Headache characteristics in obstructive sleep apnea syndrome and insomnia

OBJECTIVES: To determine headache characteristics in the obstructive sleep apnea syndrome (OSAS) and in insomnia. PATIENTS AND METHODS: Fifty-six OSAS patients and 50 insomnia patients were assessed in the same time period. Patients in both groups underwent an accurate interview to investigate headache occurrence and its characteristics. Results - Headache was reported by 49% of OSAS patients and 48% of insomnia patients. In OSAS patients headache had most frequently a tension-type pattern. Headache occurred on awakening in 74% of OSAS patients, more frequently than in insomnia patients (40%) (chi(2); P < 0.04). The occurrence of morning headache appears to be significantly correlated with nocturnal oxygen desaturation and OSAS severity. CONCLUSION: Headache is a common finding in both OSAS and insomnia patients. Because morning headache seems to be more specific for OSAS than insomnia, and in OSAS its occurrence seems to be associated with disease severity, we hypothesize the involvement of certain pathogenic mechanisms associated with OSAS.     

Marked episodic elevation of cerebrospinal fluid pressure during nocturnal sleep in patients with sleep apnea hypersomnia syndrome

The CSF pressure was measured continuously at the lumbar level during nocturnal sleep in 3 patients with sleep apnea hypersomnia syndrome. Nocturnal sleep was very unstable with frequent episodes of obstructive sleep apnea. When the patients were awake and relaxed in the supine position, their CSF pressure was stable and within the normal range. Episodic marked elevations of CSF pressure occurred frequently during sleep, and each elevation was preceded and accompanied by an episode of sleep apnea or hypopnea. Significant correlations were found between the duration of apneic episodes and increase of CSF pressure, and between decrease of SaO2 or TcPO2 and increase of CSF pressure. The duration of sleep apnea was longer, increase of CSF pressure was greater, and decreases of SaO2 and TcPO2 were more marked during REM sleep than during NREM sleep. It is suggested that the frequent marked episodic elevations of CSF pressure are caused by an increase in the intracranial vascular volume occurring mainly in response to transient hypercapnia and hypoxia, which are induced by pulmonary hypoventilation during the episodes of sleep apnea.     

Prevalence of ischemic heart disease among patients with sleep apnea syndrome

Abstract We investigated the prevalence of ischemic heart disease (IHD) in sleep apnea syndrome (SAS) and the presence of coronary risk factors involved in the onset of IHD in 386 subjects with suspected SAS due to heavy snoring. The prevalence of IHD among patients with untreated SAS was found to be 23.8%, and the percentage of patients having SAS complicated with IHD was high among those with moderate or severe SAS. Sleep apnea syndrome patients with IHD also showed high prevalences of hypertension and hyperlipidemia. It appears that sleep apnea aggravates the factors that cause coronary vascular disorders, and is involved in the onset of IHD.     

Long-term oxygen administration reduces plasma adrenomedullin levels in patients with obstructive sleep apnea syndrome

BACKGROUND AND PURPOSE: Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients compared to an age-matched control group. We further hypothesized that oxygen administration treatment may decrease OSAS-induced hypoxic stress and ADM levels. METHODS: We examined short-term and long-term oxygen administration effects on circulating ADM in 48 OSAS patients. RESULTS: The circulating levels of ADM in untreated OSAS patients were significantly greater than those in the controls. We did not observe a significant effect in 2 weeks of oxygen administration on the circulating ADM in the patients, but we observed a significant effect in long-term oxygen administration for more than 3 months on plasma ADM levels. Long-term oxygen therapy decreased both the magnitude of arterial oxygen desaturation and plasma ADM levels in patients but did not decrease blood pressure. CONCLUSIONS: These observations suggest that long-term oxygen therapy could reduce OSAS-induced nocturnal hypoxemia and plasma ADM levels in patients with OSAS.     

睡眠呼吸暂停综合征患者记忆改变的研究

目的 了解睡眠呼吸暂停综合征(SAS)患者记忆改变的特征及可能的相关因素。方法采用多导睡眠分析仪对45例SAS患者(病例组)进行整夜睡眠监测和韦氏记忆量表(WMS)检测,并与30名正常人(对照组)进行对照,对SAS患者记忆改变的危险因素进行多因素回归分析。结果(1)病例组的睡眠结构紊乱,与正常对照组比较,非快速眼动相睡眠1-2期比例高、3-4期比例低,REM睡眠少,觉醒多,睡眠潜伏期短等,差异有显著性和非常显著性(P<0.05和<0.01);(2)病例组的WMS总记忆商数低于正常对照组(分别为86.45±12.53和101.89±6.78),即刻记忆和短时记忆因子分也低于正常对照组,差异均有非常显著性(P<0.01和<0.05);(3)教育水平、睡眠潜伏期、慢波睡眠比例、快速眼动相睡眠比例、夜间觉醒次数和夜间最低血氧饱和度可能与SAS患者记忆改变有关。结论 SAS患者的记忆功能显著受损,可能与睡眠、呼吸紊乱有关。     

