OSA Therapy Research Articles

Changes the level of differentiating growth factor - GDF 15 in patients with sleep apnea syndrome after aPAP-therapy: pilot study

Comparative assessment of the level of differentiating growth factor 15 (GDF 15 ) against the background of a 6-month course of respiratory support in the mode of automatic positive pressure in the airways therapy (aPAP therapy) in patients with obstructive sleep apnea syndrome (OSA). 59 men participated in the study, the average age was 51.9±2.4 years. The main group (MG1) consisted of 30 patients with a verified diagnosis of moderate OSA. 29 men of comparable age and body weight made up the control group (CG) without an objectively confirmed diagnosis of OSA. After the stage of introduction into the study, the type of respiratory support with individual pressure settings was selected for patients with MG1. After 6 months of aPAP therapy with high compliance (at least 85%), the same patients who made up MG2 after treatment underwent repeated polysomnography (PSG) and the GDF 15 content was evaluated. Methods: questionnaire, examination, polysomnography, enzyme immunoassay of blood serum to determine the content of GDF 15. A 6-month course of aPAP therapy with a high degree of compliance significantly improved the sleep structure and breathing pattern: the representation of NREM 3 increased from 79.2±15.6 to 102.6±21.6 minutes and the REM phase from 56.9± 13.6 to 115.6±26.8. Episodes of apnea were eliminated - apnea-hypopnea index decreased from 21.1 [17.3; 39.1] to 2.5 [1.8; 4.6] and the average values of SaO2 increased from 85.9% to 91.5%. At the same time, a statistically significant excess of GDF 15 was revealed in MG1 - 20.4 [14.16; 31.71] and MG2 - 17.2 [13.63; 24.44]) in comparison with CG - 13.65 [10.7; 17.09]. Despite the lack of statistical significance, a change in the level of GDF 15 was revealed in the form of a decrease in its concentration after a 6-month course of aPAP therapy. A 6-month course of aPAP therapy made it possible to eliminate intermittent nocturnal hypoxia and improve sleep structure in patients with OSA, as well as reduce the content of GDF 15 protein in blood serum in patients with OSA. However, the tendency to decrease the content of this protein, despite the lack of statistical reliability, confirms the effectiveness of OSA therapy and the possibility of preventing early and pathological aging from the standpoint of somnology and molecular biogerontology.

The First-Line Approach in Children with Obstructive Sleep Apnea Syndrome (OSA).

Obstructive sleep apnea syndrome (OSA) is the main manifestation of sleep-disordered breathing in children. Untreated OSA can lead to a variety of complications and adverse consequences mainly due to intermittent hypoxemia. The pathogenesis of OSA is multifactorial. In children aged 2 years or older, adenoid and/or tonsil hypertrophy are the most common causes of upper airway lumen reduction; obesity becomes a major risk factor in older children and adolescents since the presence of fat in the pharyngeal soft tissue reduces the caliber of the lumen. Treatment includes surgical and non-surgical options. This narrative review summarizes the evidence available on the first-line approach in children with OSA, including clinical indications for medical therapy, its effectiveness, and possible adverse effects. Literature analysis showed that AT is the first-line treatment in most patients with adenotonsillar hypertrophy associated with OSA but medical therapy in children over 2 years old with mild OSA is a valid option. In mild OSA, a 1- to 6-month trial with intranasal steroids (INS) alone or in combination with montelukast with an appropriate follow-up can be considered. Further studies are needed to develop an algorithm that permits the selection of children with OSA who would benefit from alternatives to surgery, to define the optimal bridge therapy before surgery, to evaluate the long-term effects of INS +/- montelukast, and to compare the impact of standardized approaches for weight loss.

