Does AHI Value Enough for Evaluating the Obstructive Sleep Apnea Severity?

Effectiveness and tolerability in people with narcolepsy transitioning from sodium oxybate to low-sodium oxybate: Data from the real-world TENOR study

OBJECTIVES

The Transition Experience of persons with Narcolepsy taking Oxybate in the Real-world (TENOR) study was conducted to provide real-world insight into the experience of people with narcolepsy switching from sodium oxybate (SXB) to low-sodium oxybate (LXB; 92% less sodium than SXB).

METHODS

TENOR is a patient-centric, prospective, observational, virtual-format study. Participants were adults with narcolepsy (type 1 or 2) who were transitioning from SXB to LXB treatment (±7 days from LXB initiation). Effectiveness and tolerability data were collected online from baseline (taking SXB) through 21 weeks (taking LXB) via daily and weekly diaries and questionnaires, including the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire, short version (FOSQ-10), and the British Columbia Cognitive Complaints Inventory (BC-CCI).

RESULTS

TENOR participants (N = 85) were 73% female with a mean (SD) age of 40.3 (13.0) years. Mean (SD) ESS scores decreased numerically throughout the transition from SXB to LXB (baseline: 9.9 [5.2]; week 21: 7.5 [4.7]), with 59.5% and 75.0% of participants having scores in the normal range (≤10) at baseline and week 21, respectively. Mean (SD) FOSQ-10 scores (baseline: 14.4 [3.4]; week 21: 15.2 [3.2]) and BC-CCI scores (baseline: 6.1 [4.4]; week 21: 5.0 [4.3]) also remained stable. The most common symptoms related to tolerability reported by participants at baseline were sleep inertia, hyperhidrosis, and dizziness (45.2%, 40.5%, and 27.4%, respectively), which decreased in prevalence by week 21 (33.8%, 13.2%, and 8.8%, respectively).

CONCLUSIONS

Findings from TENOR confirm maintenance of effectiveness and tolerability when transitioning from SXB to LXB treatment.

Oxygen resaturation rate is significantly associated with objectively assessed excessive daytime sleepiness in suspected obstructive sleep apnoea patients

INTRODUCTION

Commonly utilised metrics such as the apnoea-hypopnoea index show limited correlation to excessive daytime sleepiness (EDS). Oxygen desaturation parameters show better predictive power, however oxygen resaturation parameters have not yet been investigated. Oxygen resaturation may represent increased cardiovascular fitness and thus we hypothesized that a higher resaturation rate would be protective against EDS.

METHODS

Oxygen saturation parameters were computed via ABOSA software for adult patients referred for polysomnography and multiple sleep latency test in Israel Loewenstein hospital 2001-2011. EDS was defined as a mean sleep latency (MSL) below 8 min.

RESULTS

1629 patients (75% male, 53% obese, median age of 54 years) were included for analysis. The average desaturation event nadir was 90.4% and resaturation rate 0.59%/second. Median MSL was 9.6 min, and 606 patients met criteria for EDS. Patients who were younger, female, and with larger desaturations had significantly higher resaturation rates (p < 0.001). In multivariate models, adjusted for age, sex, body mass index, and average desaturation depth, resaturation rate showed a significant negative correlation with MSL (z-score standardised beta, -1 (95%CI -0.49, -1.52)), and significantly increased odds ratio (OR) of EDS (OR, 1.28 (95%CI 1.07, 1.53)). The beta associated with resaturation rate was larger, though non-significantly, than that of desaturation depth (difference 0.36 (95% CI -1.34, 0.62), p = 0.470).

CONCLUSION

Oxygen resaturation parameters show significant associations with objectively assessed EDS independent of desaturation parameters. Thus, resaturation and desaturation parameters may reflect differing underlying mechanistic pathways and both be considered novel and appropriate markers for assessing sleep-disordered breathing and associated outcomes.

Predictors of the Efficacy for Daytime Sleepiness in Patients With Obstructive Sleep Apnea With Continual Positive Airway Pressure Therapy: A Meta-Analysis of Randomized Controlled Trials

Objective

The main aim of this meta-analysis was to evaluate the predictors of the efficacy of continuous positive airway pressure (CPAP) in ameliorating excessive daytime sleepiness (EDS) in patients with obstructive sleep apnea (OSA).

Methods

Randomized controlled trials (RCTs) published between January 1994 and October 2021 were searched in the PubMed, EMBASE, and Cochrane Library databases. The weighted mean differences (WMDs) for the Epworth Sleepiness Scale (ESS) scores, the Multiple Sleep Latency Test (MSLT), and the Maintenance of Wakefulness Test (MWT) were pooled in STATA.

