Breathing during sleep in patients with interstitial lung disease

Patients with interstitial lung disease (ILD) have a rapid shallow breathing pattern while awake that is thought to be due to activation of lung reflexes. We wondered whether sleep would result in changes in respiratory control and thus cause hypoxemia and poor sleep quality. Eleven patients with ILD (5 men and 6 women) and 11 age- and sex-matched control subjects were studied during sleep. Sleep quality was worse in patients with ILD, with more time in Stage 1 (33.7% of total sleep time (TST) versus 13.5%) and less time in REM sleep (11.8 versus 19.9% TST) than found in control subjects, and more fragmentation of sleep (13.7 +/- 3.1 arousals/h and 24.3 +/- 6.0 sleep stage changes/h versus 6.9 +/- 1.0 and 12.7 +/- 1.4, respectively). Patients with ILD with awake SaO2 less than 90% had greater abnormalities in sleep structure than did those with SaO2 greater than 90%. The incidence of apneas and hypopnea periods in patients with ILD was low (apnea plus hypoventilation index of 1.3 +/- 0.45 versus 2.9 +/- 0.82 in control subjects, p = NS). Oxygen saturation dropped during REM sleep in patients, especially in those with more severe awake hypoxemia. Expiratory time (Te), inspiratory time (Ti), and their sum (Ttot) were shorter in the patients, whereas Ti/Ttot was the same as in control subjects. No systematic changes during sleep were seen in these variables. The variability of inspiratory volume index, Ti, Te, and Ti/Ttot was similar to that in control subjects, and was lowest during NREM sleep. The incidence of snoring was comparable in patients and control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

阻塞性睡眠呼吸暂停与间质性肺疾病严重程度的临床分析

目的 分析阻塞性睡眠呼吸暂停(OSA)合并间质性肺疾病(ILD)患者的临床资料,探讨OSA与ILD患者疾病严重程度的关系.方法 回顾性分析2010年2月至2019年12月于我院诊治的51例ILD合并OSA患者的临床资料,包括动脉血气分析、B型脑钠肽,以及睡眠呼吸监测、肺功能检查、心脏彩色多普勒超声检查等数据,采用War...     

Depression is a common and chronic comorbidity in patients with interstitial lung disease

Background and objective: Little is known about depression in interstitial lung disease (ILD). The aim of this study was to determine the prevalence of depression, characterize the association of depression with clinical variables and describe the natural history of depression in patients with ILD. Methods: In this prospective cohort study, clinical variables were recorded at baseline and 6 months. Depression was measured with the Centre for Epidemiologic Studies Depression scale. Depression prevalence was determined using the established threshold of >15 points. Multivariate linear regression was used to determine the baseline features that independently correlated with baseline depression score and that predicted depression severity at follow‐up. Results: Fifty‐two subjects were enrolled, and 45 returned for follow‐up (three deaths, one lung transplant). Prevalence of depression was 21% at baseline. Independent predictors of depressive symptoms at baseline included dyspnoea severity, pain severity, sleep quality and forced vital capacity (R² 0.67). The odds of clinically meaningful depression at follow‐up were 34‐fold higher for subjects who had clinically meaningful depression at baseline compared with those who were not (95% confidence interval 3.5–422, P < 0.0005). Baseline depression score was the strongest predictor of depression score at follow‐up (r 0.59, P < 0.00005). Conclusions: Depressive symptoms in ILD are common, persistent, and strongly and independently correlated with dyspnoea, pain, sleep quality and forced vital capacity. Clinically meaningful depression at baseline is the most important predictor of depressive symptoms at follow‐up. Patients with ILD should routinely be screened for depression.     