P108 Obstructive Sleep Apnoea in Acute Coronary Syndrome: An Observational Study

Abstract Obstructive sleep apnoea (OSA) is a risk factor for cardiovascular disease. CPAP therapy is the primary treatment for OSA and is known to improve long term cardiovascular health outcomes. Recent neutral findings of randomised clinical trials have created uncertainty about whether effective CPAP therapy can improve cardiovascular health in patients with OSA. We conducted a cross-sectional observational study in patients with acute coronary syndrome (ACS) diagnosed with OSA. We aimed to characterise key surrogate markers of cardiovascular health in this cohort to inform a future intervention study of personalised OSA therapy. 70 patients with ACS (age (IQR):58[52,63]years, BMI:27[24,30]kg/m2) were recruited. A level 2 sleep study was conducted to confirm OSA diagnosis within 6 months after discharge. Carotid femoral pulse wave velocity(cfPWV), pulse wave analysis, endothelial function, heart rate variability, and baroreflex sensitivity were measured. Patients were categorised as no-mild OSA(AHI<15events/h) and moderate-severe OSA(AHI≥15events/h) for analysis. 67% of patients were found to have moderate-severe OSA(AHI≥15events/h) and 40% of patients had severe (AHI≥30events/h). cfPWV was elevated in moderate-severe OSA compared to no-mild OSA (7.4[6.6,8.5] vs. 6.1[4.7,7.1]m/s, p=0.003). This was no longer significant after adjusting for age (p=0.296) and BMI (p=0.053). cfPWV correlated with AHI (rs = 0.35, P=0.0069). Measures of pulse wave analysis, flow mediated dilatation, heart rate variability, and baroreflex sensitivity did not differ between patient groups (data not shown). OSA is highly prevalent in patients with ACS. Arterial stiffness measured by cfPWV appears to show best promise as an outcome measure for a future intervention trial of personalised OSA therapy.

Revisiting Asthma Obstructive Sleep Apnea Overlap: Current Knowledge and Future Needs.

Asthma and obstructive sleep apnea are highly prevalent conditions with a high cost burden. In addition to shared risk factors, existing data suggest a bidirectional relationship between asthma and OSA, where each condition can impact the other. Patients with asthma often complain of sleep fragmentation, nocturnal asthma symptoms, daytime sleepiness, and snoring. The prevalence of OSA increases with asthma severity, as evidenced by multiple large studies. Asthma may lower the threshold for arousal in OSA, resulting in the hypopnea with arousal phenotype. Epidemiologic studies in adults have shown that OSA is associated with worse asthma severity, increased frequency of exacerbation, and poor quality of life. The current literature assessing the relationship among OSA, asthma, and CPAP therapy is heavily dependent on observational studies. There is a need for randomized controlled trials to minimize the interference of confounding shared risk factors.

0570 Use of the ExVent Accessory with the O2Vent Optima Oral Appliance for the Treatment of Obstructive Sleep Apnea – A Clinical Trial

Abstract Introduction The ExVent is an optional accessory to the O2Vent Optima mandibular advancement device (MAD) and provides oral Expiratory Positive Airway Pressure (EPAP). Oral EPAP with the ExVent is designed to provide upper airway support via similar mechanisms of action of nasal EPAP devices in commercial distribution, e.g., passive dilatation of the airway, which reduces flow limitation. Nasal EPAP devices are in commercial distribution as stand-alone therapies for the treatment of OSA. The oral EPAP provided by the ExVent accessory is designed to augment the OSA therapy provided by the O2Vent Optima. Methods This is a prospective, open-label, single-arm study conducted at 3 sites. Subjects who have been diagnosed with mild to moderate OSA (i.e., AHI ≥ 5 and ≤ 30) were included. Screening Phase The subjects completed a PSG study to obtain the baseline AHI and confirm a diagnosis of mild to moderate OSA Home Use Phase Subjects used the O2Vent Optima + ExVent for up to 3 months and logged usage hours. Subsequent to the Home Use Phase subjects underwent an in-lab PSG sleep night while using the O2Vent Optima + ExVent. Primary Effectiveness Outcome Measure: Change in AHI between baseline and the AHI measured during the in-lab PSG sleep night using O2Vent Optima + ExVent. Safety Outcome Measure: Adverse events will be summarized descriptively in terms of type and frequency Results Patients with mild to moderate OSA were treated with Optima MAD and ExVent for 3 months at 3 different sites in North America. Preliminary data analysis demonstrated that treatment with Optima MAD and ExVent reduced AHI from 13.5±6.4/hr to 6.6±4.5/hr (p< 0.05), average 58% reduction in AHI. The lowest oxygen during sleep increased from 84.6±2.7% to 88.6±2.9% (p< 0.05). Overall success rate (>50% reduction in AHI) with treatment was 80%. During the trial patients on treatment with Optima MAD and ExVent demonstrated no excessive adverse events or device malfunction. Conclusion The clinical trial confirmed successful treatment with combined use of O2Vent Optima MAD and oral Expiratory Positive Airway Pressure accessory - ExVent in patients with mild to moderate OSA. Treatment was well tolerated with no excessive adverse effects. Support (if any)

