Inflammatory pathways in children with insufficient or disordered sleep

Autoantibodies of inflammatory cytokines as serum biomarkers in OSA patients

As many as 90% of patients with obstructive sleep apnea (OSA) may be undiagnosed. It is necessary to explore the potential value of autoantibodies against CRP, IL-6, IL-8 and TNF-α in the diagnosis of OSA. ELISA was performed to detect the level of autoantibodies against CRP, IL-6, IL-8 and TNF-α in sera from 264 OSA patients and 231 normal controls (NCs). The expression level of autoantibodies against CRP, IL-6 and IL-8 in OSA were significantly higher than that in NC while the level of anti-TNF-α was lower in OSA than that in NC. The per SD increment of anti-CRP, anti-IL-6 and anti-IL-8 autoantibodies were significantly associated with a 430%, 100% and 31% higher risk for OSA, respectively. The AUC of anti-CRP was 0.808 (95% CI: 0.771-0.845) when comparing OSA with NC, while the AUC increased to 0.876 (95% CI: 0.846-0.906) combining four autoantibodies. For discrimination of severe OSA versus NC and non-severe OSA versus NC, the AUC for four autoantibodies combination was 0.885 (95% CI: 0.851-0.918) and 0.876 (95% CI: 0.842-0.913). This study revealed the association between autoantibodies against inflammatory factors and OSA, and the combination of autoantibodies against CRP, IL-6, IL-8 and TNF-α may function as novel biomarker for monitoring the presence of OSA.

Role of epigenetic abnormalities and intervention in obstructive sleep apnea target organs

ABSTRACT

Obstructive sleep apnea (OSA) is a common condition that has considerable impacts on human health. Epigenetics has become a rapidly developing and exciting area in biology, and it is defined as heritable alterations in gene expression and has regulatory effects on disease progression. However, the published literature that is integrating both of them is not sufficient. The purpose of this article is to explore the relationship between OSA and epigenetics and to offer better diagnostic methods and treatment options. Epigenetic modifications mainly manifest as post-translational modifications in DNA and histone proteins and regulation of non-coding RNAs. Chronic intermittent hypoxia-mediated epigenetic alterations are involved in the progression of OSA and diverse multiorgan injuries, including cardiovascular disease, metabolic disorders, pulmonary hypertension, neural dysfunction, and even tumors. This article provides deeper insights into the disease mechanism of OSA and potential applications of targeted diagnosis, treatment, and prognosis in OSA complications.

Sleep and Inflammation

Sleep and inflammatory cytokines have a bidirectional relationship where circadian rhythms influence increase in levels of certain cytokines, and in return, some cytokines induce sleep, as we frequently experience during illnesses. The most commonly studied cytokines, in the context of inflammation and sleep, are interleukin 6 (IL-6), tumor necrosis factor (TNF), and (IL-1). In this article, the author follows the effect of circadian rhythms on blood levels of these cytokines and explores the changes in their levels in conditions that affect sleep, such as obstructive sleep apnea and insomnia.

Effect of Preoperative Weight Status and Disease Presentation on Postoperative Elevated Blood Pressure After Childhood Adenotonsillectomy

OBJECTIVE

To investigate the risk factors of postoperative elevated blood pressure (BP) in children with childhood obstructive sleep apnea syndrome (OSAS) after adenotonsillectomy (AT).

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary referral center.

METHODS

Two hundred forty-five consecutive children (180 boys and 65 girls, median age 6.6 years) with polysomnography-diagnosed OSAS who underwent AT between January 2010 and August 2019. Clinical, polysomnographic, and evening BP data were assessed preoperatively and postoperatively (≥3 months after AT). Changes in the variables before and after AT and between individuals with and without hypertension were compared.

RESULTS

Postoperatively, the median (interquartile range) apnea-hypopnea index significantly decreased from 10.4 (5.3-22.6) to 2.2 (1.0-3.8) events/h. In addition, the mean (standard deviation) evening diastolic BP z-score significantly decreased from 0.7 (0.94) to 0.5 (0.81) in the overall cohort, and both systolic (2.1 [0.94]-1.0 [1.31]) and diastolic BP z-scores (1.6 [0.98]-0.7 [0.85]) significantly decreased in the preoperative elevated BP subgroup. Multivariate logistic regression analysis showed that preoperative obesity (adjusted odds ratio = 4.36, 95% confidence interval = 2.24-8.49) and mean peripheral oxygen saturation <95% during sleep (adjusted odds ratio = 2.73, 95% confidence interval = 1.29-5.79) were independently associated with postoperative elevated BP.

CONCLUSION

Preoperative obesity and mean peripheral oxygen saturation <95% during sleep were significantly associated with postoperative elevated BP in the children with OSAS, further indicating the importance of careful BP monitoring in this subgroup despite AT treatment.

Evaluation of obesity and asthma as risk factors for moderate to severe obstructive sleep apnea in children

STUDY OBJECTIVES

Asthma and obesity are risk factors for obstructive sleep apnea (OSA) in children but their link to OSA severity is uncertain. We aimed at determining whether asthma or obesity were associated with an increased risk of moderate/severe OSA.

METHODS

Children undergoing a one-night polysomnography for suspicion of OSA were retrospectively included. Univariate and multivariate analyses were conducted to assess the clinical and demographic characteristics linked to moderate/severe OSA (obstructive apnea-hypopnea index ≥ 5/h of sleep) with odds ratio (OR) and 95% confidence interval reported.

RESULTS

490 children (311 (64%) boys) were included with a median [25th; 75th percentile] age of 8.7 [5.4; 12.9] years, 164 (33%) non-asthmatics non-obese, 122 (25%) obese non-asthmatics, 125 (26%) asthmatics non-obese, 79 (16%) asthmatics and obese. Moderate/severe OSA was present in 157 (32%) children (75/157 (48%) obese and 52/157 (33%) asthmatics). Independent factors associated with increased or decreased risk of moderate/severe OSA were: obesity and male sex (OR 1.82 [1.16; 2.87], P = 0.01, and 1.55 [1.02; 2.36], P = 0.04, respectively), and current asthma, age >6 years or behavioral disorders (OR 0.45 [0.29; 0.70], P < 0.001; 0.44 [0.27; 0.73], P < 0.001; and 0.55 [0.33; 0.92], P = 0.02, respectively). Abnormal resistance of the respiratory system (measured in 241 children), but not abnormal spirometry (measured in 213 children), increased the risk of moderate/severe OSA (OR 2.95 [1.46-5.96], P = 0.003).

CONCLUSIONS

In our cohort enriched in obese and asthmatic children, obesity was associated with higher risk of moderate/severe OSA whereas current asthma was not.

Experimental methods to study sleep disruption and immune balance in urban children with asthma

Study Objectives

We describe research methods developed to examine effects of sleep disruption on changes in immune balance, lung function, and cognitive performance in a sample of urban, ethnically diverse children with persistent asthma. Two case examples (8- and 10-year-old males) are presented to highlight methods of the current study and illustrate effects of experimentally disrupted sleep on the immune balance profile (Th1/Th2 cytokines), key sleep variables from polysomnography data, and lung function in our sample.

Methods

Children follow an individualized structured sleep schedule consistent with their habitual sleep need (≥9.5 hours' time in bed) for six days before a laboratory-based experimental sleep protocol. Children then spend two successive nights in the sleep lab monitored by polysomnography: a baseline night consisting of uninterrupted sleep, and a disruption night, during which they are awoken for 2 minutes between 20-minute intervals of uninterrupted sleep. Evening and morning blood draws bracket baseline and disruption nights for immune biomarker assessment.

