Cognitive changes and sleep disordered breathing in elderly: differences in race

OBJECTIVES: Sleep disordered breathing (SDB) is a highly prevalent sleep disorder in older persons. It is known to be associated with reductions in cognitive function. As part of a larger study examining SDB in African-Americans and Caucasians, it became possible to examine whether racial background may differentially affect the relationship between SDB and cognitive performance. METHODS: Community-dwelling African-American and Caucasian elderly (ages 65+) at high risk for SDB were tested at two time points. During each visit, subjects were interviewed in their homes about their sleep and medical condition. The Mini-Mental Status Examination (MMSE) was used to assess cognitive function. Objective sleep studies were recorded in the subjects' homes and scored for sleep, apneic events, and oxygen saturation levels. RESULTS: Increases in respiratory disturbance index (RDI) were associated with decreases in cognitive performance over time, after controlling for gender and education level. There were no differential effects of race on this relationship. There was no relationship between declining cognitive function and hypoxemia. CONCLUSIONS: Analyses of the data confirm that declining cognitive function in older persons with mild to moderate SDB is related to the amount of respiratory disturbances occurring at night, and suggest that the effect of SDB on cognitive decline is unrelated to race and measured hypoxemia. The large number of community-dwelling elderly with mild to moderate SDB may accrue considerable benefits (both cognitively and medically) from the treatment of SDB, even if they are not markedly hypoxemic.     

Long-term follow-up of sleep disordered breathing in older adults

OBJECTIVE: The current study was designed to determine whether, with increasing age, sleep apnea improves, becomes worse, or stays the same. BACKGROUND: There is a high prevalence of sleep disordered breathing (SDB) in older adults, but little is known about longitudinal changes. This study followed older adults to examine the natural history of SDB. METHODS: Subjects were randomly selected community-dwelling elderly (n=427). A subset of subjects was studied approximately every 2 years over an 18-year period. Overnight sleep recordings and sleep questionnaires were completed at each time point. RESULTS: Multiple linear regression showed that three variables were associated with change in respiratory disturbance index (RDI):body mass index (BMI) at initial visit (P=0.001), change in BMI (P=0.02), and a consistent self-report of high blood pressure (P=0.005). RDI increase was associated with BMI increase and presence of self-reported high blood pressure. CONCLUSIONS: The changes in RDI that occurred were associated only with changes in BMI and were independent of age. This underscores the importance of managing weight for older adults, particularly those with hypertension.     

Sleep disordered breathing in a cohort of patients with sporadic inclusion body myositis

ObjectiveThe aims of the study were: (1) to evaluate subjective sleep quality and daytime sleepiness in patients affected by sporadic inclusion-body myositis (IBM); (2) to define the sleep and sleep-related respiratory pattern in IBM patients.MethodsThirteen consecutive adult patients affected by definite IBM were enrolled, six women and seven men, mean age 66.2 ± 11.1 years (range: 50–80). Diagnosis was based on clinical and muscle biopsy studies. All patients underwent subjective sleep evaluation (Pittsburgh Sleep Quality Index, PSQI and Epworth Sleepiness Scale, ESS), oro-pharingo-esophageal scintigraphy, pulmonary function tests, psychometric measures, anatomic evaluation of upper airways, and laboratory-based polysomnography. Findings in IBM patients were compared to those obtained from a control group of 25 healthy subjects (13 men and 12 women, mean age 61.9 ± 8.6 years).ResultsDisease duration was >10 years in all. Mean IBM severity score was 28.8 ± 5.4 (range 18–36). Dysphagia was present in 10 patients. Nine patients had PSQI scores ? 5; patients had higher mean PSQI score (IBM: 7.2 ± 4.7, Controls: 2.76 ± 1.45, p = 0.005); one patient (and no controls) had EES > 9. Polysomnography showed that IBM patients, compared to controls, had lower sleep efficiency (IBM: 78.8 ± 12.0%, Controls: 94.0 ± 4.5%, p < 0.001), more awakenings (IBM: 11.9 ± 11.0, Controls: 5.2 ± 7.5, p = 0.009) and increased nocturnal time awake (IBM: 121.2 ± 82.0 min., Controls: 46.12 ± 28.8 min., p = 0.001). Seven Patients (and no controls) had polysomnographic findings consistent with sleep disordered breathing (SDB).ConclusionData suggest that sleep disruption, and in particular SDB, might be highly prevalent in IBM.SignificanceData indicate that IBM patients have poor sleep and high prevalence of SDB.     

