Excessive daytime sleepiness in patients suffering from different levels of obstructive sleep apnoea syndrome

Evaluating pharmacological treatments for excessive daytime sleepiness in obstructive sleep apnea: A comprehensive network meta-analysis and systematic review

Obstructive sleep apnea (OSA) is associated with excessive daytime sleepiness (EDS). Pharmacotherapy offers a potential treatment approach for EDS in OSA patients. This systematic review and meta-analysis aimed to assess the efficacy and safety of pharmacological interventions for alleviating EDS in patients with OSA. Following PRISMA guidelines, we included randomized controlled trials investigating pharmacological treatments for EDS in adult OSA until August 2023. We conducted meta-analysis, subgroup, and meta-regression analyses using a random effects model. Finally, a network meta-analysis synthesized direct and indirect evidence, followed by a comprehensive safety analysis. We included 32 articles in the meta-analysis (n = 3357). Pharmacotherapy showed a significant improvement in the Epworth Sleepiness Scale (ESS) score (Mean Difference (MD) -2.73, (95 % Confidence Interval (CI) [-3.25, -2.20], p < 0.01) and Maintenance of Wakefulness Test (MWT) score (MD 6.00 (95 % CI [2.66, 9.33] p < 0.01). Solriamfetol, followed by Pitolisant and modafinil, exhibited the greatest ESS reduction, while Danavorexton, followed by Solriamfetol and MK-7288, had the strongest impact on MWT. MK-7288 had the most total adverse events (AEs), followed by Danavorexton and armodafinil. Pharmacological Interventions significantly alleviate EDS in OSA patients but with heterogeneity across medications. Treatment decisions should involve a personalized assessment of patient factors and desired outcomes.

The Use of Telemedicine in the Management of Continuous Positive Airway Pressure for the Treatment of Obstructive Sleep Apnoea: A Randomised Controlled Trial

Introduction: Obstructive sleep apnea (OSA) is a condition whereby the airway gets partially or totally obstructed during sleep. Gold standard treatment for moderate to severe OSA is continuous positive airway pressure (CPAP). However, compliance with treatment is often poor, with low hours of usage and patients stopping treatment. Methods: A nonblinded, single-center, randomized controlled trial was conducted with patients randomized to 1 of 3 arms (arm 1, standard care; arm 2, modem; and arm 3, modem and DreamMapper™ app). Ninety patients diagnosed with OSA requiring CPAP were recruited. Data, including CPAP compliance, apnea/hypopnea index (AHI), and Epworth sleepiness score (ESS), were collected at baseline and 14 and 180 days post-CPAP initiation. Results: Of the group participants (N = 90), 68% were male and 32% female with a mean age of 52.0 ± 13.13 years, mean body-mass index of 36.4 ± 7.91 (kg/m2), mean ESS of 10.19 ± 5.75, and mean AHI of 43.5 ± 21.92 (events/hour). There was no statistically significant difference between the three arms in mean hours of CPAP usage in 24 hours at 14 days: arm 1, 6.22 ± 2.15; arm 2, 5.47 ± 2.25; and arm 3, 6.44 ± 1.54 (p = 0.256). There were also no statistically significant differences between the three arms in mean hours of CPAP usage in 24 hours at 180 days: arm 1, 6.20 ± 1.27; arm 2, 5.57 ± 1.49; and arm 3, 6.26 ± 1.29 (p = 0.479). Discussion and Conclusion: Compliance with CPAP treatment showed no significant differences between the three arms, with high compliance observed in all arms.

The Role of Obstructive Sleep Apnea in Vision-Threatening Diabetic Retinopathy-A National Register-Based Study

INTRODUCTION

we investigated the association between OSA and vision-threatening diabetic retinopathy (VTDR).

METHODS

we used three nationwide registers to identify subjects with and without OSA and patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM). The Danish Civil Registration System was used to link OSA with diabetes diagnosis. The primary outcome was the occurrence of VTDR in diabetic patients with and without OSA. The secondary outcome was the prevalence of diabetes mellitus in patients with and without OSA.

RESULTS

we included 532,828 diabetic subjects comprising 13,279 patients with OSA (2.5%) and 519,549 without OSA (97.5%). Diabetic patients with OSA had a 57% lower risk of VTDR compared to diabetic patients without OSA (OR 0.43, 95% CI 0.38-0.50, p < 0.0001).

CONCLUSIONS

our findings indicate that OSA is associated with a lower risk of VTDR. Since we did not adjust our outcomes for diabetes duration, hypertension control and hemoglobin A1c, future studies are needed to confirm our findings.

Moderate-to-high risk of obstructive sleep apnea with excessive daytime sleepiness is associated with postoperative neurocognitive disorders: a prospective one-year follow-up cohort study

Background

Few studies found that obstructive sleep apnea (OSA) may be related to postoperative neurocognitive disorders (PND) including postoperative delirium (POD) and cognitive decline (POCD) in the early postoperative period. However, the results are controversial and need further verification, and no research has explored the effect of OSA on the incidence of PND during the 1-year follow-up periods. Furthermore, OSA patients with excessive daytime sleepiness (EDS) as a severe phenotype have more significant neurocognitive impairments, but the relationship between OSA with EDS and PND within 1 year after surgery has not been studied.

Objectives

To explore the effect of moderate-to-high risk of OSA and the moderate-to-high risk of OSA with EDS on PND within 1 year after surgery.

Methods

In this prospective cohort study, including 227 older patients, moderate-to-high risk of OSA (using STOP-BANG), subjective EDS (using Epworth Sleepiness Scale), and objective EDS (using Actigraphy) were selected as exposures. Key outcomes included POD during hospitalization (using Confusion Assessment Method-Severity), POCD at discharge, 1-month and 1-year after surgery (using Mini-Mental State Examination and Telephone Interview for Cognitive Status-40). We applied multiple logistic regression models to estimate the effect of moderate-to-high risk of OSA and moderate-to-high risk of OSA with EDS on PND.

Results

In the multivariate analysis, moderate-to-high risk of OSA was not associated with POD during hospitalization and POCD at discharge, 1-month, and 1-year after surgery (p > 0.05). However, the moderate-to-high risk of OSA with subjective EDS was related to POCD at discharge compared to the moderate-to-high risk of OSA or normal group (no moderate-to-high risk of OSA and no EDS) (p < 0.05). In addition, moderate-to-high risk of OSA with objective EDS was associated with POCD at discharge, 1-month, and 1-year postoperatively compared to the moderate-to-high risk of OSA or normal group (p < 0.05).

Conclusion

Moderate-to-high risk of OSA with EDS, not moderate-to-high risk of OSA alone, was a clinically helpful predictor for POCD within 1-year after surgery and should be routinely assessed before surgery.

Comorbidities in Clinical and Polysomnographic Features of Obstructive Sleep Apnea: A Single Tertiary Care Center Experience

BACKGROUND

Research on obstructive sleep apnea (OSA) is inadequate in Saudi Arabia, particularly among patients with comorbidities. This study investigates comorbidities in patients with different severity of apnea based on the Apnea-Hypopnea Index (AHI).

