Continuous Positive Airway Pressure Titration Study Research Articles

Auto-PAP Titration Efficacy in Obstructive Sleep Apnea: A Single-Center Experience

ABSTRACT Introduction: Obstructive sleep apnea, often known as OSA, is a sleep-related breathing disease that, if not treated, can lead to serious disabilities or even death. Continuous positive airway pressure (CPAP) is the therapy technique that is suggested for treating severe and moderate OSA. An auto/manual CPAP titration study can be used to determine the appropriate pressure that must be maintained to treat this condition. The motive of this research is to appraise the effectiveness among OSA patients for the auto-PAP titrations. Methodology: A cross-sectional clinical prospective study was conducted at the tertiary care center. Subjects who underwent auto-PAP titration and had a diagnosis of moderate and sever OSA were included. They were evaluated for the efficacy of auto-PAP titration and other demographic features and their association with the titration efficacy. The values were compared for statistical significance. Results: The findings of the study showed that fifty percent of the cohort showed optimal titration, forty percent showed good titration, ten percent showed suitable titration, and none fell into the unacceptable group. Conclusion: According to the findings, using auto-PAP was associated with positive results in those with moderate and severe OSA. There is evidence to suggest that unattended auto-PAP titration is a very successful technique that might be regarded as a substitute for attended CPAP titrations. This would result in a reduction in the amount of labor required and the price.

P067 Patient perceived sleep quality at CPAP titration study as an early indication of short and long-term adherence to CPAP therapy.

Abstract Background Untreated obstructive sleep apnoea is associated with morbidity and diminished quality of life. Despite this, adherence to continuous positive airway pressure (CPAP) remains poor. Few studies have examined which factors from CPAP titration study affect adherence, with a paucity that evaluated perceived sleep quality and adherence. Methods We hypothesise that patients with better perceived sleep quality, at the time of their CPAP titration study will have greater uptake and adherence to CPAP. We aim to: 1. Compare the change in patients’ perceived sleep quality between diagnostic and CPAP titration studies, and future CPAP adherence at 3 and 12 months. 2. Evaluate the association between patients’ perceived sleep quality at the time of their CPAP titration study with future CPAP adherence at 3 and 12 months. 3. Evaluate factors relating to sleep architecture, and sleep disturbance that affect patients’ perceived sleep quality. Sleep studies were obtained prospectively between 2018 and 2019. Patients completed two questionnaires grading sleep quality post study. Progress to Date This study was approved as a quality activity through the Metro North Quality and Safety Unit (ID 3929). Sleep study and questionnaire data were collated and merged with adherence data. Analysis will begin shortly. Intended Outcome and Impact We intend to publish the results of this study in an international sleep journal. Positive findings may improve management of those at risk of poor adherence. Subsequent studies may evaluate the effect of early patient follow up or early motivational interviewing on uptake and adherence to CPAP.

Continuous positive airway pressure and adherence in patients with different endotypes of obstructive sleep apnea.

Determining the endotypes of obstructive sleep apnea (OSA) has potential implications for precision interventions. Here we assessed whether continuous positive airway pressure (CPAP) treatment outcomes differ across endotypic subgroups. We conducted a retrospective analysis of data obtained from 225 patients with moderate-to-severe OSA from a single sleep centre. Polysomnographic and CPAP titration study data were collected between May 2020 and January 2022. One-month CPAP treatment adherence was followed. Obstructive sleep apnea endotypes, namely arousal threshold, collapsibility, loop gain, and upper airway gain were estimated from polysomnography and dichotomised as high versus low. We examined associations between endotypic subgroups and (1) optimal CPAP titration pressure, (2) CPAP-related improvements in sleep architecture (proportions of slow-wave and rapid eye movement (REM) sleep), and (3) CPAP adherence. We observed that patients with high collapsibility required a higher CPAP pressure than those with low collapsibility (∆ = 0.4 cmH2 O, 95% confidence interval [CI] = 0.3-1.7). A larger increase in slow-wave sleep and in REM sleep proportions after CPAP treatment were observed in patients with a high arousal threshold, high collapsibility, high loop gain, or high upper airway gain than in those with low levels of endotypes. High loop gain and high collapsibility were independently associated with longer CPAP use hours per night (∆ = 0.6 h, 95% CI = 0.2-1.5 and ∆ = 0.3 h, 95% CI = 0.03-1.5, respectively). In conclusion, different endotypic subgroups of OSA exhibit a difference in outcomes of CPAP treatment. Knowledge of endotypes may help clinicians to understand which patients are expected to benefit most from CPAP therapy prior to its administration.

