Sleepiness in obstructive sleep apnea syndrome and simple snoring evaluated by the Epworth Sleepiness Scale

Revisiting the Epworth sleepiness scale : Is excessive daytime sleepiness still a valid screening tool for obstructive sleep apnea in a population at risk?

OBJECTIVE

Obstructive sleep apnea (OSA) is a common medical problem with numerous comorbidities and high costs. Since the introduction of the Epworth sleepiness scale (ESS), excessive daytime sleepiness (EDS) has been considered the most common and prominent symptom of OSA. Aim of this study was to re-evaluate the ESS for detection of OSA in a population at risk compared to the gold standard overnight polysomnography (PSG).

METHODS

A total of 266 patients (mean age 57.9 ± 11.6 years; 189 men and 77 women), referred to our sleep laboratory for probable OSA, were given ESS followed by an overnight PSG. The ESS values were compared to PSG apnea hypopnea index (AHI) with sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) calculated for ESS. The positive cut-off value for ESS was ≥ 10 and for AHI ≥ 5.

RESULTS

Only 92 (34.6%) subjects had a positive ESS. An OSA was diagnosed by PSG in 213 (80.1%) subjects: 46 having mild, 37 moderate and 130 severe apnea. Most subjects with positive ESS (88.0%) were found to have OSA but most subjects with a negative ESS (75.9%) were also positive for OSA (42% with AHI ≥ 30). The area under the receiver operating characteristic (ROC) curve for ESS was 0.60 (95% confidence interval, CI 0.54-0.66; p = 0.020) with SE 38.0%, SP 79.3%, PPV 88.0%, NPV 24.1% and DA 46.2%.

CONCLUSION

It was found that excessive daytime sleepiness, measured by ESS, is not a valuable screening tool for OSA, especially when the test is negative. Other screening tests that involve additional parameters, beside daytime sleepiness alone, should be considered.

Association between Patient- and Partner-Reported Sleepiness Using the Epworth Sleepiness Scale in Patients with Obstructive Sleep Apnoea

Excessive daytime sleepiness in obstructive sleep apnoea (OSA) is often measured differently by patients and their partners. This study investigated the association between patient- and partner-completed Epworth Sleepiness Scale (ESS) scores and a potential correlation with OSA severity. One hundred two participants, 51 patients and 51 partners, completed the ESS before and three months after initiating CPAP treatment. There was no significant difference when comparing patients’ and partners’ ESS scores at baseline (10.75 ± 5.29 vs. 11.47 ± 4.96, respectively) and at follow-up (6.04 ± 4.49 vs. 6.41 ± 4.60, respectively). There was a strong correlation between patients’ and partners’ ESS scores on both (baseline and follow-up) assessments (p < 0.001). There was significant improvement in patients’ and partners’ ESS scores after CPAP therapy (p < 0.001). There was no significant difference in patients’ or partners’ ESS scores between patients with mild, moderate or severe OSA. There was no significant correlation between oxygen desaturation index (ODI) and ESS score reported either by patient or by partner. In conclusion, our study revealed a strong correlation between patient- and partner-reported ESS scores. However, neither patient- nor partner-completed ESS scores were associated with OSA severity.

Impact of the sleep apnea management group clinic on positive airway pressure adherence

Background

Positive airway pressure (PAP) adherence is critical for managing obstructive sleep apnea (OSA). We postulate that group-based Sleep Apnea Management (SAM) clinic, which harnesses the benefits of providing mutual support as well as facilitates access to system-based resources and education, will confer improvements in PAP adherence.

Methods

Data from SAM clinic attendees from January 2017 to June 2018 were retrospectively analyzed. Adherence data at SAM baseline visit and 1-3 months follow-up were collected. Average PAP usage from all-days and days used were analyzed along with demographics, co-morbidities, and Epworth Sleepiness Scale. Adherence was defined as >4 hours a night for ≥70% of nights over a 30-day period. Key structural elements of the SAM group clinic model were co-presence of the OSA care team members and peer group support. Key efficiency elements were group education and the prompt-to-patient multidisciplinary troubleshooting adherence barriers.

