睡眠呼吸暂停低通气综合征患者多导睡眠图特征及日间嗜睡分析

目的 通过对男女睡眠呼吸暂停低通气综合征（OSA）患者多导睡眠图特征及日间嗜睡程度的对比,探究OSA患者的多导睡眠图特征及日间嗜睡程度是否存在性别差异.方法 选取2011年5月～2013年2月在华西医院睡眠中心就诊,年龄在18～65岁之间,经整夜多导睡眠呼吸监测确诊为OSA（睡眠呼吸紊乱指数,AHI≥5次/h）的患者进行回顾性分析.按性别分为男性OSA患者及女性OSA患者两组,并对两组的年龄及AHI进行配对.比较两组患者多导睡眠图所示睡眠结构、缺氧状况、多次小睡潜伏时间试验（MSLT）及Epworth嗜睡量表（ESS）评分的差异.结果 共258名患者纳入研究,其中男性129名,平均年龄（49.4±11.3）岁,平均AHI指数（35.3±26.7）次/h;女性129名,平均年龄（49.7±11.8）岁,平均AHI指数（34.1±26.7）次/h.男女OSA患者相比,女性患者睡眠潜伏期更长[（19.2± 28.1）vs.（12.9±12.9）min],睡眠效率更低[（78.5±14.1）% vs.（84.5±9.7）%],睡后觉醒时间更长[（89.8±63.8）vs.（66.1±48.4）min],总睡眠时间更短[（396.9±78.8）vs.（ 427.6± 56.1）min],多次小睡平均潜伏期更长[（9.9±3.39）vs.（9.3±3.7）min],（P均＜0.05）.男女患者呼吸事件中低通气所占比例[（39.9±26.3）% vs.（53.4±27.7）%],阻塞性呼吸暂停所占比例为[（50.81±25.88）% vs.（41.03±26.72）%],（P均＜0.05）.结论 在AHI严重程度相一致的情况下,女性患者睡眠质量更差,但男性患者日间客观嗜睡程度更重.呼吸事件中女性患者多以低通气为主,而男性患者多以阻塞性呼吸暂停为主.     

Excessive daytime sleepiness in man: multiple sleep latency measurement in narcoleptic and control subjects.

Excessive daytime sleepiness is a complaint characterizing many disorders of the wakefulness--sleep cycle. This paper addresses the complaint of sleepiness objectively by an attempt to differentiate a group of control subjects from a group of patients with unambiguous narcolepsy. Fourteen control and 27 narcoleptic subjects were evaluated by one of three protocols involving nocturnal recordings, detailed interviews, and 5 or more 20-min opportunities to sleep offered at 2-h intervals beginning at 10.00 o'clock, +/- 30 min. Each 20-min opportunity to sleep was given to subjects lying in a darkened quiet room and asked to try to fall asleep. Polysomnographic variables were monitored and sleep was scored in 30-sec epochs by standard criteria. The interval from the start of each test to the first epoch of NREM (including stage 1 sleep) or REM sleep was called sleep latency. In two of the protocols, the subjects were awakened immediately after sleep onset. In the third protocol, the subjects were awakened after 10 min of sleep. Narcoleptics consistently fell asleep much more readily than did control subjects. We conclude that the Multiple Sleep latency test, in addition to providing opportunities to clinically document sleep onset REM sleep periods, can demonstrate pathological sleepiness. Based on these data, we suggest that an average sleep latency less than 5 min be set as the minimum cutoff point for pathological sleepiness.     

Nighttime sleep and daytime functioning (sleepiness and fatigue) in less well-defined chronic rheumatic diseases with particular reference to the 'alpha-delta NREM sleep anomaly'