Heated humidified high flow nasal cannula therapy in children with obstructive sleep apnea: A randomized cross-over trial

Objective/backgroundModerate-to-severe obstructive sleep apnea (OSA) is highly prevalent in children with obesity and/or underlying medical complexity. The first line of therapy, adenotonsillectomy (AT), does not cure OSA in more than 50% of these children. Consequently, continuous positive airway pressure (CPAP) is the main therapeutic option but adherence is often poor. A potential alternative which may be associated with greater adherence is heated high-flow nasal cannula (HFNC) therapy; however, its efficacy in children with OSA has not been systematically investigated.The study aimed to compare the efficacy of HFNC with CPAP to treat moderate-to-severe OSA with the primary outcome measuring the change from baseline in the mean obstructive apnea/hypopnea index (OAHI). Participants/methodsThis was a single-blinded randomized, two period crossover trial conducted from March 2019 to December 2021 at a Canadian pediatric quaternary care hospital. Children aged 2–18 years with obesity and medical complexity diagnosed with moderate-to-severe OSA via overnight polysomnography and recommended CPAP therapy were included in the study. Following diagnostic polysomnography, each participant completed two further sleep studies; a HFNC titration study and a CPAP titration study (9 received HFNC first, and 9 received CPAP first) in a random 1:1 allocation order. ResultsEighteen participants with a mean ± SD age of 11.9 ± 3.8 years and OAHI 23.1 ± 21.7 events/hour completed the study. The mean [95% CI] reductions in OAHI (-19.8[-29.2, -10.5] vs. -18.8 [-28.2, -9.4] events/hour, p = 0.9), nadir oxygen saturation (7.1[2.2, 11.9] vs. 8.4[3.5, 13.2], p = 0.8), oxygen desaturation index (-11.6[-21.0, -2.3] vs. -16.0[-25.3, -6.6], p = 0.5) and sleep efficiency (3.5[-4.8, 11.8] vs. 9.2[0.9, 15.5], p = 0.2) with HFNC and CPAP therapy were comparable between conditions. ConclusionHFNC and CPAP therapy yield similar reductions in polysomnography quantified measures of OSA severity among children with obesity and medical complexities. Trial registrationNCT05354401 ClinicalTrials.gov.

Effects of Continuous Positive Airway Pressure on Sleep State Misperception in Patients With Obstructive Sleep Apnea.

Little is known regarding the effects of continuous positive airway pressure (CPAP) on sleep misperception in obstructive sleep apnea (OSA). Sleep state perception was measured by subtracting the objective total sleep time from the subjective sleep duration. Sleep underestimation and overestimation were defined as ± 60 minutes sleep perception. Insomnia and depressive symptoms were assessed using questionnaires. Finally, nonparametric statistical analyses were performed. Of the 339 patients with OSA included in the study, 90 (26.5%) and 45 (13.3%) showed sleep underestimation and overestimation, respectively. Overall, a significant underestimation of sleep was noted during CPAP titration comparing to a diagnostic PSG (P < 0.001). OSA patients with insomnia or depressive symptoms did not show any changes in sleep perception between diagnostic and CPAP titration studies, whereas those without insomnia or depressed mood showed significantly underestimated sleep duration during CPAP titration. Patients with OSA and either underestimated or overestimated misperception showed perceptual improvements during CPAP titration regardless of the presence of insomnia or depressive symptoms. However, of 204 patients with normal sleep perception, 138 (67.6%) and 10 (4.9%) had underestimation and overestimation of sleep during CPAP titration. CPAP titration may improve sleep perception with moderate to severe OSA who have sleep misperception. However, CPAP titration may result in sleep misperception especially underestimation of sleep in those who have normal sleep perception.