Obstructive sleep apnea and cardiovascular disease

Obstructive sleep apnea (OSA) is a common disorder associated with an increased risk of cardiovascular disease and stroke. As it is strongly associated with known cardiovascular risk factors, including obesity, insulin resistance, and dyslipidemia, OSA is an independent risk factor for hypertension and has also been implicated in the pathogenesis of congestive cardiac failure, pulmonary hypertension, arrhythmias, and atherosclerosis. Obesity is strongly linked to an increased risk of OSA, and weight loss can reduce the severity of OSA. The current standard treatment for OSA-nasal continuous positive airway pressure (CPAP)-eliminates apnea and the ensuing acute hemodynamic changes during sleep. Long-term CPAP treatment studies have shown a reduction in nocturnal cardiac ischemic episodes and improvements in daytime blood pressure levels and left ventricular function. Despite the availability of effective therapy, OSA remains an underdiagnosed and undertreated condition. A lack of physician awareness is one of the primary reasons for this deficit in diagnosis and treatment.     

阻塞性睡眠呼吸暂停与心血管疾病

本文分析关于阻塞性睡眠呼吸暂停与心血管疾病之间的关系、发生发展机制的最新进展,阐述对阻塞性睡眠呼吸暂停合并心血管疾病的患者行经鼻气道持续正压通气治疗能给患者心血管疾病的治疗、预后、康复和生活质量带来益处.本篇综述的目的 在于引起医务工作者对阻塞性呼吸暂停与心血管疾病的关系的重视,从而服务于临床.     

Obstructive sleep apnea and cardiovascular disease

Obstructive sleep apnea (OSA) is a sleep-disordered breathing condition, which is increasingly being recognized as having wide-ranging pathophysiological effects on multiple organ systems. Although multiple factors affect the incidence and severity of OSA, male sex and obesity seem to play an influential role. The apnea-ventilation cycle, characterized by abnormalities in gas exchange, exaggerated respiratory effort and frequent arousals, has been shown to have deleterious effects on circulatory hemodynamics, the autonomic milieu, hormonal balance, inflammatory and coagulation cascades, endothelial function, and the redox state, with potential cardiovascular significance. Consequently, OSA is being increasingly implicated in a multitude of cardiovascular diseases (CVD) such as hypertension, congestive heart failure, atrial fibrillation, stroke, coronary artery disease, pulmonary hypertension, and metabolic syndrome. The strength of association for individual CVD is varied, and outcomes of clinical studies are conflicting. In addition, obesity, which is closely linked to both OSA and CVD, makes it harder to ascertain the independent role of OSA on CVD. Although available evidence is inconclusive, there is an increasing recognition of the direct role for OSA in CVD. Similarly, although several studies have demonstrated the cardiovascular benefits of OSA treatment, further studies are needed to confirm this.     

慢性阻塞性肺疾病与致纤维化型间质性肺疾病患者阻塞性睡眠呼吸暂停对比研究

目的探讨阻塞性睡眠呼吸暂停(OSA)与慢性呼吸系统疾病(CRDs)交互作用可能的病理生理机制,对比评价致纤维化型间质性肺疾病(ILD)和慢性阻塞性肺疾病(COPD)患者中OSA的发生情况和严重程度。方法选择2015年9月至2018年12月于中日友好医院呼吸与危重症医学科诊断的73例COPD患者和77例致纤维化型ILD患者,进行多导睡眠监测、肺功能检查和其他临床评估。OSA定义为睡眠呼吸暂停低通气指数(AHI)≥5次/h。结果不依赖于年龄、性别、体质指数(BMI)、白日嗜睡程度及并发症情况,致纤维化型ILD患者较COPD患者发生中、重度OSA更为常见(61%vs. 44%, P=0.02),程度更为严重[AHI(22.4±16.5)次/h vs.(16.8±13.2)次/h, P=0.02]。OSA的严重程度(AHI)与COPD和ILD患者的用力肺活量、肺总量及弥散功能无关。结论 OSA常见于慢性呼吸系统疾病患者,与COPD相比,致纤维化型ILD患者的OSA更为常见,程度更为严重;静态肺功能指标与慢性呼吸系统疾病患者OSA的严重程度无关。提示有必要开展ILD疾病特异性的OSA的临床研究及治疗方式探讨。     

Assessment of sleep with polysomnography in patients with interstitial lung disease

