0693 Effects Of Solriamfetol On 24-hour Blood Pressure Patterns In Participants With Excessive Daytime Sleepiness Associated With Obstructive Sleep Apnea

Introduction

Solriamfetol is a dopamine and norepinephrine reuptake inhibitor indicated to improve wakefulness in adult patients with excessive daytime sleepiness associated with obstructive sleep apnea (OSA; 37.5-150 mg/d) or narcolepsy (75-150 mg/d). Previous studies reported small mean increases in blood pressure (BP); however, the time course of these effects has not been evaluated. In addition, effects on BP dipping, which has been shown to be a risk factor for adverse cardiovascular outcomes have not been evaluated. These analyses evaluated the effects of solriamfetol treatment on BP using 24-hour ambulatory blood pressure monitoring (ABPM) and on the percentage of OSA patients with a non-dipping BP profile.

Methods

Twenty-four-hour ABPM was conducted at baseline and week 8 in a 12-week randomized controlled trial in participants with OSA (n=474).

Results

At week 8, increases in BP were apparent in the 75 and 300 mg dose groups from ~6 AM until 8 PM. At baseline, 58% (placebo) and 55% (combined solriamfetol) of participants were non-dippers (defined as <10% decrease in mean arterial pressure [MAP] during sleep). There was no increase in the percentage of non-dippers at week 8 relative to baseline (placebo, 56%; combined solriamfetol, 53%). Results were similar when dipping was defined by changes in systolic BP and diastolic BP.

Conclusion

The effects of solriamfetol on BP at the highest approved dose of 150 mg/d are transient across the day. Solriamfetol was not observed to have an increase in non-dipping classification in participants with OSA at any dose studied.

Support

Jazz Pharmaceuticals

1202 Validation Of A Novel Wearable Home Sleep Testing Device For Assessment Of Obstructive Sleep Apnea

Introduction

There is a substantial need for an accurate and easy-to-use tool for obstructive sleep apnea (OSA) assessment. Belun Ring Platform (BRP), a novel photoplethysmography (PPG)-based home sleep apnea testing system with a proprietary deep learning algorithm, has been shown to have good sensitivity and specificity in predicting OSA in subjects without significant comorbidities and medications known to affect heart rate (HR). In this study, we further tested its performance in subjects referred for in-lab polysomnography (PSG) assessment of sleep disorders without excluding those with non-arrhythmia comorbidities or the subjects on HR-affecting medications.

Methods

PSG was recorded simultaneously with the Ring in the sleep lab and the studies were manually scored by certified sleep technicians according to the AASM Scoring manual version 2.4. Exclusion criteria include age <18, unstable cardiopulmonary status, recent hospitalization within 30 days, significant arrhythmias, baseline HR <50 or >100, home oxygen use, pacemaker/defibrillator, post-cardiac transplantation or Left ventricular assist device.

Results

A cohort of 78 individuals (26 males and 52 females, age 50.5) were studied with 26 taking HR-affecting medications. Of these, 35 (45%) had AHI < 5; 14 (18%) had AHI 5-15; 15 (19%) had AHI 15-30; 14 (18%) had AHI > 30. The Ring-REI correlated well with the PSG-AHI (r =0.83, P <0.001). The accuracy, sensitivity, specificity in categorizing AHI >15 were 0.808, 0.931, and 0.735 respectively. The positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 0.675, 0.947, 3.509, and 0.094 respectively. The use of HR-affecting medications did not significantly affect the sensitivity and specificity of BRP in predicting OSA (P =0.16 and 0.44 respectively).

Conclusion

BRP is promising as a reasonable tool for OSA assessment and can potentially be incorporated into a broad spectrum of clinical practices for identification of patients with OSA.

Support

This study is supported by a Grant from Belun Technology Company Limited.

