Reliability and Efficacy of the Epworth Sleepiness Scale: Is There Still a Place for It?

Predictors of sleepiness in a large-scale epidemiology study ESSE-RF

Introduction

To identify predictors of excessive daytime sleepiness we analyzed data from the 'Epidemiology of cardiovascular diseases in regions of Russia (ESSE-RF)' study.

Methods

Data from participants of the cohort study ESSE-RF (2012-2013), aged 25-64 years, from 13 regions of Russia were analyzed (2012-2013). The participants were interviewed regarding their sleep complaints, including difficulties with initiating and maintaining sleep, sleepiness, and use of sleeping pills. Sleepiness was considered significant if it occurred at least three times a week. The examination encompassed social, demographic, and anthropometric measures, lifestyle factors, self-reported diseases, and laboratory parameters. The final analysis included 13,255 respondents.

Results

Frequent (≥3 times/week) sleepiness was reported by 5,8%, and occasional sleepiness (1-2 times/week) by 10.8% of respondents. Multivariate regression analysis identified significant predictors of frequent sleepiness. Sleep complaints (insomnia, sleep apnea, snoring) and frequent use of sleep medication were prominent factors. Additionally, age, female gender, higher education, and retirement status were associated with sleepiness. Beyond demographics and sleep, the analysis revealed predictors: abnormal anxiety levels, low high-density lipoprotein, high salt intake and following medical conditions: arrhythmia, hypertension, myocardial infarction, other heart diseases, and renal disease.

Conclusion

This study identified a significant prevalence of EDS in Russians, aligning with global trends. However, findings suggest potential regional variations. Analysis revealed a complex interplay of factors contributing to EDS, highlighting the importance of individualized treatment approaches for improved sleep health.

Translation and validation of the Thai Version of the Japanese Sleep Questionnaire for Preschoolers (JSQ-P)

PURPOSE

This study aimed to translate and validate the Japanese Sleep Questionnaire for Preschoolers (JSQ-P) into a Thai version and to evaluate factors associated with sleep problems in preschoolers.

METHODS

The cross-cultural adaptation of JSQ-P into Thai version of JSQ-P (TH-JSQ-P) was performed including forward translation, reconciliation, backward translation, and final approval by the original creator. Children aged 2-6 years from community and clinical settings were enrolled. The TH-JSQ-P was completed by parents of preschool children twice within 10-14 days to assess its reliability and validity. Six validity tests including face validity, content validity, structural validity, construct validity, criterion validity and predictive validity were assessed. Demographic data, Epworth sleepiness scale (ESS), medical and behavior problems, and socioeconomic status were collected for analysis.

RESULTS

A total of 2613 participants completed the TH-JSQ-P, with 1207 completing it twice to assess test-retest reliability. The TH-JSQ-P had good internal consistency reliability and test-retest ability with Cronbach's alpha value of 0.898 and intraclass correlation coefficient of 0.814. The content validity was acceptable. The ESS had correlation with sleep problems in almost all subscales except for sleep habit.

CONCLUSIONS

The TH-JSQ-P is a valid and reliable instrument for evaluating sleep problems in preschool children in Thailand. It has the potential to be extensively utilized to screen for sleep problems, thereby enabling healthcare professionals to identify them early and implement prompt management.

Microstructural changes in the inferior tuberal hypothalamus correlate with daytime sleepiness in Lewy body disease

Background

Excessive daytime sleepiness (EDS) is a disabling symptom of Lewy body disorders (LBD). The hypothalamus is a key sleep-wake regulator, but its contribution to EDS in LBD remains unclear.

Objectives

Use diffusion MRI to evaluate the relationship of hypothalamic microstructure to EDS symptoms in LBD.

Methods

We studied 102 patients with clinically-defined LBD (Parkinson's disease, n=93; Parkinson's disease dementia, n=4; and dementia with Lewy bodies, n=5) and Epworth Sleepiness Scale (ESS) within 2 years of MRI. Mean diffusivity (MD) was compared between EDS+ (ESS≥10, n=37) and EDS- (ESS<10, n=65) groups in the whole hypothalamus and three subregions, covarying for age and sex. Secondary analyses tested correlations between subregion MD and continuous ESS, global cognition, and motor scores; and between subregion volume and continuous ESS.

