The impact of obstructive sleep apnea and daytime sleepiness on work limitation

BACKGROUND: Many patients with obstructive sleep apnea (OSA) participate in the work force. However, the impact of OSA and sleepiness on work performance is unclear. METHODS: To address this issue, we administered the Epworth Sleepiness Scale (ESS), the Work Limitations Questionnaire (WLQ), and an occupational survey to patients undergoing full-night polysomnography for the investigation of sleep-disordered breathing. Of 498 patients enrolled in the study, 428 (86.0%) completed the questionnaires. Their mean age+/-standard deviation (SD) was 49+/-12 years, mean body mass index (BMI) was 31+/-7 kg/m(2) mean apnea hypopnea index (AHI) was 21+/-22 events/h, and mean ESS score was 10+/-5. Subjects worked a mean of 39+/-18 h per week. The first 100 patients to complete the survey were followed up at two years. RESULTS: In the group as a whole, there was no significant relationship between severity of OSA and the four dimensions of work limitation. However, in blue-collar workers, significant differences were detected between patients with mild OSA (AHI 5-15/h) and those with severe OSA (AHI>30/h) with respect to time management (limited 23.1% of the time vs. 43.8%, p=0.05) and mental/personnel interactions (17.9% vs. 33.0%, p=0.05). In contrast, there were strong associations between subjective sleepiness (as assessed by the ESS) and three of the four scales of work limitation. That is, patients with an ESS of 5 had much less work limitation compared to those with an ESS 18 in terms of time management (19.7% vs. 38.6 %, p<0.001), mental-interpersonal relationships (15.5% vs. 36.0%, p<0.001) and work output (16.8% vs. 36.0%; p<0.001). Of the group followed up, 49 returned surveys and 33 who were using continuous positive airway pressure (CPAP) showed significant improvements between the initial and second follow-up in time management (26% vs. 9%, p=0.0005), mental-interpersonal relationships (16% vs. 11.0%, p=0.014) and work output (18% vs. 10%; p<0.009). CONCLUSION: We have demonstrated a clear relationship between excessive sleepiness and decreased work productivity in a population referred for suspected sleep-disordered breathing. Screening for sleepiness and sleep-disordered breathing in the workplace has the potential to identify a reversible cause of low work productivity.     

Prospective randomized comparison of impedance-controlled auto-continuous positive airway pressure (APAP(FOT)) with constant CPAP

Background: The measurement of impedance permits reliable detection of obstructive apneas, hypopneas and upper airways resistance syndrome.Objective: To establish whether impedance-controlled self-adjusting positive airway pressure therapy (APAP(FOT)) is equally as good as constant continuous positive airway pressure (CPAP) in the treatment of sleep apnea syndrome (OSAS).Methods: Twenty men and five women with OSAS (age 52.8+/-9.0 years, body mass index (BMI) 31.4+/-5.0 kg/m(2), AHI 32.2+/-18.1/h (mean+/-SD)) underwent baseline polysomnography, manual CPAP titration and two nights of treatment, one with APAP(FOT), one with constant CPAP.Results: With both modes, a significant reduction in respiratory disturbances was seen (apnea/hypopnea index (AHI) baseline 32.2+/-18.1/h, constant CPAP 6.6+/-8.7, APAP(FOT) 5.5+/-3.8/h, P<0.001 baseline vs. each treatment mode). Under APAP(FOT), the sleep profile was normalized (S3/4 baseline 16.3+/-13.9% total sleep time (TST), APAP(FOT) 21.6+/-10.9% TST, P<0.05, rapid eye movement (REM) 14.2+/-6.7% TST vs. 20.3+/-7.3% TST, P<0.01), while with constant CPAP, a tendency towards improvement was found. The mean treatment pressure with APAP(FOT) was significantly lower than the constant CPAP (5.7+/-2.1 vs. 8.3+/-1.6 mbar, P<0.001).Conclusion: We conclude that APAP(FOT) is at least as effective as constant CPAP in normalizing sleep and breathing in OSAS.     

