of therapy, it progressively decreases, with a considerable number of patients accepting average treatment duration below the effectiveness threshold (4 h/night). Herein, our aim was to describe and evaluate a novel telemedicine strategy for rescuing CPAP treatment in patients with low adherence after several months/years of treatment. This two-week intervention includes (1) patient support using a smartphone application, phone and voice recorder messages to be answered by a nurse, and (2) daily transmission and analysis of signals from the CPAP device and potential variation of nasal pressure if required. On average, at the end of the intervention, median CPAP adherence considerably increased by 2.17 h/night (from 3.07 to 5.24 h/night). Interestingly, the procedure was able to markedly rescue CPAP adherence: the number of patients with poor adherence (<4 h/night) was considerably reduced from 38 to 7. After one month, adherence improvement was maintained (median 5.09 h/night), and only 13 patients had poor adherence (<4 h/night). This telemedicine intervention (103€ per included patient) is a cost-effective tool for substantially increasing the number of patients with CPAP adherence above the minimum threshold for achieving positive therapeutic effects.

Ambulatory circadian monitoring in sleep disordered breathing patients and CPAP treatment.

Our aim was to evaluate the circadian rhythm of motor activity, body position and integrated variable TAP (composed by wrist Temperature, motor Activity and body Position) in Sleep Disordered Breathing (SDB), its relation to SDB severity and the effect of continuous positive airway pressure (CPAP) on these circadian rhythms. To do this, we monitored motor activity and body position rhythms of 78 SDB patients (53.3 ± 1.2 years old, 26.9% women) and 32 healthy subjects (51.4 ± 3.2 years old, 43.8% women) for 1 week. On the last day of that week, SDB patients underwent a polysomnography followed by a Maintenance of Wakefulness Test, Multiple Sleep Latency Test and Sustained Attention to Response Task protocol. A subgroup of 18 moderate to severe SDB patients was treated with CPAP and monitored again after 3 months under treatment. A non-parametrical analysis was performed to characterize the circadian patterns to assess differences between groups and associations between sleep and circadian parameters. Circadian variables were altered in SDB, exhibiting a direct relationship to SDB severity. The motor activity pattern showed a clear improvement with CPAP treatment. Thus, circadian ambulatory monitoring, including the integrated variable TAP, could be used to evaluate the circadian alterations caused by SDB and activity pattern to monitor the effect of CPAP treatment.

Alternative Procedure to Individual Nasal Pressure Titration for Sleep Apnea.

In the treatment of obstructive sleep apnea (OSA), the current standard of "CPAP titration" in the laboratory or at home is a resource demanding and costly approach that, in developed economies, markedly augments healthcare costs and in low resource economies precludes access to care altogether. Here, we discuss that current guidelines for titration of CPAP could be obviated by taking a different route that in many ways is similar to the institution of treatment in many other medical conditions. To this effect, we present novel population based data from 16,780 patients, showing that after individualized and labor-intensive and expensive CPAP titration, 86.4% of OSA patients are treated with nasal pressure settings within the range of 9 ± 2 cmH2O, and review the literature to justify the potential adoption of a standard therapeutic CPAP setting as the initial intervention which would be subsequently followed by any necessary adjustments in only a minority of patients who would not derive the necessary benefit from such standardized intervention. Assuming an 80-85% success rate as derived from our analyses, our personal view if extensively adopted could radically reduce healthcare costs and enable markedly improve access to diagnostics.

The effect of chronic intermittent hypoxia in cardiovascular gene expression is modulated by age in a mice model of sleep apnea.