Results

Of 110 SAM clinic attendees, average age was 60.9±12.7 years, 53% were men, and 46% Caucasian. At baseline, the mean for average-all-days usage was 4.2 hours, mean average-days-used usage was 5.2 hours, and mean percentage-of-days usage ≥4 hours was 57%. At follow-up, the mean average-all-days usage increased 1.2 hours (p<0.001), mean average-days-used usage increased 0.8 hours (p<0.001), and the mean percentage-of-days with usage ≥4 hours increased 16% (p<0.001). At baseline, 46% of patients met criteria for adherence, which increased to 66% at follow-up.

Conclusion

In this study, after the SAM clinic, all PAP adherence parameters improved significantly. This observational study serves as a proof of concept study for future trials pertaining to group clinic in managing PAP adherence in OSA.

Psychological Well-Being in Obstructive Sleep Apnea Syndrome Associated With Obesity: The Relationship With Personality, Cognitive Functioning, and Subjective and Objective Sleep Quality

Obstructive sleep apnea (OSA) syndrome severely affects psychological well-being. This syndrome frequently occurs in obesity; however, no previous study has investigated the level of psychological well-being in the case of OSA syndrome associated with obesity. In this work, we assessed the level of psychological well-being in fifty-two individuals affected by OSA syndrome and obesity through the Psychological General Well-Being Index. Moreover, we investigated the role of personality, cognitive functioning and attentional capabilities, subjective perception and objective measurement about sleeping, on the subjective perception of psychological well-being. Our sample reported a lower level of psychological well-being; the participants' scores were below the normative cut-off in all components, except for depression symptoms. A lower expression of harm avoidance temperament and a lower level of daily sleepiness predicted a higher level of psychological well-being. Psychological well-being seemed to be severely affected in individuals affected by OSA syndrome and obesity. The temperament and subjective perception of daily alertness and sleepiness, rather than the syndrome severity, seemed to play a crucial role in the individual perception of the psychological well-being.

Expert Opinions and Consensus Recommendations for the Evaluation and Management of Insomnia in Clinical Practice: Joint Statements of Five Italian Scientific Societies

BACKGROUND

Insomnia is the most commonly reported sleep problem in industrialized countries worldwide being present in about 36.8% of the general population. In Italy, such a percentage seems to be even higher. Although insomnia can be an independent disorder, it is most frequently observed as a comorbid condition and may precipitate, exacerbate, or prolong a broad range of comorbid conditions including physical and mental illnesses. Evaluating and targeting insomnia in the Italian clinical practice should be a priority.

METHODS

The present expert options and recommendations development process was based on the RAND/UCLA Appropriateness Method for conceptualizing, designing, and carrying out the appropriateness of procedures for the diagnosis and treatment. Only available options in Italy were taken into considerations.

RESULTS

We evaluated 12 international guidelines and 12 most recent systematic reviews for insomnia evaluation and treatment produced in the last 10 years.

CONCLUSIONS

Our findings suggested that symptoms of insomnia must always be assessed in the Italian clinical practice by evaluating nocturnal and daytime symptoms, comorbid conditions and lifestyle. In a patient with chronic insomnia with and without comorbidity, insomnia treatment should be always initiated. CBT-Insomnia therapy should be the first option accordingly to availability. The choice of the drug should be based on different factors such as type of insomnia, age, comorbidities, and potential side effects. Melatonin 2 mg prolonged release should be the first choice in subjects >55 years. If the choice would be a Z-drug or a short-acting benzodiazepine (in subjects <65 years old) or a sedating antidepressant, the use should be in the short term (≤4 weeks) and then proceeds to tapering under clinical monitoring.

Weighted Epworth sleepiness scale predicted the apnea-hypopnea index better

Background

The relationship between the Epworth sleepiness scale (ESS) and the apnea-hypopnea index (AHI) is uncertain and even poor. The major problem associated with the ESS might be a lack of consideration of weight in prediction in clinical practice. Would awarding different item-scores to the four scales of ESS items to develop a weighted ESS scoring system improve the accuracy of the AHI prediction? It is warranted to explore the intriguing hypotheses.

