Abstract Introduction Hypoglossal nerve stimulation (HGNS) is an effective therapy for moderate-to-severe obstructive sleep apnea (OSA) in patients intolerant of positive airway pressure. Comorbid insomnia (COMISA) is common and may shape their engagement. Despite reports of improved insomnia symptoms, real-world data suggest reduced adherence and increased support needs. This study evaluated the impact of COMISA on HGNS therapy patterns and outcomes. Methods We conducted a retrospective cohort study of 46 adults with OSA who underwent HGNS implantation at Mayo Clinic Rochester between July 2020 and August 2025. Patients were categorized as OSA alone or COMISA based on pre-implantation data, including documented insomnia diagnosis, insomnia severity index score ≥15, sleep initiation or maintenance complaints, hypnotic or melatonin use, participation in cognitive behavioral therapy for insomnia, or an insomnia care plan within one year prior to activation. We collected HGNS adherence metrics (30-day average nightly use, nightly pauses, percent nights used) at 1, 3, 6, and 12 months; non-visit HGNS-related clinical encounters at 6 and 12 months; and pre- and post-activation AHI from polysomnography or home sleep apnea testing. Longitudinal outcomes were analyzed using mixed-effects models with fixed effects for time and COMISA status and a random intercept for patient. Results The cohort was 54% male and 98% White, with median age 66 years and BMI 31 kg/m2 (24–34). Median pre-implant AHI was 27 (19–40), and 30 patients (65%) had COMISA. Median nightly HGNS use declined from 7.8 to 6.6 hours from 1 to 12 months; mixed-effects modeling confirmed significant decreases over time (p≤0.03). Median nightly therapy pauses increased from 0.1 to 0.5, and median non-visit clinical encounters increased cumulatively from 2.5 at 6 months to 3.0 by 12 months (both p≤0.01). Median AHI reduction was 18.5 (2–27) (p=0.047). There were no statistically significant differences between OSA-alone and COMISA groups in HGNS adherence trajectories, therapy pauses, support needs, or AHI improvement (all p>0.05). Conclusion Although HGNS use declined modestly over time, COMISA was not statistically associated with differences in adherence, clinical support needs, or treatment response. Directional trends suggest greater adaptation challenges among patients with COMISA, warranting evaluation in larger prospective studies. Support (if any)
0784 Longitudinal Outcomes and Predictors of Phenoconversion in the Mayo Clinic Isolated REM Sleep Behavior Disorder Registry
Abstract Introduction Isolated REM sleep behavior disorder (iRBD) is characterized by loss of normal REM sleep atonia and dream enactment behavior. iRBD is strongly associated with α-synucleinopathies and risk for developing Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), yet phenoconversion risk for long-term outcomes of younger women and men remains undefined. We aimed to ascertain longitudinal outcomes and phenoconversion risk in the Mayo Clinic iRBD cohort. Methods Eighty-nine of 165 registry participants with at least one-year follow-up were included. Retrospective chart review attained baseline demographics, age at presentation, baseline Timed Up and Go (TUG) and Montreal Cognitive Assessment (MoCA) scores, and phenoconversion status (iRBD, PD, DLB, mild cognitive impairment [MCI], MSA, or other). Kaplan–Meier survival analysis and Cox proportional hazards modeling were analyzed with alpha at p < 0.05. Results 68 men and 21 women had a mean age of 63 years at polysomnographic diagnosis. At follow-up, 64 (71.9%) remained iRBD; 7 (7.9%) developed PD, 11 (12.4%) developed DLB, 3 (3.4%) developed MCI, 1 (1.1%) developed MSA, and 3 (3.4%) developed another dementia. Abnormal TUG (>12 seconds) occurred in 5.9% and abnormal MoCA (< 24) in 23.3%. Phenoconversion rates were similar in women and men (p = 0.44). Older age at PSG predicted phenoconversion, corresponding to a two-fold