For the past 25 years, the 'alpha-delta NREM sleep abnormality' has been used by some as a defining or legitimizing marker for poorly defined rheumatic diseases such as fibromyalgia and chronic fatigue syndrome. Comprehensive review of the literature reveals no support for such a conclusion. Most studies involve small numbers of patients. The lack of control subjects, non-standardized recording techniques, and confusion between tonic and phasic alpha frequency activity patterns make comparison difficult. There is much evidence that this sleep EEG pattern is not only non-specific, but may actually reflect a sleep maintaining process. The 'sleep fragmentation' theory of the complaint of non-restorative sleep in this patient population is invalidated by the fact that conditions characterized by severe sleep fragmentation, such as obstructive sleep apnea, are not associated with musculoskeletal symtoms. It is difficult to attribute musculoskeletal symptoms to disorders of sleep in view of the fact that the only organ of the body known to benefit from sleep, or to be adversely affected by lack of sleep, is the brain. It is concluded that fibromyalgia and chronic fatigue syndrome are associated with subjective sleep complaints, but do not represent sleep disorders.     

Diurnal variation in daytime sleepiness of patients with sleep apnea syndrome

Diurnal variations in daytime sleepiness were studied in 26 men with sleep apnea syndrome (SAS) [age, 41.7 +/- 9.9 years (mean +/- SD); body mass index, 30.0 +/- 6.2 kg/m2; Epworth Sleepiness Score, 8.7 +/- 4.1; apnea-hypopnea index, 50.2 +/- 22.0]. Sleep latencies measured at 09.00 h, 11.00 h, 13.00 h, 15.00 h, and 17.00 h were 3.4 +/- 3.6 min, 4.7 +/- 5.5 min, 5.2 +/- 4.4 min, 5.3 +/- 5.4 min, and 9.3 +/- 7.2 min, respectively (ANOVA, P < 0.05). Daytime sleepiness in patients with SAS was more pronounced in the morning than in the afternoon and evening.     

Excessive twitch movements in rapid eye movement sleep with daytime sleepiness

Abstract  A man who showed excessive twitch movement, such as fragmentary myclonus (FM) and periodic movements in sleep (PMS) predominantly during REM sleep, is reported. He complained of excessive daytime sleepiness (EDS). After examination, his twitch movements were shown not to accompany narcolepsy, and his EDS were considered to originate from nocturnal sleep disturbance caused by FM and PMS.     

Excessive daytime sleepiness and sleep complaints among children with epilepsy

OBJECTIVE: Excessive daytime sleepiness (EDS) and sleep complaints are common among adults with epilepsy. We hypothesized that children with epilepsy have worse daytime sleepiness compared with controls. METHODS: Children with and without epilepsy between ages 8 and 18 were recruited for the study. Parents and children were asked to fill out the Pediatric Sleep Questionnaire (PSQ) and Pediatric Daytime Sleepiness Scale (PDSS), respectively. The Mann-Whitney U test was used for group comparisons, with the Fischer exact or chi2 test for categorical variables. Regression analysis was used to identify predictors of EDS. RESULTS: Twenty-six patients and matched controls were recruited for the study. Parents of children with epilepsy more often reported EDS (P < 0.001), symptoms of sleep-disordered breathing (P < 0.001), and parasomnias (P < 0.001) compared with controls. On the PDSS, children with epilepsy reported worse daytime sleepiness scores compared with controls (15.48 +/- 6.4 vs 11.88 +/- 5.25, P = 0.037). Based on conditional logistic regression modeling, symptoms of excessive daytime sleepiness [corrected] (OR = 15.3, 95% CI = 1.4-166.6) and parasomnias (OR = 12.4, 95% CI = 1.01-151.6) were significantly associated with having epilepsy when adjusted for duration of nightime sleep. Further, 10 children (38.5%) with epilepsy reported positive sleep-disordered breathing, whereas no one in the control group reported SDB (P < 0.001) [corrected] Epilepsy syndrome, anticonvulsants used, and presence or absence of seizure freedom, however, were not significant predictors of EDS among patients. CONCLUSIONS: Daytime sleepiness appears to be common in children with epilepsy, and may be due to underlying sleep disorders. Further confirmatory studies are needed using screening questionnaires and formal sleep studies to systematically study the prevalence of sleep complaints and role of sleep disorders in these patients.     