Results

A shift towards immune imbalance following the sleep disruption protocol was observed in these illustrative cases.

Conclusions

Data from these case examples provide evidence that the experimental protocol caused disruptions in sleep as observed on polysomnography and had the hypothesized downstream effects on immune balance associated with clinical asthma control. Documenting the effects of sleep disruption on immune function in children with persistent asthma is a crucial step towards understanding associations between sleep, immune balance, and asthma outcomes and provides important information for developing novel interventions for youth with asthma and suboptimal sleep.

Clinical Trials

Not applicable.

Pediatric Obstructive Sleep Apnea: What’s in a Name?

Obstructive sleep apnea is a highly prevalent disease across the lifespan and imposes substantial morbidities, some of which may become irreversible if the condition is not diagnosed and treated in a timely fashion. Here, we focus on the clinical and epidemiological characteristics of pediatric obstructive sleep apnea, describe some of the elements that by virtue of their presence facilitate the emergence of disrupted sleep and breathing and its downstream consequences, and also discuss the potential approaches to diagnosis in at-risk children.

The relationship between sleep-disordered breathing, blood pressure, and urinary cortisol and catecholamines in children

STUDY OBJECTIVES

Hypertension is a complication of obstructive sleep apnea (OSA) syndrome in adults. A correlation between OSA syndrome and elevated blood pressure (BP) is suggested in children, but its pathogenesis remains unclear. Our aim was to study the effects of sleep and sleep apnea on BP and sympathetic nervous system activation as measured by serum cortisol and urinary catecholamines. We hypothesized that children with OSA syndrome would have higher BP, urinary catecholamines, and cortisol compared with controls.

METHODS

We measured BP during polysomnography in 78 children with suspected sleep-disordered breathing and 18 nonsnoring controls. BP was measured during wakefulness and every 30-60 minutes throughout the night. All participants had 24-hour urinary catecholamine and free cortisol collections 48 hours before polysomnography.

RESULTS

BP varied with sleep stage; it was highest during wakefulness and N1 and lowest during non-rapid eye movement stage 3. Children classified as high apnea-hypopnea index (AHI) snorers (AHI >5 events/h) had a greater prevalence of systolic hypertension (57%) than low-AHI snorers (22%) and nonsnoring controls (22%; P = .04). The high-AHI snorers also had higher diastolic BP (P < .02) as well as blunted nocturnal diastolic BP changes during sleep (P = .02) compared with low-AHI snorers (AHI <5 events/h). Twenty-hour urinary free cortisol and 24-hour urinary catecholamines were not associated with BP.

CONCLUSIONS

BP in children varies with sleep stage. OSA is associated with systolic hypertension, higher BP during rapid eye movement sleep, as well as elevation of diastolic BP and blunted BP changes with sleep.

Beyond the growth delay in children with sleep-related breathing disorders: a systematic review

INTRODUCTION

The availability of high-quality studies on the association between sleep-disordered breathing in children and delayed growth associated with the hormonal profile recorded before surgery and at follow-up is limited.

EVIDENCE ACQUISITION

Medline PubMed, Scopus and WebOfScience databases were searched for relevant publications published between January 2008 to January 2020 and a total of 261 potentially eligible studies were identified.

EVIDENCE SYNTHESIS

Following review 19 papers were eligible for inclusion: seven reported a significant postsurgical increase in growth regardless of initial weight status, type of surgery, type of study design, and length of follow-up period. The only high-quality study was a randomized controlled trial that found an increased risk of obstructive sleep apnea syndrome relapse in overweight children. Twelve studies reported the significant increase in growth parameters showing that IGF-1, IGFBP-3, and ghrelin may boost growth after surgery.

CONCLUSIONS

The current systematic review demonstrates a scarcity of high-quality studies on growth delay in children with sleep-disordered breathing. Significant catch-up growth after surgery in the short term and changes in IGF-1, IGFBP-3, ghrelin, and leptin levels has been reported in most published studies.

Chemical sympathectomy reduces peripheral inflammatory responses to acute and chronic sleep fragmentation

Sleep loss contributes to the development of cardiovascular, metabolic, and neurological disorders by promoting a systemic proinflammatory phenotype. The neuroendocrine-immune mechanisms contributing to such pathologies are poorly understood. The sympathetic nervous system (SNS) regulates immunity and is often activated following sleep disturbances. The aims of this study were to determine 1) the effect of SNS inhibition on inflammatory responses to sleep fragmentation (SF) and 2) whether homeostasis can be restored after 1 wk of recovery sleep. We measured stress responses (norepinephrine and corticosterone), gene expression levels of pro- and anti-inflammatory cytokines in peripheral (heart, liver, and spleen) tissues, and protein levels of cytokines and chemokines in serum of female mice that were subjected to acute SF for 24 h, chronic SF for 8 wk, or 7 days of recovery after chronic SF. In each experiment, SF and control mice were chemically sympathectomized with 6-hydroxydopamine (6-OHDA) or injected with vehicle. Both acute and chronic SF elevated mRNA and protein levels of cytokines in peripheral tissues. Changes in inflammatory responses mirrored stress-axes activation, with increased corticosterone and norepinephrine in SF mice. 6-OHDA treatment significantly alleviated SF-induced inflammation, thus providing evidence of SNS regulation of peripheral inflammation from SF. Effects of chronic SF were more severe than acute SF, and 1 wk of recovery from SF sufficiently alleviated peripheral inflammatory responses but not NE responses.

Identification of different clinical faces of obstructive sleep apnea in children

OBJECTIVE

This study aimed to identify the heterogeneity of obstructive sleep apnea syndrome clinical presentation in children.

PARTICIPANTS

Children who were 3-14 years old and with obstructive sleep apnea syndrome after polysomnography monitoring (apnea and hypopnea index>5 or obstructive apnea index>1) in the sleep center of Beijing Children's Hospital were included.

METHODS

A sleep disorder questionnaire including different combinations of symptoms and co-morbidities of obstructive sleep apnea syndrome in children was used. A cluster analysis was used to classify the data.

RESULTS

The apnea hypopnea index alone is not adequate to predict clinical phenotypes. Based on symptoms and co-morbidities of obstructive sleep apnea syndrome, three distinct clusters were identified. They were "nocturnal snoring and daytime sleepiness group" (cluster 1), "hyperactivity group" (cluster 2), and "minimally symptomatic group" (cluster 3). A prediction model was built according to eight variables which showed statistical significance by pairwise comparison among clusters. Overall accuracy of the prediction model could reach 86%. Both the sensitivity and specificity of cluster 2 and 3 prediction were around 90%.

CONCLUSION

Children with obstructive sleep apnea syndrome have different patterns of clinical presentation and the identification of the different clinical profiles of obstructive sleep apnea syndrome can provide clues for more personalised diagnoses and therapies.

