Effects of adenotonsillectomy on plasma inflammatory biomarkers in obese children with obstructive sleep apnea: A community-based study

Positive Airway Pressure and Metabolic Markers in Children With Obstructive Sleep Apnea

BACKGROUND

Increasing evidence suggests an association between childhood obstructive sleep apnea (OSA) and metabolic syndrome, with more research available on the potential impacts of positive airway pressure (PAP) on metabolic markers in children. The purpose of this systematic review is to provide a systematic synthesis of the evidence on the effect of PAP use on metabolic markers in children with OSA.

METHODS

A search strategy with terms for "OSA" and metabolic markers in pediatrics was run to systematically assess 5 databases until August 26, 2022. Two reviewers independently screened eligible articles, extracted data, and conducted quality appraisal. Meta-analysis was done using random-effects models. Body mass index (BMI), glycemic, lipid, cardiovascular, and other metabolic and inflammatory markers were reported.

RESULTS

Sixteen studies (N = 1,213) were included, 15 observational studies and 1 randomized controlled trial (RCT); most reported outcomes in children with obesity. Meta-analysis of 4 studies found no changes in BMI at median average follow-up of 12 months after PAP initiation. A reduction in heart rate and blood pressure parameters was demonstrated in several studies in children with OSA with and without obesity at a median average follow-up of 4.9 months after PAP initiation. Research in echocardiographic outcomes is limited, including one RCT in children with Down syndrome and OSA showing no changes in heart rate variability parameters. Evidence of improvements in glycemic and/or lipid control, liver enzymes, and inflammatory markers with PAP therapy is even more limited and of limited clinical importance. Risk of bias was moderate to critical and outcome evidence very low.

CONCLUSIONS

Although evidence on effects of PAP on metabolic markers in children with OSA is encouraging, available literature is limited. Longitudinal studies are still required to further assess the long-term influence of PAP on metabolic and inflammatory markers, particularly in children with obesity.

Efficacy of adenotonsillectomy on pediatric obstructive sleep apnea and related outcomes: A narrative review of current evidence

This review summarizes the current evidence in systematic reviews, meta-analysis and randomized controlled trials regarding adenotonsillectomy outcomes in pediatric obstructive sleep apnea (OSA). Adenotonsillectomy is effective in treating OSA in children without co-morbidities, despite postoperative residual OSA remained in roughly half of these children. For children with comorbidities such as Down syndrome, Prader-Willi syndrome, sickle cell disease, or cerebral palsy, adenotonsillectomy is less effective and associated with more postoperative complications than that in children without comorbidities. For other OSA-related outcomes, evidence from meta-analyses and randomized controlled trials confirm adenotonsillectomy results in improvement of subjective OSA-related outcomes (e.g. symptoms, behaviors, and quality of life), but the results in objective OSA-related outcomes (e.g. cardiometabolic parameters or neurocognitive functions) are inconsistent. Future studies should focus on randomized controlled trials comparing objective OSA-related outcomes and the long-term effects of adenotonsillectomy in children with OSA.

Salivary biomarker C-reactive protein levels in children with sleep problems and Class II malocclusion before and after twin-block therapy

Context

Disturbances in sleep affects the overall quality of a child's life, with several short- and long-lasting consequences. Hence, early diagnosis and monitoring is crucial in the management of sleep disorders in children.

Aims

The aim of this study was to evaluate salivary C-reactive protein (CRP) levels in a group of children with Class II malocclusion and sleep problems before and after twin-block appliance therapy.

Settings and Design

The study was a prospective clinical study with a 9-month follow-up period.

Subjects and Methods

Eleven children aged 8-12 years with skeletal Class II malocclusion and at least one sleep disorder were enrolled in the study. All children were subjected to a recording of their sleep history and a clinical as well as radiographic examination. Pretreatment levels of salivary CRP were recorded. A twin-block appliance was custom made and delivered to every child. At the end of 9-month follow-up, all children were recalled for a re-evaluation of salivary biomarker levels.

Statistical Analysis

Pretreatment and posttreatment changes in biomarker levels were assessed statistically using the students paired t-test.

Results

Levels of salivary biomarker CRP were significantly decreased in children following myofunctional therapy using a twin-block appliance (P < 0.001). There was a considerable improvement in the clinical symptoms such as a decrease in snoring and noisy breathing in most children post-twin-block therapy.