METHODS

The retrospective charts review that included a cohort of 4391 patients who underwent polysomnography (PSG) between 2003 and 2019. The AHI is classified into four ordinal groups: normal, mild, moderate, and severe. Ordinal logistic regression was used to model proportional odds of a higher AHI category.

RESULTS

Gender was distributed equally in the study sample. The average age was 49.6 ± 14.8 years and the average AHI was 16.1 ± 22 per hour. Hypertension (43.2%) and diabetes mellitus (37.3%) were the most common comorbidities: Mild OSA 28.9%, Moderate OSA 15.6%, and severe 16.4%. The severity of apnea increased with age and BMI classes. The prevalence of hypertension increased with the severity of apnea: 42.9% in mild, 47.4% in moderate, and 54.6% in severe AHI. The prevalence of coronary artery disease (CAD), congestive heart failure (CHF), and diabetes mellitus (DM) increased with the severity of apnea. Comorbidities was more among OSA patients with excessive sleepiness. After adjustment for age and gender, greater proportional odds of severe AHI were observed in males (aOR = 1.8), 30-59 years (aOR = 2.064), 60 years or above (aOR = 2.873), obese class II (aOR = 2.016), obese class III (aOR = 2.527), and in patients with hypertension (aOR = 1.272).

CONCLUSION

Hypertension and obesity were highly prevalent in the study cohort and were associated with greater proportional odds of severe AHI.

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.

Optimal dose determination of enerisant (TS-091) for patients with narcolepsy: two randomized, double-blind, placebo-controlled trials

BACKGROUND

The histamine H3 receptor has emerged as one of the most promising targets of novel pharmacotherapy for narcolepsy. Studies now aim to investigate the optimal dose of enerisant, a novel H3 antagonist/inverse agonist, for the treatment of excessive daytime sleepiness in patients with narcolepsy.

METHODS

We conducted two phase 2, fixed-dose, double-blind, randomized, placebo-controlled trials in patients with narcolepsy. The first phase 2 study (Study 1) was conducted to investigate the efficacy and safety of enerisant at dosages of 25, 50, and 100 mg/day administered for 3 weeks based on the results of a phase 1 study conducted on healthy volunteers. The primary endpoint was mean sleep latency in maintenance of wakefulness test (MWT), and the secondary endpoint was the total score on the Epworth Sleepiness Scale (ESS). The dosages of enerisant in the second phase 2 study (Study 2) were set at 5 and 10 mg/day based on the simulation of receptor occupancy results from positron emission tomography study.

RESULTS

Forty-six and fifty-three patients were randomized in Study 1 and Study 2, respectively. The efficacy of enerisant was partially confirmed in Study 1 with ESS; however, the doses were not tolerated, and there were many withdrawals due to adverse events (mainly insomnia, headache, and nausea). The doses in Study 2 were well tolerated, with a lower incidence of adverse events in Study 2 than in Study 1, although the efficacy could not be confirmed with MWT and ESS in Study 2.

CONCLUSIONS

The optimal dose of enerisant could not be determined in these two studies. Although enerisant has a favorable pharmacokinetic profile, it is thought to have large interindividual variabilities in terms of efficacy and safety, suggesting the necessity of tailored dosage adjustments.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03267303 ; Registered 30 August 2017 (Study 2). Japic identifier: JapicCTI-142529 ; Registered 7 May 2014 (Study 1) and JapicCTI-173689 ; Registered 30 August 2017, https://www.clinicaltrials.jp/cti-user/trial/ShowDirect.jsp?clinicalTrialId=29277 (Study 2).

Microsleep assessment enhances interpretation of the Maintenance of Wakefulness Test

STUDY OBJECTIVES

The Maintenance of Wakefulness Test (MWT) is used to objectively evaluate an individual's ability to remain awake; however, microsleeps are not included in the assessment. We aimed to determine if microsleep data prior to sleep onset assisted in interpretation of ability to maintain wakefulness across a range of typical patient groups.

METHODS

Forty-eight patients referred for overnight polysomnography and subsequent MWT were included. Patients were divided into 3 groups (treated obstructive sleep apnea [OSA], untreated OSA, or treated idiopathic hypersomnia or narcolepsy) based on prior medical diagnosis. Demographics, clinical characteristics, polysomnography, and MWT variables, including frequency, distribution, duration, and latency of microsleeps were compared between groups.

RESULTS

Microsleeps were observed in MWT trials significantly more frequently in patients with treated idiopathic hypersomnia/narcolepsy over the course of the day (0.34 ± 0.06 vs 0.07 ± 0.02 microsleeps/min; P < .001) and in patients with untreated OSA toward the end of the day (0.31 ± 0.06 vs 0.05 ± 0.02 microsleeps/min; P < .001) compared to the group with treated OSA. Microsleeps were often observed in series and earlier in patients with treated idiopathic hypersomnia/narcolepsy (10.9 ± 1.6 minutes) and those with untreated OSA (16.2 ± 2.7 minutes) compared to the group with treated OSA (24.9 ± 3.0 minutes; P < .05), and, if taken into consideration, would increase the proportion of patients demonstrating inability to maintain wakefulness by 33% and 22%, respectively.

CONCLUSIONS

MWT performance varies significantly across patient groups. Microsleep analysis prior to sleep onset may be a more sensitive measure of patient daytime wakefulness than sleep latency alone and should be considered in MWT assessment.

CITATION

Anniss AM, Young A, O'Driscoll DM. Microsleep assessment enhances interpretation of the Maintenance of Wakefulness Test. J Clin Sleep Med. 2021;17(8):1571-1578.

The Utility of Epworth Sleepiness Scale to Screen Moderate and Severe Obstructive Sleep Apnea Preoperatively to Predict Difficult Airway

Introduction Obstructive sleep apnea (OSA) is sleep-disordered breathing characterized by repetitive episodes of partial or complete upper airway collapse in sleep leading to apnea and/or hypopnea, desaturations, sleep disruptions, and cardiovascular changes. OSA is a known cause for difficult airway, especially mask ventilation. Daytime sleepiness is one of the hallmark symptoms of OSA. So, we used the Epworth sleepiness score (ESS) in patients suspected of OSA undergoing a sleep study.

Methods Overall, 44 subjects suspected to have OSA and undergoing polysomnography were included in the study. The socio-demographic details and the complaints were recorded and the Epworth sleepiness questionnaire was administered. The severity of OSA was graded as per the American Academy of Sleep Medicine using the apnea hypopnea index.

Results A total of 44 patients were included in the study. Out of these, 19 were mild, 13 moderate, and 12 severe OSA cases, respectively. ESS of more than 10 showed a positive predictive value of 81.25% and specificity of 85% in screening patients with moderate and severe OSA. But the sensitivity and negative predictive value was only 54.16 and 60.71%, respectively.