0710 Hypoglossal Neurostimulation In Rem- Vs. Nrem-predominant Obstructive Sleep Apnea

Introduction

Obstructive sleep apnea (OSA) is a chronic condition that requires appropriate treatment strategies to optimize outcomes while minimizing risk. In addition to anatomy, physiologic factors such as arousal threshold and loop gain (i.e. “endotypes”) play a known role in the disease process. Because loop gain tends to be higher and arousal threshold lower in NREM sleep, we hypothesize that patients with NREM-predominance may achieve less success with anatomical therapy such as upper airway stimulation (UAS). Our study aims to evaluate baseline characteristics and objective results related to NREM-predominance in patients treated with UAS.

Methods

Using data from the STAR trial, we identified patients (n=103) with at least 20 minutes of REM on baseline testing and complete demographic and disease data at baseline and month 18. Baseline NREM-predominant disease (percent NREM events > 50) was defined as a binary variable. We created two cohorts: 1) patients with REM-predominant disease and 2) those with NREM-predominant disease. ODI and AHI were evaluated at month 18.

Results

Overall 62% (n=64) of patients had NREM-predominant disease at baseline. Other baseline characteristics were similar between both groups. In univariate analysis, age was significantly associated with lower AHI in the NREM-predominant population (p<0.05) but not in the REM-predominant group (p>0.05). Results were similar for ODI. For both groups, increasing age was correlated negatively with increasing AHI; this correlation was stronger in the NREM-predominant group

Conclusion

A majority of patients in the STAR trial had NREM-predominant OSA at baseline. There appears to be an interaction between NREM-predominance and age as predictors of UAS outcomes.

Support

 

0772 Effects Of Solriamfetol On 24-hour Blood Pressure Patterns In Participants With Excessive Daytime Sleepiness Associated With Narcolepsy

Introduction

Solriamfetol is a dopamine and norepinephrine reuptake inhibitor indicated to improve wakefulness in adult patients with excessive daytime sleepiness associated with narcolepsy (75-150 mg/d) or obstructive sleep apnea (37.5-150 mg/d). Previous studies reported small mean increases in blood pressure (BP); however, the time course of these effects has not been evaluated. In addition, effects on BP dipping, which has been shown to be a risk factor for adverse cardiovascular outcomes, have not been evaluated. These analyses evaluated the effects of solriamfetol treatment on BP using 24-hour ambulatory blood pressure monitoring (ABPM) and on the percentage of narcolepsy patients with a non-dipping BP profile.

Methods

Twenty-four-hour ABPM was conducted at baseline and week 8 in a 12-week randomized controlled trial in participants with narcolepsy (n=236).

Results

At week 8, increases in BP were apparent in the 150 and 300 mg dose groups from 8 AM until 4 PM and 6 PM, respectively. At baseline, 52% (placebo) and 48% (combined solriamfetol) of participants were non-dippers (defined as <10% decrease in mean arterial pressure [MAP] during sleep). There was no increase in the percentage of non-dippers at week 8 relative to baseline (placebo, 44%; combined solriamfetol, 39%). Results were similar when dipping was defined by changes in systolic BP and diastolic BP.

Conclusion

The effects of solriamfetol on BP at the highest approved dose of 150 mg/d are transient across the day. Solriamfetol was not observed to have an increase in non-dipping classification in participants with narcolepsy at any dose studied.

Support

Jazz Pharmaceuticals

0641 Effects of Weight Loss During Long-Term Solriamfetol Treatment on Cardiometabolic Indices

Introduction

Increased prevalence of obesity has been reported in patients with narcolepsy and obstructive sleep apnea (OSA). Results from a 1-year open-label extension (OLE) study showed ≥5% weight loss in 4.5%, 17.3%, and 32.4% of participants with narcolepsy or OSA receiving solriamfetol 75, 150, or 300mg/d. We examined whether clinically significant weight loss (≥5%) in this population had favorable effects on biomarkers of cardiometabolic risk compared to no such weight loss.

Methods

We evaluated changes in weight and BP (parent study baseline to OLE week 40) and clinical laboratory assessments (OLE baseline to week 40) in participants with narcolepsy (n=124) or OSA (n=250) from the OLE study.