Obstructive sleep apnea may reduce a diagnostic accuracy of video-polysomnography for idiopathic REM sleep behavior disorder

BackgroundSevere obstructive sleep apnea (OSA) in patients with rapid eye movement (REM) sleep behavior disorder (RBD) may result in frequent fragmentation of REM sleep and consequently lead to a false negative diagnosis of RBD on a video-polysomnography (video-PSG). Thus, we determined whether OSA has the negative impact on video-PSG diagnostic accuracy for RBD. MethodsPatients with clinically diagnosed idiopathic RBD were included. RBD was confirmed if a video-PSG demonstrated complex motor behavior during REM sleep or REM sleep without atonia (RWA). Motor behavior was measured using the RBD Severity Scale. Cohen's kappa coefficient was calculated for qualitative assessment of RWA. A stepwise logistic regression analysis was performed. ResultsOf a total 254 patients included, a diagnosis of RBD was confirmed by a video-PSG in 221 patients (87.0%). RWA, vocalization, and axial or proximal muscle movements in REM sleep were noted in 86.6%, 58.3%, and 35.9%, respectively. A video-PSG diagnosis of RBD was less likely associated with severe OSA (odds ratio [OR] 0.284, p = 0.010) and moderate OSA (OR 0.404, p = 0.071) whereas was more likely associated with longer REM sleep time (OR 1.036, p < 0.001). In 43 patients who underwent a continuous positive airway pressure (CPAP) titration study, a diagnosis of RBD was more common on a CPAP titration study (88.4%) than on a first video-PSG (65.1%) (p = 0.013). Twelve (27.9%) of 43 CPAP patients were diagnosed with RBD according only to CPAP titration study. ConclusionsOSA that requires CPAP may reduce a diagnostic accuracy for RBD by a video-PSG. False negative results were probably due to frequent electromyographic artifacts and/or severe sleep disruption from apneic events during REM sleep.

Average volume-assured pressure support for patients with obstructive sleep apnea with failed CPAP titration.

ObjectivesObstructive sleep apnea (OSA) is a common disease, often treated using continuous positive airway pressure (CPAP) therapy. In many cases, patients fail a CPAP titration study due to inadequate control of the apnea-hypopnea index (AHI, events/hour) or due to treatment-emergent central sleep apnea (TE-CSA). We report our experience using a mode of non-invasive ventilation for alternative treatment of these patients.Material and MethodsWe reviewed records of adults who had OSA with AHI≥15 diagnosed on polysomnography (PSG) with failed CPAP titration and in whom titrations with average volume-assured pressure support (AVAPS) with auto-titrating expiratory positive airway pressure were performed.ResultsForty-five patients, age 57.9±13.1 y, 26 males, body mass index (BMI) 40.2±8.7kg/m2. Reasons for CPAP titration failure included: TE-CSA (25, 55.6%) and inadequate control of AHI at maximum CPAP of 20cm H2O (20, 44.4%). Changes noted from baseline PSG to AVAPS titration: AHI: 65.3±29.3 decreased to 22.3±16.1 (p<0.001). Median time SpO2 ≤88%: 63.7 to 6.9min (p<0.001). In 16 patients the AHI was reduced to <15 and in 16 additional patients the AHI was reduced to <30. Improvement in AHI was not related to gender, age, or opioid use, but was correlated with BMI: ∆AHI=12.2 - (1.4 * BMI); p=0.05. AVAPS resulted in improved sleep architecture: median N3 sleep increased: 1.4% to 19.6% total sleep time (TST) (p<0.001), and median R sleep increased: 6.4% to 13.6% TST (p<0.01).DiscussionFor patients with OSA for whom CPAP titration failed, titration with AVAPS may be an effective treatment.