Erectile dysfunction, obstructive sleep apnea syndrome and nasal CPAP treatment

BACKGROUND AND PURPOSE: To evaluate the effect of one month of continuous positive airway pressure (CPAP) in a subgroup of obstructive sleep apnea (OSA) patients with erectile dysfunction (ED) and compare this subgroup with age- and body mass index (BMI)-matched OSA patients without ED. PATIENTS AND METHODS: Prospective general, sleep, psychiatric and sexologic evaluations were conducted. Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), Sleep Disorders Questionnaire (SDQ), Quality of Life SF-36, and polysomnography were used. Seventeen OSA patients with ED were compared prior to CPAP treatment and during CPAP treatment with age- and BMI-matched OSA patients without ED. Parametric and non-parametric statistics, chi-square, Fisher exact test and multiple regression analyses were performed. RESULTS: Ninety-eight men (BMI=28.8 kg/m2, apnea-hypopnea index (AHI)=49.6 events/h, ESS=14.8, BDI=8.4, and lowest SaO2=75.3%) were divided into subgroups of lowest SaO2>80% (A) and lowest SaO2< or =80% (B). (A) Forty-six men had a mean lowest SaO2 of 85.7%+/-2.9, AHI=29.5+/-17.6, age=46.3+/-9.3 years, ESS=13.6+/-4.2, BMI=25.8+/-4.8. Seven of the patients had ED. (B) Fifty-two men had a mean lowest SaO2=60.10+/-10.0%, AHI=67.4+/-24.5, BDI=9.0+/-6.9, age=47.4+/-9.4 years, ESS=16.2+/-4.4, BMI=31.4+/-5.1. Twenty-one of the patients had ED (chi2: P=0.006). Significant variables for ED were lowest SaO2 and age (r=0.17). CPAP-treated subgroup: ED subjects had significantly lower SaO2, ESS, BDI and SF-36 subscale scores than OSA controls. Nasal CPAP eliminated the differences between groups, and ED was resolved in 13 out of 17 cases. CONCLUSIONS: ED in OSAS is related to nocturnal hypoxemia, and about 75% of OSAS patients with ED treated with nasal CPAP showed remission at one-month follow-up, resulting in significant improvement in quality of life.     

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.     

Causes of excessive daytime sleepiness in hypercapnic and normocapnic obstructive sleep apnea patients

Daytime sleepiness assessed using the Epworth sleepiness scale (ESS) and polysomnography results were compared in 43 patients with obstructive sleep apnea (OSA) with concomitant chronic hypercapnia (PaCO2 53 +/- 6 mmHg), and in 58 patients with the OSA syndrome accompanied by normocapnia (PaCO2 < or = 45 mmHg, mean 39 +/- 3 mmHg). The OSA patients with hypercapnia were more sleepy than those with normocapnia (ESS 18 +/- 7 vs 15 +/- 7, p < 0.05), but apnea index values were similar in both groups (54 +/- 20 and 49 +/- 17). The following parameters of electrophysiological sleep structure were obtained in the hypercapnic OSA patients: sleep stage 1: 66 +/- 28%, stage 2: 28 +/- 27%, stage 3 + 4: 1 +/- 1%, REM sleep 5 + 6% of the total sleep time, while in the OSA patients with normocapnia: stage 1: 39 +/- 19%, stage 2: 28 +/- 27%, stage 3 + 4: 2 +/- 2%, and REM sleep 6 +/- 7% of the total sleep time. Stage 1 NREM sleep was found to be longer, and stage 2 NREM--shorter in hypercapnic than in normocapnic OSA patients (p < 0.01). CONCLUSION: Increased daytime sleepiness in both groups patients with the OSA syndrome is due to sleep fragmentation as well as to deficiency of deep and paradoxical sleep (almost absent deep sleep and extremely shortened REM sleep). Hypercapnic OSA patients' more marked sleepiness may result from a more pronounced disturbance of their sleep macrostructure, with a considerable predomination of stage I NREM sleep.     