Results

A total of 41 RCTs involving 7,332 patients were included. CPAP therapy was found to be significantly associated with changes in ESS (WMD = −2.14, P < 0.001), MSLT (WMD = 1.23, P < 0.001), and MWT (WMD = 1.6, P < 0.001). Meta-regression analysis and subgroup analysis indicated that in mild OSA, the efficacy of CPAP therapy for subjective EDS was limited to patients <50 years of age, with a baseline body mass index (BMI) of ≥30 kg/m², baseline ESS score of ≥11, therapy adherence for ≥3 h/night, and treatment duration of ≥2 months. In moderate OSA, significant differences were observed in the changes in ESS among groups stratified by baseline ESS score (P = 0.005), adherence (P < 0.001), treatment duration (P = 0.009), and trial design type (P = 0.001). In severe OSA, this difference was observed among groups stratified by baseline BMI (P = 0.028), baseline ESS score (P = 0.001), and adherence (P = 0.047). Patients with moderate-severe OSA but not mild OSA showed significant improvements in MSLT. Patients with the age <50 years or BMI ≥33 kg/m² had a more significant increase in MWT.

Conclusion

Continuous positive airway pressure therapy improved subjective and objective sleepiness in patients with OSA. Age, baseline BMI, baseline ESS score, adherence, and duration of treatment may predict the effects of CPAP on EDS in patients with OSA. Notably, the baseline ESS scores and adherence were stable predictors regardless of OSA severity.

Obstructive Sleep Apnea Syndrome Phenotyping by Cluster Analysis: Typical Sleepy, Obese Middle-aged Men with Desaturating Events are A Minority of Patients in A Multi-ethnic Cohort of 33% Women

OBJECTIVE

Several clinical obstructive sleep apnea syndrome (OSAS) phenotypes associated with heterogeneous cardiovascular risk profiles have been recently identified. The purpose of this study was to identify clusters amongst these profiles that allow for the differentiation of patients.

METHODS

This retrospective study included all moderate-to-severe OSAS patients referred to the sleep unit over a 5-year period. Demographic, symptom, comorbidity, polysomnographic, and continuous positive airway pressure (CPAP) adherence data were collected. Statistical analyses were performed to identify clusters of patients.

RESULTS

A total of 567 patients were included (67% men, 54±13 years, body mass index: 32±7 kg/m², 65% Caucasian, 32% European African). Five clusters were identified: less severe OSAS (n=172); healthier severe OSAS (n=160); poorly sleeping OSAS patients with cardiometabolic comorbidities (n=87); younger obese men with sleepiness at the wheel (n=94); sleepy obese men with very severe desaturating OSAS and cardiometabolic comorbidities (n=54). Patients in clusters 3 and 5 were older than those in clusters 2 and 4 (P=0.034). Patients in clusters 4 and 5 were significantly more obese than those in the other clusters (P=0.04). No significant differences were detected in terms of symptoms and comorbidities. Polysomnographic profiles were very discriminating between clusters. CPAP adherence was similar in all clusters but, among adherent patients, daily usage was more important in cluster 1 (less severe patients) than in cluster 5.

CONCLUSION

This study highlights that the typical sleepy obese middle-aged men with desaturating events represent only a minority of patients in our multi-ethnic moderate-to-severe OSAS cohort of 33% females.

Socioeconomic and humanistic burden of illness of excessive daytime sleepiness severity associated with obstructive sleep apnoea in the European Union 5

OBJECTIVE/BACKGROUND

Evaluate the impact of excessive daytime sleepiness (EDS) severity on burden of illness among adults with obstructive sleep apnoea (OSA) in European Union 5 (EU5) countries (France, Germany, Italy, Spain, United Kingdom).

PATIENTS/METHODS

This retrospective observational study used data from the 2017 EU5 National Health and Wellness Survey, a self-administered, internet-based, non-screening survey. Respondents who self-reported both having experienced OSA in the last 12 months and having had their OSA diagnosed by a physician were considered to have OSA. Respondents completed the Epworth Sleepiness Scale (ESS) and were consequently categorised into 4 groups: OSA-with-EDS (ESS >10) subdivided by EDS severity (mild [ESS = 11-12], moderate [ESS = 13-15], severe [ESS = 16-24]), and OSA-without-EDS (ESS ≤10). Bivariate and multivariable analyses examined group differences in health-related quality of life (HRQoL), work productivity and activity impairment, and health care utilisation.

RESULTS

The analysis included 2008 respondents with OSA: n = 661 (32.9%) with EDS (29.5% mild, 34.5% moderate, 36.0% severe) and n = 1347 without EDS. Compared with the OSA-without-EDS group, the OSA-with-EDS subgroups generally had higher rates of obesity, depression, and other reported comorbidities. Greater severity of EDS was associated with worse self-reported HRQoL (all domains, P < 0.001) and work productivity and activity impairment (absenteeism, P = 0.031; presenteeism, overall work impairment, and non-work activity impairment, P < 0.001), as well as increased numbers of health care provider visits (P < 0.001).