increase in risk with each 10-year increase (HR 2.00, 95% CI 1.15–3.52). Neither abnormal TUG nor MoCA predicted conversion. Cumulative phenoconversion was approximately 1% at 1 year, 7% at 3 years, 10% at 5 years, 30% at 10 years, 34% at 12 years, and 49% at 15 years. Mean and median time to phenoconversion was 7 years (range, 1-18 years). Conclusion We found that iRBD phenoconversion rates were lower than historically reported. Only age at presentation predicted phenoconversion, with risk doubling per decade. At 12 years, cumulative phenoconversion rate was approximately 34%. Support (if any)
0602 Personalized CPAP Adherence with SleepWell24: Early Outcomes of an Adaptive Smartphone Application Using Control Systems Engineering Approaches
Abstract Introduction Adherence to continuous positive airway pressure (CPAP) therapy is difficult for many patients with obstructive sleep apnea. Clinical outcomes are improved with CPAP adherence ≥6 hr/night, yet scalable approaches to personalized support are limited. We developed a theory-based, clinic experience–driven conceptual dynamical model for optimizing CPAP use and applied it to a ‘just-in-time’ adaptive version of SleepWell24, a smartphone application integrating near–real-time wearable data, CPAP use, and patient-reported symptoms and CPAP-related problems with evidence-based behavior change interventions. In this feasibility optimization trial, we examined patient acceptability and initial outcomes of the adaptive SleepWell24 platform, and guided by the conceptual model, evaluated a control systems engineering approach to demonstrate, in simulation, improved CPAP adherence. Methods Aim 1: Naïve CPAP users (N=10; M age=61.7, 60% female) participated in this 60-day ongoing trial. Patients were encouraged to interact daily with SleepWell24 to report symptoms, receive personalized troubleshooting recommendations, set goals, and receive feedback on CPAP use (via Wi-Fi-enabled smart plug assessing CPAP ‘on/off state’) and sleep/activity (Fitbit). We assessed SleepWell24 use, post-intervention acceptability, and consistent CPAP use defined as ≥6hr, for ≥6nights/week for ≥2 consecutive weeks. Aim 2: The conceptual model of CPAP adherence produced a dynamical system, informed by Model Predictive Control (MPC) as a decision-making algorithm to optimize CPAP use to ≥6hr/night by tailoring actionable behavioral recommendations using patient data integrated in real-time. Results Aim 1: Across the 60-day trial, average daily SleepWell24 engagement was 72.7%. Median CPAP adherence of ≥6hr/night was 65.8%. All participants (100%) rated SleepWell24 as moderately-to-totally acceptable and would recommend it; perceived helpfulness averaged 7.0 (of 10). Eighty percent achieved consistent CPAP use. Aim 2: In simulation, the MPC framework managed CPAP-associated symptoms (e.g., nasal, anxiety, leak) and adjusted CPAP use goals, improving predicted CPAP adherence and sleep duration and quality. Conclusion SleepWell24 was engaging, acceptable, and helpful, with most users reaching optimal CPAP use. We will next estimate dynamical models using data from trial patients, a necessary step towards full automation of SleepWell24. Support (if any) AASMF #285-SR-22
0632 Retrospective Cohort Analysis of Diagnostic Polysomnography to Predict Treatment Response to Hypoglossal Nerve Stimulation in Obstructive Sleep Apnea