STUDY OBJECTIVES: Chronic intermittent hypoxia (CIH) is a major determinant in obstructive sleep apnea cardiovascular morbidity and this effect is influenced by age. The objective of the present study was to assess the differential molecular mechanisms at gene-level expression involved in the cardiovascular remodeling induced by CIH according to chronological age. METHODS: Two- and 18-month-old mice (N = 8 each) were subjected to CIH or normoxia for 8 weeks. Total messenger RNA (mRNA) was extracted from left ventricle myocardium and aortic arch, and gene expression of 46 intermediaries of aging, oxidative stress, and inflammation was measured by quantitative real-time polymerase chain reaction. RESULTS: Cardiac gene expression of Nrf2 (2.05-fold increase, p < 0.001), Sod2 (1.9-fold increase, p = 0.035), Igf1r (1.4-fold increase, p = 0.028), Mtor (1.8-fold increase, p = 0.06), Foxo3 (1.5-fold increase, p = 0.020), Sirt4, Sirt6, and Sirt7 (1.3-fold increase, p = 0.012; 1.1-fold change, p = 0.031; 1.3-fold change, p = 0.029) was increased after CIH in young mice, but not in old mice. In aortic tissue, endothelial isoform of nitric oxide synthase was reduced in young mice (p < 0.001), Nrf2 was reduced in 80% (p < 0.001) in young mice and 45% (p = 0.07) in old mice, as its downstream antioxidant target Sod2 (82% reduced, p < 0.001). IL33. CONCLUSIONS: CIH effect in gene expression is organ-dependent, and is modulated by age. CIH increased transcriptional expression of genes involved in cardioprotection and cell survival in young, but not in old mice. In aortic tissue, CIH reduced gene expression related to an antioxidant response in both young and old mice, suggesting vascular oxidative stress and a proaging process.

Low-cost, easy-to-build noninvasive pressure support ventilator for under-resourced regions: open source hardware description, performance and feasibility testing.

AIM: Current pricing of commercial mechanical ventilators in low-/middle-income countries (LMICs) markedly restricts their availability, and consequently a considerable number of patients with acute/chronic respiratory failure cannot be adequately treated. Our aim was to design and test an affordable and easy-to-build noninvasive bilevel pressure ventilator to allow a reduction in the serious shortage of ventilators in LMICs. METHODS: The ventilator was built using off-the-shelf materials available via e-commerce and was based on a high-pressure blower, two pressure transducers and an Arduino Nano controller with a digital display (total retail cost <75 USD), with construction details provided open source for free replication. The ventilator was evaluated, and compared with a commercially available device (Lumis 150 ventilator; Resmed, San Diego, CA, USA): 1) in the bench setting using an actively breathing patient simulator mimicking a range of obstructive/restrictive diseases; and b) in 12 healthy volunteers wearing high airway resistance and thoracic/abdominal bands to mimic obstructive/restrictive patients. RESULTS: The designed ventilator provided inspiratory/expiratory pressures up to 20/10 cmH2O, respectively, with no faulty triggering or cycling; both in the bench test and in volunteers. The breathing difficulty score rated (1-10 scale) by the loaded breathing subjects was significantly (p<0.005) decreased from 5.45±1.68 without support to 2.83±1.66 when using the prototype ventilator, which showed no difference with the commercial device (2.80±1.48; p=1.000). CONCLUSION: The low-cost, easy-to-build noninvasive ventilator performs similarly to a high-quality commercial device, with its open-source hardware description, which will allow for free replication and use in LMICs, facilitating application of this life-saving therapy to patients who otherwise could not be treated.

Lung cancer aggressiveness in an intermittent hypoxia murine model of postmenopausal sleep apnea.

OBJECTIVE: Intermittent hypoxia (IH)-a hallmark of obstructive sleep apnea (OSA)-enhances lung cancer progression in mice via altered host immune responses that are also age and sex-dependent. However, the interactions of menopause with IH on tumor malignant properties remain unexplored. Here, we aimed to investigate lung cancer outcomes in the context of ovariectomy (OVX)-induced menopause in a murine model of OSA. METHODS: Thirty-four female mice (C57BL/6, 12-week-old) were subjected to bilateral OVX or to Sham intervention. Six months after surgery, mice were pre-exposed to either IH or room air (RA) for 2 weeks. Then, 10 lung carcinoma (LLC1) cells were injected subcutaneously in the left flank, with IH or RA exposures continued for 4 weeks. Tumor weight, tumor invasion, and spontaneous lung metastases were assessed. Tumor-associated macrophages (TAMs) were isolated and subjected to flow cytometry polarity evaluation along with assessment of TAMs modulation of LLC1 proliferation in vitro. To determine the effect of IH and OVX on each experimental variable, a two-way analysis of variance was performed. RESULTS: IH and OVX promoted a similar increase in tumor growth (∼2-fold; P = 0.05 and ∼1.74-fold; P < 0.05, respectively), and OVX-IH further increased it. Regarding lung metastasis, the concurrence of OVX in mice exposed to IH enhanced the number of metastases (23.7 ±â€Š8.0) in comparison to those without OVX (7.9 ±â€Š2.8; P < 0.05). The pro-tumoral phenotype of TAMS, assessed as M2/M1 ratio, was increased in OVX (0.06 ±â€Š0.01; P < 0.01) and IH (0.06 ±â€Š0.01; P < 0.01) compared with sham/RA conditions (0.14 ±â€Š0.03). The co-culture of TAMS with naive LLC1 cells enhanced their proliferation only under IH. CONCLUSION: In female mice, both the IH that is characteristically present in OSA and OVX as a menopause model emerge as independent contributors that promote lung cancer aggressiveness and seemingly operate through alterations in the host immune response.