Sleep remains disturbed in patients with obstructive sleep apnea treated with positive airway pressure: a three-month cohort study using continuous actigraphy

ObjectiveSome patients with obstructive sleep apnea (OSA) remain sleepy despite positive airway pressure (PAP) therapy. The mechanisms by which this occurs are unclear but could include persistently disturbed sleep. The goal of this study was to explore the relationships between subjective sleepiness and actigraphic measures of sleep during the first three months of PAP treatment.MethodsWe enrolled 80 patients with OSA and 50 comparison subjects prior to treatment and observed them through three months of PAP therapy. PAP adherence and presence of residual respiratory events were determined from PAP machine downloads. Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), and actigraphic data were collected before and at monthly intervals after starting PAP.ResultsPatients with OSA were sleepier and showed a greater degree of sleep disruption by actigraphy at the baseline. After three months of PAP, only ESS and number of awakenings (AWAKE#) normalized, while wake after sleep onset and sleep efficiency remained worse in patients with OSA. FOSQ was improved in patients with OSA but never reached the same level as that of comparison subjects. ESS and FOSQ improved slowly over the study period.ConclusionsAs a group, patients with OSA show actigraphic evidence of persistently disturbed sleep and sleepiness-related impairments in day-to-day function after three months of PAP therapy. Improvements in sleepiness evolve over months with more severely affected patients responding quicker. Persistent sleep disruption may partially explain residual sleepiness in some PAP-adherent OSA patients.     

The spontaneous eye-blink as sleepiness indicator in patients with obstructive sleep apnoea syndrome-a pilot study

BACKGROUND AND PURPOSE: To evaluate the spontaneous eye-blink as drowsiness/sleepiness indicator in patients with obstructive sleep apnoea (OSA) syndrome. PATIENTS AND METHODS: Using a contact-free sensor for the recording of spontaneous eye-blinks, we investigated the diagnostic value of spontaneous blink parameters in 21 OSA patients. Before the study, all patients underwent a night of polysomnography. Eye-blinks were studied the following morning before therapy, and again after the first therapy night with nasal continuous positive airway pressure (nCPAP), to investigate whether blink parameters reflected changes of alertness pre- and post-nCPAP treatment. General daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS). The current subjective state was determined by means of standardised questionnaires directly before recording the eye-blinks. Studies were conducted in two sleep laboratories in hospitals. RESULTS: In OSA patients with excessive daytime sleepiness (EDS; ESS >10, respiratory disturbance index [RDI]=42.4) several parameters proved informative for sleepiness diagnostics. Reduction of blink duration and reopening time as well as increase in blink frequency were significant; furthermore, proportion of long-closure duration blinks indicated reduced sleepiness. OSA patients without EDS (ESS < or =10, RDI=33.5) did not reveal systematic changes of the blink parameters registered after one night of nCPAP intervention. CONCLUSIONS: Specific parameters of the spontaneous eye-blink may be applied as a sleepiness index for diagnostics in OSA patients. Further studies are needed to prove the diagnostic value of blink parameters and their advantages in comparison to subjective measures commonly used in clinical studies.     

Prevalence and determinants of subjective sleepiness in healthy elderly with unrecognized obstructive sleep apnea

ObjectiveObstructive sleep apnea (OSA) is associated with behavioral consequences such as excessive daytime sleepiness (EDS). The aim of this study was to establish the presence of sleepiness in elderly with unrecognized OSA and the factors explaining its occurrence.MethodologyA total of 825 healthy elderly (aged ≥65 years) undergoing clinical, respiratory polygraphy, and heart-rate variability analysis were studied. According to the apnea–hypopnea index (AHI), the subjects were stratified in four categories: no-OSA (AHI <5), mild (5 > AHI <15), moderate (15 ≥ AHI <30), and severe OSA (AHI ≥30). Participants with EDS were defined on the basis of the Epworth Sleepiness Scale (ESS) score ≥10.ResultsOverall, the mean ESS score was 5.7 ± 5.6, 14.9% showing EDS with an increasing trend according to OSA severity (p <0.001). Sleepy subjects were more frequently men, having a greater body mass index (BMI), alcohol intake, depression score, and indices of OSA severity (23% of severe OSA cases being sleepy). No differences were present between sleepy and non-sleepy subjects in regard to other clinical, metabolic, and autonomic nervous system measurements. Regression analyses adjusted for age, gender, BMI, hypertension, depression score, autonomic sleep fragmentation, and AHI and/or oxygen desaturation index revealed that gender (p <0.0001), depression score (p <0.0001), and BMI (p = 0.01) were the only significant factors affecting the presence of sleepiness in this population.ConclusionsIn healthy elderly with OSA, the prevalence of EDS was low, and it affected only severe cases. Despite a weak association between the ESS score and the AHI index, male gender and depression score were the most significant predictors for the occurrence of sleepiness.     