Nighttime sleep problems and daytime sleepiness in Parkinson's disease

Our objective is to evaluate nighttime sleep problems (NSP) and daytime sleepiness (DS) in patients with Parkinson's disease (PD) compared to controls, and to assess relations with demographic, disease‐related, and clinical characteristics in patients. NSP and DS were evaluated with the SCOPA‐SLEEP questionnaire in PD patients and controls. In patients, other disease‐related and clinical characteristics were also evaluated. Four hundred twenty PD patients [mean (SD) age 61.1 (11.5) years] and 150 controls [mean (SD) age 60.9 (9.9) years] participated in the study. Compared to controls, a significantly greater proportion of patients had excessive DS (EDS) (43 vs. 10%), excessive NSP (ENSP) (27 vs. 9%), or used sleep medication (17 vs. 12%). Difficulties with falling asleep were similar in both groups. In both patients and controls, women experienced more NSP than men. In patients, depressive symptoms accounted for 21% of NSP variance and was the major contributor to the total explained variance (30%). Furthermore, NSP were related to dopamine‐agonist and levodopa dose, whereas DS was related to age, dopamine‐agonist dose, and disease severity. NSP and DS occur frequently in PD, with EDS being reported more commonly than ENSP. No strong relations were found between DS and demographic or clinical variables. The strong relation between NSP and depressive symptoms in PD calls for future studies to explore the nature of this relation. © 2007 Movement Disorder Society     

Night sleep electroencephalogram power spectral analysis in excessive daytime sleepiness disorders.

A group of 53 patients (40 males, 13 females) with mean age of 49 years, ranging from 30 to 70 years, was evaluated in the following excessive daytime sleepiness (EDS) disorders: obstructive sleep apnea syndrome (B4a), periodic movements in sleep (B5a), affective disorder (B2a), functional psychiatric non affective disorder (B2b). We considered all adult patients referred to the Center sequentially with no other distinctions but these three criteria: (a) EDS was the main complaint; (b) right handed; (c) not using psychotropic drugs for two weeks prior to the all-night polysomnography. EEG (C3/A1, C4/A2) samples from 2 to 10 minutes of each stage of the first REM cycle were chosen. The data was recorded simultaneously in magnetic tape and then fed into a computer for power spectral analysis. The percentage of power (PP) in each band calculated in relation to the total EEG power was determined of subsequent sections of 20.4 s for the following frequency bands: delta, theta, alpha and beta. The PP in all EDS patients sample had a tendency to decrease progressively from the slowest to the fastest frequency bands, in every sleep stage. PP distribution in the delta range increased progressively from stage 1 to stage 4; stage REM levels were close to stage 2 levels. In an EDS patients interhemispheric coherence was high in every band and sleep stage. B4a patients sample PP had a tendency to decrease progressively from the slowest to the fastest frequency bands, in every sleep stage; PP distribution in the delta range increased progressively from stage 1 to stage 4; stage REM levels were between stage 1 and stage 2 levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Excessive daytime sleepiness and sleep episodes in Japanese patients with Parkinson's disease

In Parkinson's disease (PD), sudden unexpected sleep episodes and excessive daytime sleepiness (EDS) while driving and engaging in social activities are important problems. We conducted a multi-center study to clarify the prevalence and contributing factor of EDS and sleep episodes in Japanese patients with PD. We evaluated 188 patients with PD (85 men, 103 women) and 144 age-matched controls for sleepiness. EDS was defined as an Epworth sleepiness scale (ESS) score of >or=10. ESS score was significantly higher (6.6+/-4.2 vs. 5.6+/-3.8) and prevalence of sleep episodes was higher in PD than in controls (6.4% vs. 0.7%). PD patients with EDS were more likely to have sleep episodes (22.5% vs. 2.0%), higher score for disease severity and depressive symptoms, and on higher dose of dopaminergic agents than those without EDS. However, there were no differences in nocturnal disturbances between the two groups. ESS score was not different between patients taking ergot and non-ergot dopamine agonists. Logistic regression analysis demonstrated that mental state, total dose of dopaminergic agents, and ESS score were significant predictors of sleep episodes. ESS score of >or=10 had 75% sensitivity and 82.4% specificity for sleep episodes. These results suggest that sleepiness in PD is dependent on disease itself and dopaminergic treatment rather than nocturnal disturbances.     