New Predictive Equation for Optimal Continuous Positive Airway Pressure in Adult Patients with Obstructive Sleep Apnea

Objective: This study aimed to develop and validate a new continuous positive airway pressure (CPAP) prediction equation and compare it with other formulas.Material and Methods: We retrospectively included patients with obstructive sleep apnea who underwent a CPAP titration study between January 2012 and December 2016. All clinical and polysomnographic data were collected. The new prediction equation was developed using the first data set, and the predictability performance was validated using the second data set.Results: Among the 266 enrolled patients, 73.7% were male, and the mean body mass index (BMI) was 30.8±7.4 kg/m2 . Five variables, namely age, BMI, neck circumference (NC), apnea–hypopnea index (AHI), and minimum pulse oxygen saturation (Min SpO2 ), highly correlated with the optimal titration pressure, and were therefore included in the equation, as stated below:Predicted pressure (cm H2 O) = 2.26 + (0.02xAge) + (0.04xBMI) + (0.11xNC) + (0.04xAHI) - (0.04xMin SpO2 )This equation accounted for 54.4% of the variance in predicting the optimal titration pressure (R2 =0.544, p-value &lt;0.001). Its optimal estimation was 62.0% in the validated group. The equation-derived predicted pressure correlated with good agreement with the laboratory-derived optimal titration pressure (r=0.70, 95% CI=0.6335–0.755, p-value&lt;0.001) according to Bland–Altman analysis. Conclusion: Our equation is highly consistent with the CPAP titration study in predicting fixed CPAP pressure, and is thereby beneficial for sleep technicians in establishing a starting pressure for such studies at a sleep laboratory.

Different scoring rules for respiratory event-related leg movements: effects on the prevalence of periodic limb movements during sleep and their association with depressive symptoms in patients with obstructive sleep apnea

BackgroundWe compared the prevalence of periodic leg movements during sleep (PLMS) according to two different scoring rules of the American Academy of Sleep Medicine (AASM) 2012 and World Association of Sleep Medicine (WASM) 2016 and determined their association with depressed mood in patients with obstructive sleep apnea (OSA). MethodsPLMS, defined as a periodic leg movements index of >15, were diagnosed on a diagnostic and continuous positive airway pressure (CPAP) titration polysomnography using the AASM 2012 and WASM 2016 rules. The Beck Depression Inventory (BDI) and Epworth Sleepiness Scale (ESS) were used, and multiple regression analyses were performed. ResultsAmong 160 OSA patients, the proportion with PLMS scored by the WASM 2016 criteria was significantly higher than that scored by the AASM 2012 criteria in a diagnostic study (20.6% vs. 16.3%, respectively; P = 0.016) but not in CPAP titration study and only in patients with severe OSA. In adjusted models, PLMS were positively associated with BDI scores and a BDI of ≥10 on both diagnostic and CPAP titration studies when scored by the WASM 2016. By contrast, when scored by the AASM 2012, PLMS were associated with BDI scores (but not BDI of ≥10) only in a CPAP titration study. ConclusionsThere are significant differences in the prevalence of PLMS and their association with depressed mood depending on the scoring rules in patients with OSA. The current AASM scoring criteria underestimate the prevalence of PLMS, and PLMS are more likely associated with depressed mood according to the WASM scoring criteria.