Results

MD was increased in EDS+ compared to EDS- only in the inferior tuberal subregion (Cohen's d=0.43, p=0.043, β=0.117±0.057), with trend level differences in the whole hypothalamus (Cohen's d=0.39, p=0.064, β=0.070±0.037) and superior tuberal subregion (Cohen's d=0.38, p=0.073, β=0.063±0.035). No difference was seen in the posterior subregion (Cohen's d=0.1, p=0.628, β=0.019±0.038). Significant correlations with continuous ESS were seen in MD of whole hypothalamus (r2=0.074, p=0.0057), superior tuberal (r2=0.081, p=0.0038), and inferior tuberal (r2=0.073, p=0.0059) subregions. There was no correlation of hypothalamic MD with global cognition or motor scores, and no correlation of whole/subregional hypothalamic volumes with ESS.

Conclusions

Daytime sleepiness associates with increased MD in the inferior tuberal hypothalamus in an LBD cohort. This suggests degeneration within this region could contribute to EDS symptoms.

Association of Sleep Problems With Dialysis Shifts in Patients Undergoing Hemodialysis in Tbilisi, Georgia

Introduction According to a 2023 poll by the International Society of Nephrology, 850 million individuals worldwide suffer from chronic kidney disease (CKD) and hemodialysis (HD) is the primary treatment for 69% of the patients with CKD. While HD effectively regulates fluid balance and electrolyte levels, patients often face challenges such as weakness, exhaustion, and cognitive changes, which impact their quality of life. Sleep-related issues, including poor quality, excessive morning sleepiness, insomnia, and restless leg syndrome (RLS), are particularly common among HD patients. These disturbances stem from various factors, including psychological discomfort and biochemical imbalances. Dialysis shifts, despite their importance, remain poorly studied regarding their impact on sleep and biochemical parameters. Our study aims to address these gaps, exploring how different dialysis shifts affect sleep quality and biochemical parameters. Our hypothesis suggests that the particular dialysis shift that hemodialysis patients undergo has an impact on the quality of sleep, with various groups exhibiting varying degrees of sleep disturbance. Simultaneously, we believe that the time of dialysis shifts could influence biochemical parameter variations, which in turn could affect the quality of sleep in hemodialysis patients. Methodology This cross-sectional study focuses on assessing sleep problems and analyzing biochemical variables among hemodialysis (HD) patients in Georgia. A total of 150 participants were selected from morning, afternoon, and evening dialysis shifts, with strict inclusion criteria and exclusion criteria. Assessment procedures involved questionnaires on sleep quality, restless leg syndrome (RLS), daytime sleepiness, and severity of insomnia. Biochemical variables were obtained from the hospital records. Statistical analyses were performed using Graph Pad Prism software (GraphPad, San Diego, USA), including ANOVA and Chi-square tests for association between biochemical variables and dialysis shifts, as well as logistic regression for assessing the influence of biochemical variables on insomnia and poor sleep quality. The significance level was set at 95%. Results Results showed that patients in the afternoon shift undergo longer sessions of hemodialysis compared to other shifts. Notably, a larger proportion of morning shift patients reported poor sleep quality, while a smaller fraction of evening shift patients experienced insomnia. There were no significant associations between dialysis shift and excessive morning sleepiness or restless leg syndrome. Potassium emerged as the sole biochemical variable exhibiting an association with all three dialysis shifts. Biochemical parameters showed no discernible impact on insomnia or poor sleep quality. Conclusion Our findings suggest an association between poor sleep quality and insomnia with dialysis shifts. Hemodialysis does influence potassium levels. However, biochemical variables like sodium, potassium, calcium, phosphorus, vitamin D3, parathyroid gland hormone (PTH), and hemoglobin do not seem to affect poor sleep quality and insomnia. Further research is needed to explore potential sleep issues with nocturnal shifts and to assess if creatinine and chloride have any influence on poor sleep quality. It is important to acknowledge dialysis shift as a contributor to sleep problems, emphasizing the need for targeted interventions to enhance the quality of life for these patients.

