成年阻塞性睡眠呼吸暂停患者多导睡眠图及临床特征分析性差异

目的:分析成年男性阻塞性睡眠呼吸暂停(OSA)患者多导睡眠图及临床特征,明确年龄对OSA严重程度的影响。方法:回顾性研究包括836名成年男性OSA患者,按年龄分为三组:青年组312人(平均年龄37.07岁),中年组359人(平均年龄52.14岁),老年组165人(平均年龄69.43岁)。分析其多导睡眠图和临床特征,并进行相关性分析。结果:中年组和老年组呼吸暂停低通气指数(AHI)、阻塞性呼吸暂停指数(OAI)、AHI-NREM和AHI-REM均无显著统计学意义(P>0.05),但均低于青年组(P<0.01);中年组和老年组的最低血氧饱和度(SaO2)均高于青年组;中枢性呼吸暂停指数(CAI)随年龄增长而升高(P<0.05)。在睡眠结构方面,老年组总睡眠时间、非快速眼动(NREM)睡眠时间和快速眼动期(REM)睡眠时间均缩短,睡眠效率亦低于青年组(P<0.01),但睡眠潜伏期和入睡后觉醒时间(WASO)明显延长(P<0.01)。年龄与以下各项均呈现显著的相关性:AHI(P<0.01),OAI(P<0.01),CAI(P<0.01),最低SaO2(P<0.01)。多重回归分析表明年龄作为独立变量分别与AHI,OAI,CAI具有相关性。结论:在成年OSA患者中,年龄与OSA严重程度具有显著的相关性,表现为OSA随年龄增长而降低。本研究为研究年龄与OSA严重程度的关系提供了新的证据。     

Does cognitive dysfunction conform to a distinctive pattern in obstructive sleep apnea syndrome?

Obstructive sleep apnea (OSA) is a recognized cause of cognitive dysfunction. By using a cross-sectional comparative study, we aimed to verify whether neuropsychological performance of untreated OSA patients conforms to a distinctive pattern. Forty-nine newly diagnosed, untreated OSA patients, 27 with multi-infarctual dementia (MID), 31 with mild to moderate dementia of Alzheimer type (DAT) and 63 with severe chronic obstructive pulmonary disease (COPD), all free from major comorbid dementing conditions were chosen for the study. The groups were matched for age and education. We found a bimodal distribution of cognitive performance in OSA group, which was therefore divided into two clusters having better (OSAb, n = 35) and worse (OSAw, n = 14) performance on a battery of 10 cognitive indexes. Cognitive performances of OSAb, OSAw, MID, DAT and COPD were compared by discriminant analysis. OSAb performed better than OSAw in all but one test. Deductive thinking and verbal attainment were more severely impaired in OSAw than in COPD patients. Constructive ability, deductive thinking and both verbal attainment and immediate memory were comparably impaired in OSAw and DAT. The mean neuropsychological scores of OSAw and MID were comparable, but 71% of OSAw patients had a distinctive cognitive profile, i.e. a group specific pattern of cognitive dysfunction, according to discriminant analysis. One of four newly diagnosed OSA patients had a severe and distinctive neuropsychological dysfunction mainly involving inductive and deductive thinking, and constructive ability. Some analogy with cognitive pattern of MID suggests that a mainly subcortical damage underlies this dysfunction.     

Altered brain activation during response inhibition in obstructive sleep apnea

This study examined response inhibition during a Go–NoGo task in individuals with obstructive sleep apnea (OSA). Fourteen OSA patients and 14 controls were studied with functional magnetic resonance imaging. Compared to controls, the OSA group showed more false positives (error of commission) during the NoGo trials with decreased brain activation in the left postcentral gyrus, cingulate gyrus and inferior parietal lobe, as well as right insula and putamen. This is consistent with previous findings of impaired performance and decreased brain activation in OSA patients during a working memory task, suggesting that compromised brain function in response to cognitive challenges may underlie some of the cognitive deficits seen in patients with OSA.     

阻塞性睡眠呼吸暂停低通气综合征合并舒张性心功能不全患者脑钠肽水平的改变

目的探讨阻塞性睡眠呼吸暂停低通气综合征（OSAHS）对舒张性心功能不全患者脑钠肽（BNP）水平的影响。方法将入选的舒张性心功能不全患者进行多导睡眠监测,根据监测结果分为无OSAHS组、轻度OSAHS组和中重度OSAHS组。分别对三组的睡眠呼吸、心脏形态及功能、血BNP值进行比较。结果三组病人的超声心动图检测的各项收缩和舒张功能指标并无明显差别;但中重度睡眠呼吸障碍组的BNP比其余两组增高,差异具有统计学意义。结论睡眠呼吸障碍可能使合并舒张性心功能不全的患者的心功能进一步恶化,并导致患者血BNP的变化。     