826 Central Sleep Apnea associated with Sodium Oxybate– A Case Series

Abstract Introduction Sodium oxybate (SO) is indicated to treat cataplexy and excessive daytime sleepiness (EDS) in patients with narcolepsy. Only a handful of cases have been reported of new-onset Central Sleep Apnea (CSA) in the setting of SO use. We present 3 patients who developed CSA in the setting of use of SO. Report of case(s) Patient 1: A 25-y/o man presented with hypersomnolence. His diagnostic polysomnogram (PSG) showed moderate Obstructive Sleep Apnea (OSA), and he was placed on Continuous Positive Airway Pressure (CPAP) therapy. Due to persistent hypersomnia in the setting of effectively treated OSA, he had a Multiple Sleep Latency Test (MSLT), which revealed pathological sleepiness with a mean latency of 3.8 minutes with a sleep-onset REM on the overnight polysomnogram. SO was started for clinical diagnosis of Narcolepsy after he failed other stimulant medications. Hypersomnolence improved though data from his PAP device, home sleep studies, re-titration studies performed when he was on SO demonstrated CSA following 1st or 2nd dose of SO. Patient 2: A 17-y/o man was diagnosed to have Narcolepsy with Cataplexy, based on PSG followed by MSLT. 20 years later, he was diagnosed with OSA based on a PSG and was treated with CPAP. A few years later, he was started on SO for fragmented sleep and EDS. A home sleep study performed when he was on SO, revealed CSA. Later, an in-lab titration study showed CSA with Cheyne-Stokes respiration (CSR), treated with Adaptive Servo-Ventilation (ASV) therapy. Patient 3: A 15-y/o man initially presented after several cataplectic episodes and was diagnosed with Narcolepsy with Cataplexy. His initial PSG showed no evidence of sleep-disordered breathing. A few years later, for persistent cataplectic events, he was started on SO with improvement in the episodes’ frequency. Several years later, a baseline PSG demonstrated OSA and CSA, with frequent CSA events soon after taking SO. The CPAP titration study, performed following the PSG, also revealed frequent CSA following the second dose of SO. Conclusion Close monitoring is warranted with SO use, given some narcolepsy patients’ predisposition to develop CSA. Follow-up studies are needed to address the pathogenesis and management strategies. Support (if any) None

An Overnight Rhythmic Sleep-Wake Pattern in Stroke and Obstructive Sleep Apnea: A Case Report and Literature Review

Background and Objective: Obstructive sleep apnea (OSA) is a common sleep breathing disorder and a comorbid condition in patients with stroke. The prevalence of sleep disorders as a stroke consequence is high. Being independent of vascular risk factors, OSA is associated with increased risk of ischemic stroke. Here, we report a patient with OSA and stroke. Case Report: This case report presents a patient with a history of stroke and hemiparesis who underwent polysomnog-raphy (PSG) for evaluating OSA because of snoring, witnessed apnea, and excessive daytime sleepiness (EDS). Then the subject underwent continuous positive airway pressure (CPAP) titration for treating OSA. In first night of PSG, there was a repetitive cyclic pattern of sleep and arousals. After CPAP titration study and with CPAP pressure of 15 cmH2o, OSA and rhythmic changes of electroencephalography (EEG) were resolved. Conclusion: OSA as a risk factor for stroke can be associated with PSG cyclic wake-sleep pattern in these patients, and this pattern can be resolved by CPAP therapy.

Clinical characteristics of Asian patients withsleep apnea with low arousal threshold and sleep structure change with continuous positive airway pressure.

Low respiratory arousal threshold (ArTH) has been observed to be prevalent in patients withobstructive sleep apnea (OSA), and is associated with poor adherence to continuous positive airway pressure (CPAP) treatment. This study aimed to examine the associations between low ArTH and clinical characteristics. The second aim was to examine sleep structure changes between diagnostic polysomnography (PSG) and CPAP titration studies. PSG data for 3718 adults who had an apnea-hypopnea index (AHI) ≥ 5 were reviewed retrospectively, as well as 206 CPAP titration studies among these participants. Participants were dichotomized into low- and high-ArTH groups according to their PSG parameters. The associations between low ArTH and clinical characteristics were examined by multivariate logistic regressions. The sleep structure changes between PSG and CPAP titration studies were examined by repeated measures ANOVA. Fifty percent of patients withOSA had low ArTH. Compared with high-ArTH patients, low-ArTH patients were less obese and composed of a higher percentage of women. In logistic regression models, low ArTH was associated with bruxism and nocturia, but not with illnesses after adjusting for AHI and body mass index. Compared with diagnostic PSG studies, low-ArTH patients had significantly decreased stage changes and increased percentage of rapid eye movement sleep during CPAP titration studies. Low ArTH was prevalent in this large sample of patients withOSA. Arousal threshold was not associated with an increased risk of physical illnesses but was with certain clinical complaints. Low-ArTH patients benefited from CPAP titration study for improved sleep structure.