Regulation of breathing pattern by IL-10

Proinflammatory cytokines like interleukin-1β (IL-1β) affect the control of breathing. Our aim is to determine the effect of the anti-inflammatory cytokine IL-10 οn the control of breathing. IL-10 knockout mice (IL-10^-/-, n = 10) and wild-type mice (IL-10^+/+, n = 10) were exposed to the following test gases: hyperoxic hypercapnia 7% CO₂-93% O₂, normoxic hypercapnia 7% CO₂-21% O₂, hypoxic hypercapnia 7% CO₂-10% O₂, and hypoxic normocapnia 3% CO₂-10% O₂. The ventilatory function was assessed using whole body plethysmography. Recombinant mouse IL-10 (rIL-10; 10 μg/kg) was administered intraperitoneally to wild-type mice (n = 10) 30 min before the onset of gas challenge. IL-10 was administered in neonatal medullary slices (10-30 ng/ml, n = 8). We found that IL-10^-/- mice exhibited consistently increased frequency and reduced tidal volume compared with IL-10^+/+ mice during room air breathing and in all test gases (by 23.62 to 33.2%, P < 0.05 and -36.23 to -41.69%, P < 0.05, respectively). In all inspired gases, the minute ventilation of IL-10^-/- mice was lower than IL-10^+/+ (by -15.67 to -22.74%, P < 0.05). The rapid shallow breathing index was higher in IL-10^-/- mice compared with IL-10^+/+ mice in all inspired gases (by 50.25 to 57.5%, P < 0.05). The intraperitoneal injection of rIL-10 caused reduction of the respiratory rate and augmentation of the tidal volume in room air and also in all inspired gases (by -12.22 to -29.53 and 32.18 to 45.11%, P < 0.05, respectively). IL-10 administration in neonatal rat (n = 8) in vitro rhythmically active medullary slice preparations did not affect either rhythmicity or peak amplitude of hypoglossal nerve discharge. In conclusion, IL-10 may induce a slower and deeper pattern of breathing.

Beneficial effects of a lifestyle intervention program on C-reactive protein: impact of cardiorespiratory fitness in obese adolescents with sleep disturbances

The objectives of this study were to assess the relationship between inflammation and obstructive sleep apnea (OSA) and determine whether the lifestyle program's effects on inflammatory markers are associated with changes in anthropometric parameters, cardiorespiratory fitness, sleep duration, and OSA severity in severely obese adolescents. Participants were aged 14.6 (SD 1.2) yr, with a body mass index (BMI) of 40.2 (SD 6.5) kg/m². Sleep, anthropometric parameters, glucose metabolism, inflammatory profile, and cardiorespiratory fitness [V̇o_2peak relative to body weight (V̇o_2peakBW) and fat-free mass (V̇o_2peakFFM)] were assessed at admission and at the end of a 9-mo lifestyle intervention program (LIP). Associations between C-reactive protein (CRP) concentrations and BMI, sex, oxygen desaturation index (ODI), sleep fragmentation, total sleep time (TST), and V̇o_2peak were assessed via ANCOVA. Twenty-three subjects completed the study. OSA subjects ( n = 13) exhibited higher CRP concentrations and a trend for higher BMI than non-OSA subjects ( P = 0.09) at admission. After intervention, OSA was normalized in six subjects, and CRP significantly decreased in the OSA group and in the whole population. In both groups, leptin levels significantly decreased, whereas adiponectin concentrations increased. At admission, BMI adjusted for sex, arousal index, ODI, TST, and V̇o_2peakBW was associated with CRP levels (adjusted r² = 0.32, P < 0.05). The decrease in CRP concentrations postintervention was associated with enhanced V̇o_2peakFFM adjusted for sex, weight loss, and changed sleep parameters (adjusted r² = 0.75, P < 0.05). Despite higher amounts of CRP in OSA subjects, obesity severity outweighs the proinflammatory effects of OSA, short sleep duration, and low cardiorespiratory fitness. However, enhanced cardiorespiratory fitness is associated with the decrease of inflammation after controlling for the same parameters.

The Relationship Between Sleep Disturbance and Disease Activity in Pediatric Patients With Inflammatory Bowel Disease

OBJECTIVE

The aim of this prospective cross sectional study was to assess the prevalence of sleep disturbance in children with inflammatory bowel disease (IBD), including the relationships between sleep, inflammatory markers, and disease activity of pediatric patients with IBD.

METHODS

Pediatric patients with IBD and parents were enrolled in the study. Patients completed the Pittsburgh Sleep Quality Index (PSQI), the Pediatric Daytime Sleepiness Scale, and the Adolescent Sleep Wake Scale (ASWS) surveys. Parents completed the Child Sleep Habits Questionnaire (CSHQ). Disease activity for Crohn disease (CD) was determined by the Pediatric Crohn Disease Activity Index and the Pediatric Ulcerative Colitis Activity Index was used to define disease activity in ulcerative colitis (UC)/indeterminate colitis patients.

RESULTS

Fifty-three pediatric patients with IBD (38 CD, 12 UC, and 3 indeterminate colitis) participated in the study. The significant correlations between the CSHQ and Pediatric Crohn Disease Activity Index (P = 0.002) and the PSQI and Pediatric Ulcerative Colitis Activity Index (P = 0.04) were found. Youth with UC and indeterminate colitis significantly reported more sleep disturbance than patients with CD, (P = 0.03, 0.05, and 0.04; PSQI, Pediatric Daytime Sleepiness Scale, ASWS, respectively). Patients self-reported significantly more sleep disturbance than was observed by parents (P < 0.0001). This study showed the significant correlations between CSHQ score compared to erythrocyte sedimentation rate and albumin (P = 0.001 and 0.03, respectively).

CONCLUSIONS

Results suggest that increased disease activity is associated with adverse effects on sleep quality. Based on the results of this study, pediatric patients with IBD should be screened for sleep disturbance.

Intermittent hypoxia promotes carcinogenesis in azoxymethane and dextran sodium sulfate-induced colon cancer model

Intermittent hypoxia (IH), a characteristic of obstructive sleep apnea, is known to promote cancer progression and aggressiveness in mouse models. However, little is known regarding the effect of IH on cancer initiation. Here, the effect of IH on carcinogenesis was explored in azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon cancer models with three different protocols. In the first protocol, two other application time points (early or late initiation of IH) were applied. In the second protocol, mice were divided into only two groups, and then exposed to either N or IH conditions for 14 days. In the third protocol, a pharmacological inhibition study for anti-inflammation (5-aminosalicylate) or anti-oxidative stress (N-acetylcysteine [NAC]) was performed. The number of tumors was significantly higher in the IH-1 than in the N or IH-2 groups. 8-oxo-2'-deoxyguanosine (8-OHdG) levels were higher in tumors of the IH-1 group than in that of the N and IH-2 groups. Gene expression related to reactive oxygen species production was higher in the IH-1 group than in the N and IH-2 groups, and it showed a positive correlation with 8-OHdG levels. Prior to cancer development 8-OHdG levels were already elevated in colonic epithelial regions in the IH group, possibly due to an imbalance between oxidative stress and antioxidant systems. NAC treatment resulted in a significant reduction in the number of tumors in mice exposed to IH. In conclusion, IH promotes carcinogenesis in a chemically-induced colon cancer model where elevated 8-OHdG may contribute to the increased tumor induction.