Conclusion

The measurement of salivary biomarker CRP could be used as an alternative and noninvasive method to evaluate prognosis of oral myofunctional therapy for children with sleep disordered breathing.

Circulating levels of adropin and diabetes: a systematic review and meta-analysis of observational studies

OBJECTIVE

Adropin, a newly identified regulatory protein has garnered attention given its potential role in metabolism regulation, especially glucose metabolism and insulin resistance. However, studies on the association between adropin and type 2 diabetes mellitus (T2DM) are equivocal. The aim of this study is to assess the association between serum adropin levels and T2DM using a systematic review and meta-analysis of observational studies.

METHODS

PubMed, Scopus, ISI Web of science, and Google Scholar were searched, up to August 2022, for studies that reported the association between serum levels of adropin in adults with T2DM compared to a control group without diabetes. A random-effect model was used to compute the pooled weighted mean difference (WMD) with 95% confidence intervals (CI).

RESULTS

Meta-analysis of 15 studies (n = 2813 participants) revealed that the serum adropin concentrations were significantly lower in patients with T2DM compared with the control group (WMD= -0.60 ng/mL, 95% CI: -0.70 to -0.49; I² = 99.5%). Subgroup analysis also found lower concentration of adropin in patients with T2DM who were otherwise healthy compared to a control group (n = 9; WMD=-0.04 ng/ml, 95% CI= -0.06 to -0.01, p = 0.002; I² = 96.4).

CONCLUSIONS

Our study showed adropin levels are lower in patients with diabetes compared to a control group without diabetes. However, the limitations of observational studies challenge the validity of the results, and further investigations are needed to confirm the veracity of these findings and additionally explore possible mechanisms.

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.

Impact of OSA treatment success on changes in hypertension and obesity: A retrospective cohort study

OBJECTIVE

Pediatric obstructive sleep apnea (OSA) has been shown to lead to the development of chronic cardiometabolic conditions, including obesity and cardiovascular disease. We sought to describe the impact of the success of continuous positive airway pressure (CPAP) and surgery, common treatment options for pediatric OSA, on cardiometabolic conditions.

METHODS

A retrospective review of patients (≤18 years) diagnosed with OSA based on a polysomnogram at a tertiary care pediatric otolaryngology practice from 2015 to 2019 was conducted. Clinical data, including the systolic blood pressure (SBP) values, body mass index (BMI), overall apnea/hypopnea index (AHI) values, and CPAP compliance, were collected. Linear mixed-effects models were developed to observe the relationship between the clinical measurements of each comorbidity and OSA treatment modalities.

RESULTS

414 patients were included. BMI and SBP measures were collected for 230 and 184 patients respectively. The difference-in-difference estimate for the SBP z-score percentile after successful treatment was -5.5 ± 2.1 percentile units per 100 days. The difference-in-difference estimate for SBP z-score percentile after successful CPAP treatment was -13.2 ± 5.1 percentile units per 100 days while the estimate after successful surgical treatment was -4.6 ± 2.4 percentile units per 100 days. No significant differences were found between clinical measures for obese patients in any treatment cohort.

CONCLUSIONS

Successful OSA management was shown to have a positive impact on SBP in hypertensive patients and no impact on BMI in obese patients. In hypertensive patients, CPAP success tripled improvements in SBP z-score percentile compared to surgical treatment success.

Chronic Intermittent Hypoxia during Sleep Causes Browning of Interscapular Adipose Tissue Accompanied by Local Insulin Resistance in Mice