Abstract Introduction Hypoglossal nerve stimulators (HGNS) are used in patients with moderate-to-severe obstructive sleep apnea (OSA) who are unable to tolerate or do not respond to continuous positive airway pressure (CPAP) therapy. However, a subgroup of patients fail to achieve resolution of OSA with HGNS alone. Previous studies have shown that lower BMI, lower nadir oxygenation, decreased sleep latency, and higher VOTE score on drug-induced sleep endoscopy (DISE) predict better treatment outcome. We hypothesize that baseline diagnostic polysomnography (PSG) may further predict which patients will achieve successful therapeutic outcome with HGNS therapy. Methods We conducted a retrospective analysis of all adult patients who underwent HGNS implantation at Mayo Clinic Arizona between 2019-2025 and had a pre-implantation diagnostic PSG available for review. Treatment success was defined by Sher Criteria: >50% reduction in post-treatment apnea hypopnea index (AHI) to a final AHI of < 20/hr. Responders met Sher criteria and non-responders did not meet Sher criteria. Demographics, sleep questionnaire results, PSG variables, and VOTE score on DISE were collected and analyzed using Spearman’s rank correlation of reduction in AHI. Results Twenty-three patients (11M/12F, median age: 69[IQR:64,75] years) met inclusion criteria. Median baseline AHI was 24[IQR:19,37]/hr. Median post-implant AHI was 8 [IQR:3, 14]/hr. Responders (n=15, 65%) and non-responders (n=8, 35%) demonstrated median post-implant AHI of 4.5[IQR:2.3,7.3]/hr and 15.7[IQR:12.3,28.5]/hr, respectively. Treatment response was associated with less time with SpO2 < 88% (T88%) (21min [IQR:3,64] vs. 73[IQR:36,105mins]; p=0.023) and higher central apnea index (CAI) (1[IQR:0.1,3] vs. 0[IQR:0,1], p=0.03) on pre-implantation PSG. Conclusion In this small cohort of OSA patients, less nocturnal hypoxemia as defined by T88% and higher baseline central apnea index were predictors of better treatment response to HGNS therapy as measured by Sher criteria. We hypothesize that greater nocturnal hypoxemia likely reflects more severe airway obstruction during sleep. Our analysis also showed that responders had higher baseline CAI than non-responders, however we believe this association is not clinically significant and likely driven by one outlier (CAI 13/hr). Further analysis in a larger HGNS cohort is needed to confirm these findings. Data enrichment efforts and more sophisticated analyses are underway. Support (if any)
0753 Oxybate Treatment Patterns in Patients with Narcolepsy: Cohort Data from Mayo Clinic and Duke Health
Abstract Introduction Sodium oxybate is strongly recommended by the American Academy of Sleep Medicine for the treatment of narcolepsy, a chronic sleep disorder characterized by excessive daytime sleepiness (EDS). This study was conducted to characterize demographic characteristics and concomitant medication use of patients with narcolepsy treated or not treated with oxybates (OXB). Methods An electronic health record–based search identified first-time patients from Mayo Clinic and Duke Health between 2002-2024 and 2012-2024, respectively. Patients had ≥1 narcolepsy-specific ICD-9/10 code and ≥1 diagnostic mention of narcolepsy in clinical notes (via natural language processing algorithm). Patients from both Mayo Clinic and Duke Health who were or were not treated with OXB were identified. Data were analyzed descriptively. Results Of 4722 patients, 654 (Mayo Clinic, n=378; Duke Health, n=276) received OXB, and 4068 (Mayo Clinic, n=2800; Duke Health, n=1268) received non-OXB treatments. The majority of patients were white (OXB-treated: 92.1%, 73.6%; non–OXB-treated: 91.1%, 69.2%) and female (OXB-treated: 68.3%, 76.8%; non–OXB-treated: 61.7%, 68.1%). Most OXB-treated patients (65.3%; 63.4%) had narcolepsy type 1 (NT1); the majority of non–OXB-treated patients (78.1%; 64.0%) had narcolepsy type 2 (NT2). The mean (SD) age of the OXB-treated cohort was younger than the non–OXB-treated cohort at the time of diagnosis (OXB-treated: 33.9 [15.3] years, 35.7 [13.2] years; non–OXB-treated: 45.5 [19.2] years, 42.5 [17.8] years). For both cohorts, the most common concomitant medications were stimulants (OXB-treated: 50.3%, 42.8%; non–OXB-treated: 41.8%, 35.2%). Conclusion In this retrospective analysis of nearly 5000 patients from Mayo Clinic and Duke Health, approximately 1 in 8 received OXB. While sodium oxybate has been approved for >2 decades and is strongly recommended for treatment of both EDS and cataplexy in narcolepsy, substantially greater OXB utilization was observed in patients with NT1. As both patients with NT1 and NT2 can experience other narcolepsy symptoms, further OXB-related education remains critical—particularly on the efficacy of sodium oxybate in the treatment of NT2. Support (if any) Avadel Pharmaceuticals