SOS score: an optimized score to screen acute stroke patients for obstructive sleep apnea

BackgroundObstructive sleep apnea (OSA) is frequent in acute stroke patients, and has been associated with higher mortality and worse prognosis. Polysomnography (PSG) is the gold standard diagnostic method for OSA, but it is impracticable as a routine for all acute stroke patients. We evaluated the accuracy of two OSA screening tools, the Berlin Questionnaire (BQ), and the Epworth Sleepiness Scale (ESS) when administered to relatives of acute stroke patients; we also compared these tools against a combined screening score (SOS score).MethodsIschemic stroke patients were submitted to a full PSG at the first night after onset of symptoms. OSA severity was measured by apnea–hypopnea index (AHI). BQ and ESS were administered to relatives of stroke patients before the PSG and compared to SOS score for accuracy and C-statistics.ResultsWe prospectively studied 39 patients. OSA (AHI ≥10/h) was present in 76.9%. The SOS score [area under the curve (AUC): 0.812; P = 0.005] and ESS (AUC: 0.789; P = 0.009) had good predictive value for OSA. The SOS score was the only tool with significant predictive value (AUC: 0.686; P = 0.048) for severe OSA (AHI ≥30/h), when compared to ESS (P = 0.119) and BQ (P = 0.191). The threshold of SOS ≤10 showed high sensitivity (90%) and negative predictive value (96.2%) for OSA; SOS ≥20 showed high specificity (100%) and positive predictive value (92.5%) for severe OSA.ConclusionsThe SOS score administered to relatives of stroke patients is a useful tool to screen for OSA and may decrease the need for PSG in acute stroke setting.     

Craniofacial abnormalities in Chinese patients with obstructive and positional sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent episodes of a complete or partial collapse of the upper airway during sleep. Traditionally, the disease is diagnosed by overnight polysomnography. Studies have shown correlation between parameters of cephalometry and severity of sleep apnea. We wish to determine the variable of craniofacial dimensions in the upper airway that contribute to OSA, and to investigate the significance of craniofacial measurements in positional and non-positional sleep apnea patients. METHODS: From July 2002 to June 2006, we studied 84 males and 15 females who came to the sleep center because of daytime sleepiness. All the participants underwent overnight polysomnography and lateral cephalograms, performed by an experienced technician. RESULTS: Craniofacial measurements of gnathion-gonion, anterior superior hyoid to mandibular plane (MP-H), posterior nasal spine (PNS) to the velum tip (SPL), widest point of the soft palate (SPW), and the product of PNS to the velum tip and widest point of the soft palate (product of soft palate (SPP)=SPL x SPW) were positively related to the apnea/hypopnea index (AHI). The velum tip to the pharyngeal wall parallel to the Frankfurt horizontal (PAS) was negatively related to the AHI. We further divided the study subjects into 4 groups according to AHI value (group 1, AHI<5; group 2, 5 or=30). Age, body mass index (BMI), neck circumference (NC), distances of PAS, SPL, SPW, SPP and angle of sella-nasion-infradentale (SNB) were significantly different depending on the degree of severity of sleep-disordered breathing (SDB). Patients who were older, with a high BMI and longer MP-H distance, had more daytime sleepiness (Epworth sleepiness scale, ESS). Furthermore, lower AHI values and longer PAS measurements were found in the positional sleep apnea group when compared to the non-positional sleep apnea group. After adjusting for confounding factors of age, BMI and NC, we found that BMI, MP-H distance and PAS measurement were correlated with severity of OSA. CONCLUSIONS: Cephalometry could be a useful and inexpensive clinical tool to evaluate Chinese patients with OSA. MP-H and PAS should be measured in Chinese patients with OSA. MP-H was correlated with ESS. The PAS measurement was narrower in non-positional OSA patients compared to positional OSA patients.     