Prevalence and neurophysiological correlates of sleep disordered breathing in pediatric type 1 narcolepsy

Study objectivesTo investigate the prevalence and neurophysiological correlates of obstructive sleep disordered breathing (OSA) in type 1 narcolepsy (NT1) children and adolescents.MethodsThirty-eight, drug-naïve, NT1 children and adolescents and 21 age- and sex-balanced clinical controls underwent nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT). According to the rules for pediatric population, an obstructive apnea-hypopnea index (Obstructive AHI) ≥ 1 (comprising obstructive and mixed events), defined comorbid OSA.ResultsNT1 children showed higher prevalence of overweight/obesity and severe nocturnal sleep disruption (lower sleep efficiency, and increased N1 sleep stage percentage) coupled with higher motor activity (periodic limb movement index [PLMi] and REM atonia index) compared to clinical controls. Sleep-related respiratory variables did not differ between NT1 and clinical controls (OSA prevalence of 13.2% and 4.8%, respectively). NT1 children with OSA were younger and showed lower N2 sleep stage percentage and higher PLMi than NT1 children without comorbid OSA. Overweight/obesity was not associated with OSA in NT1.ConclusionsDespite higher body mass index (BMI), OSA prevalence did not differ between children with NT1 and clinical controls. OSA in pediatric NT1 patients is a rare and mild comorbidity, further contributing to nocturnal sleep disruption without effects on daytime sleepiness.     

Prevalence,clinical symptoms and polysomnographic findings of REM-related sleep disordered breathing in Japanese population

BackgroundRapid eye movement sleep -predominant sleep-disordered breathing (REM-SDB) is a condition in which sleep apneas or hypopneas predominantly occur during REM sleep. This study aimed to investigate the prevalence, clinical findings including daytime sleepiness or comorbid cardio-metabolic diseases, and detailed polysomnographic features of REM-SDB in Japanese population.MethodsTotal of 1458 patients diagnosed as SDB were selected for this study. Prevalence of REM-SDB was estimated in the groups of mild, moderate and severe SDB. Polysomnographic findings, daytime sleepiness self-measured with Epworth Sleepiness Scale (ESS) and history of comorbid cardio-metabolic diseases were obtained and compared between the groups with REM-SDB and non-stage specific SDB.ResultsPrevalence of REM-SDB according to the criteria #2 was 22.1% in total SDB subjects, 46,1% in mild SDB and 18.9% in moderate SDB. None was found in severe SDB. Patients with REM-SDB showed milder SDB, higher BMI and higher female predominance than those with non-stage specific SDB. They also showed lower arousal index, respiratory arousal index per total AHI, percentage of N1 sleep, total AHI, ODI, and higher sleep efficiency. Meanwhile, maximum event durations of obstructive apnea and hypopnea were significantly longer, and the nadir SpO₂ was lower in REM-SDB. The ESS score and percentages of comorbid cardio-metabolic diseases were roughly equivalent between REM-SDB and non-stage specific SDB.ConclusionREM-SDB was associated with high obesity, female gender, and mild severity of SDB. They showed daytime sleepiness and comorbid cardio-metabolic diseases quite equally to patients with non-stage specific SDB in spite of their lower AHI and better sleep quality.     

Association between sleep disordered breathing and symptoms of attention deficits in adults: a systematic review

BackgroundIn light of previous reported associations between sleep disordered breathing (SDB) and symptoms of attention deficits, the aim of this systematic review (SR) was to evaluate this association in adults.MethodsSearches were performed on seven main databases including Embase, PubMed, Web of Science, Scopus, PsyncInfo, Livivo and Lilacs; as well as grey literature through Google Scholar, Proquest and OpenGrey. Furthermore, hand-searches were conducted on the reference lists of included articles. Experts were consulted to improve search findings. Risk of Bias was gauged using the Joanna Briggs Institute Critical Appraisal Checklist. The cumulative evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.Results2009 references were identified. After phase-1 and phase-2 of screening against eligibility criteria, eight cross-sectional and one cohort studies were retained for qualitative analysis. Five studies were included for quantitative analysis, with no significant association found (p = 0.99). From the qualitative assessment, three papers showed a positive association with at least one attention symptoms. Risk of bias was judged to be low for six studies and three were classified with moderate risk of bias. Confidence in cumulative evidence was considered very low for continuous data.ConclusionDespite the plausibility of an association between SDB and symptoms of attention deficits in adults, current published evidence does not either confirm or refute such association as inferred from its low to very low certainty level.     