0634 Volume-Assured Pressure Support is Effective Treatment for Obstructive Sleep Apnea Patients Who Failed CPAP Titration

Abstract Introduction Obstructive sleep apnea (OSA) is a common disease, often treated using continuous positive airway pressure (CPAP). In many cases, patients fail an attended CPAP titration study, often due to inadequate control of AHI, and treatment-emergent central apneas as CPAP is increased. Here, we report our experience using volume-assured pressure support (VAPS) for these patients. Methods We retrospectively reviewed records of 45 adults who had OSA diagnosed on polysomnography (PSG) in whom CPAP titration had failed. In these patients, VAPS-AE (adjustable expiratory pressure) titrations were performed. Patients with central sleep apnea on baseline PSG were excluded. Results Reasons for CPAP titration failure included: treatment emergent central apneas (25), failure of maximum CPAP pressure to treat OSA (18), and persistent hypoxia (2). Average age was 57.9±13.1, BMI was 40.2±8.7, 26 males, Epworth sleepiness score was 10.7±7.9. The following significant changes from baseline PSG to VAPS titration were observed: AHI: 65.3±29.3 to 22.3 ±16.1 (p&amp;lt;.001) events/hour. Time &amp;lt; 88% saturation: 63.7 (median) to 6.9 (median) min (p&amp;lt;.001). The number of patients with AHI&amp;lt;15 was 0 on PSG and 16 (36%) on VAPS-AE, while the number of patients with AHI&amp;lt;30 was 7 (16%) on PSG and 32 (71%) on VAPS-AE. Improvement in AHI was not related to gender, age, or narcotic use, but was correlated with BMI: ΔAHI = 12.2 - (1.4 * BMI); p=.05. VAPS resulted in improved sleep architecture: slow wave sleep increased (medians: 1.4% to 19.6% total sleep time (TST)) (p&amp;lt;.001), REM sleep increased (medians 6.4% to 13.6% TST) (p&amp;lt;.01). Conclusion For OSA patients for whom CPAP titration failed, titration with VAPS-AE was an effective treatment for many patients. Support N/A

Predictive equation for optimal continuous positive airway pressure in children with obstructive sleep apnoea.

AimA subgroup of children with obstructive sleep apnoea (OSA) requires treatment with continuous positive airway pressure (CPAP). This study's aims were: 1) to determine if the optimal CPAP for the treatment of OSA in children correlates with body mass index (BMI); 2) to determine the correlation between polysomnographic variables and optimal CPAP in children with OSA; and 3) to develop a CPAP predictive equation for children with OSA.MethodsThis was a retrospective study of children with OSA who underwent CPAP titration studies. Patients with craniofacial abnormalities (except Down syndrome) and neuromuscular diseases were excluded. Polysomnograms were done using Sandman Elite. Correlations between optimal CPAP, clinical and polysomnographic variables were analysed. A multivariable linear regression model for optimal CPAP was developed.Results198 children (mean±sd age 13.1±3.6 years) were studied. Optimal CPAP had a significant positive correlation with age (rho=0.216, p=0.002), obstructive apnoea-hypopnoea index (rho=0.421, p<0.001), 3% oxygen desaturation index (rho=0.417, p<0.001), rapid eye movement respiratory disturbance index (rho=0.378, p<0.001) and BMI z-score (rho=0.160, p=0.024); and a significant negative correlation with arterial oxygen saturation measured by pulse oximetry nadir (rho= −0.333, p<0.001). The predictive equation derived was:Optimal CPAP (cmH2O)=6.486+0.273·age (years)−0.664·adenotonsillectomy(no=1, yes=0)+2.120·Down syndrome (yes=1, no=0)+0.280·BMI z-score.ConclusionThe equation developed may help to predict optimal CPAP in children with OSA. Further studies are required to validate this equation and to determine its applicability in different populations.