Relationship between amount of sleep and daytime sleepiness in three cases

The effect of sleep amount on daytime sleepiness was investigated, and the appropriate amount of sleep for each subject was evaluated. Three children were longitudinally evaluated for three conditions: control, sleep extension, and sleep reduction. A sleep latency test was conducted five times for each condition at 2-h intervals from 10.00 hours. The results showed that the effects of sleep loss increased sleepiness at 10.00 hours and 18.00 hours, and there were positive correlations between sleep amount and sleep latency for each subject (r = 0.590-0.903). Whether or not the amount of sleep for each subject was sufficient was evaluated from the relationship between the two measures.     

Prevalence of sleep apnea and daytime sleepiness in professional truck drivers

IntroductionThe prevalence of obstructive sleep apnea (OSA) among professional truck drivers has varied from 28 to 78% in previous studies. In this study we wanted to estimate the prevalence of OSA and OSA with both subjectively measured sleepiness and objectively measured ability to stay awake (ie obstructive sleep apnea syndrome, OSAS) among professional truck drivers in Finland.Subjects and methodsAltogether 2066 professional truck drivers received a structured questionnaire. 175 drivers had a clinical examination and sleep laboratory studies, which included respiratory polygraphy (RP) and maintenance of wakefulness test (MWT). Three groups were formed: 75 subjects with suspected sleep apnea, 75 healthy controls and a random sample of 25 subjects.Results1095 drivers answered the questionnaire. RP was performed on 172 drivers and 167 drivers participated in MWT. The mean age was 40.7 years and the mean BMI was 27.7 kgm⁻². The prevalence of sleep apnea in professional truck drivers using various criteria were: AHI ≥5: 40.1%, AHI≥ 15: 16.2% and, AHI≥ 30: 7.2%. The prevalence depended on clinical history. Prevalence of AHI≥5 varied between 20 and 56.9% and prevalence of AHI≥15 was 4.3–25%. Altogether 4.8% of subjects with AHI ≥15 had abnormally short sleep latency in MWT (<19.4 min).ConclusionsModerate sleep apnea is common among professional truck drivers but significant inability to stay awake, defined as MWT <19.4 min, is found in about one of twenty professional drivers.     

Associations between sleep,daytime sleepiness and functional outcomes in adolescents with ADHD

Objective/backgroundAdolescents with attention-deficit/hyperactivity disorder (ADHD) experience greater difficulties in the domains of sleep, daytime sleepiness, and functioning compared to their peers. However, the relationship between these domains has not been fully elucidated. This study aimed to examine the relationship between sleep problems (including daytime sleepiness), ADHD severity, and functional outcomes (irritability, sluggish cognitive tempo, homework difficulties, and substance use) in a sample of adolescents with ADHD.Patients/methodsEighty-two adolescents (13–17 years) and their families participated in the study. Sleep was measured by both adolescent and parent-report. Adolescent irritability and sluggish cognitive tempo were reported by both adolescents and parents, while other variables were reported by a single reporter (homework difficulties – parent; ADHD severity – parent; substance use – adolescent). Analyses controlled for demographic factors and internalising and externalising comorbidities.ResultsA weak relationship was found between adolescent-reported sleep problems and daytime sleepiness, which became non-significant in adjusted analyses (β = −0.19, p = 0.115). In adjusted analyses, there was an association between adolescent-reported sleep problems and adolescent-reported irritability (β = −0.27, p = 0.023) as well as between adolescent-reported daytime sleepiness and parent-reported sluggish cognitive tempo (β = 0.28, p = 0.033). In adjusted analyses, parent-reported adolescent sleep problems were associated with ADHD severity (β = 0.54, p = <0.001), parent-reported sluggish cognitive tempo (β = 0.64, p = <0.001), both reporters of irritability (parent-report: β = 0.32, p = 0.004; adolescent-report: β = 0.29, p = 0.022), and homework problems (β = 0.37, p = 0.003). Parent-reported daytime sleepiness was associated with parent-reported sluggish cognitive tempo (β = 0.34, p = 0.024).ConclusionsThis study demonstrates the importance of a holistic assessment of adolescents with ADHD, not only focusing on symptomatology but also on sleep problems and functional outcomes. The importance of multi-informant assessment of sleep problems is also reinforced.     