In our study we aimed to examine the sleep structure, oxygenation and breathing pattern in interstitial lung disease (ILD) patients. We also aimed to determine whether relevance between the advanced disease and the sleep disorders exists and whether polysomnography is necessary in those patients. A total of 37 patients were examined in the study and whole night standard polysomnography was performed to all. Polysomnography results revealed that, total sleep time, time spent in NREM sleep stage III and IV, and in REM sleep were decreased. The patients had poor sleep efficiency and they spent more time as wake after sleep onset (WASO). Severe oxygen desaturations were detected during sleep and statistically significant positive correlations were found between mean awake O2 saturation and mean and lowest sleep O2 saturations. Clinical, Radiological and Physiological (CRP) scoring system was used to assess the disease stage, whether advanced or not, and statistically significant negative correlations were found between CRP score and awake and sleep O2 saturations. Obstructive sleep apnea syndrome (OSAS) was diagnosed in 24 (64.9%) patients. In those patients it was found that not the apneas but the hypopneas predominate. No difference was found among body mass indices (BMI) between the patients with and without OSAS. As a result it was concluded that a sleep study should be considered as part of the overall assessment in managing patients with ILD, and is especially indicated if there is incipient pulmonary hypertension, cor pulmonale and nocturnal arrhythmia despite normal awake blood gas tensions and symptoms as snoring and excessive day time sleepiness.     

Obstructive sleep apnea in patients with acute aortic dissection

BackgroundObstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the aortic wall. Thus, OSA may increase the risk for aortic dissection (AD).MethodsThis study enrolled 40 subjects with acute AD from four institutions; 37 completed the modified Berlin Questionnaire and 31 underwent attended overnight polysomnography. Aortic diameter was measured on a computed tomography scan at seven locations from the sinotubular junction to the diaphragm.ResultsTwenty‐seven subjects had type A dissection; 13 had type B. In those who had polysomnography apnea–hypopnea index (AHI) ranged from 0.7 to 89. Prevalence of OSA (AHI ≥ 5) was 61%. Nocturnal presentation (10 p.m.–7 a.m.) did not differ by presence/absence of OSA. The modified Berlin Questionnaire was not predictive of the presence of OSA. Among type A subjects with polysomnography (n = 23), aortic diameters at all locations were greater in the OSA group though differences were not statistically significant. Summating aortic diameters at the seven locations also yielded a numerically larger mean value in the OSA group versus the non‐OSA group.ConclusionsIn this sample of patients with acute dissection, OSA was prevalent but was not associated with a nocturnal presentation. The presence of underlying OSA may be associated with larger aortic diameters at the time of dissection compared to patients without OSA. Though differences did not meet statistical significance the current series is limited by small numbers.     

Obstructive sleep apnea is independently associated with insulin resistance

Epidemiological studies have implicated obstructive sleep apnea (OSA) as an independent comorbid factor in cardiovascular and cerebrovascular diseases. It is postulated that recurrent episodes of occlusion of upper airways during sleep result in pathophysiological changes that may predispose to vascular diseases. Insulin resistance is a known risk factor for atherosclerosis, and we postulate that OSA represents a stress that promotes insulin resistance, hence atherogenesis. This study investigated the relationship between sleep-disordered breathing and insulin resistance, indicated by fasting serum insulin level and insulin resistance index based on the homeostasis model assessment method (HOMA-IR). A total of 270 consecutive subjects (197 male) who were referred for polysomnography and who did not have known diabetes mellitus were included, and 185 were documented to have OSA defined as an apnea-hypopnea index (AHI) > or =5. OSA subjects were more insulin resistant, as indicated by higher levels of fasting serum insulin (p = 0.001) and HOMA-IR (p < 0.001); they were also older and more obese. Stepwise multiple linear regression analysis showed that obesity was the major determinant of insulin resistance but sleep-disordered breathing parameters (AHI and minimum oxygen saturation) were also independent determinants of insulin resistance (fasting insulin: AHI, p = 0.02, minimum O(2), p = 0.041; HOMA-IR: AHI, p = 0.044, minimum O(2), p = 0.022); this association between OSA and insulin resistance was seen in both obese and nonobese subjects. Each additional apnea or hypopnea per sleep hour increased the fasting insulin level and HOMA-IR by about 0.5%. Further analysis of the relationship of insulin resistance and hypertension confirmed that insulin resistance was a significant factor for hypertension in this cohort. Our findings suggest that OSA is independently associated with insulin resistance, and its role in the atherogenic potential of sleep disordered breathing is worthy of further exploration.     