Specific patterns of laryngeal electromyography during wakefulness are associated to sleep disordered breathing and nocturnal stridor in multiple system atrophy

BackgroundNocturnal stridor and respiratory abnormalities are important features of multiple system atrophy (MSA) with relevance to patient survival, and they are detected and evaluated mainly through video-polysomnography (video-PSG). Diurnal laryngoscopy seems to yield abnormal findings only in the presence of significant vocal cord (VC) dysfunction.AimTo assess whether specific electrophysiological patterns of diurnal EMG of VC muscles may indicate nocturnal stridor or respiratory dysfunctions in MSA patients.Materials and methodsSeventeen patients with probable MSA were examined. A full-night video-PSG to collect standard breathing parameters (apnea/hypopnea index, mean HbSAO₂, oxygen desaturation index, total sleep time with HbSaO₂ below 90%) was performed in all the patients. Laryngoscopy and EMG investigation of adductor (thyroarytenoid-TA) and abductor (posterior cricoarytenoid-PCA) muscles of the VCs were also performed.ResultsBoth the laryngeal EMG abnormalities (based on MUAP analysis and kinesiologic EMG investigation of VC muscles) and the laryngoscopic alterations correlated with video-PSG respiratory abnormalities. Specific patterns of EMG findings were consistently found in MSA subjects with nocturnal stridor detected at PSG. In particular, the following EMG findings were related to the severity of breathing abnormalities and the presence of stridor on video-PSG: neurogenic pattern on MUAP analysis of the PCA, paradoxical activation of the TA during inspiration and tonic EMG activity of the TA during quiet breathing.ConclusionsElectromyographic/kinesiologic investigation of VC muscles during wakefulness provides additional information on the pathophysiology of the respiratory abnormalities in MSA patients that could be useful for guiding the choice of the best appropriate treatment and care.     

Sleep-disordered breathing and wake-up stroke: a differential association depending on etiologic subtypes

Background and purposeObstructive sleep apnea (OSA) is a modifiable risk factor for stroke, but there are limited data on which stroke subtypes are associated with OSA. The aim of this study was to assess the risk for wake-up stroke (WUS) associated with OSA according to each etiologic subtype to elucidate the pathophysiologic mechanism of OSA-associated stroke.MethodWe investigated 557 consecutive patients who were admitted with acute ischemic stroke in two regional comprehensive stroke centers using a standardized protocol including the Berlin questionnaire to identify symptoms of OSA prior to stroke. The collected stroke data included the time of onset, risk factors, and etiologic subtype. Stratified analysis according to sex was conducted because sex has been reported to be an effect modifier of OSA on cardiovascular outcomes. The association between preexisting OSA symptoms and WUS depending on etiologic subtypes was assessed using multivariate logistic regression analysis.ResultsPreexisting OSA symptoms were associated with the risk of overall WUS in men. Snoring was associated with WUS in large artery atherosclerosis [adjusted odds ratio, 2.67 (1.15–6.23)], and apnea was associated with WUS in small vessel occlusion [adjusted odds ratio, 8.21 (1.15–58.53)], whereas OSA symptoms were not significantly associated with WUS in cardioembolism. Associations between OSA and WUS were not found in women.ConclusionThis study demonstrated the differential influences of OSA on WUS depending on etiologic subtypes, suggesting more vulnerability in large artery atherosclerosis and small vessel occlusion. Sex is a significant effect modifier of the association between OSA and WUS.     

The effect of seasonality on sleep-disordered breathing severity in children

Objective

Sleep-disordered breathing (SDB) is a common disorder associated with substantial morbidity that occurs in otherwise healthy children. Atopy, asthma, and viral upper respiratory tract infections are known risk factors for pediatric SDB that exhibit seasonal variability. The aim of our study was to investigate the effect of seasonality on SDB severity in children and adolescents referred for polysomnographic evaluation for suspected SDB and to examine the effect of atopy/asthma on this variability.

Methods

The medical records of all children and adolescents referred for a polysomnography (PSG) for suspected SDB between 2008 and 2010 were retrospectively assessed for seasonal patterns. The effect of atopy/asthma, age, and obesity on seasonal variability was investigated.