Mobile health application to support CPAP therapy in obstructive sleep apnoea: design, feasibility and perspectives.

BACKGROUND: Current continuous positive airway pressure (CPAP) devices can be monitored remotely; however, in-person visits are kept for clinical follow-up in order to promote CPAP use and resolve potential side-effects. Mobile health is a promising way to provide remote and easy clinical control for CPAP follow-up and support. We aimed to evaluate the feasibility and acceptance by obstructive sleep apnoea (OSA) patients and healthcare professionals of a newly designed mobile app (Appnea-Q) to promote clinical control through a self-monitoring tool for patients with CPAP supervised by sleep professionals. METHODS: Appnea-Q incorporates a simple follow-up questionnaire with automated responses, together with frequent problems and lifestyle recommendations sections. Feasibility, acceptance and usefulness were assessed. First, an internal validation was performed during outpatient CPAP follow-up visits with sleep professionals from various sleep units. Second, an external validation was performed in a subgroup of 15 patients at home. RESULTS: Most patients (n=75) considered the app useful and were willing to use it and recommend it (72-88%). Up to 64.87% agreed on its capacity to reduce hospital visits. Appnea-Q was rated as acceptable (79.37±19.29) by the system usability score. Sleep professionals (n=30) concurred on its usefulness for OSA patient follow-up, particularly during the first month of CPAP therapy. The external validation showed its feasibility among 11 out of 15 patients and their data were received accordingly on the professionals' web platform. CONCLUSIONS: According to our validation process, and the viewpoints of the patients and professionals, our new mobile app is a feasible and well-received tool for personal OSA management. Future clinical trials should substantiate its performance and cost-effectiveness in the clinical arena.

Effect of obstructive sleep apnoea and its treatment with continuous positive airway pressure on the prevalence of cardiovascular events in patients with acute coronary syndrome (ISAACC study): a randomised controlled trial.