Efficacy of Auto-PAP Titration in Obstructive Sleep Apnea: Single-center Experience

Background: Obstructive sleep apnea (OSA) is a sleep-associated breathing disorder, which left untreated can cause severe morbidities or even mortality. The recommended treatment strategy for moderate-to-severe OSA is continuous positive airway pressure (CPAP). The optimal pressure required for OSA can be measured by either manual CPAP titration or auto-CPAP titration study. Objective: To assess the efficacy of auto-PAP titration for OSA patients. Methodology: This was a cross-sectional study conducted on Pulmonary Medicine Sleep Lab at Amrita Institute of Medical Sciences, Kochi. Fifty patients who have undergone full-night polysomnography and followed with auto-PAP titration are included in the study. The research was approved by the institutional ethics committee. Results: In the study cohort, 50% showed optimal titration, 40% good titration, 10% adequate titration and none in unacceptable category. The results showed that auto-PAP usage has good result in moderate-to-severe OSA. Conclusion: Unattended auto-PAP titration seems to be highly effective modality which can be considered as an alternative to attended CPAP titration, thus reducing labor intensiveness and cost.

Diabetes sleep treatment trial: Premise, design, and methodology

The Diabetes Sleep Treatment Trial (DSTT) is a multi-site, double-blinded, randomized, sham-controlled trial. The study objective is to test whether treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) treatment results in improved glycemic control and diabetes self-management behavior compared to participants on a sham-CPAP (sub-therapeutic) device in participants with type 2 diabetes mellitus (T2DM) and co-morbid OSA. The purpose of this paper is to describe the premise for the DSTT, the study design, and the methodology used in this on-going trial. The target enrollment is 210 randomly assigned participants recruited from two sites. The primary outcome for glucose control is HbA1C; additional outcomes for diabetes self-management include objectively measured steps walked and subjectively measured diabetes-related distress, diabetes empowerment, and diabetes knowledge. All participants receive individual diabetes education and counseling for 6 weeks over two individual sessions and three telephone calls. Participants are randomized to receive either sham or active CPAP for 12 weeks, after which, they “guess” their group assignment; this will assist in determining the success of blinding participants to treatment group assignment. Participants revealed to be on active CPAP will be encouraged to continue CPAP for an additional 12 weeks; participants who had been on sham devices will be encouraged to have a repeat CPAP titration study and to crossover to active CPAP treatment for 24 weeks. An intention-to-treat approach will be used for efficacy analyses. The trial is registered with Clinicaltrials.gov (NCT01901055).

Cardiac effects of CPAP treatment in patients with obstructive sleep apnea and atrial fibrillation.

Obstructive sleep apnea (OSA) has been recognized as an independent risk factor for the development and progression of atrial fibrillation (AF). We aimed to investigate the changes in heart rate and atrial and ventricular ectopy after continuous positive airway pressure (CPAP) treatment in patients with OSA and AF. Consecutive patients with AF underwent ambulatory sleep monitoring, and OSA was defined as an Apnea-Hypopnea-Index (AHI) ≥ 5/h. Treated patients completed in-laboratory CPAP titration study. A 24-h ECG Holter was performed at baseline and at 3 and 6months after CPAP treatment. One hundred patients (70% males) with AF were included in the final analysis. OSA was diagnosed in 85% of patients. There were no significant changes in mean 24-h heart rate in patients with paroxysmal or permanent AF at 3 and 6months of treatment compared to baseline. In patients with paroxysmal AF (n = 29), atrial and ventricular ectopy counts/24h significantly decreased at 3months compared to baseline (median (IQR) 351 (2049) to 57 (182), P = 0.002; 68 (105) to 16 (133), P = 0.01 respectively). At 6months follow-up, the atrial ectopy count/24h significantly decreased in patients with paroxysmal AF compared to baseline (median (IQR) 351 (2049) to 31 (113), P = 0.016, n = 14). In patients with permanent AF (n = 15), there was a significant reduction in ventricular ectopy count/24h at 3months compared to baseline (median (IQR) 100 (1116) to 33 (418), P = 0.02). There is a significant decrease in atrial and ventricular ectopy count/24h in patients with AF and OSA at 3 and 6months of CPAP treatment compared to baseline.

Complex sleep apnea after full-night and split-night polysomnography: the Greek experience.