Alpha-2-adrenergic agonists reduce resting energy expenditure in humans during external cooling

Intravenous alpha-2-adrenergic receptor agonists reduce energy expenditure and lower the temperature when shivering begins in humans, allowing a decrease in core body temperature. Because there are few data about similar effects from oral drugs, we tested whether single oral doses of the sedative dexmedetomidine (1 µg/kg sublingual or 4 µg/kg swallowed) or the muscle relaxant tizanidine (8 mg or 16 mg), combined with surface cooling, reduce energy expenditure and core body temperature in humans. A total of 26 healthy participants completed 41 one-day laboratory studies measuring core body temperature using an ingested telemetry capsule and measuring energy expenditure using indirect calorimetry for up to 6 hours after drug ingestion. Dexmedetomidine induced a median 13% - 19% peak reduction and tizanidine induced a median 15% - 22% peak reduction in energy expenditure relative to baseline. Core body temperature decreased a median of 0.5°C - 0.6°C and 0.5°C - 0.7°C respectively. Decreases in temperature occurred after peak reductions in energy expenditure. Energy expenditure increased with a decrease in core temperature in control participants but did not occur after 4 µg/kg dexmedetomidine or 16 mg tizanidine. Plasma levels of dexmedetomidine but not tizanidine were related to mean temperature change. Decreases in heart rate, blood pressure, respiratory rate, cardiac stroke volume index, and cardiac index were associated with the change in metabolic rate after higher drug doses. We conclude that both oral dexmedetomidine and oral tizanidine reduce energy expenditure and allow decrease in core temperature in humans.

Patient-Reported Outcomes of Maxillomandibular Surgery for Obstructive Sleep Apnea Treatment: A Scoping Review

(1) Background: The present scoping review aims to scrutinize all existing patient-reported outcomes and assess the perspectives of obstructive sleep apnea patients after maxillomandibular surgery. (2) Methods: The review was carried out according to the extensions for scoping reviews using the PRISMA-ScR guidelines. Several databases were used to carry out the initial search. This study included randomized controlled trials, cohort studies, cross-sectional and case-control studies. The included studies considered patients with obstructive sleep apnea who were submitted to orthognathic surgery as the main subjects, and the patient's perception of quality of life, satisfaction, treatment experience and side effects were assessed. (3) Results: From 1407 examined articles, a total of 16 were included. Most of the included studies used more than one questionnaire to assess quality of life, except for five articles. The most commonly referred instruments were the Epworth Sleepiness Scale, SF-36, the Functional Outcomes of Sleep and Ottawa Sleep Apnea. The most commonly assessed outcomes were sleep quality, daytime function, facial aesthetics, dental function and emotional health. (4) Conclusions: The number of variables that can be evaluated from a patient's perspective are endless, as are the tools available to assess them. Not all of these tools, which are generally questionnaires, assess all the various outcomes, and some do not compare the pre- and post-surgical situations. Most of them are generic and lack specificity for obstructive sleep apnea.

Obstructive sleep apnoea-hypopnoea syndrome

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a common disorder characterised by repetitive episodes of the complete or partial collapse of the pharyngeal airway during sleep. This results in cessation (apnoea) or reduction (hypopnoea) of airflow, leading to oxygen desaturation and sleep fragmentation. An individual's disposition to develop OSAHS depends on the collapsibility of a segment of the upper airway. The degree of collapsibility can be quantified by the balance between occluding or extraluminal pressures of the surrounding tissues. Patients can experience snoring, unrefreshing sleep, witnessed apnoeas, waking with a choking sensation and excessive daytime sleepiness. OSAHS has a broad range of consequences, including cardiovascular, metabolic, and neurocognitive sequelae. Treatment options include lifestyle measures, in particular weight loss, and strategies to maintain upper airway patency overnight, including continuous positive airway pressure, mandibular advancement devices and positional modifiers.

Prevalence and incidence of narcolepsy symptoms in the US general population

Objective

The objectives of this study are to evaluate the prevalence and incidence of Narcolepsy type 1 and type 2 and to determine the prevalence of narcolepsy diagnosis criteria in the US general population.

Methods

This longitudinal study was conducted in the adult US general population in two occasions. The initial interviews included 15 states (Arizona, California, Colorado, Florida, Idaho, Missouri, New York, North Carolina, North Dakota, Oregon, Pennsylvania, South Dakota, Texas, Washington, and Wyoming). The follow-up interviews, was done three years later in eight of these states. Of the 19,136 contacted individuals, 15,929 completed the initial interview and 10,931 completed the follow-up. Participants were interviewed using the Sleep-EVAL system, an artificial intelligence tool. Narcolepsy Type 1 (with cataplexy) and Narcolepsy Type 2 (without cataplexy) were defined according to the ICSD-3 classification. Symptoms of narcolepsy were assessed by frequency per week and duration. Medical visits and diagnoses were also collected.