Obstructive sleep apnea (OSA) is a highly prevalent condition, characterized by intermittent hypoxia (IH), sleep disruption, and altered autonomic nervous system function. OSA has been independently associated with dyslipidemia, insulin resistance, and metabolic syndrome. Brown adipose tissue (BAT) has been suggested as a modulator of systemic glucose tolerance through adaptive thermogenesis. Reductions in BAT mass have been associated with obesity and metabolic syndrome. No studies have systematically characterized the effects of chronic IH on BAT. Thus, we aimed to delineate IH effects on BAT and concomitant metabolic changes. C57BL/6J 8-week-old male mice were randomly assigned to IH during sleep (alternating 90 s cycles of 6.5% F_IO₂ followed by 21% F_IO₂) or normoxia (room air, RA) for 10 weeks. Mice were subjected to glucose tolerance testing and ¹⁸F-FDG PET-MRI towards the end of the exposures followed by BAT tissues analyses for morphological and global transcriptomic changes. Animals exposed to IH were glucose intolerant despite lower total body weight and adiposity. BAT tissues in IH-exposed mice demonstrated characteristic changes associated with "browning"-smaller lipids, increased vascularity, and a trend towards higher protein levels of UCP1. Conversely, mitochondrial DNA content and protein levels of respiratory chain complex III were reduced. Pro-inflammatory macrophages were more abundant in IH-exposed BAT. Transcriptomic analysis revealed increases in fatty acid oxidation and oxidative stress pathways in IH-exposed BAT, along with a reduction in pathways related to myogenesis, hypoxia, and IL-4 anti-inflammatory response. Functionally, IH-exposed BAT demonstrated reduced absorption of glucose on PET scans and reduced phosphorylation of AKT in response to insulin. Current studies provide initial evidence for the presence of a maladaptive response of interscapular BAT in response to chronic IH mimicking OSA, resulting in a paradoxical divergence, namely, BAT browning but tissue-specific and systemic insulin resistance. We postulate that oxidative stress, mitochondrial dysfunction, and inflammation may underlie these dichotomous outcomes in BAT.

Serum leptin differs in children with obstructive sleep apnea: A meta-analysis and PRISMA compliant article

BACKGROUND

Obstructive sleep apnea (OSA) as an independent cardiovascular risk factor has been proposed, but the mechanisms underlying cardiovascular disease is far from being completely elucidated. Leptin, an inflammatory cytokine produced by adipocytes, contributes to the modulation of metabolism, respiratory control, and inflammation, which are factors associated with cardiovascular disease. Serum levels of leptin in children with OSA have shown conflicting results in previous studies.

METHODS

We performed a meta-analysis to clarify the correlation between leptin expression of the OSA patients following the PRISMA. PubMed, Embase, and Web of Science were systematically searched for relevant studies, and then independently screened by two researchers, and analyzed the data through STATA version 12.0.

RESULTS

In a total of 5 articles including 469 participants, the data analysis showed that serum leptin levels were elevated in children with OSA (MD, 6.36; 95% CI, 0.24-12.49, P < .001), compared to the control group. Subgroup analysis were performed based on body mass index. The results of subgroup analysis demonstrated that the serum leptin concentration was correlated with body mass index in children with OSA (MD, 9.70; 95% CI, 0.22-11.18, P < .001).

CONCLUSIONS

The serum leptin levels were elevated in children with OSA, compared to the control group. It could add to our developing understanding of the pathogenesis and potential treatments for children with OSA, and help us to recognize the relevance of OSA in determining cardiovascular issues among children.

PAI-1: A Major Player in the Vascular Dysfunction in Obstructive Sleep Apnea?

Obstructive sleep apnea is a chronic and prevalent condition that is associated with endothelial dysfunction, atherosclerosis, and imposes excess overall cardiovascular risk and mortality. Despite its high prevalence and the susceptibility of CVD patients to OSA-mediated stressors, OSA is still under-recognized and untreated in cardiovascular practice. Moreover, conventional OSA treatments have yielded either controversial or disappointing results in terms of protection against CVD, prompting the need for the identification of additional mechanisms and associated adjuvant therapies. Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of tissue-type plasminogen activator (tPA) and urinary-type plasminogen activator (uPA), is a key regulator of fibrinolysis and cell migration. Indeed, elevated PAI-1 expression is associated with major cardiovascular adverse events that have been attributed to its antifibrinolytic activity. However, extensive evidence indicates that PAI-1 can induce endothelial dysfunction and atherosclerosis through complex interactions within the vasculature in an antifibrinolytic-independent matter. Elevated PAI-1 levels have been reported in OSA patients. However, the impact of PAI-1 on OSA-induced CVD has not been addressed to date. Here, we provide a comprehensive review on the mechanisms by which OSA and its most detrimental perturbation, intermittent hypoxia (IH), can enhance the transcription of PAI-1. We also propose causal pathways by which PAI-1 can promote atherosclerosis in OSA, thereby identifying PAI-1 as a potential therapeutic target in OSA-induced CVD.