Methods

Seven hundred fifty-six adult patients with suspicion of obstructive sleep apnoea syndrome (OSAS) were prospectively recruited to a derivation cohort. This was tested against a prospective validation cohort of 810 adult patients with suspected OSAS. Each ESS item’s increased odds ratio for the corresponding AHI was calculated using univariate logistic regression. The receiver operating characteristic curves were created and the areas under the curves (AUCs) were calculated to illustrate and compare the accuracy of the indices.

Results

The higher the ESS item-score, the closer the relationship with the corresponding AHI. The odds ratios decreased as a result of the increased AHI. The ESS items were of unequal weight in predicting the corresponding AHI and a weighted ESS was developed. The coincidence rates with the corresponding AHI, body mass indices, and neck circumferences rose as the scores increased, whereas nocturnal nadir oxygen saturations decreased, and the weighted ESS was more strongly associated with these indices, compared with the ESS. The capability in predicting the patients without OSAS or with severe OSAS was strong, especially the latter, and the weighted ESS orchestrated manifest improvement in screening the patients with simple snoring. The patterns of sensitivities, specificities, and Youden’s indices of the four ranks of weighted ESS for predicting the corresponding AHI were better than those of the ESS, and the AUCs of weighted ESS were greater than the corresponding areas of ESS in the two cohorts.

Conclusions

The weighted ESS orchestrated significant improvement in predicting the AHI, indicating that the capability in predicting the patients without OSAS or with severe OSAS was strong, which might have implications for clinical triage decisions to prioritize patients for polysomnography.

Validation of the Arabic Version of the Epworth Sleepiness Scale among the Yemeni Medical Students

The study was conducted with the aim to assess the psychometric measures of an adapted Arabic version of the Epworth Sleepiness Scale (ESS) among medical students at Sana'a University, Yemen. The cross-sectional study targeted 360 students (males: 176; females: 184) from the preclinical 3^rd year (N: 197) and the final clinical year (N: 163). Participants self-filled an Arabic and slightly modified version of the 8-item Epworth Sleepiness Scale. Exploratory Principal Component Analysis (PCA) and Confirmatory Factor Analyses (CFA) were conducted on two equal subsets of the sample (N: 180 each). The PCA yielded a two-dimension model subsequently confirmed by factor analysis. The first dimension was grouped on three items while the second dimension had five items reflecting the respondents' propensity to sleep during “interactive situations” and “sitting and lying,” respectively. The model had an acceptable goodness of fit measures for the overall ESS (CMINDF = 2.362, CFI = 0.91, IFI = 0.92) and acceptable reliability indicators (factor 1 α = 0.65, factor 2 α = 0.62). However, due to weak variance explanation (0.07) of item 6 (sitting and talking) in factor 1, analysis was repeated excluding this item. The 7-item model was also two-dimensional, valid, and reliable. The reliability indicators were acceptable with α = 0.65 for factor 1 (4 items of interactive situations) and 0.62 for factor 2 (3 items of sitting) and overall α = 0.68. Overall, the ESS is a useful tool. Factor analysis produced a two-factor model of 7 items with good validity and reasonable reliability that can be used in diagnosing daytime sleepiness among young Yemeni adults.

Sleeping with One Eye Open: The Sleep experience of Family Members Providing Palliative Care at Home

Purpose: To empirically describe the sleep experience of family caregivers (n=13) of advanced cancer patients. Method: Mixed methodology using: family interviews; Epworth Sleepiness Scale (ESS); Pittsburgh Sleep Quality Index (PSQI); and actigraphy measurement. Qualitative data analysis utilized constant comparative content techniques. Actiware for the actigraphy data and the Statistical Package for the Social Sciences-15 (SPSS-15) generated descriptive and correlation statistics. Findings: The over arching theme “sleeping with one eye open” captures the vigilant nature of caregivers’ sleep experiences. Caregiver narratives were validated by quantitative findings: 5 of the family caregivers (38.5 percent) had an ESS score ≥ 11 indicative of excessive daytime sleepiness, all caregivers had a PSQI global score > 5 indicative of moderate to severe sleep problems, and actigraphy scores — including total sleep time, sleep efficiency, and time awake after sleep onset — fell beyond normal values documented in the literature. Conclusion: Impeccable assessment of the patient's and family's sleep status, sleep education, intervention strategies, and high-quality respite services are critical in community-based palliative care.