The Global Problem of Insufficient Sleep and Its Serious Public Health Implications

Good sleep is necessary for good physical and mental health and a good quality of life. Insufficient sleep is a pervasive and prominent problem in the modern 24-h society. A considerable body of evidence suggests that insufficient sleep causes hosts of adverse medical and mental dysfunctions. An extensive literature search was done in all the major databases for “insufficient sleep” and “public health implications” in this review. Globally, insufficient sleep is prevalent across various age groups, considered to be a public health epidemic that is often unrecognized, under-reported, and that has rather high economic costs. This paper addresses a brief overview on insufficient sleep, causes, and consequences, and how it adds to the existing burden of diseases. Insufficient sleep leads to the derailment of body systems, leading to increased incidences of cardiovascular morbidity, increased chances of diabetes mellitus, obesity, derailment of cognitive functions, vehicular accidents, and increased accidents at workplaces. The increased usage of smart phones and electronic devices is worsening the epidemic. Adolescents with insufficient sleep are likely to be overweight and may suffer from depressive symptoms. The paper concludes by emphasizing sleep quality assessments as an important early risk indicator, thereby reducing the incidence of a wide spectrum of morbidities.

Obstructive sleep apnoea is associated with progression of arterial stiffness independent of obesity in participants without hypertension: A KoGES Prospective Cohort Study

Accumulating evidence shows that obstructive sleep apnoea (OSA) is associated with an increased risk of cardiovascular disease. However, there are no published prospective studies on the relationship between OSA and the progression of arterial stiffness. We hypothesised that OSA would increase the risk of arterial stiffness progression, independent of obesity. In the present large cohort study, 1921 participants were randomly selected and underwent polysomnography. The brachial ankle pulse wave velocity (baPWV) was measured at baseline and during the follow-period using a standard protocol. Elevated baPWV was defined as a value greater than the cut-off of highest tertile level in the complete study cohort. The percentage of elevated baPWV and the ΔbaPWV significantly increased with OSA severity. After adjusting for potential confounding factors, participants with moderate-to-severe OSA without hypertension had a significantly higher risk of elevated ΔbaPWV than those without OSA. More importantly, using multivariate mixed-effect models, we found that the ΔbaPWV over 6 years significantly differed according to OSA severity. Therefore, moderate-to-severe OSA in participants without hypertension was a predictor of future burden of arterial stiffness progression, independent of obesity, suggesting that it may contribute to the increased risk of cardiovascular disease.

Sex differences in sleep apnea and comorbid neurodegenerative diseases

Sleep apnea is a disorder, which increasingly affects people worldwide. Whether the associated hypoxic events during sleep are central or obstructive in origin, the end result is excessive daytime sleepiness and an increased risk for several comorbidities, such as cardiovascular and neurodegenerative disorders. Sleep apnea is diagnosed more frequently in men than women, suggesting a role of sex hormones in the pathology of the disease. Furthermore, there are sex differences in the development and progression of comorbid diseases associated with sleep apnea. Therefore, treatment of sleep apnea may be clinically relevant for prevention of subsequent sex-specific comorbid disorders. While the impact sleep apnea has on cardiovascular events has been the subject of many research studies, the role of sleep apnea in neurodegeneration is less established. Here we review known risk factors for sleep apnea and the implications of the observed sex differences in this disease. We also summarize the evidence and mechanisms for how sleep apnea may contribute to the onset of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Comparison of two exhaled biomarkers in children with and without sleep disordered breathing

OBJECTIVE

Airway oxidative stress and inflammation are likely to be involved in sleep disordered breathing (SDB) in children. We aimed to measure concentrations of 8-isoprostane (8-IsoP) in the exhaled breath condensate (EBC) and exhaled nitric oxide (FE_NO) in patients with SBD and healthy children, in order to assess the relationship between these two biomarkers, disease severity, and overnight changes.

METHODS

Patients with SDB (n = 46) and healthy controls (n = 20) aged 4.5-15.1 years (M/F: 36/30) underwent exhaled measurements. Patients with SDB underwent standard polysomnography to define primary snoring (PS: AHI < 1) and obstructive sleep apnea (OSA). Upon awakening the following morning, FE_NO was measured and EBC was collected for the measurement of EBC 8-IsoP.

RESULTS

OSA patients yielded higher awakening levels of 8-IsoP in EBC than PS patients and control subjects. The 8-IsoP levels, though not FE_NO, correlated with AHI (r = 0.40, p = 0.003) and SaO2 (r = -0.50, p = 0.001). Cut-off levels of 8-IsoP predicted OSA with a high AUC value (0.84, p = 0.000). Sensitivity and specificity for 8-IsoP levels above the percentile 50 (33.3 pg/mL) were 76.5% and 78.1%, respectively. 8-IsoP levels did not change from the evening to morning session, whereas morning FE_NO levels rose significantly only in patients with mild OSA (p = 0.03).

CONCLUSION

Levels of 8-IsoP, though not FE_NO, distinguish children with OSA from those with PS or healthy, correlate with disease severity and closely predict OSA in the whole sample.

Concurrent Presence of Obstructive Sleep Apnea and Elevated Homocysteine Levels Exacerbate the Development of Hypertension: A KoGES Six-year Follow-up Study

Accumulating evidence has revealed that obstructive sleep apnea (OSA) and high homocysteine (Hcy) levels play important roles in the increased risk of hypertension and cardiovascular disease. We investigated whether the presence of elevated Hcy levels among individuals with OSA increase the risk of hypertension in a cohort study. A total of 1825 participants were selected from the cohort study. A high homocysteine level (Hcy) was defined as those in the 75th percentile of Hcy levels of the study cohort. The prevalence of hypertension was higher among subjects with OSA and high Hcy levels than among the other groups stratified by the presence of OSA and high Hcy levels. The incidence of hypertension at 6-year follow-up was: Hcy[-]/OSA[-] vs. Hcy[+]/OSA[-] vs. Hcy[-]/OSA[+] vs. Hcy[+]/OSA[+], 14.2% vs. 19.8% vs. 24.2% vs. 36.1%. After adjusting for confounding factors, subjects with OSA and high Hcy levels had a 1.86-fold risk of developing hypertension compared to those without OSA and high Hcy levels. Moderate to severe OSA group with the highest tertile of Hcy levels had a 2.31-fold increased risk of developing hypertension. Interaction between Hcy and OSA on development of hypertension was significant, suggesting that these conditions may constitute an important determinant.

The Relationship between Sleep Disturbance, Quality of Life and Psychosocial Functioning in Pediatric Patients with Inflammatory Bowel Disease

BACKGROUND

Pediatric patients with inflammatory bowel disease (IBD) are at risk for psychiatric symptoms that impact quality of life (QoL) and psychosocial functioning. Sleep disturbance has been reported to impose adverse effects on host defense mechanisms by affecting the magnitude and characteristics of the inflammatory response. The current study sought to assess the relationships among sleep disturbance, QoL, and psychosocial functioning in children with IBD.

METHODS

Pediatric IBD patients completed multiple measures of sleep and daytime functioning as well as measures of QoL and psychosocial functioning. The parents completed complementary measures of sleep, QoL, and psychosocial functioning. The HRQOL results for subjects with IBD were compared to a healthy control group.

RESULTS

Fifty-three children with pediatric IBD and their parents were enrolled in the study. QoL was positively associated with sleep quality, based on significant negative correlations between QoL and both sleep quality and daytime sleepiness scales (r = -0.62, -0.57; p value <0.001, respectively). Patients with CD reported significantly better QoL and psychosocial functioning than patients with UC. The QoL was similar between IBD patients and healthy controls.

CONCLUSIONS

The present study suggests that a positive association exists between sleep functioning and QoL in pediatric patients with IBD. Patients with pediatric IBD should be screened for sleep disturbance, QoL and psychosocial functioning. Prevention and intervention strategies of sleep disturbance aimed at improving QoL and psychosocial functioning in children with IBD should be developed and evaluated.