Conclusion ESS being a simple questionnaire can be easily used preoperatively. A score of more than 10 effectively diagnoses moderate and severe OSA, but less than 10 cannot rule out OSA

Association between excessive daytime sleepiness, REM phenotype and severity of obstructive sleep apnea

The aim of the study was to compare REM-dependent and REM-independent, obstructive sleep apnea syndrome (OSA) patients in relation to their daily sleepiness assessed by Epworth sleepiness scale (ESS). The study included 1863 consecutive patients, who were referred to a sleep centre with a presumed diagnosis of OSA. Following polysomnography, 292 patients fulfilled criteria for either REM-dependent OSA (REM-OSA, n = 102) or REM-independent OSA (nREM-OSA, n = 190). Both study groups were matched regarding sex and age. REM-OSA group had two times lower median apnoea-hypopnea index (AHI) compared to nREM-OSA (p < 0.001), yet day-time sleepiness measured by ESS was similar: median score 9.0 (6.0–11.0) and 8.0 (4.8–11.0), p = 0.109, respectively. Subsequent post-hoc ANCOVA analysis, with covariates (BMI, percent of total sleep time spent in REM stage, percent of total sleep time spent in the supine position), has shown statistically significant difference between study groups regarding AHI (p < 0.001) and no difference regarding ESS score (p = 0.063). Despite two times lower AHI, patients with REM-OSA present with similar day-time sleepiness as those with REM independent OSA. Daily sleepiness may be stronger associated with apneas/hypopneas occurring in REM than nREM sleep.

Obstructive sleep apnea syndrome and autonomic dysfunction

Autonomic nervous system (ANS) has been extensively explored in obstructive sleep apnea (OSA). Autonomic alterations in these patients have been described by means of several methods, evaluating ANS function both directly with microneurography and indirectly through baroreflex sensitivity (BRS, by the sequence method or the cross-spectral approach), heart rate variability analysis (HRV, both in the time and frequency domain) during sleep and wake, or conventional laboratory tests, including cold pressor test, hand grip test or measurement of urinary cathecolamine excretion. Several studies in OSA patients have shown ANS alterations, in particular sympathetic overactivity, both acutely during apnea events and chronically during the daytime, being both also involved in cardiovascular consequences of sleep disordered breathing. The association between OSA and sympathetic dysregulation suggests a dose response relationship between OSA severity and the degree of sympathetic overactivity and this association seems to be reversible as the treatment of OSA is implemented. Additionally ANS is involved in regulating visceral and humoral functions to maintain the body homeostasis and in reaction and adaptation to external and internal stressor stimuli. However, the vast majority of studies have focussed on cardiovascular alterations, which are easier to measure, somewhat neglecting the other functions regulated by ANS. More evidence is therefore needed to better characterize the impact that sleep disorder breathing may have on ANS both in the short and long term.

Is self-report sleepiness associated with cognitive performance in temporal lobe epilepsy?

OBJECTIVES

Sleepiness and cognitive impairment are common symptoms observed in patients with epilepsy. We investigate whether self-reported sleepiness is associated with cognitive performance in patients with refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Seventy-one consecutive patients with MTLE-HS were evaluated with the Stanford Sleepiness Scale (SSS) before neuropsychological evaluation. Their mean SSS scores were compared with controls. Each cognitive test was compared between patients with (SSS ≥ 3) or without sleepiness (SSS < 3). Imbalances were controlled by regression analysis. Patients reported a significantly higher degree of sleepiness than controls (p < 0.0001). After multiple linear regression analysis, only one test (RAVLT total) remained associated with self-reported sleepiness.

CONCLUSION

Self-reported sleepiness was significantly higher in MTLE-HS patients than controls, but did not affect their cognitive performance. If confirmed in other populations, our results may have implications for decision making about sleepiness screening in neuropsychological settings.

Daytime Sleepiness in Patients Diagnosed with Sarcoidosis Compared with the General Population

Background

The aim of this study was to analyze daytime sleepiness in a sample of patients diagnosed with sarcoidosis.

Methods

A sample of 1197 German sarcoidosis patients was examined with the Epworth Sleepiness Scale (ESS), the Fatigue Assessment Scale, the Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, and the Short-Form Health Survey (SF-8). The patients' ESS mean scores were compared with those obtained from a large general population sample.

Results

Exactly 50% of the patients reached the criterion (ESS > 10) for excessive daytime sleepiness, compared with only 22.1% in the general population. The effect size for the mean score difference between both samples was d=0.62. The number of affected organs and the number of concomitant diseases proved to be significant independent predictors of daytime sleepiness. Sleepiness was associated with fatigue (r=0.45), anxiety (r=0.23), depression (r=0.28), sleep problems (r=0.23), and detriments in physical (r=-0.29) and mental (r=-0.28) quality of life.

Conclusions

The issue of excessive daytime sleepiness should be considered in the management of sarcoidosis.

The relationships between improvements in daytime sleepiness, fatigue and depression and psychomotor vigilance task testing with CPAP use in patients with obstructive sleep apnea

OBJECTIVE

The purpose of this study was to determine if the subjective improvements in daytime sleepiness, fatigue and depression experienced by patients with obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) therapy predict an objective improvement in vigilance, and whether patients with mild-to-moderate OSA differ from patients with severe OSA in this regard.

METHODS

A total of 182 patients underwent psychomotor vigilance task (PVT) testing and measurements of subjective daytime sleepiness, fatigue and depression at baseline and after a minimum of one month of adherent CPAP use at an adequate pressure.

RESULTS

Patients with both mild-to-moderate (n = 92) and severe (n = 90) OSA experienced improvements in subjective daytime sleepiness, fatigue and depression, but objective improvement in vigilance was only seen in patients with severe OSA. In patients with severe OSA, while a correlation was found between improvements in daytime sleepiness and some PVT parameters, changes in subjective daytime sleepiness, fatigue and depression scores were not predictive of objective improvement in vigilance while controlling for all these subjective symptoms and for age, gender, body mass index, apnea-hypopnea index/respiratory event index and total sleep time/total recording time with pulse oximetry below 90%.

CONCLUSIONS

We found no predictive relationship between subjective improvements in daytime sleepiness, fatigue and depression and objective vigilance with CPAP use in patients with OSA. These results suggest that subjective complaints of daytime impairment and objective measures of vigilance in patients with OSA should be assessed separately while evaluating the efficacy of CPAP therapy on daytime functioning.

Cyclic Alternating Pattern in Obstructive Sleep Apnea Patients with versus without Excessive Sleepiness

Background

One of the main hypotheses on the development of daytime sleepiness (ES) is increased arousal in obstructive sleep apnea (OSA). Cyclic alternating pattern (CAP) is considered to be the main expression of sleep microstructure rather than arousal. Therefore, we aimed to investigate whether there is any difference between OSA patients with versus without ES in terms of the parameters of sleep macro- and microstructure and which variables are associated with Epworth Sleepiness Scale (ESS) score.

Methods

Thirty-eight male patients with moderate to severe OSA were divided into two subgroups by having been used to ESS as ES or non-ES.

Results

There was no difference between two groups in clinical characteristics and macrostructure parameters of sleep. However, ES group had significantly higher CAP rate, CAP duration, number of CAP cycles, and duration and rate of the subtypes A2 (p = 0.033, 0.019, 0.013, and 0.019, respectively) and lower mean phase B duration (p = 0.028) compared with non-ES group. In correlation analysis, ESS score was not correlated with any CAP measure.