Diagnosis and treatment of obstructive sleep apnea during pregnancy

PURPOSE OF REVIEW

This review aims to provide an update on recent advances in the diagnosis and treatment of obstructive sleep apnea (OSA) during pregnancy and its effect on maternal and fetal outcomes.

RECENT FINDINGS

Current OSA screening tools may not perform well in this population. There are some pieces of evidence linking poorer maternal and neonatal outcome with pregnant patients having OSA. At present, there are inadequate data on which to base fetal or maternal parameters for treatment of OSA, and no evidence that treatment in the short-term impacts maternal or neonatal outcomes.

SUMMARY

Further research is needed to help in the detection and treatment of OSA in pregnancy.

Risk of obstructive sleep apnea and excessive daytime sleepiness in hospitalized psychiatric patients

OBJECTIVES

This study evaluated the risk of developing obstructive sleep apnea (OSA) and excessive daytime sleepiness (EDS) in hospitalized psychiatric patients at the American University of Beirut Medical Center (AUB-MC). Factors associated with OSA and EDS occurrence in this sample were also examined.

METHODS

The Berlin questionnaire and the Epworth sleepiness scale; which respectively evaluate OSA and EDS symptoms, were administered to individuals hospitalized at an acute psychiatric treatment unit at the AUB-MC between the dates of January 2014 and October 2016. Additional data collected included general demographics, psychiatric diagnoses, and questionnaires evaluating depression and anxiety symptoms. Statistical analyses utilizing SPSS were performed to determine the prevalence of OSA and EDS, as well as their respective associations with patient profiles.

RESULTS

Our results showed that 39.5% of participants were found to have a high risk of sleep apnea and 9.9% of the participants were found to have abnormal daytime sleepiness. The risk of developing OSA was associated with a higher body mass index (BMI) (P=0.02), and depression severity (patient health questionnaire 9 score) (P=0.01). Increasing severity of depressive symptoms was associated with a higher risk of sleep apnea (P=0.01). BMI (odds ratio [OR] =5.97, 95% confidence interval [CI] 1.89-18.82) and depression severity (OR =4.04, 95% CI 1.80-9.07) were also found to be predictors of OSA. The psychiatric diagnoses of the participants were not found to have a significant association with the risk of sleep apnea.

CONCLUSION

The risk of OSA is increased among hospitalized psychiatric patients, and this condition can have detrimental effects on psychiatric patients. OSA appears to be under-recognized in this population, psychiatrists should screen for OSA in hospitalized psychiatric patients and refer them for diagnostic testing or treatment when indicated.

Efficacy of a Mandibular Advancement Appliance on Sleep Disordered Breathing in Children: A Study Protocol of a Crossover Randomized Controlled Trial

BACKGROUND

Sleep-Disordered Breathing (SDB) varies from habitual snoring to partial or complete obstruction of the upper airway and can be found in up to 10% of children. SDB can significantly affect children's wellbeing, as it can cause growth disorders, educational and behavioral problems, and even life-threatening conditions, such as cardiorespiratory failure. Adenotonsillectomy represents the primary treatment for pediatric SDB where adeno-tonsillar hypertrophy is indicated. For those with craniofacial anomalies, or for whom adenotonsillectomy or other treatment modalities have failed, or surgery is contra-indicated, mandibular advancement splints (MAS) may represent a viable treatment option. Whilst the efficacy of these appliances has been consistently demonstrated in adults, there is little information about their effectiveness in children.

AIMS

To determine the efficacy of mandibular advancement appliances for the management of SDB and related health problems in children.