Metabolic alterations and systemic inflammation in overweight/obese children with obstructive sleep apnea

Aim and objective

Systemic inflammation has been documented in obstructive sleep apnea (OSA). However studies on childhood OSA and systemic inflammation are limited. This study aimed to determine the relation between OSA in overweight/obese children and various inflammatory markers.

Material and methods

In this cross sectional study, we enrolled 247 overweight/ obese children from pediatric outpatient services. We evaluated demographic and clinical details, anthropometric parameters, body composition and estimation of inflammatory cytokines such as interleukin (IL) 6, IL-8, IL-10, IL-17, IL-18, IL-23, macrophage migration inhibitory factor (MIF), high sensitive C-reactive protein (Hs-CRP), tumor necrosis factor-alpha (TNF-α), plasminogen activator inhibitor-1 (PAI-1) and leptin levels. Overnight polysomnography was performed.

Findings

A total of 247 children (190 with OSA and 57 without OSA) were enrolled. OSA was documented on polysomnography in 40% of patients. We observed significantly high values body mass index, waist circumference (WC), % body fat, fasting blood glucose (FBG), alanine transaminase (ALT), alkaline phosphate, fasting insulin and HOMA-IR in children with OSA. Inflammatory markers IL-6, IL-8, IL-17, IL-18, MIF, Hs CRP, TNF- α, PAI-1, and leptin levels were significantly higher in OSA patients (p<0.05). There was strong positive correlation of IL-6, IL-8, IL-17, IL-23, MIF, Hs CRP, TNF-A, PAI-1 and leptin with BMI, % body fat, AHI, fasting Insulin, triglyceride, FBG, WC, HOMA-IR, AST and ALT.

Conclusion

Children with OSA have increased obesity, insulin resistance and systemic inflammation. Further studies are require to confirm our findings and evaluate their utility in diagnosis of OSAs, assessing severity and possible interventions.

Phenotypic variance in pediatric obstructive sleep apnea

It is crucial that clinicians understand what underpins the considerable phenotypic variance in pediatric obstructive sleep apnea syndrome (OSAS), if they are to implement individually tailored phenotype-based approaches to diagnosis and management. This review summarizes the current literature on how disease severity, comorbidities, genetic and environmental/lifestyle factors interact to determine the overall OSAS phenotype. The first part discusses the impact of these factors on OSAS-related morbidity in the context of otherwise healthy children, whilst the second half details children with complex conditions, particularly focusing on the anatomical and functional abnormalities predisposing to upper airway obstruction unique to each condition. One can then understand the need for a multidimensional assessment strategy for pediatric OSAS; one that incorporates the history, physical examination, sleep study results, and biomarkers to enable precise stratification, so vital for effective determination of the timing and the nature of the therapeutic interventions required.

Elevation of CD40/CD40L Inflammatory Pathway Molecules in Carotid Plaques from Moderate-and-Severe Obstructive Sleep Apnea Patients

A chronic inflammatory process characteristic of obstructive sleep apnea promotes vascular endothelial dysfunction and atherogenesis. This process can lead to destabilization and rupture of cardiovascular plaques, which clinically manifests as an acute coronary syndrome or stroke. The aim of this study was to investigate the inflammatory pathway leading to plaque destabilization in non-to-mild and moderate-to-severe groups of OSA patients. This prospective study involved enrollment of patients scheduled for endarterectomy. A sleep study was performed prior to surgery. Immunohistochemistry was performed on atherosclerotic plaques from carotid arteries obtained during standard open endarterectomy to determine levels of CD40, CD40L receptors, MCP-1, and MMP-9. The 46 patients included 14 controls, 13 with mild, 11 with moderate, and 8 with severe OSA. Increased expression of CD40, CD40L receptors, MCP-1, and MMP-9 were found to be proportionate with OSA severity. However, significant differences among groups were observed only for MCP-1 (p = 0.014). Increased expression of inflammatory markers (CD40, CD40L, MCP-1, MMP-9) is associated with increasing OSA severity. This suggests the CD40-CD4-L inflammatory pathway may contribute to plaque instability and rupture in OSA patients.