Sleep and breathing in professional football players

OBJECTIVES: To evaluate sleep in professional football players and describe clinical features of players at risk for sleep for sleep-disordered breathing (SDB).METHODS: The Multivariable Apnea Prediction (MAP) index was used to stratify players into high (MAP> or =0.5) and low (MAP<0.5) risk for SDB. Players from both risk groups were randomly selected for overnight polysomnography, with over-sampling from the High-risk group. Of 302 players from eight professional football teams; 52 underwent attended polysomnography. Anthropometrics including neck circumference, airway size (Mallampati score, maxillary overjet) and sleepiness measured by Epworth scores (ESS) were recorded. The primary outcome measures were ESS and an apnea-hypopnea index (AHI) > or =10.RESULTS: Ninety-two percent of players were <30 years old (mean (SD) age: 25.5+/-2.7 years) with large necks (45.2+/-3.6 cm) and elevated BMI (31.5+/-4.6). More than 20% of players had an ESS>10 with ESS highest in habitual snorers. An AHI of > or =10 was found in 13 (34%, 95% confidence interval (CI) 21-50%) high-risk players but only one (7%, 95% CI 1-31%) of 14 low-risk players. Offensive (9) or defensive (3) linemen accounted for the majority of the positive cases. Based on our sample, we estimate the prevalence of SDB to be 14% (2-25%).CONCLUSIONS: Excessive daytime sleepiness (EDS) is present in a large fraction of professional football players. Some but not all of this may be due to an increased prevalence of SDB. Further study is required to understand all of the factors responsible for EDS and to determine which of the biggest players will have SDB, which may impact not only performance and productivity but also future health.     

Atomoxetine improves sleepiness and global severity of illness but not the respiratory disturbance index in mild to moderate obstructive sleep apnea with sleepiness

BACKGROUND AND PURPOSE: Norepinephrine reuptake inhibitors such as protriptyline have been shown to improve sleepiness in sleep apnea, with or without improvement in the respiratory disturbance index (RDI). This study was performed to evaluate whether the selective norepinephrine reuptake inhibitor atomoxetine improves sleepiness, the clinical global impression (CGI) of severity of illness, and the RDI in patients with mild to moderate obstructive sleep apnea with excessive sleepiness. METHODS: Patients aged 18-60 years with RDI (including apneas, hypopneas with desaturations and hypopneas with arousals) >5/h sleep, apnea-hypopnea index (AHI; including apneas, hypopneas with 4% desaturations, but not apneas with arousals) <15/h sleep, and excessive sleepiness (Epworth Sleepiness Scale [ESS]>or=10) received open-label treatment with atomoxetine 40-80 mg HS for 4 weeks, with repeat polysomnography at the end of treatment. Of 20 patients screened, 17 started treatment and 15 completed treatment. RESULTS: ESS improved from 15.3 to 10.5 and CGI improved from 4.3 to 3.1 (both significant at p<0.01), but there was no significant change in RDI. ESS and CGI improved in a linear fashion across the weeks of treatment. Sleep efficiency and % stage rapid eye movement (REM) sleep were decreased, and % stage 1, awakenings and wake after sleep onset were increased. CONCLUSIONS: Atomoxetine improved sleepiness and the CGI in patients with mild to moderate obstructive sleep apnea with sleepiness. However, it did not improve the RDI.     

Reciprocal interactions between spontaneous and respiratory arousals in adults with suspected sleep-disordered breathing

BACKGROUND AND PURPOSE: Excessive daytime sleepiness (EDS) is a major consequence of sleep-disordered breathing (SDB) in adults. In snoring children, spontaneous and respiratory arousals display reciprocal interactions, allowing for development of a new quantitative measure, the sleep pressure score (SPS), which provides intra-polysomnographic estimates of sleep pressure/disruption. The aim of the present study was to assess the interactions between respiratory and spontaneous arousals in adults with suspected SDB, and to examine whether the SPS and the Epworth sleepiness scale (ESS) are correlated. PATIENTS AND METHODS: Retrospective chart review of 530 adult patients who underwent polysomnographic evaluation for suspected SDB in two medical centers was performed. Polysomnographic studies reports, patients' demographics and ESS scores were reviewed. RESULTS: Spontaneous and respiratory arousal indices and the apnea-hypopnea index (AHI) displayed negative and positive correlations respectively (r=-0.25, r=0.97, P<0.0001) indicating reciprocal interactions between respiratory and spontaneous arousals during sleep. The AHI corresponding to the SPS at which the respiratory arousal/total arousal fraction exceeded the spontaneous arousal/total arousal fraction occurred at approximately 14/h of total sleep time (TST) (compared to 7/h TST in children) (P<0.001). No correlation was found between SPS values and ESS scores. CONCLUSIONS: As in children, snoring adults exhibit reciprocal interactions between respiratory and spontaneous arousals that can also be expressed as a single quantitative measure, the SPS, which is highly dependent on the severity of SDB and could possibly serve as a more reliable index of sleep disruption, considering that the ESS is unrelated to either SPS or AHI.     