METHODS/DESIGN

The study will be designed as a single-blind crossover randomized controlled trial with administration of both an "Active MAS" (Twin-block) and a "Sham MAS." Eligible participants will be children aged 8-12 years whose parents report they snore ≥3 nights per week. Sixteen children will enter the full study after confirming other inclusion criteria, particularly Skeletal class I or class II confirmed by lateral cephalometric radiograph. Each child will be randomly assigned to either a treatment sequence starting with the Active or the Sham MAS. Participants will wear the appliances for 3 weeks separated by a 2-week washout period. For each participant, home-based polysomnographic data will be collected four times; once before and once after each treatment period. The Apnea Hypopnea Index (AHI) will represent the main outcome variable. Secondary outcomes will include, snoring frequency, masseter muscle activity, sleep symptoms, quality of life, daytime sleepiness, children behavior, and nocturnal enuresis. In addition, blood samples will be collected to assess growth hormone changes.

TRIAL REGISTRATION

This study was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR): [ACTRN12614001013651].

Validation of the Arabic version of the Epworth sleepiness scale

BACKGROUND

The Epworth Sleepiness Scale (ESS) is a questionnaire widely used in developed countries to measure daytime sleepiness and diagnose sleep disorders.

OBJECTIVE

This study aimed to develop an ESS questionnaire for the Arabic population (ArESS), to determine ArESS internal consistency, and to measure ArESS test-retest reproducibility. It also investigated whether the normal range of ESS scores of healthy people in different cultures are similar.

METHODS

The original ESS questionnaire was translated from English to Arabic and back-translated to English. In both the English and Arabic translations of the survey, ESS consists of eight different situations. The subject was asked to rate the chance of dozing in each situation on a scale of 0-3 with total scores ranging between 0 (normal sleep) and 24 (very sleepy). An Arabic translation of the ESS questionnaire was administered to 90 healthy subjects.

RESULTS

Item analysis revealed high internal consistency within ArESS questionnaire (Cronbach's alpha=0.86 in the initial test, and 0.89 in the retest). The test-retest intra-class correlation coefficient (ICC) shows that the test-retest reliability was substantially high: ICC=0.86 (95% confidence interval: 0.789-0.909, p-value<0.001). The difference in ArESS scores between the initial test and retest was not significantly different from zero (average difference=-0.19, t=-0.51, df=89, p-value=0.611). In this study, the averages of the ESS scores (6.3 ± 4.7, range 0-20 in the initial test and 6.5 ± 5.3, range 0-20 in the retest) are considered high in Western cultures.

CONCLUSIONS

The study shows that the ArESS is a valid and reliable tool that can be used in Arabic-speaking populations to measure daytime sleepiness. The current study has shown that the average ESS score of healthy Arabian subjects is significantly higher than in Western cultures.

Excessive daytime sleepiness in late pregnancy may not always be normal: results from a cross-sectional study

PURPOSE

Many changes that normally occur during pregnancy disrupt sleep and may lead to excessive daytime sleepiness (EDS). However, given that pregnancy may also predispose to the development of sleep-disordered breathing (SDB), we sought to investigate whether EDS may be associated with snoring, gasping, or apneas, further suggesting SDB.

METHODS

A cross-sectional survey of women in the immediate postpartum period was conducted. Participants answered questions from the multivariable apnea prediction index regarding snoring, gasping, and witnessed apneas in the last 3 months of pregnancy. Participants were also asked to answer Epworth Sleepiness Scale (ESS) questions, and a score 0-24 was calculated (>10 considered abnormal). Medical history and medication use were obtained both by history and review of the medical record.

RESULTS

Out of 1,000 women recruited, 990 women answered the ESS questionnaire completely. Mean prepregnancy body mass index (BMI) was 26.1 ± 6.2 with 21.7 % of the sample having a prepregnancy BMI ≥30. Mean ESS score was 7.1 ± 3.9, and 1.7 % of the total sample scored 16 or greater. ESS increased significantly with age, BMI, and neck circumference. All three symptoms of SDB were associated with higher mean ESS scores. In a multiple linear regression analysis, loud snoring, gasping, and apneas were statistically significant independent predictors of mean ESS score.