Excessive daytime sleepiness and sleep benefit in Parkinson's disease: a community-based study.

The objective of this study was to investigate the frequency of excessive daytime sleepiness (EDS) and the beneficial effect of sleep on motor performance in an unselected community-based sample of patients with Parkinson's disease (PD). Furthermore, we wanted to identify possible risk factors to these phenomena. Detailed information on somnolence and sleep during daytime, as well as sleep benefit (SB) on awakening, was collected through a questionnaire among 245 patients with PD. Daytime somnolence was graded in groups of no somnolence, mild daytime sleepiness, and EDS. In addition, the occurrence of somnolence in the patients with PD was compared with the occurrence among control groups of patients with diabetes mellitus and of healthy elderly subjects. The correlations between EDS and SB and various motor- and non-motor symptoms of PD were evaluated. Among the patients with PD, 15.5% experienced EDS, significantly more than in the patients with diabetes mellitus (4%) and the healthy control subjects (1%). The frequency of mild daytime sleepiness was similar (10%) in patients with PD and control subjects. The patients with EDS had significantly higher staging of PD, were more disabled, and showed a higher frequency of cognitive decline compared with the patients without somnolence. They also had been using levodopa for a longer time and had more hallucinations. The occurrence of nocturnal sleeping problems and the use of sleeping pills was similar in the two groups, as was the mean age at examination, duration of PD, and presence of fluctuations and dyskinesias. SB was found in 42.2% of the patients with PD. These patients had been using levodopa for significantly longer and had significantly more fluctuations and dyskinesias compared with the patients without SB. Our results suggest that mild daytime sleepiness may be a result of normal aging, whereas more severe EDS can be explained by the neuropathologic changes of PD. The data from this community-based study confirms the previously reported high frequencies of SB.     

Excessive daytime sleepiness in myotonic dystrophy.

The aim of the present study was to assess whether or not there is any correlation between magnetic resonance imaging (MRI) abnormalities and excessive daytime sleepiness (EDS) in a consecutive series of patients with myotonic dystrophy (MD). The influences of nocturnal breathing abnormalities and sleep morphology on EDS were also evaluated. Ten MD patients were studied by means of an all-night polysomnographic recording, the multiple sleep latency test (MSLT) and MRI. Diagnosis of MD was established on the basis of the clinical and electrophysiological evidence of myotonia as well as of the characteristic genetic pattern. No patient had respiratory failure. Polysomnography and MSLT were also evaluated in ten healthy age-matched controls under the same environmental conditions. The mean MSLT value was significantly lower in patients than in controls. Five of the ten patients were found to have pathological EDS. The quantitative sleep variables and the nocturnal apnoeas in these five patients were not significantly different from those of the patients without EDS. As two patients did not undergo MRI because of claustrophobia, the MRI data were considered in eight patients. Corpus callosum (CC) atrophy was detected in four patients, whereas three patients showed hyperintense areas in the white matter. No correlation was found between EDS and MRI indexes of subcortical atrophy as well as volume of the hyperintense areas. By contrast, a correlation was found between the MSLT value and the reduction in the anterior area of the CC. Our data suggest that CC atrophy might occur in MD patients, and that the size of the CC anterior area might be associated with EDS.     

Automatic detection of cortical arousals in sleep and their contribution to daytime sleepiness

ObjectiveSignificant interscorer variability is found in manual scoring of arousals in polysomnographic recordings (PSGs). We propose a fully automatic method, the Multimodal Arousal Detector (MAD), for detecting arousals.MethodsA deep neural network was trained on 2,889 PSGs to detect cortical arousals and wakefulness in 1-second intervals. Furthermore, the relationship between MAD-predicted labels on PSGs and next day mean sleep latency (MSL) on a multiple sleep latency test (MSLT), a reflection of daytime sleepiness, was analyzed in 1447 MSLT instances in 873 subjects.ResultsIn a dataset of 1,026 PSGs, the MAD achieved an F1 score of 0.76 for arousal detection, while wakefulness was predicted with an accuracy of 0.95. In 60 PSGs scored by nine expert technicians, the MAD performed comparable to four and significantly outperformed five expert technicians for arousal detection. After controlling for known covariates, a doubling of the arousal index was associated with an average decrease in MSL of 40 seconds (p = 0.0075).ConclusionsThe MAD performed better or comparable to human expert scorers. The MAD-predicted arousals were shown to be significant predictors of MSL.SignificanceThis study validates a fully automatic method for scoring arousals in PSGs.     