Liver X Receptor Gene Expression is Enhanced in Children with Obstructive Sleep Apnea-Hyperpnoea Syndrome and Cyclooxygenase-2 (COX-2) is Correlated with Severity of Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS)

BACKGROUND Liver X receptor (LXR) is a nuclear receptor presenting in macrophages; it works indispensably in lipid metabolism control and also negatively regulates the expression of inflammatory genes in macrophages. There are many LXR-related studies in adults with metabolic syndrome but rare reports in obese children with obstructive sleep apnea-hypopnea syndrome (OSAHS). The aim of this study was to investigate the expression of LXR, cholesterol ester transfer protein (CETP), and cyclooxygenase-2 (COX-2) genes in obese children with OSAHS compared with obese children without OSAHS and non-obese children. MATERIAL AND METHODS Sleep monitoring was conducted in 80 obese children with sleep disorders. Fasting morning blood samples from the 80 obese children and 51 normal children were collected and separated, so that macrophages were obtained after culture. Fluorescence quantitative real-time PCR (RT-PCR) was used to detect expression levels of the LXR, CETP, and COX-2 genes. RESULTS LXR, COX-2, and CETP levels in the OSAHS group were higher than those in the other two groups (P<0.05), and the LXR levels in the group of obese children without OSAHS were higher than those in control group (P<0.05). COX-2 expression in the group with moderate to severe OSAHS was higher than that in the group with mild OSAHS (P<0.05). Meanwhile, there were no significant differences in the LXR and CETP levels between the moderate to severe OSAHS group and the mild OSAHS group (P>0.05). CONCLUSIONS LXR gene expression was significantly increased in obese children with OSAHS. The severity of OSAHS was positively correlated with COX-2 levels.

Red cell distribution width as a novel predictor of postoperative respiratory adverse events after adenotonsillectomy

BACKGROUND

Respiratory adverse events are commonly observed after adenotonsillectomy in children with sleep-disordered breathing. Preoperative prediction of these events enhances quality of care and resource management in facilities while encouraging precautions against them. Red cell distribution width, a measure of erythrocyte size variability, has recently been linked to adverse outcomes in a variety of disorders. Red cell distribution width has also been found to be associated with severity of obstructive sleep apnea in adults due to hypoxia-mediated inflammation.

AIM

The objective of this study was to evaluate whether elevated red cell distribution width is associated with postoperative respiratory adverse events in children with symptoms of sleep-disordered breathing.

METHODS

A prospective, observational, assessor-blinded study was conducted with consecutive children undergoing elective adenotonsillectomy for treatment of sleep-disordered breathing. Under general anesthesia, adenoidectomy was performed by curettage, and tonsillectomy was carried out by dissection. The primary outcome was the occurrence of an adverse event during emergence or in the postanesthesia care unit (PACU).

RESULTS

Among 287 patients, with mean ± sd age 7.49 ± 3.21, the frequency of respiratory complications during emergence was 62 (22.30%) and in PACU was 56 (20.14%). Mean ± sd red cell distribution width was 14.36 ± 1.06 in patients with complications and higher than that in those without complications 13.53 ± 0.59. Red cell distribution width had an adjusted odds ratio 7.28 (95% CI: 4.30-13.28) and area under the curve value 0.74 (95% CI: 0.67-0.81) to predict postoperative complications. A cutoff value for red cell distribution width was found to be 14.7.

CONCLUSION

Our study showed that preoperative elevated red cell distribution width is associated with an increased risk of respiratory adverse events in children undergoing adenotonsillectomy for sleep-disordered breathing.

Severe asthma in children

Most children with asthma have their disease easily controlled if low-dose inhaled corticosteroids (ICSs) are regularly and correctly administered. If a child presents with asthma which is apparently resistant to therapy with high-dose ICS and other controllers, then they have problematic severe asthma. However, in light of the UK National Review of Asthma Deaths, definitions of severe asthma based solely on the levels of prescribed treatment are too narrow. A detailed assessment of all such children should be performed. First, the diagnosis of asthma should be confirmed, then co-morbidities assessed. Next, a nurse-led assessment further characterizes the problem, conventionally categorizing the child as either having difficult asthma or severe therapy-resistant asthma. Here, we reassess in particular the interactions between, and management of, these two categories, highlighting that this dichotomous classification may need reconsideration. We use bronchoscopy and an intramuscular steroid injection to determine if the child has steroid-resistant asthma, using a novel, multidomain approach because the adult definition does not apply to around half the children we see. Finally, we highlight some mechanistic data which have emerged from this protocol such as the absence of T-helper 2 (TH2) cytokines even in eosinophilic severe asthma and the potential role of the innate epithelial cytokine IL-33, novel data on lineage negative innate lymphoid cells, which we can measure in induced sputum, and demonstrating that intraepithelial neutrophils are associated with better, not worse asthma outcomes. Severe paediatric asthma is very different from severe asthma in adults, and approaches must not be uncritically extrapolated from adult disease to children.

Sleepiness in Children: An Update

Sleep is essential for children's learning, memory processes, school performance, and general well-being. The prevalence of sleepiness in children is approximately 4%. Reductions of sleep duration have daytime consequences, including sleepiness, behavior problems, cognitive deficits, poor school performance, inflammation, and metabolic dysfunction. Chronic pain, movement disorders, and sleep-disordered breathing also may lead to daytime somnolence, inattention, hyperactivity, oppositional behaviors, and mood dysregulation. Parent-report questionnaires are useful tools to assess subjective sleepiness in children. Sleepiness in children may be secondary to a sleep problem, such as narcolepsy, central hypersomnia, Kleine-Levin disease, or circadian rhythm disorder.

Concurrent presence of inflammation and obstructive sleep apnea exacerbates the risk of metabolic syndrome: A KoGES 6-year follow-up study

Obstructive sleep apnea (OSA) leads to multiple end-organ morbidities that are mediated by the cumulative burden of oxidative stress and inflammation. Both OSA and inflammation play key roles in increased risk of cardiovascular disease (CVD). Thus, we hypothesized that the combination of inflammation and OSA could accelerate the development of metabolic syndrome (MetS) in a large cohort study.A total of 1835 participants were randomly selected from the ongoing Korean Genome and Epidemiology Study for the years between 2007 and 2015. Overnight polysomnography was performed on each participant. Blood was drawn for biochemical analyses. Participants with high or low inflammation were divided by high-sensitivity C-reactive protein (hsCRP). MetS was defined using the criteria of the modified National Cholesterol Education Program, Adult Treatment Panel III.The prevalence of MetS was higher among the subjects with OSA and high hsCRP levels than among the other corresponding groups. The incidence of MetS among the 4 groups stratified by OSA and inflammation status at the 6-year follow-up was 11.8%, 19.9%, 25.8%, and 36.0% (HsCRP[-]/OSA[-] vs HsCRP[+]/OSA[-] vs HsCRP[-]/OSA[+] vs HsCRP[+]/OSA[+], P < 0.01). After adjusting for age, sex, smoking, alcohol status, BMI, and change in BMI (ΔBMI) in a multiple logistic regression, the subjects with OSA and high hsCRP levels at follow-up had a 2.22-fold risk of developing MetS, as compared with those with no-OSA and low hsCRP levels (P < 0.01).MetS is more prevalent in the concurrent presence of inflammation and OSA. The combination of these conditions is associated with higher risk of MetS. Additional research is needed to help further define the significance of the combined effect of OSA and subclinical inflammation on the development of MetS in the context of reduction of CVD risk.