An association between oxygen desaturation and D-dimer in patients with obstructive sleep apnea syndrome

D-dimer, a degradation product of fibrin, is being increasingly used as a marker and prognostic factor in various thrombotic diseases. Previous reports have shown that obstructive sleep apnea is associated with platelet activation and hypercoagulability. The aim of the study was to assess the potential role of the plasma D-dimer test in patients with obstructive sleep apnea. We designed a prospective group comparison study in a tertiary-care, university-affiliated medical center. One hundred and three patients of mean age 57 years (range 50-76 years) with symptoms suggestive of obstructive sleep apnea were included. Polysomnography was performed in all cases, and blood was collected for plasma D-dimer measurement by MiniQuant turbidmetric assay. The demographic and polysomnograph data were compared between patients with normal and high (> 250 ng/ml) D-dimer levels.The group with higher D-dimer values had lower mean minimal oxygen saturation (72.1 +/- 16.4 vs. 81.7 +/- 11.6%, p = 0.008) and a longer mean period of oxygen saturation below 90% (84.1 +/- 86.2 vs. 38.5 +/- 70.8 minutes, p = 0.032). There was no correlation of respiratory disturbance index and sleep architecture with D-dimer values. We concluded that sleep apnea syndrome is associated with fibrinolytic activity. Oxygen desaturation seems to be one of the mediatory factors in the putative connection between obstructive sleep apnea and hypercoagulability state.     

Fatigue, sleep, and nocturnal complaints in patients with amyotrophic lateral sclerosis

Background and purpose: Fatigue is a common symptom in amyotrophic lateral sclerosis (ALS). Although sleep disturbances are a candidate factor that may interfere with fatigue in patients with ALS, the role of sleep‐related abnormalities in determining fatigue in ALS is unknown. Objective: To evaluate the frequency and determinants of fatigue in a group of 91 consecutive patients with ALS, with special attention to the relationship between fatigue and sleep problems. Methods: Measures included the Fatigue Severity Scale (FSS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), ALS Functional Rating Scale‐Revised (ALSFRS‐R), and Beck Depression Inventory (BDI). Results: The mean FSS score was 4.35 ± 1.1, and 48 patients with ALS (52.75%) reported clinical significant fatigue. FSS score correlated with ALSFRS‐R score, forced vital capacity, ESS, BDI, and global PSQI score. Patients with fatigue were significantly more disabled and more frequently reported difficulties staying asleep and nocturnal complaints, such as nocturia and disturbing muscle cramps. After multivariate analysis, patients’ disability and nocturnal complaints were significantly associated with fatigue. Conclusion: In this study, we demonstrated that fatigue, a troublesome and disabling symptom in ALS, is associated with physical impairment and night‐time complaints (such as nocturia and muscle cramps), suggesting that treating sleep problems might be useful in alleviating fatigue in these patients.     

Electrophysiological recording of nocturnal sleep and the multiple sleep latency test in obstructive sleep apnea syndrome

Polysomnographic studies were performed in 6 patients with obstructive sleep apnoea syndrome (OSA). The sleep study consisted of: electroencephalography, electromyography, electrooculography, electrocardiography, pulse oximetry and observation of respiration. During day multiple sleep latency tests were performed. In all patients fragmentation of sleep with prevalent stages 1. and 2. of NREM and occasionally deep sleep and REM phase were observed. Concomitantly with the appearance of electrophysiologic sleep stages the muscle tone decreased and episodes of obstructive apnoea occurred. The periods of sleep and apnoea alternated with wakefulness and breathing. In MSLF the mean latency was 3 +/- 2 min. In OSA syndrome episodes of obstructive sleep apnoea cause sleep fragmentation and prevalence of light sleep stages. Excessive daytime somnolence observed in this syndrome is caused by sleep disturbances. MSLT demonstrated pathologic hypersomnolence in OSA syndrome.     

Driving impairment in patients with obstructive sleep apnea syndrome

Drivers with obstructive sleep apnea syndrome (OSAS) have an increased risk of motor vehicle crashes. Unfortunately, neither clinical nor polysomnographic features allow clinicians to reliably identify high-risk drivers. One potential means of identifying these drivers is with the use of driving simulators. Several investigators have shown that OSAS patients perform worse than healthy control drivers and results from our studies have demonstrated declines in driving performance during EEG-defined "microsleeps." The use of simulators, and in-vehicle detection and alerting devices may mitigate some of the suffering caused by these crashes.     