Psychometric evaluation of daytime sleepiness and nocturnal sleep onset scales in a representative community sample.

BACKGROUND: The public health importance of daytime sleepiness as a risk factor for accidents, interpersonal problems, and decreased productivity has been recognized. However, epidemiologic research on this topic has been limited by the reliance on laboratory measures (i.e., the Multiple Sleep Latency Test-MSLT). Two scales, daytime sleepiness and nocturnal sleep onset, have been identified from the self-report Sleep-Wake Activity Inventory (SWAI) in a clinic sample and validated against the MSLT. This study evaluates the replicability of the two scales in a population sample and assesses potential thresholds in scale scores that distinguish normal from pathologic levels of daytime sleepiness and difficulty falling asleep. METHODS: The sample consisted of 2181 subjects 18-45 years old in the Detroit metropolitan area. All sleep characteristic information covered the 2 weeks prior to interview. Split-half sample factor analyses were conducted to assess replicability of the results. Distribution of scale scores and their relation to construct validity variables were used to evaluate possible thresholds. RESULTS: A two-factor model appeared to best account for the variation among the 12 items from the SWAI. The two factors accounted for 50% of the variance in both split-half sample analyses. The revised eight-item daytime sleepiness and two-item nocturnal sleep onset scales showed good and fair internal consistency respectively across both split-half samples. There appeared to be a "natural break" in daytime sleepiness scale scores that was associated with a substantial and consistent change in number of hours slept. No breaks appeared in nocturnal sleep onset scores. CONCLUSIONS: This study replicated the results of the clinic-based study and suggested a potentially useful diagnostic threshold for self-report excessive daytime sleepiness. Epidemiology of sleep depends on the ability to move from the laboratory to population surveys in reliable and valid ways. Development of self-report is a step in that direction.     

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

BackgroundMany patients with obstructive sleep apnea (OSA) participate in the work force. However, the impact of OSA and sleepiness on work performance is unclear.MethodsTo 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 ± 12years, mean body mass index (BMI) was 31 ± 7 kg/m² 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.ResultsIn 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).ConclusionWe 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.     

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.     

Correlates of daytime sleepiness in patients with asthma

BACKGROUND AND PURPOSE: Patients with asthma often complain of daytime sleepiness, which is usually attributed to a direct effect of asthma on nocturnal sleep quality. We investigated this and other potential explanations for daytime sleepiness among asthmatics. PATIENTS AND METHODS: One hundred fifteen adult asthmatics were assessed for perceived daytime sleepiness (one question item), subjective sleepiness (Epworth Sleepiness Scale score, ESS), obstructive sleep apnea risk (Sleep Apnea scale score within Sleep Disorders Questionnaire, SA-SDQ), asthma severity step, relevant comorbid conditions, and current asthma medications. RESULTS: Among all subjects, 55% perceived excessive daytime sleepiness and 47% had ESS>10. Most subjects reported snoring (n=99, or 86%) and many snored habitually (n=44, 38%). The ESS correlated with SA-SDQ (P<0.0001), male gender (P=0.01), and asthma severity step (P=0.04). In a multiple regression model, the ESS was independently associated with SA-SDQ (P=0.0003) and male gender (P=0.02), but not with asthma severity step (P=0.51). There were no correlations between ESS and age, body mass index (BMI), forced expiratory volume in one second as percent of predicted value (FEV(1)%), comorbidities, or medication used to treat asthma. CONCLUSIONS: Sleepiness is common in asthmatics and may reflect occult obstructive sleep apnea more often than effects of asthma itself, other comorbid conditions, or asthma medications.