0427 Airway Pressures Define Collapsibility of Specific Pharyngeal Sites of Obstruction during Drug-induced Sleep Endoscopy

Abstract Introduction Obstructive sleep apnea (OSA) is characterized by repetitive episodes of pharyngeal obstruction at one or more collapse sites. Multilevel collapse is a negative predictive factor for PAP-alternative surgical treatments. Pharyngeal manometry during drug-induced sleep endoscopy (DISE) permits an objective evaluation of anatomical obstruction sites and mechanisms, and may play a role in patient selection for PAP alternative therapies. We hypothesized that patients with multilevel collapse would have primary velopharyngeal collapse and secondary, downstream sites. Methods This prospective cohort of twenty consecutive patients with diagnosed OSA underwent DISE with nasal airflow monitoring and pharyngeal manometry. Two pressure catheters were placed at the (1) distal margin of the soft palate (Pus) and (2) retroepiglottic space (Pds). We sought to delineate site(s) of collapse by evaluating dissociations in airflow and air pressure during inspiratory flow limitation and/or complete obstruction. The primary site of collapse was defined by the initial segment at which inspiratory airflow and pressure dissociated (the critical pressure, Pcrit). Secondary site(s) were defined as the pressure at which the Pus and/or Pds signals subsequently dissociated (beyond the initial point of maximal flow). Results Twenty-one patients were evaluated of which signal quality and catheter placement in twenty were sufficient for analysis. Participants were elderly (58.3±14.3yrs, mean±SD), overweight (BMI 28.7±2. kg/m2), and had moderate-severe OSA (AHI 28.2±14.2 events/hour). Six patients had a single site of collapse, of which one was naso-palatal (Pcrit -2.6cmH2O) and five were infra-palatal (mean Pcrit -1.3cmH2O). In the patients with multilevel collapse (N=14), all had primary naso-palatal collapse (mean Pcrit 0.17±2.0cmH2O) and secondary infra-palatal sites of collapse (mean Pcrit -11.7±5.8cmH2O). Pcrit differed between the primary and secondary site by 11.9±6.5cmH2O (p< 0.01). Conclusion These findings suggest that single-site pharyngeal collapse is usually infra-palatal. In contrast, multilevel collapse is primarily due to velopharyngeal collapse with varying degrees of instability in downstream pharyngeal segments. When secondary infra-palatal sites readily collapse with minimal additional respiratory effort, laxity of the tongue and/or lateral walls may be strongly implicated in the pathogenesis of pharyngeal obstruction. Future studies can utilize pharyngomanometry to further target specific pharyngeal structures for OSA therapy. Support (if any) National Institutes of Health 1R01HL144859 (PIs: Schwartz, Dedhia)

Relationship Between Obstructive Sleep Apnea Severity and Serum Endocan Levels in Patients With Hypertension