Diagnostic use of daytime polysomnography versus nocturnal polysomnography in sleep apnea syndrome

The usefulness of daytime polysomnography (DPSG) in the diagnosis of sleep apnea syndrome (SAS) is examined. Diagnostic use was investigated by conducting DPSG of two different time periods (Group M, 11.00–14.00 h, and Group A, 15.00–18.00 h). The subjects were 30 patients (28 men and two women; mean age, 54.0 years). Nocturnal polysomnography (NPSG) and DPSG were investigated by comparing indices of sleep, apnea index (AI) and arterial oxygen saturation (SaO₂). There was no significant difference among these indices but there was a significant positive correlation between NPSG and DPSG in all variables related to sleep apnea. Moreover, there was no significant difference in the frequency of each type of apnea between NPSG and DPSG in either group. These findings suggest that DPSG is useful not only in diagnosing SAS but in evaluating its severity.     

High sleep-related breathing disorders among HIV-infected patients with sleep complaints

BackgroundSleep-related breathing disorders (SRBD) not only adversely impact cardiovascular and pulmonary functions but also reduce the quality of life. This study attempted to investigate the severity and related factors of SRBD among human immunodeficiency virus (HIV)-infected people with sleep complaints.MethodsA cross-sectional study was conducted among HIV-infected people with Pittsburgh Sleep Quality Index (PSQI) values above 5 points. SRBDs were defined as Apnea-Hypopnea Index (AHI) over 5 events/hour by full channel home-based polysomnography (PSG). An AHI greater than 30 was categorized as moderate to severe apnea. All of the participants were asked to rate the severity of their snoring, complete a snore outcomes survey (SOS) and complete the PSQI. Multiple logistic regression analysis was conducted to examine the associated factors of severity of SRBD among HIV-infected people.ResultsOf 54 male HIV-positive patients with sleep complaints, 34 subjects (62.96%) were diagnosed with SRBDs, and 29.63% were categorized as having moderate to severe SRBD. SOS score was significantly associated with HIV patients with moderate to severe SRBD (adjusted odds ratio = 0.93, 95% CI: 0.87–1.00, p = 0.045).ConclusionsSRBDs is highly prevalent in male HIV-infected people with sleep complaints. Intensive snoring was one of the indicators associated with the occurrence of moderate to severe SRBDs among HIV-infected people. Healthcare professionals should include snoring screening in the regular course of clinical HIV care.     

Epworth Sleepiness Scale and sleep studies in patients with obstructive sleep apnea syndrome

Excessive daytime sleepiness (EDS) is the major symptom of patients with obstructive sleep apnea syndrome (OSAS). In this study, we examined the relationship between subjective EDS scored with the Epworth Sleepiness Scale (ESS), objective EDS measured with the multiple sleep latency test (MSLT) and sleep variables evaluated with polysomnography for patients with OSAS. Subjects were 10 patients (51.7+/-19.0 years old). The average ESS and MSLT scores were 10.6+/-5.6 and 7.7+/-5.6, respectively. There was no significant relationship between ESS and MSLT. The Multiple Sleep Latency Test had a significant negative relationship with the number of awakenings and the apnea/hypopnea index. No relationship was found between nocturnal hypoxia and either ESS or MSLT. Our findings suggest that objective EDS in OSAS is related with fragmentation of sleep, and that several patients are not aware of their EDS.     

Severity of nocturnal hypoxia and daytime hypercapnia predicts CPAP failure in patients with COPD and obstructive sleep apnea overlap syndrome

BackgroundObstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are independent risk factors for cardiovascular diseases. In patients with OSA and concurrent COPD, continuous positive airway pressure (CPAP) therapy improves survival. Nevertheless, a significant proportion of such patients do not tolerate CPAP. The aim of the present study was to analyze early predictors of CPAP failure in patients with OSA and concurrent COPD, and to evaluate the effects of bilevel positive airway pressure (BiPAP) in this high-risk group of patients.MethodsA post hoc analysis from the database of 2100 patients diagnosed with OSA between 2012 and 2014 identified 84 subjects as having concomitant COPD and meeting inclusion criteria. Demographic data, pulmonary function tests, OSA parameters, blood gases, response to CPAP and BiPAP titration, and two months of therapy were collected. A multivariate model was generated to find determinants of CPAP failure.ResultsPrimary CPAP failure was found in 23% of patients who were more obese (p = 0.018), had worse lung function, lower PO₂ (p = 0.023) and higher PCO₂ while awake (p < 0.001), and more sleep time with an SpO₂ < 90% (CT90%) (p < 0.001) compared to those who responded to CPAP. In multivariate analysis, PCO₂ while awake [odds ratio (OR) 29.5, confidence interval (CI) 2.22–391, p = 0.010] and CT90% (OR 1.06, CI 1.01–1.11, p = 0.017) independently predicted CPAP failure after adjustments for covariates. The BiPAP therapy was well tolerated and effectively alleviated hypercapnia in all patients with primary CPAP failure.ConclusionsDaytime hypercapnia and nocturnal hypoxia are independent predictors of early CPAP failure in patients with the OSA–COPD overlap syndrome.     