Genomic approaches to understanding obstructive sleep apnea

Obstructive sleep apnea (OSA) is an increasingly recognized, common chronic disease in the developed nations and is a complex disease that has high social and economic costs. OSA and its associated 'intermediate' phenotypes-craniofacial structure, body fat distribution and metabolism, and neurological control of the upper airway muscles and of sleep and circadian rhythm-are under a substantial degree of genetic control. Investigating the genetic aetiology of OSA offers a means of better understanding its pathogenesis, with the goal of improving preventive strategies, diagnostic tools and therapies. Molecular studies of OSA itself are in their infancy, but considerable effort and expense has already been expended in attempts to detect genetic loci contributing to OSA-associated intermediate phenotypes, such as obesity. However, many of the fundamental questions relating to the genetic epidemiology of OSA and associated factors remain unanswered. This chapter reviews the current state of knowledge of the genetics of OSA, with a focus on genomic approaches to understanding sleep disorders.     

Combined bipolar radiofrequency surgery of the tongue base and uvulopalatopharyngoplasty for obstructive sleep apnea

Introduction

The aim of the study was to investigate the effectiveness of combined bipolar radiofrequency surgery of the tongue base (RFBT) and uvulopalatopharyngoplasty (UPPP) in a single session for obstructive sleep apnea and whether this combination is safe and well tolerated.

Material and methods

Seventy-nine patients with obstructive sleep apnea and both palatal and retroglossal obstruction underwent UPPP with bipolar RFBT. The control group consisted of 35 patients treated by UPPP alone.

Results

The apnea-hypopnea index significantly decreased from 28.7 to 14.1. The oxygen desaturation index decreased from 15.1 to 10.3. Mean oxygen saturation was unchanged. Subjectively, the Epworth Sleepiness Scale was significantly improved from 10.6 to 7.3, and the snoring level decreased from 8.4 to 6.0. The overall treatment success rate increased from 41.9% for UPPP alone to 51.7% for UPPP + RFBT. No serious adverse events occurred. Two patients had postoperative bleeding from the tonsillar bed after UPPP. Four patients had ulceration of the base of the tongue after RFBT with spontaneous cure. One patient had a taste change in half of the tongue that resolved within two months.

Conclusions

Combined bipolar RFBT and UPPP in a single session is well tolerated and safe surgery in the treatment of obstructive sleep apnea. It is effective in reducing respiratory parameters and subjective symptoms of obstructive sleep apnea. Further advantages are a single session, simple feasibility, bipolar technique and short time of the procedure.     

Pulse transit time as a surrogate measure of changes in systolic arterial pressure in children during sleep

Pulse transit time has been proposed as a surrogate measure of systolic arterial pressure, as it is dependent upon arterial stiffness. Past research has shown that pulse transit time has a significant inverse relationship to systolic arterial pressure in adults; however, studies in children are limited. This study aimed to explore the relationship between systolic arterial pressure and pulse transit time in children during sleep. Twenty‐five children (13.1 ± 1.6 years, 48% male) underwent overnight polysomnography (PSG) with a simultaneous recording of continuous systolic arterial pressure and photoplethysmography. Pulse transit time was calculated as the time delay between the R‐wave peak of the electrocardiogram (ECG) to the 50% point of the upstroke of the corresponding photoplethysmography waveform; 500 beats of simultaneous systolic arterial pressure and pulse transit time were analysed in each sleep stage for each child. Pulse transit time was normalized to each subject's mean wake pulse transit time. The ability of pulse transit time to predict systolic arterial pressure change was determined by linear mixed‐effects modelling. Significant negative correlations between pulse transit time and systolic arterial pressure were found for individual children for each sleep stage [mean correlations for cohort: non‐rapid eye movement (NREM) sleep 1 and 2 r = ?0.57, slow wave sleep (SWS) r = ?0.76, REM r = ?0.65, P < 0.01 for all]. Linear mixed‐model analysis demonstrated that changes in pulse transit time were a significant predictor of changes in systolic arterial pressure for each sleep stage (P < 0.001). The model of pulse transit time‐predicted systolic arterial pressure closely tracked actual systolic arterial pressure changes over time. This study demonstrated that pulse transit time was accurate in tracking systolic arterial pressure changes over time. Thus, the use of pulse transit time as a surrogate measure of changes in systolic arterial pressure in children is a valid, non‐invasive and inexpensive method with many potential applications.     