Conclusions

OSA patients with ES have increased CAP measures rather than those without ES.

Risk of Sleepiness-Related Accidents in Switzerland: Results of an Online Sleep Apnea Risk Questionnaire and Awareness Campaigns

Objectives

Obstructive sleep apnea syndrome (OSAS) is associated with major morbidity and mortality but OSAS is frequently under recognized. To promote awareness of OSAS, the Swiss Lung League launched an online questionnaire combined with annual advertisements in mass media. Characteristics of participants, prevalence of sleep apnea, OSAS-related symptoms, and their association with accidents were investigated.

Methods

A questionnaire was created incorporating anthropometrics, the Epworth sleepiness scale (ESS), the OSAS domain of the sleep disorders questionnaire (SDQ), and a question on accidents related to sleepiness.

Results

A total of 198,422 persons participated, 63% were male, mean (±SD) age was 45 (±16) years, weight 80 (±18) kg, height 173 (±9) cm, and body mass index 26.7 (±5.4) kg/m². Some male (19%) and female (17%) participants had both elevated ESS and SAS scores (SAS > 35 (m)/SAS > 31 (f) and ESS > 10) and were suspected of having sleep apnea. In all, 6,654 (3.4%) had suffered an accident related to sleepiness. In multivariate regression analysis, ESS item #8 (falling asleep on the wheel, while stopping for a few minutes in traffic) was closest related to suffering an accident (OR 2.8).

Conclusion

The OSAS awareness campaign of the Swiss Lung League reached a large number of people of both genders and of a wide age range. Many participants suffered from excessive sleepiness and symptoms of sleep apnea were highly prevalent. The campaign raised awareness of OSAS and contributed to the diagnosis and treatment of sleep apnea, thereby possibly preventing related morbidity and mortality.

Clinical and polysomnographic predictors of severe obstructive sleep apnea in the South Indian population

Background:

With the emergence of lifestyle diseases in epidemic proportions, obstructive sleep apnea (OSA) is being increasingly recognized in less developed countries as well.

Aim:

We sought to study the demographic, clinical, and polysomnographic (PSG) predictors of OSA severity in a cohort of South Indian patients.

Materials and Methods:

Consecutive patients with PSG proven OSA [apnea hypopnea index (AHI) ≥5/h] were prospectively recruited. The study period was from January 2012 to December 2012. Demographic data, history of vascular risk factors, substance abuse, sleep quality, snoring, and witnessed apneas were collected using a structured pro forma. In addition, PSG variables such as AHI, sleep latency and efficiency, duration of slow wave and rapid eye movement (REM) sleep, and other parameters were collected. Correlations between AHI severity and clinical and PSG parameters were done.

Results:

There were 152 (119 males and 33 females) subjects with a mean age of 53.8 years and body mass index (BMI) of 29.31. Mean AHI was 36.2/h (range: 5.1-110) and 66 subjects had severe OSA. Around 12% had the presenting complaint as insomnia, mainly of sleep maintenance. Of the subjects, 35% had witnessed apneas and 67% had excessive daytime sleepiness (EDS); 40% of patients had ≥2 risk factors. PSG parameters showed short sleep onset latency with a high arousal index. Mean apnea duration was 24.92 s. We found that age >55 years, BMI >25 kg/m², witnessed apneas, EDS, hypertension, dyslipidemia, reduced slow wave sleep duration, mean apnea duration >20 s, and desaturation index >10/h correlated well with OSA severity while the arousal index, sleep latency and efficiency, and exposure to smoking and alcohol showed no association.

Conclusions:

Older subjects with witnessed apneas are likely to have more severe OSA. Even though overall sleep architecture was similar between the groups, severe OSA had shorter slow wave sleep, longer apneas, and higher nocturnal hypoxemia.

Normative values of the Epworth Sleepiness Scale (ESS), derived from a large German sample

PURPOSE

Daytime sleepiness is associated with several medical problems. The aim of this paper is to provide normative values for one of the most often used questionnaires measuring daytime sleepiness, the Epworth Sleepiness Scale (ESS).

METHODS

A large sample of 9711 people from the German general population took part in this study. In addition to the ESS, several other questionnaires were used, and sociodemographic and behavioral factors were recorded.

RESULTS

Normative values for the ESS are given. According to the generally accepted criterion ESS > 10, 23 % of the sample showed excessive daytime sleepiness. Males reported significantly more daytime sleepiness than females (effect size d = 0.19). In the age range of 40-80 years, a continuous decline of daytime sleepiness was observed. Psychometric properties of the ESS were good. Alcohol intake and nicotine consumption were marginally associated with daytime sleepiness, and obese people reported significantly more sleepiness than people of normal weight (OR = 1.39).

CONCLUSIONS

The normative tables allow clinicians and researchers to assess the degree of their patients' daytime sleepiness, especially in the upper range of scores.

A review of neurocognitive function and obstructive sleep apnea with or without daytime sleepiness

Excessive daytime sleepiness (EDS) and neurocognitive dysfunction are commonly observed in patients with obstructive sleep apnea (OSA), and these daytime functional deficits can be reversed partly or completely with treatment such as continuous positive airway pressure (CPAP). Although daytime sleepiness is a possible etiology for neurocognitive dysfunction in OSA patients, EDS is not universally present in all patients with OSA. The objective of this review is to summarize the relationship between neurocognitive function and EDS in OSA, as well as the difference in cognitive domains, improvement, and application of CPAP therapy between patients with and without EDS. Two authors independently searched PubMED/Medline, The Cochrane Library and Scopus through May 27, 2015. Sixty-five articles were included in this review. The literature demonstrated a wide range of neurocognitive deficits in OSA patients with EDS, but no more extensive and complex cognitive domains (eg, executive function) in patients without EDS. However, the current literature had very few studies with large sample sizes and extended follow-up that evaluated the effect of CPAP for OSA in patients with and without sleepiness. CPAP failed to improve cognitive dysfunction in OSA patients without EDS after short-term therapy. The evidence suggests that daytime sleepiness possibly relates to the domain and extent of cognitive impairments in OSA, and CPAP therapy has little effect on the improvement of cognitive deficits in OSA patients without EDS. We recommend that additional prospective studies be performed to further quantify the relationship between neurocognitive function in OSA patients with and without EDS.

Intermittent hypoxemia and sleep fragmentation: associations with daytime alertness in obese sleep apnea patients living at moderate altitude

BACKGROUND

Although obstructive sleep apnea (OSA) has long been associated with daytime sleepiness, far less is known about its association with the ability to remain awake. The aim of this study was to examine the relative importance of inter-correlated measures of OSA severity (eg, various indices of oxygen saturation and sleep fragmentation) in the ability to stay alert as measured objectively by the Maintenance of Wakefulness Test (MWT), defined by a mean sleep latency of ≥12 min.

METHODS

Seventy-eight obese women and men of similar age and body mass index living at altitude (Mexico City) underwent standard polysomnography, MWT, and completed validated sleep-related questionnaires.