Results

A total of 2178 children and adolescents (65% boys) were included. The mean age of the cohort was 4.9 ± 3.5 years (range, 3 months–18 years). Eighteen percent of patients had a history of asthma/atopy. The mean obstructive apnea–hypopnea index (OAHI) in the winter was significantly higher compared to the summer (9.1 ± 9.6 vs 7.5 ± 7.0; P = .01; Cohen d = 0.19), particularly in children younger than the age of 5 years (10.2 ± 10.5 vs 7.9 ± 7.3; P = .008; Cohen d = 0.25). Asthma/atopy had no significant effect on seasonal variability.

Conclusions

SDB severity alters in a season-dependent manner in children and adolescents referred for polysomnographic evaluation for suspected SDB. These alterations are more prominent in children younger than the age of 5 years. The presence of asthma/atopy does not contribute to this seasonal variability. These findings suggest that viral respiratory infections are most likely the major contributor for the seasonal variability observed in pediatric SDB; additionally, the time of the year when a child is evaluated for suspected SDB may affect the clinical management and outcome in borderline cases.     

脑梗死急性期超敏C反应蛋白水平与神经功能恢复的关系

目的探讨脑梗死急性期超敏C反应蛋白（hs-CRP）水平与脑梗死神经功能恢复的关系。方法选取发病72h内的急性脑梗死患者269例,入院第2天测定hs-CRP,按hs-CRP水平分为低hs-CRP组（hs-CRP≤3mg/L）及高hs-CRP组（hs-CRP〉3mg/L）,比较2组患者的临床资料,分析影响hs-CRP水平的因素;入选患者进行90d随访,比较2组患者90d时神经功能恢复情况（改良Rankin量表评分3～6分为恢复不良）,分析影响神经功能恢复的因素。结果 共266例患者完成随访,hs-CRP中位数3.15mg/L（1.12～8.89mg/L）。高hs-CRP组（138例）年龄较大（P〈0.001）,糖尿病发病率较高（P=0.001）,房颤发病率较高（P=0.004）,入院时脑梗死较严重（P=0.003）;高龄、合并糖尿病及房颤、入院时脑梗死严重程度与hs-CRP水平高独立相关（P均〈0.05）;高hs-CRP组神经功能恢复不良比例高于低hs-CRP组（P〈0.001）;hs-CRP升高与神经功能恢复不良独立相关（OR1.213,P=0.001,Logistic分析）。结论 高龄、糖尿病史、房颤病史、脑梗死严重程度重可能是hs-CRP升高的独立危险因素;hs-CRP升高可能是神经功能恢复不良的独立危险因素。     

Short-term outcome of patients with cardiac- and thrombo-embolic cerebral infarcts

OBJECTIVES: It has already been demonstrated by previous studies that patients suffering from a cardiac-embolic stroke (CES) have a worse outcome than those with a thrombo-embolic stroke (TES). Many factors, such as age, initial stroke severity, stroke recurrence and vascular risk factors have been quoted as a possible explanation. The present retrospective study re-investigates more in detail which variables are the most important to explain the difference in disability between patients with CES and with TES on hospital discharge. PATIENTS AND METHODS: Seven hundred forty-two consecutive patients with a territorial infarct were admitted to the Stroke Unit of the Ghent University Hospital between October 2002 and June 2007. The groups of CES and TES consisted, respectively of 283 and of 459 patients. Age, gender, vascular risk factors including previous strokes and pacemaker implantation, initial stroke severity and outcome, determined by the mean modified Rankin (mR) scale on hospital discharge, were compared between both groups. RESULTS: Although the hospital stay of the patients with CES and TES was quite similar, the former group was much older with more females, more vascular risk factors, worse neurological deficit on admission and more disability on discharge. On logistic regression analysis coronary artery disease, isolated atrial fibrillation and cardiac valve disorder appear as independent predictors of stroke outcome. CONCLUSION: The worse outcome in the CES patients is mainly due to the cardiac status of the patients.     

Increased serum levels of advanced glycation end-products is associated with severity of sleep disordered breathing but not insulin sensitivity in non-diabetic men with obstructive sleep apnoea

Background

Patients with diabetes mellitus are known to have increased serum levels of advanced glycation end-products (AGEs), and this is also associated with insulin resistance. This study aimed to investigate the relationship between serum AGEs and insulin sensitivity in non-diabetic subjects with obstructive sleep apnoea (OSA).

Methods

Adult males with no known comorbidities were recruited from the sleep clinic of a university teaching hospital. They underwent overnight in-laboratory polysomnography. Fasting blood was taken to measure serum AGE and plasma glucose levels. Insulin sensitivity was estimated using the short insulin tolerance test.