Correlations among Epworth Sleepiness Scale scores, multiple sleep latency tests and psychological symptoms

The aim of this study was to identify factors other than objective sleep tendency associated with scores on the Epworth Sleepiness Scale (ESS). There were 225 subjects, of whom 40% had obstructive sleep apnoea (OSA), 16% had simple snoring, and 4.9% had snoring with sleep disruption (upper airway resistance syndrome); 9.3% had narcolepsy and 7.5% had hypersomnolence without REM sleep abnormalities; 12% had chronic fatigue syndrome; 7.5% had periodic limb movement disorder and 3% had diurnal rhythm disorders. ESS, the results of overnight polysomnography and multiple sleep latency test (MSLT) and SCL-90 as a measure of psychological symptoms were recorded. The ESS score and the mean sleep latency (MSL) were correlated (Spearman ö =−0.30, P <0.0001). The MSL was correlated with total sleep time (TST) and with sleep efficiency but not with apnoea/hypopnoea index. There was no association between the MSL and any aspect of SCL-90 scores, except a borderline significant association with the somatisation subscale. The ESS was correlated with TST but not with sleep efficiency or apnoea/hypopnoea index. The ESS was correlated with all subscales of the SCL-90 except psychoticism. An ESS≥10 had poor sensitivity and specificity as a predictor of MSL <10 min or MSL <5 min. We conclude that the MSLT and the ESS are not interchangeable. The ESS was influenced by psychological factors by which the MSL was not affected. The ESS cannot be used to demonstrate or exclude sleepiness as it is measured by MSLT.     

Association between polysomnographic sleep measures and health-related quality of life in obstructive sleep apnea

Many facets of health-related quality of life are diminished in obstructive sleep apnea (OSA) as they are in other chronic medical conditions. We speculated that impairment in health-related quality of life (HRQoL) might result from the fatigue and daytime somnolence associated with the sleep disorder, as an indirect result from the fragmentation of night-time sleep in OSA. Our hypothesis was that sleep fragmentation measures would correlate with poorer HRQoL measured by medical outcomes study (MOS) subscales. Thirty-nine patients with polysomnographically-confirmed OSA participated in this study. Pearson's correlations were performed with the following sleep architecture variables: wake after sleep onset, the total number of brief arousals, the number of respiratory-related arousals, the rate of respiratory events per hour, and total sleep time. To our surprise, although the total number of arousals was associated with health distress (r=-0.481, P < 0.005), it did not correlate with any other subscales indicating poorer physical and mental health. The relatively insensitive measure of total sleep time (TST) correlated in the expected direction with most subscales. However, after controlling for age and gender, respiratory disturbance indices (RDI) and/or number of arousals emerged as significantly associated with mobility, cognitive functioning, social functioning, energy and fatigue, and health distress. Our findings suggest that polysomnographic indicators of sleep quality and sleep continuity may be an important influence determining many aspects of HRQoL in OSA patients.     

Dry mouth upon awakening in obstructive sleep apnea

The aim was to assess the significance of dry mouth upon awakening as a symptom of obstructive sleep apnea (OSA). The participants were 668 consecutive adults referred for polysomnographic evaluation (PSG) because of snoring and suspected OSA, and 582 adults who were attending a general health check‐up. Data were obtained from self‐administered questionnaires and PSG evaluation. The participants were asked to answer the following question: ‘During the last month, did you experience waking up in the morning with a dry mouth?’. The response scale consisted of five categories: ‘never’, ‘rarely’, ‘sometimes’, often’, or ‘almost always’. We classified patients as having dry mouth upon awakening complaint only if they reported experiencing the symptom ‘almost always’. The prevalence of dry mouth upon awakening was twofold higher in patients with OSA (31.4%) than in primary snorers (16.4%, P < 0.001), and increased linearly from 22.4%, to 34.5%, and 40.7% in mild, moderate, and severe OSA respectively (P < 0.001). The prevalence of dry mouth upon awakening in the control group was 3.2%. Logistic regression results indicated that this symptom significantly differentiated OSA patients from primary snorers after adjusting for age, BMI, gender, hypertension, and other classical OSA symptoms (OR 2.33, 95% CI 1.34–4.07). Dry mouth upon awakening appears as a significant symptom of OSA. We suggest that increased sleep time spent with an open mouth is a likely explanation for these findings.     

Cortical processing of respiratory afferent stimuli during sleep in children with the obstructive sleep apnea syndrome

STUDY OBJECTIVES: Children with the obstructive sleep apnea syndrome (OSAS) have blunted upper airway responses to negative pressure, but the underlying cause remains unknown. Cortical processing of respiratory afferent information can be tested by measuring respiratory-related evoked potentials (RREPs). We hypothesized that children with OSAS have blunted RREP responses compared to normal children during sleep. DESIGN: During sleep, RREPs were obtained from EEG electrodes Fz, Cz, Pz during stage 2 sleep, slow wave sleep (SWS), and REM sleep. RREPs were produced with multiple short occlusions of the upper airway. SETTING: Sleep laboratory. PARTICIPANTS: 9 children with OSAS and 12 normal controls. MEASUREMENTS AND RESULTS: Children with OSAS had significantly decreased evoked K-complex production in stage 2 sleep and slow wave sleep and significantly reduced RREP N350 and P900 components in slow wave sleep. There were no significant differences in any of the measured RREP components in stage 2 sleep, and the only REM difference was decreased P2 amplitude. CONCLUSIONS: Results indicate that in children with OSAS, cortical processing of respiratory-related information measured with RREPs persists throughout sleep; however, RREPs during SWS are blunted compared to those seen in control children. Possible causes for this difference include a congenital deficit in neural processing reflective of a predisposition to develop OSAS, or changes in the upper airway rendering the airway less capable of transducing pressure changes following occlusion. Further research is required to evaluate RREPs after effective surgical treatment of OSAS in children, in order to distinguish between these alternatives.     