BACKGROUND: Despite the improvement in the prognosis of acute coronary syndrome (ACS), substantial morbidity and mortality remain. We aimed to evaluate the effect of obstructive sleep apnoea (OSA) and its treatment with continuous positive airway pressure (CPAP) on the clinical evolution of patients with ACS. METHODS: We designed a multicentre, open-label, parallel-group, randomised controlled trial of patients with ACS at 15 hospitals in Spain. Eligible non-sleepy patients were men and women aged 18 years and older, admitted to hospital for documented symptoms of ACS. All patients underwent respiratory polygraphy during the first 24-72 h after admission. OSA patients were randomly assigned (1:1) to CPAP treatment plus usual care (CPAP group) or usual care alone (UC group) by a computerised system available 24 h a day. A group of patients with ACS but without OSA was also included as a reference group. Because of the nature of the intervention, the trial intervention could not be masked to either investigators or patients. Patients were monitored and followed for a minimum of 1 year. Patients were examined at the time of inclusion; after 1 month, 3 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months; and every 12 months thereafter, if applicable, during the follow-up period. The primary endpoint was the prevalence of a composite of cardiovascular events (cardiovascular death or non-fatal events [Acute myocardial infarction, non-fatal stroke, hospital admission for heart failure, and new hospitalisations for unstable angina or transient ischaemic attack]) in patients followed up for a minimum of 1 year. The primary analysis was done according to the intention-to-treat principle. This study is registered with Clinicaltrials.gov, NCT01335087 and is now closed. FINDINGS: Between April 25, 2011, and Feb 2, 2018, a total of 2834 patients with ACS had respiratory polygraphy, of whom 2551 (90·01%) were recruited. 1264 (49·55%) patients had OSA and were randomly assigned to the CPAP group (n=633) or the UC group (n=631). 1287 (50·45%) patients did not have OSA, of whom 603 (46·85%) were randomly assigned to the reference group. Patients were followed up for a median of 3·35 years (IQR 1·50-5·31). The prevalence of cardiovascular events was similar in the CPAP and UC groups (98 events [16%] vs 108 events [17%]; hazard ratio [HR] 0·89 [95% CI 0·68-1·17]; p=0·40) during follow-up. Mean time of adherence to CPAP treatment was 2·78 h/night (SD 2·73). The prevalence of cardiovascular events was similar between patients in the reference group (90 [15%] events) and those in the UC group (102 (17%) events) during follow-up (1·01 [0·76-1·35]; p=0·93). The prevalence of cardiovascular events seem not to be related to CPAP compliance or OSA severity. 464 (74%) of 629 patients in the CPAP group had 1538 serious adverse events and 406 (65%) of 626 patients in the UC group had 1764 serious adverse events. INTERPRETATION: Among non-sleepy patients with ACS, the presence of OSA was not associated with an increased prevalence of cardiovascular events and treatment with CPAP did not significantly reduce this prevalence. FUNDING: ResMed (Australia), Fondo de Investigación Sanitaria (Fondo Europeo de Desarrollo Regional), the Spanish Respiratory Society, the Catalonian Cardiology Society, Esteve-Teijin, Oxigen Salud, and ALLER.

Intra- and Inter-Physician Agreement in Therapeutic Decision for Sleep Apnea Syndrome.

BACKGROUND: Large variation in diagnostic procedures and treatment recommendations may hinder the management of obstructive sleep apnea (OSA) and also compromise correct interpretation of the results of multicenter clinical trials, especially in subjects with non-severe OSA. The aim of this study was to analyze the therapeutic decision-making between different sleep physicians in patients with AHI<40events/h. METHODS: Six experienced senior sleep specialists from different sleep centers of Spain were asked to make a therapeutic decision (CPAP treatment) based on anonymized recordings of patients with suspected OSA that has previously performed a sleep study. The clinical data was shown in an online database and included anthropometric features, clinical questionnaires, comorbidities, physical examination and sleep study results. Intra- and inter-observer decision-making were analyzed by the Fleiss' Kappa statistics (Kappa). RESULTS: A total of 720 medical decisions were taken to analyze the agreement between sleep professionals. Overall intra-observer evaluation reliability was almost perfect (Kappa=0.83, 95% CI, 0.75-0.90, p<0.001). However, overall inter-observer concordance decreased to moderate agreement (Kappa=0.46, 95% CI, 0.42-0.51, p<0.001). Nevertheless, it was especially low when considering AHI<15events/h. CONCLUSIONS: This study demonstrates a good intra-observer concordance in the therapeutic decision-making of different sleep physicians treating patients with low/moderate OSA. However, when analyzing inter-observer agreement the results were considerably worse. These findings underline the importance of developing improved consensus management protocols.

Effect of age on the cardiovascular remodelling induced by chronic intermittent hypoxia as a murine model of sleep apnoea.