0755 Patient-Reported Improvement in Hypersomnolence Measures in Participants with Narcolepsy Taking >9 Gram Dosage of Low-Sodium Oxybate in the DUET Study
Abstract Introduction Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment; NCT05875974) was the first study to evaluate effectiveness/safety of low-sodium oxybate (LXB; Xywav®) >9 g/night (outside the recommended range: 6–9 g/night). This analysis evaluated changes in patient-reported hypersomnolence measures in participants with narcolepsy taking LXB >9 g/night compared with LXB 9 g/night. Methods DUET was a phase 4, prospective, open-label study with screening, 8-day LXB 9 g/night (9g-baseline), titration/optimization, stable-dose, and 8-day end-of-treatment (EOT) optimized LXB >9 g/night (up to 12g; >9g-EOT) periods. Patient-reported measures included Epworth Sleepiness Scale (ESS), electronic sleep diaries (completed daily during 9g-baseline and >9g-EOT; subjective total sleep time [TST], number of awakenings, sleep efficiency [TST divided by time in bed], sleep quality [5-point scale; “very good” to “very poor”], and how rested/refreshed the participant felt upon awakening [5-point scale; “very well” to “not at all”]), Karolinska Sleepiness Scale (KSS; administered 90 minutes post-polysomnography awakening at 9g-baseline and >9g-EOT), and Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10). LSM differences (95% CI) from 9g-baseline to >9g-EOT (nominal P-values) were 9g-baseline-adjusted. Results Forty-eight participants took LXB >9g (mean±SD age: 39.2±10.9 years; 62.5% female). Total stable-dose LXB (mean±SD) was 11.1±1.0 g/night (n=45). From 9g-baseline to >9g-EOT, ESS scores improved (LSM [95% CI]: –3.1 [–4.2, –1.9]; P< 0.0001; n=44), nocturnal TST increased (0.3h [0.1, 0.4]; P=0.0163; n=26), sleep efficiency increased (3.8% [1.7, 5.9]; P=0.0011; n=26), and number of awakenings remained stable (–0.2 [–0.7, 0.3]; P=0.3959; n=26). Percentage of participants rating sleep quality as “very good”/”good” increased from 26.9% (9g-baseline) to 61.5% (>9g-EOT), as did rested sleep (“very well”/”well”/”somewhat” rested) from 57.7% to 69.2%, respectively. From 9g-baseline to >9g-EOT, KSS scores decreased (–0.9 [–1.4, –0.4]; P=0.0004; n=39); FOSQ-10 scores also increased (1.3 [0.5, 2.0]; P=0.0014; n=40). Of 48 participants, 36 (75.0%) experienced ≥1 TEAE (mostly mild/moderate and 1 serious [syncope, unrelated to treatment]). No changes in respiratory polysomnography measures were observed. Conclusion Participants with narcolepsy who optimized to LXB >9 g/night, relative to 9 g/night, reported increased sleep quality and restfulness that paralleled improvements in daytime sleepiness and daytime functioning. TEAEs were consistent with those at lower dosages. Support (if any) Jazz Pharmaceuticals
1239 An Estimate of Solid Waste Produced by CPAP Treatment in the United States
Abstract Introduction Obstructive sleep apnea is an increasingly common condition seen in sleep medicine with prevalence estimates of up to 1 billion patients globally. Treatment with CPAP machines is the mainstay of therapy for patients with moderate-severe OSA, but is resource intensive due to the need for complex electronic equipment and frequent supply refills. The United States healthcare system is estimated to produce.9 million tons of solid waste annually; however, it has not been determined how sleep medicine clinical practices contribute to this total. The purpose of this study was to estimate the total solid waste produced by the treatment of moderate-severe OSA with CPAP in the U.S. over a 10 year period. Methods We modeled waste generation under a steady-state CPAP-treated population (4.8 or 