CONCLUSIONS

EDS measured by ESS is a common finding in pregnancy. Snoring, gasping, and apneas appear to be independent predictors of mean ESS scores.

Assessment of subclinical left ventricular dysfunction in obstructive sleep apnea patients with speckle tracking echocardiography

In this study, our aim was to evaluate the LV (left ventricle) subclinical myocardial dysfunction using the two-dimensional speckle tracking echocardiography (2D-STE) method on obstructive sleep apnea (OSA) patients with preserved left ventricular ejection fraction (LVEF) and without any confounding disease that may result myocardial dysfunction. Twenty-one healthy individuals and 58 OSA patients were enrolled in the study. The patients were categorized into mild, moderate and severe OSA groups according to the apnea-hypopnea index (AHI). Conventional- and tissue Doppler echocardiography imagings were performed in all the individuals besides the 2D-STE. The longitudinal strain (S) and systolic strain rate (SR(S)) values decreased as the severity of disease increased from moderate towards severe OSA. The circumferential S and SR(S) values were observed to be lower in the severe OSA patients. Despite the increase in the radial S and SR(S) in moderate and mild OSA patients, these measurements decreased in those with severe OSA. Although the longitudinal, circumferential and radial early diastolic strain rates (SR(E)) decreased as the severity of disease increased form moderate to severe, the late diastolic strain rates (SR(A)) were observed to increase. In the early stages of OSA, longitudinal systolic LV dysfunction is detected in addition to the diastolic dysfunction. The circumferential mechanics of the LV deteriorate in the later stages of the OSA. Despite a compensatory increase in the radial LV function in the early stages of OSA, in later stages, the LV radial function also deteriorates. The assessment of the myocardial functions using the STE method in patients with OSA with preserved LVEF has the potential to detect the subclinical LV dysfunction and might provide useful information for risk stratification.

Assessment of left atrial dysfunction in obstructive sleep apnea patients with the two dimensional speckle-tracking echocardiography

BACKGROUND

The aim of this study was to compare left atrial (LA) longutidinal myocardial function in obstructive sleep apnea (OSA) patients with healthy individuals using two-dimensional speckle-tracking echocardiography method (2D-STE).

METHOD

Twenty one healthy individuals and 58 OSA patients were included. According to the AHI (apnea hypopnea index) patients were examined in mild, moderate and severe OSA groups. Images of the LA were acquired from the apical two- and four-chamber views. LA strain(LA(S)) and strain rate(LA(SR)) parameters [systolic (S), early diastolic (E), late diastolic (A) during atrial contraction] were assessed.

RESULTS

LA(S-S), LA(SR-S), LA(S-E) and LA(SR-E) values decreased with severity of OSA. Severe OSA patients have lower LA(S-S) and LA(SR-S) values (p < 0.03). While a difference in the LA(SR-E) value between groups was significant beginning with the moderate OSA group (p < 0.03), no LA(S-E) value differences were observed between moderate and mild OSA groups (p > 0.03). LA(S-A) and LA(SR-A) values were increasing with the disease severity up to moderate OSA. LA(S-A) and LA(SR-A) values of moderate OSA were greater than the mild OSA patients and healthy individuals (p < 0.03). These were lower in severe OSA than the moderate OSA (p < 0.03), however, they were greater than the healthy individuals (p < 0.03). The AHI was found to be negatively correlated with the LA(S-S), LA(SR-S) LA(S-E), LA(SR-E), whereas AHI was not correlated with the LA(S-A), LA(SR-A) values.

CONCLUSION

LA remodeling and dysfunction that accompany OSA can be detected in the subclinical stage with a detailed evaluation of active and passive functions of the LA using the 2D-STE method.