Results

Participants were aged between 18 and 102 years of age (mean 45.8 ± 17.9 years), 51.3 % were women. The prevalence of narcolepsy with cataplexy was 12.6 per 100,000 individuals (95 % C.I., 0 to 30) and narcolepsy without cataplexy was 25.1 per 100,000. The incidence per year was 2.6 per 100,000 individuals (95 % C.I., 0 to 11).

Conclusions

Narcolepsy is a rare condition affecting 37.7/100,000 individuals (126,191 individuals in the current US population). Our US general population prevalence is in line with rates found in community-based studies but lower than what is reported in claim database studies.

CPAP adherence after ambulatory and in-hospital management in patients aged 65 years and older

OBJECTIVES

The aims of this study are to evaluate the early adherence to CPAP treatment in patients aged 65 years and older and to compare ambulatory (ACPAP) and in-hospital (HCPAP) management in starting CPAP treatment.

METHODS

Adherence to CPAP therapy at 3 months was retrospectively studied in patients on whom CPAP therapy was initiated between 1 January 2020 and 31 December 2021. Patients in the ACPAP group were selected based on the current Belgian reimbursement criteria (OAHI ≥30/h and few comorbidities).

RESULTS

146 patients were studied (median OAHI 43.35/h [32.02; 57.40]; median age 69 [67.0; 73.0]): 116 (79.5%) patients in the HCPAP and 30 (20.5%) in the ACPAP group. Based on an adherence threshold of average CPAP use of ≥ 4 hours per day, 120 (82%) patients were adherent to the treatment; 94 (81%) patients in the HCPAP and 26 (86.7%) in the ACPAP group. The median CPAP use for the total population was 6.4 h/day [4.89; 7.34], reaching 6.3 h/d [4.79; 7.15] for the HCPAP group and 6.8 h/d [6.21; 8.06] for the ACPAP group (p = 0.019). Insomnia was a significant risk factor for non-adherence (OR 5.16 [1.64; 16.08], p = 0.0043) but the ACPAP method was not (OR 0.66 [0.18; 1.91], p = 0.4748).

CONCLUSION

Early CPAP adherence in patients ≥ 65 years old was good in terms of average use per day and proportion of adherent patients. ACPAP method was not a risk factor for lower CPAP adherence in patients presenting severe OSAS (OAHI ≥30/h) and few comorbidities.

Emergence of different dimensions of sleepiness in a general population sample: An EPISONO study

INTRODUCTION

Recent evidence supports the idea that sleepiness has several dimensions, comprising psychophysiological phenomena, such as sleep propensity and sleepiness perception. The Epworth Sleepiness Scale (ESS) is among one of the most used sleepiness assessment tools, but recent data suggest that it might not detect problematic impairments in sleep health. More research is warranted investigating sleepiness dimensions with large sample sizes, using both objective and subjective methods of analyzing sleep.

METHODS

We used data from the Epidemiological Sleep Study (EPISONO), a major study carried out in Brazil using a representative sample of 1042 participants of the general population of Sao Paulo city, who completed questionnaires and underwent type I polysomnography. Sleepiness was measured by the ESS (sleep propensity) and the UNIFESP Sleep Questionnaire, which asked about the frequency of feeling sleepy during the day (sleepiness perception). The participants were distributed into 4 groups in respect of excessive daytime sleepiness (EDS) according to the following criteria: 1) having an ESS score >10 (ESS group). 2) feeling sleepy ≥3 times per week (Frequent EDS group). 3) the combined criteria (Combined EDS group). 4) having no evidence of EDS (no EDS group). The UNIFESP Sleep Questionnaire was used to obtain self-reported sleep duration, sleep debt, and sleep duration variability. Participants also completed the Pittsburgh Sleep Quality Index, the Insomnia Severity Index, and a pre-polysomnography sleep questionnaire.