BACKGROUND AND OBJECTIVE: Chronic intermittent hypoxia (CIH) is a major determinant of the cardiovascular morbidity associated with obstructive sleep apnoea (OSA), and the magnitude of CIH impact may be influenced by ageing. Here, we assessed the role of ageing in the early cardiovascular structural remodelling induced by severe CIH in a murine model of OSA. METHODS: Cardiovascular remodelling was assessed in young (2 months old, n = 20) and aged (18 months old, n = 20) C57BL/6 female mice exposed to CIH (20% O2 for 40 s, 5% O2 for 20 s) or normoxia (room air) for 8 weeks (6 h/day). RESULTS: Early vascular remodelling was observed in young mice exposed to CIH as illustrated by intima-media thickening (mean change: 4.6 ± 2.6 µm; P = 0.02), elastin fibre disorganization (mean change: 9.2 ± 4.5%; P = 0.02) and fragmentation (mean change: 2.5 ± 0.8%; P = 0.03), and collagen (mean change: 3.2 ± 0.6%; P = 0.001) and mucopolysaccharide accumulation (mean change: 2.4 ± 0.8%; P = 0.01). In contrast, vascular remodelling was not apparent in aged mice exposed to CIH. Furthermore, left ventricular perivascular fibrosis (mean change: 0.71 ± 0.1; P < 0.001) and hypertrophy (mean change: 0.17 ± 0.1; P = 0.038) were increased by CIH exposure in young mice, but not in aged mice. Principal component analysis identified similar cardiovascular alterations among the young mice exposed to CIH and both older mouse groups, suggesting that CIH induces premature cardiovascular senescence. CONCLUSION: Cardiovascular remodelling induced by severe CIH is affected by the age at which CIH onset occurs, suggesting that the deleterious cardiovascular effects associated with CIH may be more pronounced in younger populations, and such changes resemble chronological age-related declines in cardiovascular structural integrity.

Comprehensive management of obstructive sleep apnea by telemedicine: Clinical improvement and cost-effectiveness of a Virtual Sleep Unit. A randomized controlled trial.

INTRODUCTION: Obstructive sleep apnea (OSA) is a prevalent disease associated with significant morbidity and high healthcare costs. Information and communication technology could offer cost-effective management options. OBJECTIVES: To evaluate an out-of-hospital Virtual Sleep Unit (VSU) based on telemedicine to manage all patients with suspected OSA, including those with and without continuous positive airway pressure (CPAP) therapy. METHODS: This was an open randomized controlled trial. Patients with suspected OSA were randomized to hospital routine (HR) or VSU groups to compare the clinical improvement and cost-effectiveness in a non-inferiority analysis. Improvement was assessed by changes in the Quebec Sleep Questionnaire (QSQ), EuroQol (EQ-5D and EQ-VAS), and Epworth Sleepiness Scale (ESS). The follow-up was 3 months. Cost-effectiveness was assessed by a Bayesian analysis based on quality-adjusted life-years (QALYs). RESULTS: The HR group (n: 92; 78% OSA, 57% CPAP) compared with the VSU group (n: 94; 83% OSA, 43% CPAP) showed: CPAP compliance was similar in both groups, the QSQ social interactions domain improved significantly more in the HR group whereas the EQ-VAS improved more in the VSU group. Total and OSA-related costs were lower in the VSU group than the HR. The Bayesian cost-effectiveness analysis showed that VSU was cost-effective for a wide range of willingness to pay for QALYs. CONCLUSIONS: The VSU offered a cost-effective means of improving QALYs than HR. However, the assessment of its clinical improvement was influenced by the choice of the questionnaire; hence, additional measurements of clinical improvement are needed. Our findings indicate that VSU could help with the management of many patients, irrespective of CPAP use.

New organisation for follow-up and assessment of treatment efficacy in sleep apnoea.

Obstructive sleep apnoea (OSA) is a highly prevalent disease, and there is an increased demand for OSA diagnosis and treatment. However, resources are limited compared with the growing needs for OSA diagnosis and management, and alternative strategies need to be developed to optimise the OSA clinical pathway. In this review, we propose a management strategy for OSA, and in general for sleep-disordered breathing, to be implemented from diagnosis to follow-up. For this purpose, the best current options seem to be: 1) networking at different levels of care, from primary physicians to specialised sleep laboratories; and 2) use of telemedicine. Telemedicine can contribute to the improved cost-effectiveness of OSA management during both the diagnostic and therapeutic phases. However, although the technology is already in place and different commercial platforms are in use, it is still unclear how to use telemedicine effectively in the sleep field. Application of telemedicine for titration of positive airway pressure treatment, follow-up to improve compliance to treatment through early identification and solution of problems, and teleconsultation all appear to be promising areas for improved OSA management.

Aortic remodelling induced by obstructive apneas is normalized with mesenchymal stem cells infusion.