24 million patients), assuming an annual 15% exit/entry rate. Each new patient was assigned a CPAP machine at initiation; existing users contributed waste from ongoing consumable use. Waste calculations included machine and accessory weight (masks, tubing, filters). We evaluated scenarios by varying mask type distribution, tubing type (heated; non-heated), and machine/supply replacement schedules to create total waste estimates. Results The solid waste associated with treating 4.8 million U.S. patients with moderate-severe OSA over ten years ranged from 88.7 to 104.4 kilotons. Maximum waste occurred with heated tubing use, CMS replacement schedules, 5-year device replacement, regardless of mask mix (104.4-104.5 kilotons). Waste was reduced by 15% using lightweight tubing and extending device life to 7 years, and by 45% using a reduced replacement schedule modeled on French practice (2–4 masks/year, 1 tubing/filter/year, 1 water reservoir/year). Conclusion Treatment with CPAP is a resource intensive therapy that produces a significant amount of plastic and electronic waste annually, likely contributing to ongoing environmental and climate degradation. Extending CPAP machine and supply lifespan and selecting for lighter PAP supplies, such as non-heated tubing, can significantly reduce the waste associated with U.S. CPAP use. Support (if any)
1246 Examining Unaddressed Needs in Narcolepsy Type 1 Care to Inform Clinical Practice Improvements
Abstract Introduction As targeted treatments for narcolepsy type 1 (NT1) emerge, timely diagnosis and care planning are essential to optimize outcomes. This ongoing initiative aims to identify and address barriers to NT1 recognition and treatment to support practice improvements and patient-centered care. Methods Patient surveys (N=38) were collected in August 2025 through collaboration with the Hypersomnia Foundation to inform an ongoing initiative at five US sleep centers. Results from patient surveys are reviewed at expert-led clinic-based sessions to identify patient needs in care, and case-based discussions challenge participants to apply the latest evidence into practice scenarios. Pre- and post-session surveys are designed to measure the impact on knowledge, confidence, and self-reported performance. Additionally, clinicians will develop strategies for care improvement. Results The top patient-reported barriers to NT1 diagnosis were finding a provider familiar with sleep disorders (42%) and limited appointments/referrals (26%). Ninety-five percent waited over 1 year for formal diagnosis (1-5 years, 71%; 5-10 years, 19%; >10 years, 5%). Narcolepsy symptoms had a significant impact on daily living (82%; 4 or 5 on a 5-point Likert scale), with many patients reporting fatigue (63%), excessive daytime sleepiness (58%), disrupted nighttime sleep (53%), sleep paralysis (50%), and cataplexy (37%) despite treatment. Patients’ top treatment goals were finding a treatment that is effective for their symptoms/type of narcolepsy (61%) and that improves daily functioning/quality of life (55%). However, 19% (1, 2, or 3 on a 5-point Likert scale) reported their care team had not discussed treatment options and 37% (1, 2, or 3 on a 5-point Likert scale) were not routinely asked about treatment goals. Patients were interested in discussing the cause of narcolepsy (63%) and their preferences for treatment (61%). Preliminary findings from the clinic-based sessions have generated practical strategies to address identified gaps in NT1 care. Conclusion Patient surveys uncovered persistent challenges in NT1 diagnosis, communication, and treatment planning. Incorporating these perspectives and case-based scenarios into clinic-based sessions have the potential to improve focused approaches to care and can provide a foundation for integrating evidence into practice as the NT1 landscape evolves. Support (if any) This program was supported by an educational grant from Takeda Pharmaceuticals U.S.A., Inc.