RESULTS

After removing participants with missing data, there were 620 participants with no EDS, 255 individuals in the ESS group, 68 in the Frequent EDS group, and 73 in the Combined EDS group. Compared to the no EDS group, the ESS and Combined EDS groups had significantly increased sleep efficiency, diminished sleep latency, wake after sleep onset, and self-reported weekly sleep duration. The Frequent and Combined EDS groups had significantly higher scores in the Insomnia Severity Index and Pittsburgh Sleep Quality Index. All EDS groups had an increased likelihood of nonrestorative sleep. EDS frequency and the ESS scores were significantly correlated.

CONCLUSIONS

Participants with a high sleep propensity had a profile suggesting prior sleep deprivation, while high sleepiness perception was associated with impaired sleep quality. These findings indicated that, in the general population, these instruments evaluated separate sleepiness dimensions with different associations, highlighting that screening using a combination of instruments might be more effective in detecting impairments in sleep health.

Subclinical epileptiform activity and sleep disturbances in Alzheimer's disease

INTRODUCTION

Subclinical epileptiform activity (SEA) and sleep disturbances are frequent in Alzheimer's disease (AD). Both have an important relation to cognition and potential therapeutic implications. We aimed to study a possible relationship between SEA and sleep disturbances in AD.

METHODS

In this cross-sectional study, we performed a 24-h ambulatory EEG and polysomnography in 48 AD patients without diagnosis of epilepsy and 34 control subjects.

RESULTS

SEA, mainly detected in frontotemporal brain regions during N2 with a median of three spikes/night [IQR1-17], was three times more prevalent in AD. AD patients had lower sleep efficacy, longer wake after sleep onset, more awakenings, more N1%, less REM sleep and a higher apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). Sleep was not different between AD subgroup with SEA (AD-Epi+) and without SEA (AD-Epi-); however, compared to controls, REM% was decreased and AHI and ODI were increased in the AD-Epi+ subgroup.

DISCUSSION

Decreased REM sleep and more severe sleep-disordered breathing might be related to SEA in AD. These results could have diagnostic and therapeutic implications and warrant further study at the intersection between sleep and epileptiform activity in AD.

Fabry disease and sleep disorders: a systematic review

Background

Fabry disease (FD) is an X-chromosome-linked disorder characterized by a reduced or complete absence of the enzyme α-galactosidase, resulting in the accumulation of lysosomal globotriaosylceramide. Despite the presence of these deposits in multiple organs, the problem of sleep disorders within this population has very rarely been documented.

Objective

This study aimed to investigate the types and prevalence of sleep disorders among patients with FD.

Methods

Screening of the following medical databases using key terms was performed on 10 February 2023: PubMed, Scopus, and Embase. A total of 136 records were identified. The quality assessment of the studies was conducted by using tools from the National Institutes of Health (NIH) and critical appraisal tools from the Joanna Briggs Institute (JBI).

Results

The study included nine studies on sleep disorders in patients with FD. The overall quality of the majority of these studies was assessed as either poor or fair. Among 330 patients, there was a slightly higher representation of female patients (56%). Sleep problems manifested 4-5 years after the onset of FD and sometimes even after 10-11 years. Genotypes of disease associated with sleep problems were rarely described. Within the FD population, the most commonly reported conditions were excessive daytime sleepiness (EDS) as well as obstructive and central sleep apnea (OSA, CSA). However, EDS occurred more frequently in FD patients, while the prevalence of OSA and CSA was within the ranges observed in the general population. The studies included indicated a lack of association between organ impairment by primary disease and EDS and OSA. The effectiveness of enzyme replacement therapy (ERT) in treating sleep disorders was not demonstrated.

Conclusion

The findings of this report revealed the presence of many sleep-related disorders within the FD population. However, very few studies on this subject are available, and their limited results make it difficult to truly assess the real extent of the prevalence of sleep disturbances among these individuals. There is a need to conduct further studies on this topic, involving a larger group of patients. It is important to note that there are no guidelines available for the treatment of sleep disorders in patients with FD.

Patient-reported outcomes with hypoglossal nerve stimulation for treatment of obstructive sleep apnea: a systematic review and meta-analysis

INTRODUCTION

Hypoglossal nerve stimulation (HNS) has recently been introduced as an alternative treatment for patients with OSA. A large number of studies have demonstrated substantial changes in OSA with this therapy by reducing respiratory events and improving symptoms such as daytime sleepiness and quality of life. The objective of this review was to conduct a systematic review and meta-analysis to evaluate patient-reported outcomes and experience with HNS therapy.