Results

Of 374 participants, 96 (25.7%) had ≥5% weight loss and 34 (9.1%) had ≥5% weight gain. Demographics were similar in those with and without (n=278) ≥5% weight loss. From baseline to week 40, among participants with weight loss, there were decreases in percentage with high (ie, >ULN) serum glucose (36.6% to 28.1%) or triglycerides (26.6% to 21.9%), whereas among participants without weight loss, there was an increase in percentage with high glucose (43.3% to 50%) and no change in percentage with high triglycerides (37.1% to 37.2%). The percentage of participants with high total cholesterol was stable among participants with weight loss (22.3% to 22.9%) and increased (32.7% to 37.2%) in participants without weight loss. Participants with weight loss had mean±SD reductions in SBP (-2.6±11.4mmHg) and DBP (-1.0±9.0mmHg), whereas participants without weight loss had increases of +0.65±12.5mmHg and +1.2±8.7mmHg, respectively.

Conclusion

Among solriamfetol-treated participants with ≥5% weight loss, there

were decreases in BP and percentage of participants with high glucose and triglycerides. Further research is required to examine prospective long-term effects of solriamfetol on specific biomarkers of cardiometabolic risk.

Support

Jazz Pharmaceuticals

Subgrouping persons with snoring and/or apnea by using anthropometric and cephalometric measures

Craniofacial and anthropometric characteristics are identified risk factors for obstructive sleep apnea syndrome (OSAS). Phase 1 of this study used cephalometric radiographs to record craniofacial measurements from 60 OSAS subjects with a respiratory disturbances index (RDI) of 20 or greater (group A) and 60 subjects with a history of loud snoring and an RDI less than 20 (group B). From this data set, a craniofacial risk index (CRI) was constructed using age, body mass index (BMI), and 14 cephalometric measures previously reported to be associated with OSAS. A separating boundary (CRIS) was established by using discriminant analysis to differentiate between the two groups. All measurements were determined by an investigator who was blinded to the subjects' RDI score. Phase 2 used a second sample of 19 group A and 47 group B subjects to test the ability of the CRI derived from the first sample to classify subjects in this second sample into the correct age group. The CRI was able to classify correctly 72.3% (34 of 47) of the group A subjects when all variables were used in the discriminant model. Using only four variables (age, BMI, hyoid mandibular plane distance, and tongue length) selected by the stepwise method, 72.3% (34 of 47) of the group B subjects and 78.7% of group A subjects were classified correctly. These results suggest that a stepwise CRI could be used to classify heterogeneous groups of individuals with increased RDI into subgroups with varying degrees of anatomic risk for disease. Such subgrouping by anatomic risk could be important in determining the pathophysiology of OSAS because it is likely that differences in upper airway anatomy among individuals interacts with a variety of other factors to produce clinical illness.

Cephalometric assessment of snoring and nonsnoring children

STUDY OBJECTIVE

To determine the differences in craniofacial cephalometric variables between snoring and nonsnoring children.

DESIGN

Cross-sectional.

SETTING

Case Western Reserve University Dental School, Department of Orthodontics, and local Cleveland orthodontic private practices.

PATIENTS

Twenty-eight snoring and 28 nonsnoring children between the ages of 7 years and 14 years. Nonsnoring subjects were matched to snoring subjects by age, sex, and ethnicity (mean [+/- SD] age, 10+/-2 years; 82% white, 64% female).

INTERVENTIONS

None.

MEASUREMENTS

Snoring was assessed using a sleep behavior questionnaire administered to parents or guardians. The cephalometric radiographs of the study subjects were traced by a single investigator, and 1 angular measurement and 11 linear measurements of hard and soft tissues were recorded. The paired Student's t test was used to analyze the cephalometric data.

RESULTS

Snoring children manifest a significantly narrower anterior-posterior dimension of the pharynx at the superior and most narrow widths. Snoring children also had a greater length from the hyoid to the mandibular plane.

CONCLUSIONS

Snoring children appear to present craniofacial factors that differ from those of nonsnoring children.

Sleep disorders in regional sleep centers: a national cooperative study. Coleman II Study Investigators

STUDY OBJECTIVE

In the last two decades there has been an increase in the awareness of and professional expertise in sleep disorders. The objective of this study was to determine the spectrum of sleep-related disorders diagnosed in regional sleep centers and compare this to a previous survey published in 1982.