Obstructive Sleep Apnea Is Associated with Elevated High Sensitivity C-Reactive Protein Levels Independent of Obesity: Korean Genome and Epidemiology Study

Obstructive sleep apnea syndrome (OSA) has been recognized as a common health problem, and increasing obesity rates have led to further remarkable increases in the prevalence of OSA, along with more prominent cardiovascular morbidities. Though previous studies have reported an independent relationship between elevated high sensitivity C-reactive protein (hsCRP) levels and OSA, the issue remains controversial owing to inadequate consideration of obesity and various confounding factors. So far, few population based studies of association between OSA and hsCRP levels have been published. Therefore, the purpose of the present study was to investigate whether OSA is associated with increased hsCRP levels independent of obesity in a large population-based study. A total of 1,835 subjects (968 men and 867 women) were selected from a larger cohort of the ongoing Korean Genome and Epidemiology Study (KoGES). Overnight polysomnography was performed on each participant. All participants underwent anthropometric measurements and biochemical analyses, including analysis of lipid profiles and hsCRP levels. Based on anthropometric data, body mass index (BMI) and waist hip ratio (WHR) were calculated and fat mass (FM) were measured by means of multi-frequency bioelectrical impedance analysis (BIA). Mild OSA and moderate to severe OSA were defined by an AHI >5 and ≥15, respectively. The population was sub-divided into 3 groups based on the tertile cut-points for the distribution of hsCRP levels. The percentage of participants in the highest tertile of hsCRP increased dose-dependently according to the severity of OSA. After adjustment for potential confounders and obesity-related variables (BMI, WHR, and body fat) in a multiple logistic model, participants with moderate to severe OSA had 1.73-, 2.01-, and 1.61-fold greater risks of being in the highest tertile of hsCRP levels than participants with non-OSA, respectively. Interaction between obesity (BMI ≥25kg/m²) and the presence of moderate-to-severe OSA was significant on the middle tertile levels of hsCRP (OR = 2.4), but not on the highest tertile, compared to the lowest tertile. OSA is independently associated with elevated hsCRP levels and may reflect an increased risk for cardiovascular morbidity. However, we found that OSA and obesity interactively contribute to individuals with general levels of hsCRP (<1.01 mg/dl). The short-term and long-term effects of elevated hsCRP levels on cardiovascular risk in the context of OSA remain to be defined in future studies.

Substance Use as a Risk Factor for Sleep Problems Among Adolescents Presenting to the Emergency Department

OBJECTIVES

To determine correlates of sleep problems among adolescents. Specifically, to assess the relative strength of associations between sleep problems and dating victimization, reasons for emergency department (ED) visit, depression, unhealthy alcohol use, and other drug use (marijuana, nonmedical use of prescription opioids, stimulants, and tranquilizers).

METHODS

A total of 1852 adolescents aged 14 to 20 years presenting for care to the University of Michigan Emergency Department, Ann Arbor, Michigan, during 2011-2012, self-administered a computerized health survey. Sleep problems were identified if any of the 4 items on the Sleep Problems Questionnaire were rated by a patient as greater than 3 on a 0 to 5 scale. Adolescents who were too sick to be screened in the ED were eligible to participate in the study during their inpatient stay. Exclusion criteria for baseline included insufficient cognitive orientation precluding informed consent, not having parent/guardian present if younger than 18 years, medical severity precluding participation, active suicidal/homicidal ideation, non-English-speaking, deaf/visually impaired, or already participated in this study on a prior visit.

RESULTS

23.5% of adolescents reported clinically significant sleep problems. Female gender, depression, dating victimization, tobacco use, nonmedical use of prescription medication, and an ED visit for medical reasons were each associated with sleep problems among adolescents, even while controlling for age, other types of drug use, receiving public assistance, and dropping out of school.

CONCLUSIONS

These exploratory findings indicate that ED-based screening and brief intervention approaches addressing substance use and/or dating victimization may need to account for previously undiagnosed sleep problems.

Obstructive sleep apnoea in children with obesity

AIMS

The aim of this study was to identify factors that predict risk of obstructive sleep apnoea (OSA) in obese children, which could aid in prioritising sleep studies.

METHODS

A retrospective chart review was undertaken of obese children seen in the KOALA weight management clinic and Sleep clinic. Data collected included demographics, clinical history, examination findings, biochemical markers, and polysomnogram results.

RESULTS

Two hundred seventy-two obese children were seen in the KOALA clinic out of which 54 (20%) were also seen in the Sleep clinic because of snoring. Thirty-two were referred by the KOALA clinic; the remaining 22 were referred by other medical practitioners prior to being seen in the KOALA clinic. Thirty-nine had polysomnograms. The time from referral to Sleep clinic ranged from 10 days to 1.5 years with 50% seen within 6 months; with similar time gap between the blood tests and time of polysomnograms. Thirty-six percent (14/39) were reported to have OSA. Six children were Aboriginal/Torres Strait Islander (ATSI) and all had OSA, which was statistically significant (P = 0.004). There was a statistically significant correlation between high-sensitivity C-reactive protein (hs-CRP) and obstructive event index (OEI) in rapid eye movement (REM) sleep. (r = 0.50, P = 0.04). Correlation between low-density lipoprotein (LDL) and OEI in REM was r = 0.36, P = 0.06, which approached significance.

CONCLUSIONS

Ethnicity was a significant factor with more obese ATSI children having OSA. The significant correlation between hs-CRP with OEI is consistent with findings of previous studies. Several factors (glycosylated haemoglobin, LDL) approached significance.

C-reactive Protein as a Potential Biomarker of Residual Obstructive Sleep Apnea Following Adenotonsillectomy in Children

STUDY OBJECTIVES

Adenotonsillectomy (AT) is first-line treatment for pediatric obstructive sleep apnea (OSA), with most children having improvements in polysomnography (PSG). However, many children have residual OSA following AT as determined through PSG. Identification of a biomarker of residual disease would be clinically meaningful to detect children at risk. We hypothesize serum high-sensitivity C-reactive protein (hsCRP), an inflammatory biomarker, is predictive of residual OSA following AT.

METHODS

PSG was performed both preoperatively and postoperatively on children undergoing AT for the diagnosis of OSA. HsCRP serum concentrations were determined in all children pre-AT, and in most children post-AT. Resolution of OSA after AT was defined by a post-AT apnea-hypopnea index (AHI) < 1.5/h total sleep time (TST). Residual OSA was defined as a post-AT AHI > 5/h TST, which is considered clinically significant.

RESULTS

AT significantly improved the AHI from 15.9 ± 16.4 to 4.1 ± 5.3/h TST in 182 children (P < 0.001). Of 182 children, residual OSA (post-AT AHI > 5) was seen in 46 children (25%). Among children who had hsCRP levels measured pre- and post-AT (n = 155), mean hsCRP levels pre-AT were 0.98 ± 1.91 mg/L and were significantly reduced post-AT (0.63 ± 2.24 mg/dL; P = 0.011). Stratification into post-AT AHI groups corresponding to < 1.5/h TST, 1.5/h TST < AHI < 5/h TST, and AHI > 5/h TST revealed post-AT hsCRP levels of 0.09 ± 0.12, 0.57 ± 2.28, and 1.49 ± 3.34 mg/L with statistical significance emerging comparing residual AHI > 5/h TST compared to post-AT AHI < 1.5/h TST (P = 0.006). Hierarchical multivariate modeling confirmed that pre-AT AHI and post-AT hsCRP levels were most significantly associated with residual OSA.