Obstructive sleep apnea (OSA) is common in middle-aged adults and has been associated with various cardiovascular disorders; endothelial dysfunction may play a role in the pathogenesis of these disorders in patients with OSA. Endothelial cell specific molecule-1 (endocan) is a marker of vascular pathology, which is correlated with endothelial dysfunction. This study investigates the relationship between serum endocan levels and OSA severity in patients with hypertension. A retrospective review included 48 patients with OSA and hypertension but without conventional cardiovascular risk factors, and 67 patients with OSA who did not have hypertension. The correlation between serum endocan levels and the apnea-hypopnea index (AHI) was investigated in both groups. There was a significant correlation between the serum endocan level and the AHI in patients with OSA and hypertension (r = 0.308; P = .033), but there was no such correlation in patients without hypertension (r = 0.193; P = .118). However, when both groups were combined (ie, all patients with OSA), there was a significant correlation between serum endocan levels and the AHI (r = 0.228; P = .014). On multiple logistic regression analysis, endocan levels were independent predictors of OSA severity in patients with OSA and hypertension (P = .029). In patients with OSA and hypertension, serum endocan levels are significantly correlated with the AHI. Measurement of endocan may have a place in evaluating patients with OSA and hypertension for adverse cardiovascular events, and they may even help to guide OSA therapy for these patients.

EE144 APAP and Telemonitoring for Initiation and Follow-up of OSA Therapy in Germany: Economic and Environmental Evaluation

EE144 APAP and Telemonitoring for Initiation and Follow-up of OSA Therapy in Germany: Economic and Environmental Evaluation

Protocolizing perioperative OSA screening and management: moving in the right direction.

Protocolizing perioperative OSA screening and management: moving in the right direction.

0068 Impact of OSA Therapy on Healthcare Economics: Actuarial Analysis of OSA Prevalence, Therapy Adherence, Co-morbidity, and Costs in a Large CMS Population Cohort

Abstract Introduction Research studying the economics of OSA therapy faces confounds including the prevalence of undiagnosed OSA, rate of diagnosed patients declining therapy, spectrum of treatment adherence, and effects of concurrent co-morbidity. We provide an actuarial analysis to study the economic impact of OSA therapy, accounting for these confounds, using the 2016-2018 Medicare 5% LDS Analytical File, a random sample of Medicare Claims containing approximately 2.9 million patients/year, resulting in N=2,001,538 eligible Fee-For-Service patients excluding managed care patients and incomplete data. Methods We segmented the study population into three cohorts and three 12-month time-periods. The cohorts analyzed were A) patients with OSA diagnosis and >12 months treatment, B) patients with OSA and <12 months treatment, and C) patients with OSA diagnosis who never received treatment, resulting in 1,351,838 patient-months. We analyzed the healthcare costs in each cohort in the year before treatment, the first year of treatment, and following treatment year. We applied actuarial risk adjustment within each cohort and time-period to provide a risk-adjusted cost comparison. Results were analyzed cross-sectionally given zero-to-seven co-morbidities among obesity, hypertension, type-II diabetes, depression, COPD, CHF, and/or prior stroke, facility-vs-home testing, and with-or-without surgical procedures. Results The average per-patient-per-month (PPPM) total medical spending was highest in the diagnosed-but-never-treated cohort-C ($1,375), second highest in <12-months treatment cohort-B ($1,005), and lowest in >12-months treatment cohort-A ($983). In both cohorts that started therapy, average/quantile costs decreased from pre-treatment year to post-treatment year, and from the first-to-second year on therapy. Compared to no-therapy cohort-C, costs were 29% lower in cohort-A and 27% lower in cohort-B. Among co-morbid, 75th quartile of cost members, we observed similar differences (18% and 16%) but larger absolute dollars. Patients undergoing surgical procedures had higher costs but lower spend reduction in initial and following year of therapy (22% and 5%). Conclusion We observed significant differences in cost between OSA patients that started treatment versus those that did not, and those differences further increased the year following therapy onset. These findings imply that receiving treatment for OSA reduces a patients overall medical spend. In terms of mean cost, the >12-month and <12-month cohorts costs fell in both follow-up treatment years. Support (If Any)

0790 Racial Differences in Self-Efficacy for Positive Airway Pressure Therapy Among Individuals Newly Diagnosed with Obstructive Sleep Apnea