Obstructive sleep apnea in atrial fibrillation patients

A high prevalence of obstructive sleep apnea has been demonstrated in patients with atrial fibrillation. Our comments want to emphasize the importance of identifying and treating a large proportion of patients with atrial fibrillation who have undiagnosed obstructive sleep apnea as an additional preventive strategy for atrial fibrillation patients.     

Obstructive sleep apnea syndrome is a systemic disease. Current evidence

Obstructive sleep apnea syndrome (OSAS) is a highly prevalent sleep disorder, characterized by repeated disruptions of breathing during sleep. This disease has many potential consequences including excessive daytime sleepiness, neurocognitive deterioration, endocrinologic and metabolic effects, and decreased quality of life. Metabolic syndrome is another highly prevalence emerging public health problem that represents a constellation of cardiovascular risk factors. Each single component of the cluster increases the cardiovascular risk, but the combination of factors is much more significant. It has been suggested that the presence of OSAS may increase the risk of developing some metabolic syndrome features. Moreover, OSAS patients are at an increased risk for vascular events, which represent the greatest morbidity and mortality of all associated complications. Although the etiology of OSAS is uncertain, intense local and systemic inflammation is present. A variety of phenomena are implicated in this disease such as modifications in the autonomic nervous system, hypoxemia-reoxygenation cycles, inflammation, and coagulation-fibrinolysis imbalance. OSAS patients also present increased levels of certain biomarkers linked to endocrine-metabolic and cardiovascular alterations among other systemic consequences. All of this indicates that, more than a local abnormality, OSAS should be considered a systemic disease.     

Obstructive sleep apnea

This chapter provides an account of obstructive sleep apnea that is designed for clinicians. Current ideas about the mechanism of upper airway obstruction are reviewed, and the clinical features are discussed in a manner intended to facilitate the clinical assessment of such patients. Various forms of treatment are reviewed, with major emphasis given to the use of nasal positive airway pressure, a form of therapy developed by the authors.     

Obstructive sleep apnea

Purpose

Attempts to understand the causes of cognitive impairment in obstructive sleep apnea (OSA) are complicated by the overlap among clinical and demographic factors that may impact cognition. The goal of the current study was to isolate the contribution of hypoxemia to cognitive impairment in OSA.

Methods

Two groups of 20 patients with newly diagnosed OSA were compared. The groups differed on severity of hypoxemia but not other demographic (e.g., age, gender, education, estimated premorbid IQ) or clinical (e.g., sleep related respiratory disturbances, daytime sleepiness, depressive symptoms) variables. Participants completed polysonmography and cognitive assessment.

Results

We compared patients with high and low hypoxemia on measures of memory, attention, executive functioning, and motor coordination using independent sample t-tests. The high hypoxemia group performed significantly better on immediate recall (Hopkins Verbal Learning Test — Revised; t?=??2.50, p?<?0.02) than the low hypoxemia group. No group differences were observed on other neuropsychological measures.

Conclusions

This study is one of the first to compare the cognitive performance of patients with high and low hypoxemia after controlling for demographic factors and aspects of OSA severity that could confound the relationship. In our carefully matched sample, we observed an unexpected advantage of higher hypoxemia on memory. These preliminary findings are discussed in the context of basic science literature on the protective effects of adaptation to intermittent hypoxemia. Our data suggest that the association between hypoxemia and cognition may not straightforward. Future research targeting the effects of hypoxemia on cognition controlling for other clinical factors in large groups of patients with OSA will be important.