CONCLUSIONS

Compared to patients with OSA but without EDS, those with EDS had substantially higher socioeconomic and humanistic burden of disease, which was more profound among those reporting greater EDS.

A novel parameter is better than the AHI to assess nocturnal hypoxaemia and excessive daytime sleepiness in obstructive sleep apnoea

To evaluate whether the percentage of total sleep time spent with apnoea and hypopnoea duration time (AHT%) is better than the apnoea-hypopnoea index (AHI) for the assessment of nocturnal hypoxaemia and excessive daytime sleepiness (EDS) in patients with obstructive sleep apnoea (OSA). Patients with suspected OSA were enrolled. Polysomnography, Epworth Sleepiness Scale, self-administered surveys and anthropometric measures were performed. The efficiency of AHT% and the AHI was evaluated for nocturnal hypoxaemia and EDS. A total of 160 eligible participants were analysed. The median AHT% in normal, mild, moderate and severe OSA patients was significantly different in the four-group patients with OSA. Spearman rank correlations analysis found that the associations were stronger between AHT% with percentage of total sleep time and O₂ saturation of < 90% and minimum nocturnal oxygen saturation than these parameters with the AHI. AHT% had a greater area under the curve than the AHI for predicting EDS in patients with OSA. AHT% was significantly higher in the EDS group. We present a novel parameter, AHT%, to evaluate nocturnal hypoxaemia and EDS in OSA patients. AHT% partially compensates for the shortcomings of the AHI. AHT% is better than the AHI for assessing nocturnal hypoxaemia and EDS. AHT% reflects different clinical characteristics associated with OSA from a new perspective.

A New Wearable System for Home Sleep Apnea Testing, Screening, and Classification

We propose an unobtrusive, wearable, and wireless system for the pre-screening and follow-up in the domestic environment of specific sleep-related breathing disorders. This group of diseases manifests with episodes of apnea and hypopnea of central or obstructive origin, and it can be disabling, with several drawbacks that interfere in the daily patient life. The gold standard for their diagnosis and grading is polysomnography, which is a time-consuming, scarcely available test with many wired electrodes disseminated on the body, requiring hospitalization and long waiting times. It is limited by the night-by-night variability of sleep disorders, while inevitably causing sleep alteration and fragmentation itself. For these reasons, only a small percentage of patients achieve a definitive diagnosis and are followed-up. Our device integrates photoplethysmography, an accelerometer, a microcontroller, and a bluetooth transmission unit. It acquires data during the whole night and transmits to a PC for off-line processing. It is positioned on the nasal septum and detects apnea episodes using the modulation of the photoplethysmography signal during the breath. In those time intervals where the photoplethysmography is detecting an apnea, the accelerometer discriminates obstructive from central type thanks to its excellent sensitivity to thoraco-abdominal movements. Tests were performed on a hospitalized patient wearing our integrated system and the type III home sleep apnea testing recommended by The American Academy of Sleep Medicine. Results are encouraging: sensitivity and precision around 90% were achieved in detecting more than 500 apnea episodes. Least thoraco-abdominal movements and body position were successfully classified in lying down control subjects, paving the way toward apnea type classification.

Severity of Desaturations Reflects OSA-Related Daytime Sleepiness Better Than AHI

STUDY OBJECTIVES

The aim was to investigate how the severity of apneas, hypopneas, and related desaturations is associated with obstructive sleep apnea (OSA)-related daytime sleepiness.

METHODS

Multiple Sleep Latency Tests and polysomnographic recordings of 362 patients with OSA were retrospectively analyzed and novel diagnostic parameters (eg, obstruction severity and desaturation severity), incorporating severity of apneas, hypopneas, and desaturations, were computed. Conventional statistical analysis and multivariate analyses were utilized to investigate connection of apnea-hypopnea index (AHI), oxygen desaturation index (ODI), conventional hypoxemia parameters, and novel diagnostic parameters with mean daytime sleep latency (MSL).

RESULTS

In the whole population, 10% increase in values of desaturation severity (risk ratio = 2.01, P < .001), obstruction severity (risk ratio = 2.18, P < .001) and time below 90% saturation (t_90%) (risk ratio = 2.05, P < .001) induced significantly higher risk of having mean daytime sleep latency ≤ 5 minutes compared to 10% increase in AHI (risk ratio = 1.63, P < .05). In severe OSA, desaturation severity had significantly (P < .02) stronger negative correlation (ρ = -.489, P < .001) with mean daytime sleep latency compared to AHI (ρ = -.402, P < 0.001) and ODI (ρ = -.393, P < .001). Based on general regression model, desaturation severity and male sex were the most significant factors predicting daytime sleep latency.