Vagus nerve stimulation reduces daytime sleepiness in epilepsy patients

BACKGROUND: Given that vagal afferents project to brainstem regions that promote alertness, the authors tested the hypothesis that vagus nerve stimulation (VNS) would improve daytime sleepiness in patients with epilepsy. METHODS: Sixteen subjects with medically refractory seizures underwent polysomnography and multiple sleep latency tests (MSLT) and completed the Epworth Sleepiness Scale (ESS), a measure of subjective daytime sleepiness, before and after 3 months of VNS. Most subjects (>80%) were maintained on constant doses of antiepileptic medications. RESULTS: In the 15 subjects who completed baseline and treatment MSLT, the mean sleep latency (MSL) improved from 6.4 +/- 4.1 minutes to 9.8 +/- 5.8 minutes (+/- SD; p = 0.033), indicating reduced daytime sleepiness. All subjects with stimulus intensities of < or =1.5 mA showed improved MSL. In the 16 subjects who completed baseline and treatment ESS, the mean ESS score decreased from 7.2 +/- 4.4 to 5.6 +/- 4.5 points (p = 0.049). Improvements in MSLT and ESS were not correlated with reduction in seizure frequency. Sleep-onset REM periods occurred more frequently in treatment naps as compared to baseline naps (p < 0.008; Cochran-Mantel-Haenszel test). The amount of REM sleep or other sleep stages recorded on overnight polysomnography did not change with VNS treatment. CONCLUSIONS: Treatment with VNS at low stimulus intensities improves daytime sleepiness, even in subjects without reductions in seizure frequency. Daytime REM sleep is enhanced with VNS. These findings support the role of VNS in activating cholinergic and other brain regions that promote alertness.     

Idiopathic edema is associated with obstructive sleep apnea in women

BACKGROUND AND PURPOSE: This study was undertaken to clarify whether idiopathic edema is a marker for obstructive sleep apnea (OSA), independent of level of obesity, in patients with normal left ventricular function. PATIENTS AND METHODS: Seventy-eight ambulatory, obese, adults, 44 with bilateral, pitting pre-tibial edema, and 34 without edema, from an inner city family practice and a suburban family practice enrolled from July 1995 until March 2003. Edematous subjects, but not non-edematous subjects, underwent echocardiography, urinalysis, and blood test evaluations to ensure that cardiac, renal, hepatic, and thyroid functions were normal. All subjects underwent spirometry, pulse oximetry on room air, and polysomnography evaluations. RESULTS: Compared to the non-edematous subjects, the edematous subjects were more obese (body mass index=47.0+/-9.3 versus 36.5+/-4.6 kg/m2, P=0.002), had more severe OSA (apnea-hypopnea index (AHI)=34.1+/-27.7 versus 17.0+/-19.4, P=0.002), and had lower oxygen saturations (96.2+/-2.0 versus 97.1+/-1.5%, P=0.05). Using an AHI > or = 15 as the criteria for diagnosing OSA, there was an association between edema and OSA in women (P=0.02) but not men. CONCLUSIONS: In subjects with normal left ventricular function, idiopathic edema is associated with OSA in women.     