CONCLUSIONS

Even though AT improves OSA in most children, residual OSA is frequent. Assessment of post-AT hsCRP levels emerges as a potentially useful biomarker predicting residual OSA.

Is there an effect of obstructive sleep apnea syndrome on oxidative stress and inflammatory parameters in patients with craniofacial anomalies?

The aim of this study was to test the hypothesis that obstructive sleep apnea syndrome (OSAS) exhibits oxidative stress and inflammation in patients who have a congenital, craniofacial anomaly.This prospective, cross-sectional cohort study included ambulant sleep study data to asses OSAS in patients with syndromic craniosynostosis and Treacher Collins syndrome. Laboratory analyses were performed including malondialdehyde, tumor necrosis factor α (TNF-α), interleukin 6, and high-sensitivity C-reactive protein.Forty-eight patients were included; 11 were adults; 37 were children. The patients' body mass indexes were normal, with a median (SD) of 0.7 (-1.82 to 2.48) in children and 20.5 (15.2-29.4) in adults. Obstructive sleep apnea syndrome was diagnosed in 23 of 48 patients. It was mild (median obstructive apnea-hypopnea index [oAHI], 2.3; oxygenation-desaturation index [ODI], 0.9) in 16 patients and moderate/severe in 7 patients (median oAHI, 10.8; ODI, 5.0). Neither oxidative stress nor inflammation had a correlation with the oAHI and ODI. Only TNF-α was found significantly higher in both the OSAS and non-OSAS groups compared with the reference values (median, 15.1 pg/mL and 12.3 pg/mL versus 4.05 [0.0-8.1 pg/mL], P < 0.001 and P < 0.001, respectively).Based on our findings we conclude that (mainly mild) OSAS, oxidative stress, as well as high-sensitivity C-reactive protein and interleukin 6 levels are not abnormal in the day time in a population of nonobese patients with a craniofacial anomaly. The increased level of TNF-α cannot be explained by OSAS. Future research should focus on mapping chronobiologic changes for further interpretation of the results.

Obesity and Altered Sleep: A Pathway to Metabolic Derangements in Children?

Obstructive sleep apnea (OSA) is a frequent disorder in children and is primarily associated with adenotonsillar hypertrophy. The prominent increases in childhood overweight and obesity rates in the world even among youngest of children have translated into parallel increases in the prevalence of OSA, and such trends are undoubtedly associated with deleterious global health outcomes and life expectancy. Even an obesity phenotype in childhood OSA, more close to the adult type, has been recently proposed. Reciprocal interactions between sleep in general, OSA, obesity, and disruptions of metabolic homeostasis have emerged in recent years. These associations have suggested the a priori involvement of complex sets of metabolic and inflammatory pathways, all of which may underlie an increased risk for increased orexigenic behaviors and dysfunctional satiety, hyperlipidemia, and insulin resistance that ultimately favor the emergence of metabolic syndrome. Here, we review some of the critical evidence supporting the proposed associations between sleep disruption and the metabolism-obesity complex. In addition, we describe the more recent evidence linking the potential interactive roles of OSA and obesity on metabolic phenotype.

Nasal nitric oxide in sleep-disordered breathing in children

BACKGROUND

Inflammation plays a role in the pathogenesis and consequences of sleep-disordered breathing (SDB). The nasal mucosa and paranasal sinuses produce high levels of nitric oxide (NO). In asthma, exhaled NO is a marker of airway inflammation. There is only limited information whether nasal NO (nNO) accompanies also chronic upper airway obstruction, specifically, SDB. The objective of this study was to investigate nNO levels in children with SDB in comparison to healthy non-snoring children.

METHODS

Nasal NO was measured in children who underwent overnight polysomnographic studies due to habitual snoring and suspected SDB and in healthy non-snoring controls.

RESULTS

One hundred and eleven children participated in the study: 28 with obstructive sleep apnea (OSA), 60 with primary snoring (PS), and 23 controls. Nasal NO levels were significantly higher in children with OSA and PS compared to controls (867.4 ± 371.5, 902.0 ± 330.9, 644.1 ± 166.5 ppb, respectively, p = 0.047). No difference was observed between children with OSA and PS. No correlations were found between nNO levels and any of the PSG variables, nor with age, BMI percentile or tonsils size.

CONCLUSIONS

Compared to healthy controls, nNO is increased in children with SDB, but it is not correlated with disease severity. This is probably due to the local mechanical processes and snoring.

Acute sleep fragmentation induces tissue-specific changes in cytokine gene expression and increases serum corticosterone concentration

Sleep deprivation induces acute inflammation and increased glucocorticosteroids in vertebrates, but effects from fragmented, or intermittent, sleep are poorly understood. Considering the latter is more representative of sleep apnea in humans, we investigated changes in proinflammatory (IL-1β, TNF-α) and anti-inflammatory (TGF-β1) cytokine gene expression in the periphery (liver, spleen, fat, and heart) and brain (hypothalamus, prefrontal cortex, and hippocampus) of a murine model exposed to varying intensities of sleep fragmentation (SF). Additionally, serum corticosterone was assessed. Sleep was disrupted in male C57BL/6J mice using an automated sleep fragmentation chamber that moves a sweeping bar at specified intervals (Lafayette Industries). Mice were exposed to bar sweeps every 20 s (high sleep fragmentation, HSF), 120 s (low sleep fragmentation, LSF), or the bar remained stationary (control). Trunk blood and tissue samples were collected after 24 h of SF. We predicted that HSF mice would exhibit increased proinflammatory expression, decreased anti-inflammatory expression, and elevated stress hormones in relation to LSF and controls. SF significantly elevated IL-1β gene expression in adipose tissue, heart (HSF only), and hypothalamus (LSF only) relative to controls. SF did not increase TNF-α expression in any of the tissues measured. HSF increased TGF-β1 expression in the hypothalamus and hippocampus relative to other groups. Serum corticosterone concentration was significantly different among groups, with HSF mice exhibiting the highest, LSF intermediate, and controls with the lowest concentration. This indicates that 24 h of SF is a potent inducer of inflammation and stress hormones in the periphery, but leads to upregulation of anti-inflammatory cytokines in the brain.

Sleep-disordered breathing, sleep duration, and childhood overweight: a longitudinal cohort study

OBJECTIVES

To examine independent associations between sleep-disordered breathing (SDB), sleep duration from birth through 6.75 years, and body mass index (BMI) through 15 years of age in a population-based cohort.

STUDY DESIGN

The Avon Longitudinal Study of Parents and Children collected parent questionnaire data on child sleep duration and SDB symptoms from birth through 6.75 years and child BMI from the Avon Longitudinal Study of Parents and Children research clinics (n = 1899). For SDB, logistic regression models-minimal, confounder, and confounder + sleep duration adjusted-examined associations with BMI at 7, 10, and 15 years of age. For short sleep duration (≤10th percentile), comparable SDB-adjusted models examined associations with BMI at 15 years of age.