Treatment-emergent central sleep apnea (TE-CSA) is defined as the emergence or persistence of central respiratory events during the initiation of positive airway pressure (PAP) without a back-up rate in obstructive sleep apnea (OSA) patients and after significant resolution of obstructive events. Previous studies have estimated a prevalence from 0.56 to 20.3%. The aim of this study was to establish the prevalence of TE-CSA in a Greek adult population. One thousand fifty nine patients with newly diagnosed OSA, who were referred to the Sleep Disorders Center of Evangelismos Hospital of Athens over an 18-month period, were included in this study. A split-night polysomnography (PSG), or two formal overnight PSGs (diagnostic and continuous PAP (CPAP) titration study), were performed. Patients with OSA were divided in two groups; the first group included 277 patients, who underwent two separate studies (diagnostic and CPAP titration study), and the second group 782 patients, who underwent split-night studies. The prevalence of TE-CSA in the first group was 2.53% (7 patients), and in the second group was 5.63% (44 patients). The prevalence of TE-CSA in Greece was lower compared to most previous reported studies. The significant variation in the prevalence of TE-CSA between different centers throughout the world is mainly associated with the used diagnostic criteria as well as methodological and technical aspects.

The Efficacy of Low-Level Continuous Positive Airway Pressure for the Treatment of Snoring.

To assess effects of low-level continuous positive airway pressure (CPAP) on snoring in habitual snorers without obstructive sleep apnea (OSA). A multicenter prospective in-laboratory reversal crossover intervention trial was conducted between September 2013 and August 2014. Habitual snorers were included if they snored (inspiratory sound pressure level ≥ 40 dBA) for ≥ 30% all sleep breaths on a baseline sleep study (Night 1), and if significant OSA and daytime somnolence were absent. Included participants then underwent a CPAP titration study at 2, 4, or 6 cm H2O (Night 2) to examine snoring responses to step-increases in nasal pressure, a treatment night at optimal pressure (Night 3), followed by baseline night (Night 4). At each pressure, snoring intensity was measured on each breath. Snoring frequency was quantified as a percentage of sleep breaths at thresholds of 40, 45, 50, and 55 dBA. Sleep architecture and OSA severity were characterized using standard measurements. On baseline sleep studies, participants demonstrated snoring at ≥ 40 dBA on 53 ± 3% and ≥ 45 dBA on 35 ± 4% of breaths. Snoring frequency decreased progressively as nasal pressure increased from 0 to 4 cm H2O at each threshold, and plateaued thereafter. CPAP decreased snoring frequency by 67% and 85% at 40 and 45 dBA, respectively. Intervention did not alter sleep architecture and sleep apnea decreased minimally. Low-level CPAP below the range required to treat OSA diminished nocturnal snoring, and produced uniform reduction in nightly noise production below the World Health Organization's limit of 45 dBA. ClinicalTrials.gov, identifier: NCT01949584.

Comparative study on optimal continuous positive airway pressure and predicted continuous positive airway pressure in obstructive sleep apnoea

Background: Continuous positive airway pressure (CPAP) is the first line non-invasive and safest treatment of obstructive sleep apnoea (OSA). Optimal CPAP therapy prescribed is obtained by manual titration in lab setting. Due to lack of data in Indian population predicted CPAP pressure proposed by Hoffstein is used using body mass index (BMI), neck circumference (NC) and apnoea-hypopnoea index (AHI) to correlate with the optimal pressure by automatic CPAP titration.Methods: The study was of retrospective and observational type. It included OSA patients diagnosed by overnight polysomnography (PSG) who had undergone automatic CPAP titration. The correlation of optimal pressure of automatic CPAP and predicted CPAP was studied.Results: A total of 30 patients were included in the study of which 23 were males and 7 were females. It was found that 28 patients had severe OSA and 2 had moderate OSA. AHI significantly improved (P = 0.000) with automatic CPAP titration. The mean CPAP predicted pressure (8.77±2.05) was found lower than the therapeutic optimal pressure (13.03±3.18) prescribed and the value exceeded the range ±2 in 76% of patients.Conclusions: Use of automatic CPAP limits the role for predicted formula for in lab titration/unattended home setting and patients who don’t undergo CPAP titration study, reducing the cost of testing. However, the predicted pressure could be used as a starting pressure for initiation of CPAP titration in lab setting for manual titration.