METHODS

A systematic literature search of MEDLINE, Cochrane, and Web of Science was performed to identify randomized controlled and observational studies reporting subjective outcomes with different HNS systems in patients with OSA. Abstracts of 406 articles were screened and a subset of 55 articles were reviewed for eligibility. Risk of bias was assessed using the ROBINS-I tool. Meta-analysis using RevMan was performed when > 2 studies were identified that reported data on a specific outcome.

RESULTS

Thirty-four publications reporting data on 3785 patients with a mean follow-up of 11.8 ± 12.2 months were identified and included in the meta-analysis. The analysis revealed a pooled effect of 4.59 points improvement in daytime sleepiness as measured by the ESS questionnaire (Z = 42.82, p < .001), 2.84 points improvement in daytime functioning as measured by the FOSQ score (Z = 28.38, p < .001), and 1.77 points improvement in sleep quality as measured by the PSQI questionnaire (Z = 2.53, p = .010). Patient-reported experience was consistently positive and revealed additional relevant aspects from this perspective.

CONCLUSION

HNS therapy significantly improves quality of life in patients with OSA and reliably produces clinically meaningful effects on daytime sleepiness, daytime functioning, and sleep quality. Treatment regularly meets or exceeds the minimum clinically important differences defined for the respective instruments. Additional research is needed to further investigate effects on quality of life beyond improvements in daytime sleepiness and daytime functioning.

Effect of Aerobic Exercise Training on Sleep and Core Temperature in Middle-Aged Women with Chronic Insomnia: A Randomized Controlled Trial

BACKGROUND

Exercise represents a viable non-pharmacological intervention to help treating insomnia but the interaction mechanisms between sleep and physical activity still remain poorly understood. The aim of this study was to investigate the effect of a aerobic exercise training intervention on sleep and core temperature.

METHODS

Twenty-four adult women suffering from insomnia participated in this study. They were randomized into an exercise group and a control group. Aerobic exercise training consisted in moderate to vigorous aerobic exercise training for 12 weeks. Outcome measures included both subjective (Insomnia Severity Index, ISI) and objective (actigraphy recordings) sleep quality assessments, and core body temperature continuously recorded for a minimum 24 h.

RESULTS

The exercise group showed a decrease in ISI (p < 0.001) and in various objective sleep parameters. The core temperature batyphase value was lowered (p = 0.037) whereas its amplitude was larger (p = 0.002). We also found a tight correlation between the evolution of insomnia and the evolution of mean night-time core temperature and batyphase values.

CONCLUSIONS

A moderate to vigorous aerobic exercise program appears to be an effective non-drug therapy for improving sleep in women with insomnia. In addition, exercise programs should aim to increase core body temperature during practice to induce sleep-promoting adaptations and rebound.

Insomnia in Patients Undergoing Hypoglossal Nerve Stimulation Therapy for Obstructive Sleep Apnea

Hypoglossal nerve stimulation (HGNS) is a treatment for obstructive sleep apnea (OSA) patients with intolerance of positive airway pressure therapy. Comorbid insomnia is quite prevalent in OSA patients. We investigated the impact of insomnia and excessive daytime sleepiness (EDS) on polysomnography metrics after HGNS treatment. Data of 27 consecutive patients (9 female; mean age 55.52 ± 8.6 years) were retrospectively evaluated. Insomnia was assessed using the ISI (insomnia severity index) and EDS using the Epworth sleepiness scale (ESS). The median ISI was reduced significantly 3 months after HGNS activation (preoperative: 19; postoperative: 14; p < 0.01). Significant correlations emerged between preoperative ISI and postoperative AHI (apnea/hypopnea index; Spearman’s rho = 0.4, p < 0.05), ∆ AHI (r = −0.51, p < 0.01) and ∆ ODI (oxygen desaturation index; r = −0.48, p < 0.05). ISI correlated strongly with EES both preoperatively (r = 0.46; p < 0.02) and postoperatively (r = 0.79; p < 0.001). Therefore, HGNS therapy is associated with a significant reduction of insomnia-related symptoms, in addition to the improvement in respiratory metrics in OSA. Nonetheless, the preoperative severity of patient-reported insomnia symptoms was inversely correlated with the respiratory PSG-outcomes after HGNS. Insomnia should be considered in studies of EDS in OSA patients, especially those treated with HGNS.