CONCLUSIONS

Severity of sleep-related breathing cessations and desaturations is a stronger contributor to daytime sleepiness than AHI or ODI and therefore should be included in the diagnostics and severity assessment of OSA.

CITATION

Kainulainen S, Töyräs J, Oksenberg A, Korkalainen H, Sefa S, Kulkas A, Leppänen T. Severity of desaturations reflects OSA-related daytime sleepiness better than AHI. J Clin Sleep Med. 2019;15(8):1135-1142.

Smoking and sleep apnea duration mediated the sex difference in daytime sleepiness in OSA patients

PURPOSE

Daytime sleepiness is a common symptom of obstructive sleep apnea (OSA) and is more common in men, but the underlying mechanism remains unclear. The aim of this study was to assess whether or not sex differences in daytime sleepiness persisted after controlling for age and OSA severity and to explore the factors contributing to daytime sleepiness in patients with OSA.

METHODS

A total of 104 pairs of patients with OSA, matched by age and apnea-hypopnea index (AHI), were enrolled in this retrospective study. Demographic data were collected; daytime sleepiness was measured by the Epworth Sleepiness Scale (ESS); and polysomnography (PSG) was performed on each participant. These measurements were compared between sexes, and the factors affecting daytime sleepiness were explored with correlation and multivariate linear regression analyses.

RESULTS

Men had significantly higher ESS scores (p = 0.021) than women. Regarding demographics, BMI, neck/height ratio, and proportion of habitual smoking and alcohol intake were significantly higher in men. Regarding PSG findings, men had more rapid eye movement sleep, a longer mean apnea-hypopnea duration, and a longer mean apnea duration (MAD). Regression analysis showed that two sex-associated variables, habitual smoking (β = 0.189, p = 0.006) and MAD (β = 0.154, p = 0.024), had the strongest association with ESS scores. Further analysis revealed that MAD was significantly influenced by apnea index (β = 0.306, p < 0.001) and sex (β = - 0.193, p = 0.003).

CONCLUSION

The sex difference in daytime sleepiness persists in patients with OSA, even after matching AHI and age. The difference is mediated by sex-specific smoking habits and sex differences in apnea duration.

Social support, mastery, sleep-related problems and their association with functional status in untreated obstructive sleep apnoea patients

BACKGROUND

Social support and mastery are important aspects in the treatment of chronic diseases, however their role in connection with Obstructive Sleep Apnoea (OSA) remains unclear.

OBJECTIVES

The study examined the associations between social support, mastery, sleep-related problems and functional status in untreated OSA patients.

METHODS

All patients in this cross-sectional study completed the Multidimensional Scale of Perceived Social Support, the Pearlin Mastery Scale, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale and the Functional Outcomes of Sleep Questionnaire. Multiple linear regression and mediation analyses were used to analyse the data.

RESULTS

Participants were 150 newly diagnosed OSA patients (Apnoea-Hypopnoea Index-AHI≥5; 68% male; mean age 48.9 ± 9.5years). Compared with social support, mastery was more strongly associated with functional status. The indirect effects of sleep-related problems on functional status via mastery varied between 17.7% and 23.3%.

CONCLUSIONS

Supporting OSA patients' sense of mastery may significantly contribute to better disease management.

Sinonasal Characteristics in Patients with Obstructive Sleep Apnea Compared to Healthy Controls

Background. The difference in nasal obstruction between OSA patients and healthy individuals is not adequately documented. Our aim was to describe the sinonasal quality of life and nasal function in OSA patients and healthy controls using the sinonasal outcome test-20 (SNOT-20), nasal obstruction visual analog scale (NO-VAS), and peak nasal inspiratory flow (PNIF). Methodology and Principal. Ninety-three OSA patients and 92 controls were included in a case-control study from 2010 to 2015. Results. Mean SNOT-20 score in the OSA group was 1.69 (SD 0.84) compared to 0.55 (SD 0.69) in controls (p < 0.001, 95% CI [0.9, 1.4]). The mean NO-VAS score was 41.3 (SD 12.8) and 14.7 (SD 14.4) in the OSA group and controls, respectively, (p < 0.001, 95% CI [22.7, 30.6]). PNIF measured 105 litres/minute in the OSA group and 117 litres/minute in controls (p < 0.01, 95% CI [−21.8, −3.71]). There was a positive correlation between subjective nasal obstruction and change in PNIF after decongestion in the control group alone. Conclusions. OSA patients have a reduced sinonasal QoL and lower peak nasal inspiratory flow compared to controls. Treatment of nasal obstruction in OSA patients should be made a priority along with treatment of the ailment itself.