Abstract Introduction Continuous positive airway pressure (CPAP) therapy is the first-line treatment for OSA, yet its effectiveness is limited by poor adherence. Self-efficacy is an individual’s belief that they can successfully execute a behavior to achieve a desired outcome. Evidence shows that self-efficacy predicts adherence to and outcomes of CPAP therapy, as do race and ethnicity. Little, however, is known about how self-efficacy may differ between racial and ethnic groups. Accordingly, we aimed to determine whether self-efficacy for CPAP differs by race and ethnicity among individuals newly diagnosed with OSA. Methods Adults newly diagnosed with OSA and prescribed CPAP who were enrolled in the NICEPAP Study (n=267, NCT05067088), a prospective, observational cohort study investigating predictors of CPAP adherence were assessed. Those with need for non-CPAP therapy or with unstable medical conditions (e.g., cancer receiving chemotherapy, severe lung, heart or mental health disorders) were excluded. Exposures were race and ethnicity. Outcomes were subscale scores of the Self-Efficacy Measure for Sleep Apnea (SEMSA) completed prior to CPAP initiation: perceived risk, outcome expectancy, and self-efficacy. SEMSA sub-scale scores for race/ethnicity were compared using Kruskal-Wallis test. Medians (Q1, Q3) are reported. Results We analyzed data for 52 participants (33 women) enrolled to date who identified as White (n=29), Black (n=14), More than one race (n=5) and Other (N=5). Participants were 51.0 (36.8, 58.8) years old with an apnea-hypopnea index of 17.0/hour (11.1, 26.0) and body-mass-index of 35.0 (31.6, 43.5) kg/m2. Baseline characteristics did not differ by race, except higher poverty (p=0.005) and less completed years of education (p=0.010) for Black participants. The SEMSA scores were not statistically different between each race. However, self-efficacy was significantly lower for Black participants vs. rest of the cohort combined (2.4 (1.9, 3.1) vs. 3.3 (2.7, 3.8) p=0.020). Poverty, but not education, may be a potential mediator of this relationship (mediation analysis p=0.052). There were no differences in SEMSA scores between Hispanic and Non-Hispanic participants. Conclusion In our cohort, self-efficacy for OSA therapy was lower for Black participants compared to those of other races. Targeting early interventions to improve CPAP self-efficacy in Black patients may improve OSA therapy outcomes. Support (If Any)

Factors associated with treatment outcomes after use of auto-titrating CPAP therapy in adults with obstructive sleep apnea.

To determine factors that are associated with OSA therapy outcomes with auto-titrating positive airway pressure (APAP). We sequentially grouped patients from a retrospective cohort based on APAP efficacy (sufficiently vs. insufficiently treated; insufficiently treatment defined as residual AHI of ≥ 5), therapy adherence (adherent vs. non-adherent, non-adherence defined as < 70% usage for ≥ 4h/night), and therapy outcomes (optimal vs. non-optimal and non-optimal outcomes defined as non-adherent and/or insufficiently treated). We subsequently compared each group. The insufficiently treated were older (68.4 ± 12.5 vs. 60.4 ± 13.1years, p < 0.01) and had lower BMI (31.9 ± 6.3 vs. 37.9 ± 9.1kg/m2, p < 0.01). They had higher baseline central apnea indices (CAI), longer leaks, higher peak pressures, and were less compliant. The non-adherent were younger (61.1 ± 12.6 vs. 65.5 ± 13.2years, p = 0.03) and comprised more females (56.1 vs. 43.9%, p = 0.04). The leak duration per usage hour was higher in the non-compliant (median: 1.5; IQR 7.9 vs. median: 0.3; IQR 1.9min/h; p < 0.01). The non-optimally treated had lower BMI, longer leaks, and less nightly usage. Multivariate analyses showed that leak duration was the common factor associated with treatment effectiveness and optimal therapy outcomes. Various demographic and clinical factors were associated with treatment efficacy and adherence. However, leak duration was the common factor related to treatment efficacy and overall optimal therapy outcomes.