RESULTS

Men had more severe sleep apnea than women (p = 0.002) and were also less alert on MWT (p = 0.022). Logistic regression models indicated that measures of desaturation consistently predicted MWT-defined alertness, whereas varied measures of sleep fragmentation did not. Nearly a third of the variance (r(2) = 0.304) in MWT-defined alertness was accounted for by the number of desaturations per hour of sleep (p = 0.003), which is considerably higher than other studies have reported in different populations.

CONCLUSION

The ability to remain awake in obese patients is best accounted for by hypoxemia rather than sleep fragmentation. Whether the size of this effect reflects differences in the population under study (eg, extent of obesity, racial background, residence at moderate altitude) and/or is a function of the measurement of alertness with the MWT remains uncertain.

Predictors for Development of Excessive Daytime Sleepiness in Women: A Population-Based 10-Year Follow-Up

STUDY OBJECTIVES

To analyze predictors of excessive daytime sleepiness (EDS) and to analyze how changes within risk factors over time predict incident EDS in women.

DESIGN

Population-based prospective study.

SETTING

General population of the City of Uppsala, Sweden.

PARTICIPANTS

From a random, general population sample of 7,051 women from the Sleep and HEalth in women ("SHE") cohort, 4,322 women without EDS at baseline were followed up after 10 y.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

At baseline and follow-up, women answered a questionnaire on sleeping habits, somatic disease, obesity, insomnia, anxiety and depression, lifestyle, and social factors. The risk of incident EDS was analyzed from changes over time in risk factors using logistic regression modeling. Of the women, EDS developed in 7.9%. Incident: insomnia (adjusted odds ratio = 5.01; 95% confidence interval 3.63-6.92), anxiety and/or depression (3.34; 2.22-5.02), somatic disease (1.73; 1.17-2.55), obesity (1.91; 1.14-2.57), snoring (1.91; 1.17-3.10) and smoking (4.31; 1.95-9.54) were all independent risk factors for the development of EDS. In addition, persistent: insomnia (4.44; 2.97-6.65) and anxiety and/or depression (4.91; 3.17-7.62) increased the risk of developing EDS. Apart from incident: snoring and obesity, similar results were obtained when only including women without somatic disease in the analyses.

CONCLUSION

Insomnia, anxiety and/or depression, and smoking were the most important factors for predicting incident excessive daytime sleepiness (EDS) and, in addition, somatic disease, obesity, and snoring predicted EDS. It is important not only to treat these conditions but also to inform women of the importance of a healthy lifestyle in order to prevent and reduce EDS in women.

The Oxford Sleep Resistance test (OSLER) and the Multiple Unprepared Reaction Time Test (MURT) detect vigilance modifications in sleep apnea patients

STUDY OBJECTIVES

The Oxford Sleep Resistance Test (OSLER) is a behavioral test that measures a subject's ability to maintain wakefulness and assesses daytime vigilance. The multiple unprepared reaction time (MURT) test measures a subject's reaction time in response to a series of visual or audible stimuli.

METHODS

We recruited 34 healthy controls in order to determine the normative data for MURT. Then we evaluated modifications in OSLER and MURT values in 192 patients who were referred for suspicion of sleep apnea. We performed OSLER (three 40-min sessions) and MURT (two 10-min sessions) tests at baseline. Of 173 treated OSA patients, 29 professional drivers were retested within six months of treatment.

RESULTS

MURT values above 250 ms can be considered abnormal. The OSLER error index (the number of all errors divided by the duration of the session in hours) correlated statistically significantly with sleep latency, MURT time, and ESS. Treatment improved OSLER sleep latency from 33 min 4 s to 36 min 48 s, OSLER error index from 66/h to 26/h, and MURT time from 278 ms to 224 ms; these differences were statistically significant.

CONCLUSIONS

OSLER and MURT tests are practical and reliable tools for measuring improvement in vigilance due to sleep apnea therapy in professional drivers.

[Diagnostic accuracy of Epworth sleepiness scale in the acute phase of myocardial infarction]

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is underdiagnosed in cardiologist daily practice, especially in patients with acute coronary syndrome. Its diagnosis is based on a polysomnography study. The Epworth Sleepiness Scale (ESS) stands as a simple and rapid means to select patients for the sleep investigation.

AIM

The aim of this study was to determine the diagnostic accuracy of the ESS for screening OSAS in patients with ST elevation myocardial infarction.

METHODS

We conducted a prospective study of 120 consecutive patients admitted for acute myocardial infarction, from April 2011 to March 2012. Daytime sleepiness was evaluated using the ESS, when patients were in the intensive care unit. All patients have undergone an overnight sleep study using a portable diagnostic device, in the 15 days following the acute coronary syndrome. The diagnostic of OSA was considered as apnea-hypopnea index (AHI) of ≥5 events/hour, severe OSA was defined as AHI of ≥30.

RESULTS

The study included 120 patients comprising 102 men and 18 women. The mean age was 58 ± 12 years. Smoking was the major cardiovascular risk factor with 72% of all patients; prevalence of diabetes was 40% and hypertension was found in 44% of the population. The prevalence of OSA was 79%. Severe OSA was diagnosed in 16% of all patients and mean AHI was 15.76 ± 14.93. Mean ESS was 2.2 ± 1.84 in the global population while it was 5.2 ± 1.2 in patients with severe OSAS. Multivariate analysis showed that ESS score ≥ 4 was an independent predictive factor for severe OSA (OR=28; 95% IC: 8-101; P<0.001).

CONCLUSION

The prevalence of OSA in patients with acute myocardial infarction was very high. ESS score ≥ 4 was an independent predictive factor for severe OSA. Despite its subjective feature, the ESS seems to be an interesting score for screening patients to undergo polysomnography.

Understanding the Outcomes Measures used in Huntington Disease Pharmacological Trials: A Systematic Review

BACKGROUND

The identification of the gene mutation causing Huntington disease has raised hopes for new treatments to ease symptoms and slow functional decline. As such, there has been a push towards designing efficient pharmacological trials (i.e., drug trials), especially with regard to selecting outcomes measures that are both brief and sensitive to changes across the course of the disease, from subtle prodromal changes, to more severe end-stage changes.

OBJECTIVES

Recently, to aid in efficient development of new HD research studies, the National Institute of Neurological Disorders and Stroke (NINDS) published recommendations for measurement selection in HD. While these recommendations are helpful, many of the recommended measures have little published data in HD. As such, we conducted a systematic review of the literature to identify the most common outcomes measures used in HD clinical trials.

METHODS

Major medical databases, including PubMed, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, were used to identify peer-reviewed journal articles in English from 2001 through April 2013; 151 pharmacological trials were identified.

RESULTS

The majority of HD clinical trials employed clinician-reported outcomes measures (93%); patient reported outcome measures (11%) and observer reported outcome measures (3%) were used with much less frequency.

CONCLUSIONS

We provide a review of the most commonly used measures across these trials, compare these measures to the clinical recommendations made by the NINDS working groups, and provide recommendations for selecting measures for future clinical trials that meet the Food and Drug Administration standards.