RESULTS

Children with the worst SDB symptoms vs asymptomatic children, had increased odds of overweight at 7 (OR = 2.08, 95% CI = 1.04-4.17), 10 (OR = 1.79, 95% CI = 1.02-3.16), and 15 years of age (OR = 2.25, 95% CI = 1.27-3.97) in models adjusted for sleep duration. Similarly, short sleep duration at ≈5-6 years was associated with overweight at 15 years, independent of SDB. Children with short sleep duration at 4.75 years were more likely to be overweight at 15 years in minimally (OR = 2.21, 95% CI = 1.52-3.20), confounder (OR = 1.99, 95% CI = 1.34-2.96), and SDB-adjusted (OR = 2.04, 95% CI = 1.36-3.04) models.

CONCLUSIONS

Both SDB and short sleep duration significantly and independently increase children's odds of becoming overweight. Findings underscore the potential importance of early identification and remediation of SDB, along with insufficient sleep, as strategies for reducing childhood obesity.

Effect of chronic continual- and intermittent hypoxia-induced systemic inflammation on the cardiovascular system in rats

PURPOSE

Obstructive sleep apnea syndrome (OSAS) has been recognized as an important risk factor for cardiovascular morbidity and mortality. However, the underlying mechanisms are poorly understood. Present study aimed to investigate the role of NF-κB-dependent inflammation pathways in pathophysiological responses of cardiovascular system in OSAS.

METHODS

Thirty male specific pathogen-free (SPF) Sprague-Dawley rats were randomly assigned to normoxia (N) group, continual hypoxia (CH) group, and intermittent hypoxia (IH) group (n = 10) and were exposed to N (21% O2), CH (8% O2), or IH (6-11% O2 for 10 s and 21% O2 for 80 s in every 90 s) for 8 h/day for 35 days. The hemodynamic and pathomorphologic effects of IH and CH exposure were investigated as well as the expression of NF-κB-dependent inflammation factors.

RESULTS

Chronic IH or CH significantly increased mean pulmonary arterial pressure (mPAP) in rats, while no significant changes occurred in mean carotid arterial pressure (mCAP). The ratio of right ventricle (RV) to left ventricle (LV) + septum (S) was significantly increased by both IH and CH, suggesting RV hypertrophy was induced by IH or CH. Elastic fiber staining showed an irregular pattern of elastic fiber distribution after hypoxia, and aortic tunica media thickness was increased. Both chronic IH and CH upregulated the expressions of transcription factor NF-κB and related pro-inflammatory cytokines and adhesion molecules.

CONCLUSIONS

The current study expands our understanding that both IH and CH could activate the expression of NF-κB and related inflammatory factors as well as cause pathophysiologic damage to the cardiovascular system in OSAS. All these results provide further support to an emerging hypothesis that activation of NF-κB-dependent inflammation may play a central role in the pathophysiology of cardiovascular dysfunction in OSAS.

Chronic sleep fragmentation induces endothelial dysfunction and structural vascular changes in mice

STUDY OBJECTIVES

Sleep fragmentation (SF) is a common occurrence and constitutes a major characteristic of obstructive sleep apnea (OSA). SF has been implicated in multiple OSA-related morbidities, but it is unclear whether SF underlies any of the cardiovascular morbidities of OSA. We hypothesized that long-term SF exposures may lead to endothelial dysfunction and altered vessel wall structure.

METHODS AND RESULTS

Adult male C57BL/6J mice were fed normal chow and exposed to daylight SF or control sleep (CTL) for 20 weeks. Telemetric blood pressure and endothelial function were assessed weekly using a modified laser-Doppler hyperemic test. Atherosclerotic plaques, elastic fiber disruption, lumen area, wall thickness, foam cells, and macrophage recruitment, as well as expression of senescence-associated markers were examined in excised aortas. Increased latencies to reach baseline perfusion levels during the post-occlusive period emerged in SF mice with increased systemic BP values starting at 8 weeks of SF and persisting thereafter. No obvious atherosclerotic plaques emerged, but marked elastic fiber disruption and fiber disorganization were apparent in SF-exposed mice, along with increases in the number of foam cells and macrophages in the aorta wall. Senescence markers showed reduced TERT and cyclin A and increased p16INK4a expression, with higher IL-6 plasma levels in SF-exposed mice.

CONCLUSIONS

Long-term sleep fragmentation induces vascular endothelial dysfunction and mild blood pressure increases. Sleep fragmentation also leads to morphologic vessel changes characterized by elastic fiber disruption and disorganization, increased recruitment of inflammatory cells, and altered expression of senescence markers, thereby supporting a role for sleep fragmentation in the cardiovascular morbidity of OSA.

Nitric oxide production by monocytes in children with OSA and endothelial dysfunction

Endothelial dysfunction in the context of paediatric sleep apnoea is associated with distinctive alterations in circulating monocyte subsets and reduced NO production by monocytes.

Assessment of sleep problems in children with familial Mediterranean fever

AIMS

This study aimed to investigate sleep patterns, sleep disturbances and possible factors that are associated with sleep disturbances among children with familial Mediterranean fever (FMF).

PATIENTS AND METHODS

Fifty-one patients with FMF and 84 age- and sex-matched healthy controls were enrolled in the study. The patients who had an attack during the last 2 weeks were not included. Demographic data, FMF symptoms, disease duration, dose of colchicine, disease severity score, number of attacks in the last year, MEFV mutation and serum C-reactive protein (CRP) levels were recorded for each patient. A Children's Sleep Habits Questionnaire was performed.

RESULTS

The total sleep scores of the patients with FMF were significantly higher than the control group. Total sleep durations were similar between FMF patients and controls. Children with FMF had significantly higher scores regarding sleep-onset delay, sleep anxiety, night wakings and sleep-disordered breathing when compared to healthy controls. There was a significant positive correlation between number of attacks in the last year and sleep onset delay, night wakings and sleep disordered-breathing. Disease severity score and CRP levels were not associated with any of the subscale scores. The patients with exertional leg pain had significantly higher total sleep scores than the ones without. Furthermore, patients with exertional leg pain had significantly higher subscale scores regarding sleep onset delay, parasomnias and sleep-disordered breathing.

CONCLUSION

This study showed for the first time that children with FMF had more sleep disturbances than their healthy peers. Higher numbers of attacks and exertional leg pain were associated with poor sleep quality. In conclusion, this study underlines the need to assess and manage sleep problems in children with FMF.

Contextualised urinary biomarker analysis facilitates diagnosis of paediatric obstructive sleep apnoea

BACKGROUND

Intrinsic variance of the urine proteome limits the discriminative power of proteomic analysis and complicates potential biomarker detection in the context of paediatric sleep disorders.

METHODS AND RESULTS

Using a rigorous workflow for proteomic analysis of urine, we demonstrate that gender and diurnal effects constitute two important sources of variability in healthy children. In the context of disease, complex pathophysiological perturbations magnify these proteomic differences and therefore require contextualised biomarker analysis. Indeed, by performing biomarker discovery in a gender- and diurnal-dependent manner, we identified ∼30-fold more candidate biomarkers of paediatric obstructive sleep apnoea (OSA), a highly prevalent condition in children characterised by repetitive episodes of intermittent hypoxia and hypercapnia, and sleep fragmentation in the context of recurrent upper airway obstructive events during sleep. Remarkably, biomarkers were highly specific for gender and sampling time as poor overlap (∼3%) was observed in the proteins identified in boys and girls across morning and bedtime samples.

CONCLUSIONS

As no clinical basis to explain gender-specific effects in OSA or healthy children is apparent, we propose that implementation of contextualised biomarker strategies will be applicable to a broad range of human diseases, and may be specifically applicable to paediatric OSA.