453 Cost-Effectiveness of Requalifying for Positive Airway Pressure Treatment After Initial Nonadherence

Abstract Introduction Obstructive sleep apnea (OSA) is effectively treated with continuous positive airway pressure (CPAP). However, many people are not able to become adherent in the initial 90-day trial window for this therapy. Medicare requires a polysomnography and repeat trial documenting adherence before continuing payment for these services. Oral appliance therapy (OAT) is also an OSA first-line therapy but is less effective than CPAP. Methods We created a decision tree to model 4 strategies over a 5-year time horizon: (1) current policy, (2) direct referral for CPAP equipment, (3) OAT followed by CPAP under current policy, and (4) OAT followed by direct CPAP referral in a the Medicare population with mild-moderate OSA and nonadherence to a first attempt at CPAP therapy. Medicare fee schedules in 2020 defined costs. Incremental cost-effectiveness (ICER) was used to identify the supreme strategy Results The current policy was the most expensive. Both the current policy and direct DME referral were dominated by starting with OAT. OAT followed by titration was the most cost-effective strategy with an ICER of $42,586.47. The ICER was sensitive to adherence in the direct CPAP strategy and probability of getting CPAP equipment (vs. lost to follow-up). Conclusion Starting with OAT therapy in those that were CPAP nonadherent on first attempt is cost-effective. Despite decreased effectiveness, the increase adherence to OAT make it an attractive option for retrial of OSA therapy. If OAT therapy fails, the current policy is more cost-effective than direct CPAP referral. Support (if any) This study was supported Career Development Award IK2CX001882 from the United States (U.S.) Department of Veterans Affairs Clinical Sciences Research and Development Service. The contents of this work do not represent the views of the Department of Veterans Affairs or the United States government.

Obstructive sleep apnea and atrial fibrillation: we need to go step by step.

Citation:Sanchez-de-la-Torre M, Lee C-H, Barbe F. Obstructive sleep apnea and atrial fibrillation: we need to go step by step. J Clin Sleep Med. 2021;17(5):869–870.

Randomized Controlled Trial of Solriamfetol for Excessive Daytime Sleepiness in OSA: An Analysis of Subgroups Adherent or Nonadherent to OSA Treatment

BackgroundSolriamfetol, a dopamine-norepinephrine reuptake inhibitor, is approved in the United States to improve wakefulness in adults with excessive daytime sleepiness (EDS) associated with OSA (37.5-150 mg/d).Research QuestionDoes solriamfetol have differential effects on EDS based on adherence to primary OSA therapy and does solriamfetol affect primary OSA therapy use?Study Design and MethodsParticipants were randomized to 12 weeks of placebo or solriamfetol 37.5, 75, 150, or 300 mg/d (stratified by primary OSA therapy adherence). Coprimary end points were week 12 change from baseline in 40-min Maintenance of Wakefulness Test (MWT) and Epworth Sleepiness Scale (ESS) in the modified intention-to-treat population. Primary OSA therapy use (hours per night, % nights) and safety were evaluated.ResultsAt baseline, 324 participants (70.6%) adhered to OSA therapy (positive airway pressure use ≥ 4 h/night on ≥ 70% nights, surgical intervention, or oral appliance use on ≥ 70% nights) and 135 participants (29.4%) did not adhere. Least squares (LS) mean differences from placebo in MWT sleep latency (minutes) in the 37.5-, 75-, 150-, and 300-mg/d groups among adherent participants were 4.8 (95% CI, 0.6-9.0), 8.4 (95% CI, 4.3-12.5), 10.2 (95% CI, 6.8-13.6), and 12.5 (95% CI, 9.0-15.9) and among nonadherent participants were 3.7 (95% CI, –2.0 to 9.4), 9.9 (95% CI, 4.4-15.4), 11.9 (95% CI, 7.5-16.3), and 13.5 (95% CI, 8.8-18.3). On ESS, LS mean differences from placebo in the 37.5-, 75-, 150-, and 300-mg/d groups among adherent participants were –2.4 (95% CI, –4.2 to –0.5), –1.3 (95% CI, –3.1 to 0.5), –4.2 (95% CI, –5.7 to –2.7), and –4.7 (95% CI, –6.1 to –3.2) and among nonadherent participants were –0.7 (95% CI, –3.5 to 2.1), –2.6 (95% CI, –5.4 to 0.1), –5.0 (95% CI, –7.2 to –2.9), and –4.6 (95% CI, –7.0 to –2.3). Common adverse events included headache, nausea, anxiety, decreased appetite, nasopharyngitis, and diarrhea. No clinically meaningful changes were seen in primary OSA therapy use with solriamfetol.InterpretationSolriamfetol improved EDS in OSA regardless of primary OSA therapy adherence. Primary OSA therapy use was unaffected with solriamfetol.Trial RegistryClinicalTrials.gov; No.: NCT02348606; URL: www.clinicaltrials.gov; EU Clinical Trials Register; No.: EudraCT2014-005514-31; URL: www.clinicaltrialsregister.eu