Obstructive sleep apnoea: a case-control study

INTRODUCTION: Obstructive sleep apnoea (OSA), is characterized by loud snoring and excessive daytime sleepiness. Though the gold standard for diagnosis is overnight polysomnography (PSG), sleep questionnaires have also been used to diagnose this with good predictive value. MATERIAL AND METHODS: A pre-designed proforma with clinical details, symptom-specific questions for diagnosis of OSA, and Epworth Sleepiness Scale (ESS) was administered to 20 patients presenting to the Sleep Disorder Clinic of our hospital and to 40 age and sex-matched relatives (control group). The students 't-test' and chi-square were used as the statistical tests. RESULTS: There were 20 patients with a mean age of 41+/- 8 years, and 40 controls with a mean age of 41 +/- 6 years (P=>0.05). Seven had family history of snoring in the study group and 3 in the control group (P=0.02). Four had met with road traffic accidents in the study group and none in the control group (P=0.001). The body mass index (BMI) was 29.9 (SD 4.4) in the study group and 24.5 (SD3.5) in the controls (P=0.001). The mean ESS was 13.3 +/- 6 in the patients and 4.2+ 4 in the controls (P=0.001). A larger number of patients with OSA had hypertension: 5/20 vs. 3/40 (P=0.01). CONCLUSION: Patients with OSA had significantly higher BMI and ESS score, and were more likely to have hypertension and road traffic accidents. Increased awareness of this entity is essential.     

阻塞性睡眠呼吸暂停低通气综合征患者的睡眠障碍

目的 探讨不同程度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者睡眠障碍和夜间缺氧的发生特点和影响因素.方法 对425例打鼾患者应用Epworth嗜睡量表进行问卷调查,计算嗜睡评分;用多导睡眠监测仪(PSG)进行整夜睡眠监测,分析患者睡眠结构和夜间反复低氧的特点与嗜睡评分及临床症状之间的相关性.结果 按呼吸暂停低通气指数(AHI)将425例患者分为单纯鼾症组65例(15.3%);OSAHS患者360例(84.7%),其中轻度OSAHS组96例(22.6%),中度OSAHS组77例(18.1%),重度OSAHS组187例(44.O%).OSAHS患者随着病情加重,嗜睡评分明显升高,组间比较差异均有统计学意义.OSAHS患者与单纯鼾症组比较,睡眠效率、非快速眼球运动1和2期(NREMl+2)睡眠时间增长,3和4期(NREM3+4)睡眠时间缩短;氧减指数(ODI)、脉搏氧饱和度低于90%的时间[T(SpO2<90%)]增高,最低脉搏氧饱和度(LSpO2)降低.随着OSAHS病情加重,各指标变化越大.相关分析提示,嗜睡评分与AHI呈正相关(r=0.474,P<0.01),两者与ODI、T(SpO2<90%)及NREMl+2睡眠时间呈正相关(嗜睡评分r=0.392、0.356、0.194,AHI r=0.714、0.682、0.365;均P<0.01),与LSpO2和NREM3+4睡眠时间呈负相关(嗜睡评分r=-0.414、-0.196,AHI r=-0.740、-0.385;均P<0.01),其中LSp02、ODI、T(SpO2<90%)为主要影响因素.临床上患者出现白天嗜睡、记忆力下降、疲乏、口于、夜间憋醒、晨起头痛等主要症状,重度患者白天嗜睡症状的发生率达73.3%(137/187).结论 不同程度OSAHS患者均存在睡眠障碍,患者嗜睡的严重程度与睡眠结构的改变部分相关,而与缺氧情况呈明显相关.随着疾病严重程度的加重,睡眠障碍和缺氧越明显,嗜睡评分越高.     

Factors influencing subjective sleepiness in patients with obstructive sleep apnea syndrome

The aim of the present paper was to clarify the factors influencing subjective daytime sleepiness in patients with obstructive sleep apnea syndrome (OSAS). Subjects included 230 adult male OSAS patients aged 20-73 years. Single and multiple linear regression analyses were performed to estimate the association between the Epworth Sleepiness Scale (ESS) and the following variables: Minnesota Multiphasic Personality Inventory (MMPI), Self-Rating Depression Scale (SDS), age, body mass index (BMI), sleep duration during the preceding month and apnea-hypopnea index (AHI). Single linear regression analysis showed that age had a negative association with ESS score, while BMI, AHI, SDS, hypochondriasis (Hs), hysteria, psychopathic deviant, psychasthenia, schizophrenia and hypomania on the MMPI had a positive association with ESS score. However, the other remaining parameters such as nocturnal sleep duration during the preceding month, depression, masculinity-femininity, paranoia, social introversion on the MMPI had no statistical association with ESS score. Multiple linear regression analysis with stepwise elimination method was applied to choose the significant factors associated with ESS. It was found that three variables including age, AHI and Hs scores were independent factors influencing ESS score. The R(2) for the model was 0.14, suggesting that these factors account for 14% of possible variance of subjective daytime sleepiness of OSAS patients. These results suggest that subjective daytime sleepiness in patients with OSAS may be influenced not only by the severity of respiratory disorder indices but also by certain personality characteristics affecting Hs score and by age.     