DESIGN

A two-month prospective point-prevalence survey

SETTING

Nineteen accredited regional sleep centers in the United States.

PARTICIPANTS

Patients evaluated at regional sleep centers during a two-month period.

INTERVENTIONS

NA.

RESULTS

Obstructive sleep apnea, narcolepsy, and restless legs syndrome were the top three reported primary diagnoses with a prevalence of 67.8%, 4.9%, and 3.2%, respectively. The entire range of sleep disorders, however, was represented in the study sample. Nearly a third of patients had either a primary or secondary diagnosis of a non-respiratory sleep disorder. Referral physicians were most likely to be from internal medicine, pulmonary medicine, and otolaryngology. Compared to the previous survey from 1982, there has been an absolute increase in patient referrals/center with a two- to four-fold increase in the number of patients/center with a final diagnosis of a non-respiratory sleep-related problem. Moreover, there has been a greater than twenty-fold increase in the diagnosis of obstructive sleep apnea.

CONCLUSION

Regional sleep centers are encountering increasing patient referrals and a broad range of sleep-related disorders. The predominant reasons for referral are related to obstructive sleep apnea, narcolepsy, and restless legs syndrome.

Responses of upper airway, intercostal and diaphragm muscle activity to stimulation of oesophageal afferents in dogs

The effects of oesophageal distension on respiratory patterns and the moving average electromyogram (e.m.g.) activity of three upper airway muscles--the alae nasi, the genioglossus, and the posterior cricoarytenoid--and four chest wall muscles--the costal and crural diaphragm and the inspiratory and expiratory intercostals--were examined in ten anaesthetized, tracheostomized, spontaneously breathing dogs. Distension was produced by inflations of a balloon placed in the middle part of the thoracic oesophagus with volumes of air ranging from 50 to 200 ml. Oesophageal distension increased respiratory frequency, mainly due to a significant shortening of the expiratory time. Activity of both the costal and crural parts of the diaphragm was inhibited with oesophageal distension, whereas that of the inspiratory intercostal muscles increased, tending to maintain a near-normal tidal volume and end-tidal CO2. Phasic inspiratory activity of all three upper airway muscles increased in response to oesophageal distension, as did the activity of the expiratory intercostal muscles. The changes in the breathing pattern and the electrical activity of all muscles in response to oesophageal distension were immediate, occurring during the first breath after the balloon was inflated. The responses were graded, so that increases in the volume of the oesophageal balloon progressively increased the activity of the upper airway and intercostal muscles, and decreased diaphragm activity. Bilateral vagotomy abolished the effects of oesophageal distension on upper airway and chest wall muscle activity, suggesting that vagal afferents constitute the major pathway for the reflex.

Effect of transrespiratory pressure on PETCO2-PaCO2 and ventilatory reflexes in humans

Inspiratory muscle activity increases when lung volume is increased by continuous positive-pressure breathing in conscious human subjects (Green et al., Respir. Physiol. 35: 283-300, 1978). Because end-tidal CO2 pressure (PETCO2) does not change, these increases have not been attributed to chemoreflexes. However, continuous positive-pressure breathing at 20 cmH2O influences the end-tidal to arterial CO2 pressure differences (Folkow and Pappenheimer, J. Appl. Physiol. 8: 102-110, 1955). We have compared PETCO2 with arterial CO2 pressure (PaCO2). We have compared PETCO2 with arterial CO2 pressure (PaCO2) in healthy human subjects exposed to continuous positive airway pressure (10 cmH2O) or continuous negative pressure around the torso (-15 cmH2O) sufficient to increase mean lung volume by about 650 ml. The difference between PETCO2 and PaCO2 was not decreased, and we conclude that PETCO2 is a valid measure of chemical drive to ventilation in such circumstances. We observed substantial increases in respiratory muscle electromyograms during pressure breathing as seen previously and conclude this response must originate by proprioception. On average, the compensation of tidal volume thus afforded was complete, but the wide variability of individual responses suggests that there was a large cerebral cortical component in the responses seen here.