睡眠呼吸暂停综合征合并卒中的相关因素分析

目的::分析睡眠呼吸暂停综合征(sleep apnea syndrome,SAS)合并卒中患者的血清炎性标志物和血管内皮功能指标的表达水平,并探讨与SAS发生卒中相关的危险因素。方法::研究对象包括35例单纯SAS患者以及38例SAS合并卒中的患者。检测并比较2组患者血清内皮型一氧化氮合酶、丙二醛和肿瘤坏死因子α的表达水平。分析与SAS患者发生卒中相关的危险因素。结果::SAS合并卒中患者的血清内皮型一氧化氮合酶、丙二醛和肿瘤坏死因子α水平均显著高于单纯SAS患者(P值均=0.000)。单因素分析结果显示,性别(P=0.012)、年龄(P=0.009)、SAS病程(P=0.000)和高血压病史(P=0.000)均与SAS合并卒中相关;多因素分析结果显示,SAS病程[风险比为9.12(95%可信区间:2.15~13.88),P=0.000]和高血压病史[风险比为5.05(95%可信区间:2.74~10.52),P=0.000]是SAS合并卒中的独立影响因素。结论::SAS合并卒中患者的血清炎性标志物和血管内皮功能指标的表达水平显著升高,提示内皮功能损害进一步加重。SAS病程1年和有高血压病史的SAS患者更易发生卒中。     

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.     

Mechanism of gastroesophageal reflux in patients with obstructive sleep apnea syndrome

Background It has been reported that the prevalence of gastroesophageal reflux (GER) disease is high in patients with obstructive sleep apnea (OSA). End‐inspiratory intra‐esophageal pressure decreases progressively during OSA, which has been thought to facilitate GER in OSA patients. The aim of our study was to clarify the mechanisms of GER during sleep (sleep‐GER) in OSA patients. Methods Eight OSA patients with reflux esophagitis (RE), nine OSA patients without RE, and eight healthy controls were studied. Polysomnography with concurrent esophageal manometry and pH recording were performed. Key Results Significantly more sleep‐GER occurred in OSA patients with RE than without RE or in controls (P < 0.05). The severity of OSA did not differ between OSA patients with RE and without RE. Sleep‐GER was mainly caused by transient lower esophageal sphincter relaxation (TLESR), but not by negative intra‐esophageal pressure during OSA. During OSA gastroesophageal junction pressure progressively increased synchronous to intra‐esophageal pressure decrease. OSA patients had significantly more TLESR events during sleep related to preceding arousals and shallow sleep, but the number of TLESR events was not related to RE. Conclusions & Inferences In OSA patients, sleep‐GER was mainly caused by TLESR, but not by negative intra‐esophageal pressure due to OSA.     

P300 abnormalities in patients with severe sleep apnea syndrome.

We investigated the mechanism of abnormal P300 findings in the patients with severe sleep apnea syndrome (SAS). Compared with controls, SAS patients showed significantly longer latency of P300. Not the mean sleep latency in multiple sleep latency test but the percentage of total periods in which percentage desaturation time fell below 90% to total sleep time correlated with P300 latency in the patients. During nasal CPAP treatment, P300 latency was significantly shortened in the patients under 45 years, while the elderly patients did not show statistical change. We speculated that P300 latencies might be prolonged due to nocturnal hypoxia with SAS and the abnormality might be irreversible, especially in elderly patients.     

Oxidative stress biomarkers in patients with untreated obstructive sleep apnea syndrome

BackgroundThe pathogenic role of oxidative stress in obstructive sleep apnea syndrome (OSAS) is still a matter of debate, with different studies obtaining contrasting results.MethodsThe aim of the present study was to evaluate three well-known markers of oxidative stress (advanced oxidation protein products [AOPP], ferric reducing antioxidant power [FRAP], and total glutathione [GSH]) in a cohort of 41 untreated patients with a new diagnosis of OSAS.ResultsWe observed that OSAS patients showed increased protein oxidative damage and impaired antioxidant defenses. Patients with more severe OSAS had a lower total antioxidant capability. Preliminary data on a subgroup of patients (n = 7) treated with CPAP show a significant increment of the FRAP values (P < 0.005).ConclusionsOur findings indicate that such oxidative stress markers may be useful to detect and monitor redox imbalance in OSAS. Moreover, FRAP might be a new useful biomarker to monitor in vivo the oxidative response to CPAP therapy.