Comparative effects of CPAP and mandibular advancement splint therapy on blood pressure variability in moderate to severe obstructive sleep apnoea

BackgroundObstructive sleep apnoea (OSA) is associated with increased blood pressure variability (BPV) and are risk factors for cardiovascular disease. We aimed to assess the comparative effects of two OSA therapies, continuous positive airway pressure (CPAP) and mandibular advancement splint (MAS), on BPV. MethodsThis is a secondary analysis of data collected as part of a previously published randomised crossover trial of one month each of CPAP and MAS therapy. BPV was determined from 24-h-ambulatory blood pressure recordings in 92 patients with moderate to severe OSA at baseline and after one month of optimised treatment with each modality. BPV was assessed by three measures: Standard deviation of the mean (SD), Coefficient of variation (CoV), and the Average Real Variability (ARV) index. ResultsNeither CPAP nor MAS therapy improved BPV, with no difference between treatments. BPV did not change in hypertensive OSA patients, however, there was a reduction in ARV of diastolic blood pressure in the effectively treated compared to ineffectively treated CPAP patients, Δ ARV 24-h-DBP (mmHg), −0.72 ± 2.14, 0.34 ± 1.52, P = 0.02, respectively. There was no difference between effective versus ineffective MAS treatment, Δ ARV 24-h-DBP (mmHg), −0.04 ± 2.4, 0.02 ± 1.9, P = 1.00, respectively. ConclusionsOne month of optimised CPAP or MAS therapy did not improve short term BPV in patients with moderate to severe OSA. The subgroup of patients on effective CPAP showed some improvement in BPV with CPAP but not MAS. Further work on the effect of OSA therapy on BPV following long-term therapy is needed.

Mandibular Advancement Devices for OSA: An Alternative to CPAP?

Obstructive sleep apnea (OSA) is a prevalent condition causing unrefreshing sleep and excessive daytime sleepiness. It has individual socioeconomic impacts and, through association with increased risk of road traffic accidents, diabetes, and cardiovascular disease, OSA is a public health issue. Continuous positive airway pressure (CPAP) is the first-line treatment for moderate-to-severe OSA. It is effective in improving excessive daytime sleepiness and quality of life. There is also evidence that CPAP therapy has cardiovascular benefits although nature and extent remain uncertain. Despite its benefits, a significant proportion of patients are unable to tolerate CPAP. There are also patients with mild but symptomatic disease, for whom CPAP is usually not available or appropriate, so there is a need for other treatment options. Mandibular advancement devices (MADs) offer an effective alternative to CPAP and can improve daytime symptoms and quality of life. There are many devices available, representing a range of complexity and cost. It is challenging to properly evaluate the effectiveness of this ever-evolving range. The more basic MADs are cheaper and more accessible but are less well tolerated. More complex devices are better tolerated and may be more effective. However, they are more expensive and often require dental expertise, so access is more limited. Efforts continue to try to improve accessibility to effective MAD therapy. Alongside increasing awareness, this may be facilitated by developing and refining devices that could be fitted by non-dental clinicians, and potentially by patients themselves. Research efforts need to focus on determining how to efficiently identify patients who are likely to respond to MAD therapy, so as to improve clinical and cost-effectiveness of OSA therapy overall.