Hypoadiponectinemia is Related to Sympathetic Activation and Severity of Obstructive Sleep Apnea

Study Objectives:

Hypoadiponectinemia is associated with cardiovascular morbidity and diabetes mellitus. We hypothesize that adiponectin may be downregulated in sleep apnea through various mechanisms, contributing to cardiometabolic risks. This study investigated the relationship between serum adiponectin and sleep disordered breathing and its potential determinants.

Design:

Cross-sectional study.

Subjects and setting:

Adult men without prevailing medical comorbidity from the sleep clinic in a teaching hospital.

Measurements & Results:

One hundred thirty-four men underwent polysomnography, with mean age of 43.9 (9.8) years, and median apnea-hypopnea index (AHI) of 17.1 (5.7, 46.6). Overnight urine samples for catecholamines and blood samples for analyses of insulin, glucose and adiponectin levels from fasting subjects were taken. Insulin resistance was estimated by homeostasis model assessment (HOMA-IR). Magnetic resonance imaging was performed to quantify the amount of abdominal visceral fat. Serum adiponectin level, adjusted for age, body mass index, and visceral fat volume, was significantly lower in subjects with severe obstructive sleep apnea (AHI ≥ 30) compared with those with an AHI of less than 30: 4.0 (3.1, 5.4) versus 5.4 (3.6, 7.9) μg/mL, P = 0.039. After we adjusted for adiposity, adiponectin levels remained negatively correlated with AHI (P = 0.037), arousal index (P = 0.022), HOMA-IR/fasting insulin (P < 0.001), and urinary norepinephrine and normetanephrine (P < 0.008). In a multiple stepwise regression model, the independent determinants of adiponectin after adjustment for adiposity were HOMA-IR (P < 0.001) and urinary norepinephrine and normetanephrine (P = 0.037).

Conclusions:

Adiponectin was suppressed in subjects with severe obstructive sleep apnea, independent of obesity. Adiponectin levels were determined by insulin resistance and sympathetic activation, factors that may be totally or partially attributed to sleep disordered breathing.

Citation:

Lam JCM; Xu A; Tam S; Khong PL; Yao TJ; Lam DCL; Lai AYK; Lam B; Lam KSL; Ip MSM. Hypoadiponectinemia is related to sympathetic activation and severity of obstructive sleep apnea. SLEEP 2008;31(12):1721–1727.     

Does nasal decongestion improve obstructive sleep apnea?

Whether nasal congestion promotes obstructive sleep apnea is controversial. Therefore, we performed a randomized placebo-controlled cross-over trial on the effects of topical nasal decongestion in patients with obstructive sleep apnea syndrome (OSA) and nasal congestion. Twelve OSA patients with chronic nasal congestion (mean +/- SD age 49.1 +/- 11.1 years, apnea/hypopnea index 32.6 +/- 24.5/h) were treated with nasal xylometazoline or placebo for 1 week each. At the end of treatment periods, polysomnography including monitoring of nasal conductance by an unobtrusive technique, vigilance by the OSLER test, and symptom scores were assessed. Data from xylometazoline and placebo treatments were compared. Mean nocturnal nasal conductance on xylometazoline was significantly higher than on placebo (8.6 +/- 5.3 versus 6.3 +/- 5.8 mL s(-1)Pa(-1), P < 0.05) but the apnea/hypopnea index was similar (29.3 +/- 32.5/h versus 33.2 +/- 32.8/h, P = NS). However, 30-210 min after application of xylometazoline, at the time of the maximal pharmacologic effect, the apnea/hypopnea index was slightly reduced (27.3 +/- 30.5/h versus 33.2 +/- 33.9/h, P < 0.05). Xylometazoline did not alter sleep quality, sleep resistance time (33.6 +/- 8.8 versus 33.4 +/- 10.1 min, P = NS) and subjective sleepiness (Epworth score 10.5 +/- 3.8 versus 11.8 +/- 4.4, P = NS). The reduced apnea/hypopnea index during maximal nasal decongestion by xylometazoline suggests a pathophysiologic link but the efficacy of nasal decongestion was not sufficient to provide a clinically substantial improvement of OSA.