Attending rounds: a patient with drug-resistant hypertension

Drug-resistant hypertension is present in about one in eight patients with high BP. It can be a frustrating and expensive condition to pursue from an office-based perspective. In this review, utilizing the American Heart Association scientific statement on drug-resistant hypertension as a guide, a case of drug-resistant hypertension is presented and walked through exactly as encountered by the author. Woven into the discussion is a combination of insights from the literature on this topic, blended with the experience of the author. This is not intended as an exhaustive review of each step in the evaluation and management process but, rather, as an overview incorporating a few carefully chosen references and, hopefully, a logical and useful approach to a common clinical challenge.

How is the Epworth Sleepiness Scale related with subjective sleep quality and polysomnographic features in patients with sleep-disordered breathing?

PURPOSE

To determine the relationship between the Epworth Sleepiness Scale (ESS) and the Subjective Sleep Quality (SSQ) or polysomnographic (PSG) features in patients with sleep-disordered breathing (SDB).

METHODS

This is a retrospective study that included 646 untreated patients with a PSG diagnosis of primary snoring (PS) or obstructive sleep apnea syndrome. Patients with SDB were grouped into four categories according to ESS scores: no diurnal sleepiness (DS) = 0-6; mild DS = 7-12; moderate DS = 13-18, and severe DS = ≥19. Analyses of variance were performed to compare SSQ or PSG features among the four ESS severity categories.

RESULTS

We found a significant increase in subjective sleep time in the group of patients with severe DS. With regard to PSG data, we also identified increases in total sleep time (TST) and rapid eye movement (REM) in the group of patients with severe DS.

CONCLUSION

Unexpectedly, DS severity was related with increases in TST and REM sleep. As has been described in SDB patients, a change in muscular tonus throughout sleep onset (and depth) is a causal factor of SDB features and DS impairment. Therefore, we propose that increases in TST and REM are worsening factors of SDB and consequently, also in DS.

The normal-weight snorer: polysomnographic study and correlation with upper airway morphological alterations

Obesity is recognized as playing an important role in causing snoring and in turning simple snoring into obstructive sleep apnea syndrome (OSAS). From our series of patients with sleep disturbances, we studied a group of 43 normal-weight snorers in whom we detected a significant number of OSAS episodes. An articulated diagnostic protocol was adopted, and Müller's maneuver was extensively applied. The resulting data were compared to data from a group of 43 obese patients from the same series. The major risk factor for developing OSAS in normal-weight snorers appears to be anatomic abnormalities, in particular, septal deviation and base of tongue hypertrophy. Soft palate hypertrophy alone is not enough, although in obese snorers it can produce a sleep disorder. The normal-weight snorer needs to be thoroughly investigated because of the significant risk of developing OSAS and for the detection of multiple concomitant sites of obstruction.

Use of the Epworth Sleepiness Scale in Chinese patients with obstructive sleep apnea and normal hospital employees

OBJECTIVE

To determine the use of the Epworth Sleepiness Scale (ESS) in Chinese patients with obstructive sleep apnea syndrome (OSA) and normal hospital employees.

METHODS

Our sample consisted of 61 healthy controls and 100 patients with OSA. The test-retest reliability, internal consistency, and concurrent validity of the Chinese version of the ESS were analyzed. We also compared the ESS scores between controls and patients, studied the association between the ESS score and the apnea-hypopnea index (AHI) and minimum oxygen saturation (mO(2)), and examined to what extent the ESS score was predictive of mean sleep latency of the Multiple Sleep Latency Test (MSLT).

RESULTS

The Chinese version of the ESS was found to have satisfactory reliability and validity. The mean+/-S.D. of ESS scores in normals was 7.5+/-3.0; in patients, it was 13.2+/-4.7. The ESS score had a negative association with mean sleep latency of the MSLT (rho=-0.42, P=0.0001) but no correlation with the AHI and mO(2). ESS scores of 14 and above significantly predicted a low mean sleep latency of the MSLT.

CONCLUSION

The ESS should be included as one of the methods for assessing sleepiness in clinic samples of patients with OSA. Our data showed that the ESS was useful to separate patients with and without pathological degree of objective daytime sleepiness as determined by the MSLT.