Results

In total, 105 subjects with a mean age of 43.5 (standard deviation [SD] 9.2) years, mean body mass index of 27.1 (SD 4.0) kg/m², and median apnoea-hypopnoea index (AHI) of 17 (interquartile range 5-46) were analysed. Serum AGE levels were significantly higher in subjects with OSA (AHI ?5), compared with those without OSA (AHI <5) (3.9 [SD 1.2] vs. 3.2 [SD 0.8] μg/ml, respectively; P = 0.037) after adjusting for confounders. AGE levels were positively correlated with AHI (r = 0.318, P = 0.001), but not with insulin sensitivity. AGE levels decreased in subjects with moderate-to-severe OSA who received continuous positive airway pressure (CPAP) treatment for three months (n = 18, P = 0.017).

Conclusions

Serum AGE levels correlate with AHI in non-diabetic adult males. This relationship cannot be explained by insulin sensitivity. Supporting the hypothesis of a direct relationship between AHI and AGEs, AGE levels were found to decline with CPAP therapy.     

Sleep disordered breathing and subclinical impairment of respiratory function are common in sporadic inclusion body myositis

Relatively little is known about frequency and extent of respiratory problems in sporadic inclusion body myositis (IBM). To address this issue a study of peripheral muscle and respiratory function and related symptoms was performed in a cohort with biopsy-proven IBM. Dyspnoea, daytime sleepiness, dysphagia, spirometry, respiratory muscle strength, arterial blood gas tensions and ventilation during sleep were assessed. Sixteen patients were studied (10 males; age 68.1 ± 9.9 years; disease duration 11.9 ± 5.0 years; body mass index 28.5 ± 4.0 kg/m²). Four reported excessive daytime sleepiness; 8 had at least mild dysphagia; forced vital capacity was <80% predicted normal in 7; sniff nasal inspiratory pressure was reduced in 3; daytime hypoxemia was present in 9 and hypercapnia in one. Sleep study was performed in 15 and revealed sleep disordered breathing (apnoea–hypopnoea index 23.4 ± 12.8 (range 7–50.3) events/h) in all. There were no consistent relationships between respiratory function impairment, occurrence of sleep disordered breathing, and severity of peripheral muscle weakness. Thus, asymptomatic impairment of respiratory function was common and sleep disordered breathing observed in all patients tested, irrespective of daytime respiratory function. This suggests respiratory function testing, including sleep study, should be performed routinely in IBM, irrespective of peripheral muscle function or other disease severity parameters.     

Sleepiness and activity in heart failure patients with reduced ejection fraction and central sleep-disordered breathing

ObjectivePatients with heart failure (HF) and sleep disordered breathing (SDB) are typically not sleepy, unlike patients without heart failure. Previous work in HF patients with obstructive SDB suggested that sleepiness was associated with a reduction in daytime activity. The consequences of predominately central SDB on sleepiness in HF are less well understood. The aim of this study was to test the hypothesis that subjective sleepiness is associated with reduced daytime activity in HF patients with central SDB, compared to those without SDB.MethodsThe Epworth Sleepiness Scale (ESS), nocturnal polysomnography, and 14 days of wrist watch actigraphy were used to assess subjective daytime sleepiness, nocturnal sleep and breathing, and 24-h activity levels, respectively.ResultsA total of 54 patients with HF were studied, nine had obstructive SDB and were removed from further analysis. Of the patients, 23 had HF with predominantly central SDB (HF-CSA; apnea–hypopnea index (AHI) median 20.6 (IQR 12.9–40.2)/h), and 22 had noSDB (HF-noSDB; AHI 3.7 (2.5–5.9)/h). The median patient age was 68 years (range 59–73 years). There were no significant differences either in ESS score (HF-CSA; 8 [4–10] vs. HF-noSDB; 8 (6–12); p = 0.49) or in duration of daytime activity (HF-CSA 14.5 (14.1–15.2) and HF-noSDB 15.1 (14.4–15.3) hours; p = 0.10) between the groups.ConclusionHF patients with predominately central SDB are not subjectively sleepy compared to those without SDB, despite reduced sleep quality. We speculate that the lack of sleepiness (based on ESS score) may be due to increased sympathetic nerve activity, although further studies are needed due to the small number (n = 5) of sleepy HF-CSA patients. Daytime activity was not different between HF-noSDB and HF-CSA patients.