Association Between Nocturnal Hypoxemia and Cancer Incidence in Patients Investigated for OSA: Data From a Large Multicenter French Cohort

Previous studies have yielded inconsistent findings regarding the association between OSA and cancer in humans. Is there an association between indexes of sleep-disordered breathing severity and cancer incidence in patients investigated for suspected OSA? Data from a large multicenter cohort of cancer-free patients investigated for OSA were linked to health administrative data to identify new-onset cancer. Kaplan-Meier survival analysis and Cox proportional hazards models were used to evaluate the association of cancer incidence with OSA severity and nocturnal hypoxemia. After a median follow-up period of 5.8 years (interquartile range, 3.8-7.8), 718 of 8,748 patients (8.2%) had received a diagnosis of cancer. On unadjusted Kaplan-Meier survival analyses, cancer incidence was associated with increasing severity of OSA (log-rank test, P< .0005) and nocturnal hypoxemia (log-rank test, P< .0001 for both oxygen desaturation index and percent night time with oxygen saturation< 90%[T90]). After adjustment for anthropomorphic data, smoking and alcohol consumption, comorbid cardiac, metabolic, and respiratory diseases, marital status, type of sleep study, and study site, only T90 was associated with cancer incidence (adjusted hazard ratio, 1.33; 95%CI, 1.05-1.68 for T90≥ 13%vs< 0.01%; P= .02). On stratified analyses, the association between T90 and cancer appeared stronger in older patients with obesity and no adequate OSA therapy. Among the most frequent cancer sites, nocturnal hypoxemia was associated with lung and breast malignancies. Nocturnal hypoxemia was associated with all-cancer incidence in patients investigated for OSA. Whether OSA therapy might reduce the risk of cancer needs further evaluation.

0640 Initial Sleep Center Evaluation and Follow Up Improves Positive Airway Pressure (PAP) Therapy Adherence When Compared to Direct Referrals Without Sleep Physician Follow Up: A Retrospective Study

Abstract Introduction Obstructive sleep apnea (OSA) affects 26% of adults and positive airway pressure (PAP) is the gold-standard of therapy. Factors affecting PAP adherence—use &amp;gt;4 hours in a 24-hour period—have been studied extensively. We compared of the three months (or other time frame) PAP adherence between patients seen by a sleep specialist prior to OSA diagnosis versus patients referred directly for OSA testing by non-sleep specialist providers. The goal of the study was to understand the impact of sleep consultation on PAP adherence. Methods Direct referral (DR) patients underwent polysomnography (PSG) and received PAP devices prior to the sleep clinic visit. In contrast, sleep center patients (SC) had a sleep clinic visit with a sleep physician or APRN prior to PSG. Eighty-four patients were included in this study, 42 DR and 42 SC patients. Exclusion criteria were age &amp;lt;18 years old, absence of baseline PSG, and lack of 90-day compliance data. Covariates included demographics, body mass index (BMI), AHI, nadir oxygen saturation, demographics, and Epworth Sleepiness Scale (ESS) score. Objective PAP adherence for first 90 days was the primary outcome. Results Age (p=0.1), ESS (p=0.3), BMI (p=0.6), and AHI (p=0.9) were not significantly different between the groups. SC patients had greater PAP adherence (4.77 hours, 95%CI: 4.1 to 5.4) compared to DR patients (3.61 hours, 95%CI: 2.88 to 4.33, p=0.02). SC patients were also 8 times more likely to follow up in clinic within 1 year of starting PAP treatment (Likelihood Ratio 8.25, p=0.004). Conclusion While possibly more time-efficient for patients, direct referrals may ultimately result in lower PAP adherence due to missed opportunities for receiving education about OSA and PAP therapy. This is consistent with findings from a previous meta-analysis demonstrating that educational interventions improve PAP adherence. Moving forward, we will continue encouraging directly referred patients to follow up in the sleep center after PSG. Support None

Distributions of OSA therapy outcomes based on a trial oral appliance and/or supine avoidance

Distributions of OSA therapy outcomes based on a trial oral appliance and/or supine avoidance