Evening and morning blood gases in patients with obstructive sleep apnea

BACKGROUND AND PURPOSE: The purpose of this study was to see if blood oxygen levels deteriorate overnight during obstructive sleep apnea (OSA). Before and after sleep, arterial blood gases (ABGs) in OSA subjects and controls were drawn during a diagnostic night, as well as during a continuous positive airway pressure (CPAP) night for the OSA subjects. PATIENTS AND METHODS: Subjects, both male and female, were referred to our sleep laboratory for symptoms of daytime somnolence. Subjects consisted of a control group (N=13) with a mean apnea hypopnea index (AHI) of 3.3 events/h and a study group (N=22) with a mean baseline AHI of 57 events/h. RESULTS: With the subject supine, resting room air ABGs were drawn at 'lights out' on the evening before (PM) nocturnal polysomnography and in the morning (AM) at discontinuation ('lights on') of the sleep study. In controls, PM PaO(2) (79.4+/-9.7 mmHg) was not significantly different from AM PaO(2) (80.2+/-8.9 mmHg, P=0.5). In apneic subjects, the PM PaO(2) was 78.7+/-7.2 mmHg compared to an AM PaO(2) of 72.6+/-8.3 mmHg (P<0.05). The AM PaO(2) after a night of CPAP treatment in the OSA subjects was 77.5+/-10.2 mmHg compared to the PM PaO(2) of 76.0+/-6.0 mmHg (NS). The PM and AM PaCO(2)s were not different in controls or in study subjects under baseline conditions. However, during titration with nasal CPAP, the PaCO(2) was significantly higher in the morning after CPAP treatment [43.1+/-4.8 vs. 46.1+/-4.8 mmHg, respectively (P<0.05)]. CONCLUSIONS: OSA subjects showed a fall in overnight resting oxygenation. This could be accounted for by overnight deterioration of gas exchange and is ameliorated by CPAP.     

Effects of an individualized exercise training program on severity markers of obstructive sleep apnea syndrome: a randomised controlled trial

ObjectiveObstructive sleep apnea (OSA) is a high prevalent disorder with severe consequences including sleepiness, metabolic, and cardiovascular disorders. The aim of this study was to assess the effect of an individualized exercise-training (IET) program with educational sessions vs educational sessions alone on severity markers of OSA over an eight-week duration.MethodsThis was a randomised, controlled, parallel-design study. In sum, 64 patients with moderate-to-severe OSA (apnea-hypopnea index AHI 15–45/hour), low physical activity level (Voorrips<9), body-mass index (BMI) <40 kg/m² were included in intervention group (IG) or control group (CG), and 54 patients finished the study. All underwent polysomnography (PSG), multiple sleep latency test (MSLT), constant workload exercise test, blood samples and fulfilled questionnaires twice. The primary endpoint was the change in apnea-hypopnea (AHI) at eight weeks from baseline. Main secondary endpoints were daytime sleepiness assessed by questionnaire and objective tests.ResultsNo significant between-group differences were found for changes in AHI. A reduction in AHI was found in IG only (p = 0.005). Compared to CG, exercise training leads to a greater decrease in AHI during REM sleep (p = 0.0004), with a significant increase in mean daytime sleep latency (p = 0.02). Between-group differences were significant for weight reduction, severity of fatigue, insomnia and depressive symptoms with trend for sleepiness symptoms.ConclusionsIn adult patients with moderate-to-severe OSA, IET did not decrease AHI compared to the control group but improved markers of severity of OSA, in particular AHI in rapid eye movement (REM) sleep and objective daytime sleepiness. Adding personalized exercise training to the management of patients with OSA should be considered.ClinicalTrials.gov identifierNCT01256307.