Obstructive sleep apnea syndrome (OSA) promotes aortic dilatation, increased stiffness and accelerated atherosclerosis, but the mechanisms of vascular remodelling are not known. We aimed to assess vascular remodelling, its mechanisms, and the effect of mesenchymal stem cells (MSC) infusions in a clinically relevant rat model of chronic OSA involving recurrent airway obstructions leading thoracic pressure swings and intermittent hypoxia/hypercapnia (OSA-rats). Another group of rats were placed in the same setup without air obstructions (Sham-rats) and were considered controls. Our study demonstrates that chronic, non-invasive repetitive airway obstructions mimicking OSA promote remarkable structural changes of the descending thoracic aorta such as eccentric aortic hypertrophy due to an increased wall thickness and lumen diameter, an increase in the number of elastin fibers which, in contrast, get ruptured, but no changes in tunica media fibrosis. As putative molecular mechanisms of the OSA-induced vascular changes we identified an increase in reactive oxygen species and renin-angiotensin system markers and an imbalance in oxide nitric synthesis. Our results also indicate that MSC infusion blunts the OSA-related vascular changes, most probably due to their anti-inflammatory properties.

Effects of a Combined Community Exercise Program in Obstructive Sleep Apnea Syndrome: A Randomized Clinical Trial.

Physical activity is associated with a decreased prevalence of obstructive sleep apnea and improved sleep efficiency. Studies on the effects of a comprehensive exercise program in a community setting remain limited. Our objective was to investigate the effects of a combined physical and oropharyngeal exercise program on the apnea-hypopnea index in patients with moderate to severe obstructive sleep apnea. This was a randomized clinical trial where the intervention group followed an eight-week urban-walking program, oropharyngeal exercises, and diet and sleep recommendations. The control group followed diet and sleep recommendations. A total of 33 patients were enrolled and randomized and, finally, 27 patients were included in the study (IG, 14; CG, 13) Obstructive sleep apnea patients were analyzed with a median age of 67 (52⁻74) and median apnea-hypopnea index of 32 events/h (25⁻41). The apnea-hypopnea index did not differ between groups pre- and post-intervention. However, in intervention patients younger than 60 (n = 6) a reduction of the apnea-hypopnea index from 29.5 (21.8⁻48.3) to 15.5 (11⁻34) events/h (p = 0.028) was observed. While a comprehensive multimodal program does not modify the apnea-hypopnea index, it could reduce body weight and increase the walking distance of patients with moderate to severe obstructive sleep apnea. Patients younger than 60 may also present a decreased apnea-hypopnea index after intervention.

Anthropometrical phenotypes are important when explaining obstructive sleep apnea in female bariatric cohorts.

Central obesity is the main risk factor for obstructive sleep apnea (OSA). Whether there exists a central-obesity anthropometric that better explains apnea-hypopnea index (AHI) variability in the general population and in sleep cohorts is unknown, and this is even less explored among increasing grades of obesity. The objective of the study is to investigate whether there is an anthropometric that better explains AHI variability in a sample of morbidly obese women awaiting bariatric surgery (BS). A prospective multicentre cross-sectional study was conducted in consecutive women before BS. Demographic and anthropometric characteristics included age, body mass index (BMI), neck circumference (NC), waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR). OSA was diagnosed by polysomnography. The capacity of anthropometrics to explain AHI variance was investigated using regression linear models. A total of 115 women were evaluated: age, 44 ± 10 years; BMI, 46 ± 5 kg/m2 ; AHI, 35 ± 26 events/hr. AHI was associated with all anthropometrics except weight, height and HC. The best univariate predictor was WHR, which accounted for 15% of AHI variance. The simplest model (age + BMI) accounted for 9%, which increased to 20% when applying more complex measurements (age + BMI + NC + WC + HC). The explanatory capacity did not change significantly when applying a simpler model (age + WHR + NC, 19%). In this female morbidly obese cohort, anthropometrics explained one-fifth of AHI variability. WHR is the best univariate parameter and models including waist and neck data provide more information than BMI when explaining AHI variability. Thus, even in young women with extreme obesity, OSA seems to be linked to a specific central-obesity phenotype rather than to a whole-obesity pattern.