Do all individuals with sleep apnea suffer from daytime sleepiness? A preliminary investigation

We derived descriptive characteristics related to habitual sleep duration and insomnia for individuals newly diagnosed with sleep apnea/hypopnea syndrome and evaluated how sleep apnea/hypopnea syndrome, insomnia, depression, and sleep duration relate to sleepiness and fatigue. In total, 100 participants were divided into three sleep groups: short (<7 hours), long (≥ 8 hours), and midrange (7-7.9 hours). Polysomnography, insomnia, sleepiness, fatigue, depression, and gender were assessed. Half of the participants were short sleepers. They were more likely to have insomnia than midrange or long sleepers and they were more likely to be sleepy than midrange or long sleepers, regardless of insomnia.

Pittsburgh and Epworth sleep scale items: accuracy of ratings across different reporting periods

This study examined the ecological validity of sleep experience reports across different lengths of reporting periods. The accuracy of item responses on the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) across 3-, 7-, and 28-day reporting periods was examined in relation to electronic daily item ratings. Primary care clinic patients (N = 119) were recruited, and were not required to have sleep problems to participate. Analyses found few differences in item scores when electronic daily ratings were compared with recall ratings, regardless of the length of the reporting period. However, within-subjects analyses indicated low levels of accuracy in recall of sleep items for specific days in the last week. Thus, for the purpose of between-subject comparisons, patients generally can provide accurate recall of sleep experiences; studies requiring finer-grained analysis across time and within-subjects require daily diary methodology.

Can we get more from the Epworth Sleepiness Scale (ESS) than just a single score? A confirmatory factor analysis of the ESS

PURPOSE

The Epworth Sleepiness Scale (ESS) is a widely used tool for measuring sleepiness. In addition to providing a single measure of sleepiness (a one-factor structure), the ESS also has the capacity to provide additional information about specific factors that facilitate sleep onset, including a person's posture, activity and environment. These features of sleepiness are referred to as somnificity. This study evaluates and compares the fit of a one-factor structure (sleepiness) and three-factor structure (reflecting low, medium and high levels of somnificity) for the ESS.

METHODS

All participants (a community sample N = 356 and a clinical sample N = 679) were administered the ESS. Confirmatory factor analysis was used to evaluate and compare the fit of one- and three-factor models of the ESS.

RESULTS

In both samples, a three-factor structure (community sample adjusted X (2) = 2.95, root mean square error of approximation (RMSEA) = 0.07, Comparative Fit Index (CFI) = 0.95; clinical sample adjusted X (2) = 3.98, RMSEA = 0.07, CFI = 0.98) provided a level of model fit that was at least as good as the one-factor structure (community sample adjusted X (2) = 5.01, RMSEA = 0.11, CFI = 0.87; clinical sample adjusted X (2) = 8.87, RMSEA = 0.11, CFI = 0.92).

CONCLUSIONS

In addition to a single measure of sleepiness, the ESS can provide subscale scores which relate to three underlying levels of somnificity. These findings suggest that the ESS can be used to measure an individual's overall sleep propensity as well as more specific measures of sleep propensity in low, moderate and high levels of situational somnificity.

Epworth Sleepiness Scale in obstructive sleep apnea syndrome--an underestimated subjective scale

Excessive daytime sleepiness is a major symptom in obstructive sleep apnea syndrome (OSAS) and can be evaluated using both subjective and objective methods. The Epworth Sleepiness Scale (ESS) is a simple and validated questionnaire for assessing subjective daytime sleepiness in the context of sleep disorders. Although its subjective character may limit the accurate expression of daytime sleepiness, the clinical benefit of sequential ESS is clear and demonstrates how ESS scores evolve in individual patients and how these scores may relate to various parameters. In this context we compared the severity of daytime sleepiness reported at baseline visit with severity of baseline sleepiness assessed, retrospectively, after treatment with automatic positive airway pressure (APAP). We conducted a prospective study that included 66 patients evaluated in a sleep clinic diagnosed with OSAS. The diagnosis was confirmed by in-laboratory or portable sleep studies. Their mean age was 53.3 years and the majority were men (88%, n=58). The ESS was answered during the first interview (baseline daytime sleepiness). During follow-up visits, after APAP treatment, the patient was asked to assess baseline sleepiness, retrospectively, as well as post-treatment sleepiness. The mean baseline ESS score was 11.8, mean retrospective baseline ESS 15.4, with a mean difference of 3.55 (p<0.001 t-Test) and post-treatment ESS 7.3. There was no significant correlation between the difference in ESS score (baseline - retrospective baseline) with the average daily (hours) use of APAP, the apnea-hypopnea index (AHI), the minimal recorded SatO(2), disease duration, body mass index (BMI) and age. Our findings confirm that the severity of subjective sleepiness reported before treatment with positive airway pressure is often underestimated by patients with OSAS.

Disorders of glucose metabolism and insulin resistance in patients with obstructive sleep apnoea syndrome

OBJECTIVE

Insulin resistance (IR) and disorders of glucose metabolism (DGM) are risk factors for cardiovascular diseases. There are different reasons for development of DGM in patients with obstructive sleep apnoea syndrome (OSAS) and this association is controversial. We investigated the frequency of DGM and IR in patients with OSAS and determining factors for these disorders.

METHOD

One hundred and twelve untreated patients with OSAS and 19 non-apnoeic snoring subjects upon polysomnography were included in this study. Oral glucose tolerance test (OGTT) was performed in all subjects who had fasting blood glucose < 125 mg/dl. IR method was analysed using homeostasis assessment model (HOMA-IR). Diabetes mellitus (DM), impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were defined according to values of OGTT. DGM was defined as having one of the diagnoses of DM, IGT or IFG. Subjective sleepiness of all subjects was assessed with Epworth Sleepiness Scale (ESS). Excessive daytime sleepiness (EDS) was described as ESS score ≥ 10.

RESULTS

Fasting glucose and the rate of DGM in patients with OSAS were higher than in non-apnoeic snoring subjects. DGM were shown in % 15.7 of non-apnoeic snoring subjects, 29.6% of mild sleep apnoea, 50% of moderate sleep apnoea and 61.8% of severe sleep apnoea. The rate of DGM in patients with moderate and severe OSAS was higher than in non-apnoeic snoring subjects and in patients with severe OSAS higher than in patients with mild OSAS. DGM are associated with body mass index (BMI), severity of OSAS, arousal index and EDS. In addition, IR is associated with apnoea hypopnoea index, BMI, arousal index and ESS score.

CONCLUSION

Obstructive sleep apnoea syndrome is associated with high frequency of DGM. In addition, the progression of disease from simple snoring and mild OSAS to severe OSAS increases the rate of DGM. Thus, DGM especially in patients with severe OSAS should be examined in regular periods.

Obstructive sleep apnea is associated with fatigue in multiple sclerosis

Background:

Multiple sclerosis (MS) patients often suffer from fatigue.

Objective:

We evaluated the relationship of obstructive sleep apnea (OSA) to fatigue and sleepiness in MS patients.