0429 Hypnotic Use Does Not Increase the Risk of Incident Mild Cognitive Impairment/Dementia: A Retrospective Cohort Study
Abstract Introduction Observational studies have reported associations between hypnotic use and increased risk of cognitive decline. These findings may reflect confounding from insomnia severity, healthcare utilization, and comorbidity burden. We evaluated whether hypnotic exposure is independently associated with incident mild cognitive impairment (MCI) or dementia after rigorous adjustment, including a comprehensive propensity score (PS) and Apolipoprotein E (APOE) ε4 status. Methods We conducted a retrospective cohort study using a biobank sample with linked electronic health records and genetic data. Hypnotic exposure was derived from orders data and categorized as unexposed (n=27,055), single prescription (n=4243), shorter-term use (n=3999), long-term use (≥6 orders for ≥1 year; n=3214), and by drug class: benzodiazepines (n=376), Z-drugs (n=6222), trazodone (n=2395), and mixed exposure (≥2 classes; n=2435). Incident MCI/dementia diagnoses (ICD-9/10) occurring ≥12 months after initial prescription constituted outcomes. The PS modeled likelihood of receiving hypnotics based on demographics; sleep-related conditions; healthcare utilization (record length, visit frequency, diagnostic burden); psychiatric comorbidities; alcohol use and chronic pain. Hypnotic users were 1:2 matched to unexposed individuals on age, sex, healthcare utilization, and PS. Cox proportional hazards models with a 60-month lag tested associations of exposure category, duration, and class with outcomes. Models adjusted for all PS covariates, cardiovascular risk score, and APOE ε4 status. Results Matched but unadjusted analyses suggested slightly higher hazards of MCI/dementia among hypnotic users versus unexposed (HR=1.08; CI=0.99–1.18). However, after PS adjustment and APOE ε4 inclusion, hypnotic users showed significantly lower hazards (HR=0.81; CI=0.74–0.89). Class-specific analyses indicated reduced hazards for Z-drugs (HR=0.83; CI=0.74–0.93), trazodone (HR=0.71; CI=0.60–0.86), and mixed users (HR=0.79; CI=0.68–0.91), with all classes showing lower hazards than benzodiazepine-only users. Long-term hypnotic use was associated with lower hazards than no prescription (HR=0.69; CI=0.61–0.80), single prescription (HR=0.81; CI=0.68–0.97), or short-term use (HR=0.76; CI=0.65–0.90). Conclusion The elevated cognitive risk among hypnotic users appears largely attributable to underlying clinical/utilization factors rather than hypnotic exposure itself. After comprehensive confounding control, all hypnotic classes except benzodiazepines demonstrated lower risk of MCI/dementia. These findings underscore the need for rigorous adjustment in studies of insomnia pharmacotherapy and suggest potential protective effects of certain hypnotics that warrant further investigation. Support (if any) None
0640 Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea in Recurrent Pneumothorax: A Novel and Safe Therapeutic Approach in the First Reported Case
Abstract Introduction Positive airway pressure (PAP) therapy is the standard treatment for obstructive sleep apnea (OSA); however, its use may be contraindicated in patients with recurrent pneumothorax, particularly in the presence of emphysematous lung disease and bleb formation. Hypoglossal nerve stimulation (HGNS) offers a non–positive-pressure alternative for appropriately selected patients. We describe what is, to our knowledge, the first reported case of successful HGNS therapy in an older adult with severe OSA and multiple recurrent pneumothoraces. Methods An 87-year-old man with severe OSA (baseline AHI 38, predominantly obstructive events) experienced multiple right-sided pneumothoraces beginning in December 2022, several of which were temporally associated with BiPAP use at 17/9 cm H₂O. His episodes required repeated interventions, including chest tubes, thoracoscopy with apical bleb resection and pleurodesis, and several pigtail catheter placements. Chest CT imaging demonstrated emphysema with multiple blebs, raising concern for the safety of continued PAP therapy. A mandibular advancement device was deemed inappropriate due to disease severity. The patient’s BMI was 27 kg/m2. HGNS was considered a suitable alternative. Results HGNS implantation was completed without complications. At activation, both the sensation and functional thresholds measured 0.8 V, with excellent tongue protrusion and waveform quality. The device was programmed to 0.8–1.8 V with a 30-minute start delay, 12-hour nightly duration, and 15-minute pause. On follow-up, the patient demonstrated excellent adherence (average 70 hours/week), progressed to level 8 (1.6 V), and reported significant clinical improvement with resolution of snoring and apneas. Functional threshold and waveform analysis at 1.6 V remained optimal. Importantly, the patient tolerated HGNS well without any further episodes of pneumothorax following implantation. Conclusion HGNS may represent a safe and effective alternative to PAP therapy in patients at risk for pneumothorax. While positive pressure ventilation can theoretically worsen pneumothorax by increasing pleural pressure, HGNS operates through an entirely different mechanism: it maintains upper airway patency without altering intrathoracic pressure dynamics, making it a potentially safer option for select high-risk OSA patients. Support (if any)