Methods:

Ambulatory MS patients without known sleep disorders and healthy controls underwent diagnostic polysomnography and a multiple sleep latency test (objective sleepiness measure). Fatigue was measured with the Fatigue Severity Scale (FSS) and the Multidimensional Fatigue Inventory (MFI), and subjective sleepiness by Epworth Sleepiness Scale. Covariates included age, sex, body mass index, Expanded Disability Status Scale (EDSS), depression, pain, nocturia, restless legs syndrome, and medication.

Results:

OSA (apnea–hypopnea index ≥15) was found in 36 of 62 MS subjects and 15 of 32 controls. After adjusting for confounders, severe fatigue (FSS ≥5) and MFI-mental fatigue (>group median) were associated with OSA and respiratory-related arousals in MS, but not control subjects. Subjective and objective sleepiness were not related to OSA in either group. In a multivariate model, variables independently associated with severe fatigue in MS were severe OSA [OR 17.33, 95% CI 2.53–199.84], EDSS [OR 1.88, 95% CI 1.21–3.25], and immunomodulating treatment [OR 0.14, 95% CI 0.023–0.65].

Conclusions:

OSA was frequent in MS and was associated with fatigue but not sleepiness, independent of MS-related disability and other covariates.

Assessment of predictive ability of Epworth scoring in screening of patients with sleep apnoea

METHOD

Numerous studies have considered the benefits, and the disadvantages, of the Epworth Sleepiness Scale. Following an extensive literature review, we found that the evidence was inconclusive as regards the diagnostic efficacy of Epworth scoring for obstructive sleep apnoea syndrome. We undertook a retrospective study of 343 patients who underwent a sleep assessment over a 10-year period at the Monklands Hospital.

ANALYSIS AND RESULTS

A total of 238 patients did not have sleep apnoea whereas 105 patients did. The mean Epworth score in patients with obstructive sleep apnoea syndrome was 10.94 (95 per cent confidence interval 9.46-11.42), and in the non-apnoeic group it was 7.73 (95 per cent confidence interval 7.04-8.41). Logistic regression and receiver operating characteristic curves were used to assess the predictive ability of Epworth scoring. The scores only explained 7-10 per cent of the variation in the probability of occurrence of obstructive sleep apnoea syndrome. The odds ratio for Epworth scoring was 1.118, and only 69 per cent of cases were correctly classified by the Scale.

CONCLUSIONS

The literature review suggested that the Epworth Sleepiness Scale is associated with a low effect size and/or low predictive value when correlated or regressed on the Apnoea-Hypopnoea Index or Respiratory Disturbance Index, thus limiting its value as a screening test. Our study concluded that the Epworth Scale is only marginally useful in predicting the occurrence of obstructive sleep apnoea syndrome. We believe that every patient with a direct or witnessed history of sleep apnoea with obstructive symptoms have some form of sleep assessment.

Cognition and daytime functioning in sleep-related breathing disorders

Sleep-related breathing disorders encompass a range of disorders in which abnormal ventilation occurs during sleep as a result of partial or complete obstruction of the upper airway, altered respiratory drive, abnormal chest wall movement, or respiratory muscle function. The most common of these is obstructive sleep apnea (OSA), occurring in both adults and children, and causing significant cognitive and daytime dysfunction and reduced quality of life. OSA patients experience repetitive brief cessation of breathing throughout the night, which causes intermittent hypoxemia (reductions in hemoglobin oxygen levels) and fragmented sleep patterns. These nocturnal events result in excessive daytime sleepiness, and changes in mood and cognition. Chronic excessive sleepiness during the day is a common symptom of sleep-related breathing disorders, which is assessed in sleep clinics both subjectively (questionnaire) and objectively (sleep latency tests). Mood changes are often reported by patients, including irritability, fatigue, depression, and anxiety. A wide range of cognitive deficits have been identified in untreated OSA patients, from attentional and vigilance, to memory and executive functions, and more complex tasks such as simulated driving. These changes are reflected in patient reports of difficulty in concentrating, increased forgetfulness, an inability to make decisions, and falling asleep at the wheel of a motor vehicle. These cognitive changes can also have significant downstream effects on daily functioning. Moderate to severe cases of the disorder are at a higher risk of having a motor vehicle accident, and may also have difficulties at work or school. A number of comorbidities may also influence the cognitive changes in OSA patients, including hypertension, diabetes, and stroke. These diseases can cause changes to neural vasculature and result in neural damage, leading to cognitive impairments. Examination of OSA patients using neuroimaging techniques such as structural magnetic resonance imaging and proton magnetic resonance spectroscopy has observed significant changes to brain structure and metabolism. The downstream effects of neural, cognitive, and daytime functional impairments can be significant if left untreated. A better understanding of the cognitive effects of these disorders, and development of more effective assessment tools for diagnosis, will aid early intervention and improve quality of life of the patient.

Cognitive profile and brain morphological changes in obstructive sleep apnea

Obstructive sleep apnea (OSA) is accompanied by neurocognitive impairment, likely mediated by injury to various brain regions. We evaluated brain morphological changes in patients with OSA and their relationship to neuropsychological and oximetric data. Sixteen patients affected by moderate-severe OSA (age: 55.8±6.7 years, 13 males) and fourteen control subjects (age: 57.6±5.1 years, 9 males) underwent 3.0 Tesla brain magnetic resonance imaging (MRI) and neuropsychological testing evaluating short- and long-term memory, executive functions, language, attention, praxia and non-verbal learning. Volumetric segmentation of cortical and subcortical structures and voxel-based morphometry (VBM) were performed. Patients and controls differed significantly in Rey Auditory-Verbal Learning test (immediate and delayed recall), Stroop test and Digit span backward scores. Volumes of cortical gray matter (GM), right hippocampus, right and left caudate were smaller in patients compared to controls, with also brain parenchymal fraction (a normalized measure of cerebral atrophy) approaching statistical significance. Differences remained significant after controlling for comorbidities (hypertension, diabetes, smoking, hypercholesterolemia). VBM analysis showed regions of decreased GM volume in right and left hippocampus and within more lateral temporal areas in patients with OSA. Our findings indicate that the significant cognitive impairment seen in patients with moderate-severe OSA is associated with brain tissue damage in regions involved in several cognitive tasks. We conclude that OSA can increase brain susceptibility to the effects of aging and other clinical and pathological occurrences.

Metamemory Beliefs and Episodic Memory in Obstructive Sleep Apnea Syndrome

This study assessed metamemory and its role in actual episodic memory performance in 26 patients with obstructive sleep apnea syndrome and 27 healthy controls. Metamemory knowledge and memory beliefs were assessed using the Metamemory Inventory in Adulthood. Episodic memory performance was investigated with the Remember/Know paradigm. Subjective sleepiness was evaluated. Patients underwent a polysomnographic assessment. In contrast to the control group's more stable memory beliefs, patients self-assessed their memory as declining across time, and felt more anxious about their memory. There was only a modest difference between patients' self-perceptions of their memory capacities and those of the control group, but patients' actual memory performance was strongly disturbed. While the later was significantly correlated with severity of obstructive sleep apnea, scores on the Metamemory Inventory in Adulthood scales were not correlated with physiological measures, subjective sleepiness, or episodic memory performance. Obstructive sleep apnea may affect prefrontal cortex functioning and hence the ability to assess one's own memory impairment.

Relationship between obstructive sleep apnea severity and sleep, depression and anxiety symptoms in newly-diagnosed patients

Obstructive sleep apnea (OSA) occurs in at least 10% of the population, and leads to higher morbidity and mortality; however, relationships between OSA severity and sleep or psychological symptoms are unclear. Existing studies include samples with wide-ranging comorbidities, so we assessed relationships between severity of OSA and common sleep and psychological disturbances in recently diagnosed OSA patients with minimal co-morbidities. We studied 49 newly diagnosed, untreated OSA patients without major co-morbidities such as mental illness, cardiovascular disease, or stroke; subjects were not using psychoactive medications or tobacco (mean +/- std age: 46.8+/-9.1 years; apnea/hyponea index [AHI]: 32.1+/-20.5 events/hour; female/male: 12/37; weight <125 kg). We evaluated relationships between the AHI and daytime sleepiness (Epworth Sleepiness Scale; ESS), sleep quality (Pittsburg Sleep Quality Index; PSQI), depressive symptoms (Beck Depression Inventory-II; BDI), and anxiety symptoms (Beck Anxiety Inventory; BAI), as well as sex and body mass index (BMI). AHI was similar in females and males. Mean levels of all symptoms were above normal thresholds, but AHI was not correlated with age, ESS, PSQI, BDI, or BAI; only BMI was correlated with OSA severity. No differences in mean AHI appeared when subjects were grouped by normal versus elevated values of ESS, PSQI, BDI, or BAI. Consistent with other studies, a strong link between OSA severity and psychological symptoms did not appear in these newly diagnosed patients, suggesting that mechanisms additional to the number and frequency of hypoxic events and arousals occurring with apneas contribute to adverse health effects in OSA. OSA patients presenting with mild or moderate severity, and no major co-morbidities will not necessarily have low levels of sleep or psychological disturbances.

Obstructive sleep apnea (OSA) and depressive symptoms

BACKGROUND

The relationship between obstructive sleep apnea (OSA) and depressive symptoms is ambiguous in the literature.

PURPOSE

To investigate if there is a correlation between depressive symptoms and the severity of OSA.

METHOD

A retrospective, cross-sectional study of data from 123 consecutive adults patients with neither mental illness nor psychotropic drugs intake, referred to a sleep laboratory for an evaluation of OSA. For the statistical analysis (uni- and multivariate), we used the following variables: gender and age, as well as scores based on several scales and indexes such as Beck Depressive Inventory (BDI), Epworth Sleepiness Scale (ESS), Body Mass Index (BMI) and Apnea-Hypopnea Index (AHI).

RESULTS

Univariate analysis found a weak but statistically significant negative correlation between BDI and AHI. However, with the multivariate logistic regression analysis model, the inverse relation between AHI and BDI no longer has statistical significance.

CONCLUSION

There is no causal relationship between OSA and depressive symptoms in the population studied.

Modafinil reduces patient-reported tiredness after sedation/analgesia but does not improve patient psychomotor skills

BACKGROUND

Early recovery of patients following sedation/analgesia and anesthesia is important in ambulatory practice. The aim of this study was to assess whether modafinil, used for the treatment of narcolepsy, improves recovery following sedation/analgesia.

METHODS

Patients scheduled for extracorporeal shock wave lithotripsy were randomly assigned to one of four groups. Two groups received a combination of fentanyl/midazolam with either modafinil or placebo. The remaining groups received remifentanil/propofol with either modafinil or placebo. Modafinil 200 mg was administered to the treatment group patients 1 h before sedation/analgesia. Groups were compared using the digital symbol substitution test (DSST), trail making test (TMT), observer scale of sedation and analgesia (OAA/S) and Aldrete score. Verbal rating scale (VRS) scores for secondary outcome variables e.g. energy, tiredness and dizziness were also recorded before and after treatment.

RESULTS

Sixty-seven patients successfully completed the study. Groups received similar doses of sedation and analgesic drugs. No statistically significant difference was found for DSST between groups. No significant adverse effects occurred in relation to modafinil. No statistically significant difference between groups was identified for TMT, OAA/S and Aldrete scores. The mean VRS score for tiredness was lesser in the modafinil/fentanyl/midazolam group [1.3 (2.0)] compared with the placebo group [3.8 (2.5)], P=0.02. Such a difference was not found between the remifentanil/propofol groups [placebo 2.6 (2.2) vs. modafinil 3.1(2.7)], p>0.05. Dizziness was greater in the modafinil/remifentanil/propofol group 1.7 (2.0) vs. placebo 0.0 (0.5), p<0.05.

CONCLUSION

Modafinil reduces patient-reported tiredness after sedation/analgesia but does not improve recovery in terms of objective measures of patient psychomotor skills.

Sleep effects on breathing and respiratory diseases

To understand normal sleep pattern and physiological changes during sleep, sleep and breathing interaction, nomenclature and scales used in sleep study, discuss the effect of rapid eye movements and non-rapid eye movements while sleep and to review the effects of obstructive and restrictive lung disease on gas exchange during sleep and sleep architecture.

Maintenance of wakefulness test in military personnel with upper airway resistance syndrome and mild to moderate obstructive sleep apnea

BACKGROUND

Sleep-disordered breathing (SDB) and the associated symptom of excessive daytime sleepiness (EDS) in military personnel has influential consequences in both the garrison and the deployed environments. The maintenance of wakefulness test (MWT) is a daytime study used to evaluate the tendency to stay awake. We evaluated consecutive patients diagnosed with mild to moderate obstructive sleep apnea (OSA) and upper airway resistance syndrome (UARS) to provide an objective measure of their EDS using the MWT.

MATERIALS AND METHODS

All military personnel referred between February 2004 and March 2005 with a clinical evaluation suspicious for SDB were evaluated with an overnight polysomnography (PSG). After overnight PSG, military personnel with mild to moderate OSA and UARS were evaluated with a 40-min protocol MWT. Abnormal MWT was defined as sleep onset latency mean below 19.4 min (<2 SD below the mean).

RESULTS

Sixty-two military personnel met entry criteria. Fifty-nine were men. Nineteen patients (32%) were diagnosed with UARS with a mean respiratory disturbance index of 11/h (5-20/h). Forty-one (68%) of the military personnel had OSA with a mean apnea-hypopnea index of 12/h (5-29/h). As a collective group, the mean Epworth Sleepiness Scale was elevated at 13/24 (1-24). This subjective excessive sleepiness was assessed with the MWT test, which resulted in a group mean MWT sleep onset latency of 27 min (5-40 min). Eighteen soldiers (30% of the total patients) had abnormal MWTs [six patients (33.3%) with UARS and 12 (67%) with OSA].

CONCLUSION

Military personnel with mild to moderate OSA and UARS often have abnormal MWTs and therefore have a pathological tendency to fall asleep. This EDS could pose a safety hazard in those personnel, military or civilian, who operate dangerous vehicles, machinery, or carry a firearm. Military personnel with untreated SDB are also at risk for the consequences of decreased mental alertness and decreased cognitive functioning due to daytime sleepiness.