Coagulation and Fibrinolysis in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a common disease which is characterised by repetitive collapse of the upper airways during sleep resulting in chronic intermittent hypoxaemia and frequent microarousals, consequently leading to sympathetic overflow, enhanced oxidative stress, systemic inflammation, and metabolic disturbances. OSA is associated with increased risk for cardiovascular morbidity and mortality, and accelerated coagulation, platelet activation, and impaired fibrinolysis serve the link between OSA and cardiovascular disease. In this article we briefly describe physiological coagulation and fibrinolysis focusing on processes which could be altered in OSA. Then, we discuss how OSA-associated disturbances, such as hypoxaemia, sympathetic system activation, and systemic inflammation, affect these processes. Finally, we critically review the literature on OSA-related changes in markers of coagulation and fibrinolysis, discuss potential reasons for discrepancies, and comment on the clinical implications and future research needs.

Effects of continuous positive airway pressure on resolvin and matrix metalloproteinase-9 in patients with obstructive sleep apnea

PURPOSE

Resolvin is a checkpoint controller in inflammation. Matrix metalloproteinase-9 (MMP-9) is an airway remodeling regulator. We evaluated the levels of resolvin and MMP-9 protein in the serum and exhaled breath condensate (EBC) before and after continuous positive airway pressure (CPAP) treatment.

METHOD

We enrolled 20 non-OSA snorers and 40 patients with moderate to severe OSA scheduled for CPAP treatment. ELISA was used to assess resolvin and MMP-9 levels in the serum and EBC. All patients underwent sleep assessment at baseline and 3 months after CPAP.

RESULTS

There was no between-group difference; moreover, there were no differences in the pre- and post-treatment serum levels of resolvin and MMP-9 in patients with OSA. Compared with non-OSA snorers, patients with OSA had lower resolvin and higher MMP-9 levels in the EBC. After CPAP treatment, the EBC levels of resolvin and MMP-9 in patients with OSA returned to normal.

CONCLUSIONS

Successful OSA treatment by CPAP can normalize EBC levels of resolvin and MMP-9.

The gut microbiome as a target for adjuvant therapy in obstructive sleep apnea

Introduction: Gut dysbiosis is assumed to play a role in obstructive sleep apnea (OSA)-associated morbidities. Pre- and probiotics, short chain fatty acids (SCFA) and fecal matter transplantation (FMT) may offer potential as novel therapeutic strategies that target this gut dysbiosis. As more mechanisms of OSA-induced dysbiosis are being elucidated, these novel approaches are being tested in preclinical and clinical development. Areas covered: We examined the evidence linking OSA to gut dysbiosis and discuss the effects of pre- and probiotics on associated cardiometabolic, neurobehavioral and gastrointestinal disorders. The therapeutic potential of SCFA and FMT are also discussed. We reviewed the National Center for Biotechnology Information database, including PubMed and PubMed Central between 2000 - 2020. Expert opinion: To date, there are no clinical trials and only limited evidence from animal studies describing the beneficial effects of pre- and probiotic supplementation on OSA-mediated dysbiosis. Thus, more work is necessary to assess whether prebiotics, probiotics and SCFA are promising future novel strategies for targeting OSA-mediated dysbiosis.

Does non-invasive ventilation change metabolic markers in children with obstructive sleep apnoea? A systematic review and meta-analysis study protocol

INTRODUCTION

Obstructive sleep apnoea (OSA) is not only common within paediatrics but is associated with critical childhood metabolic morbidity such as obesity, cardiovascular disease and glucose tolerance impairment. Increasing evidence suggests an association between childhood OSA and metabolic syndrome such as markers of cardiovascular disease, systemic hypertension, glucose intoleranceand increased lipid profile. Recent studies have targeted changes in metabolic markers in children using non-invasive ventilation (NIV) but no systematic reviews are available to summarise this emerging evidence. The purpose of this systematic review is to provide systematic synthesis of the evidence on the effect of NIV use on metabolic markers in children with OSA.

METHODS AND ANALYSIS

A systematic search of electronic databases and grey literature will include paediatric interventional studies (random controlled trials, cohort studies) with and without a comparison group. Two reviewers will independently undertake the two step process of title/abstract and full-text screening. Data will be extracted and assessed, with aggregate data being reported. When the data allow, meta-analysis will be performed.

ETHICS AND DISSEMINATION

There are no ethical concerns with this systematic review, as data have previously been published. This review will inform clinicians taking care of children with OSA and obesity/metabolic syndrome about the potential effects of NIV therapies on metabolic markers and has the potential to change the approach to childhood OSA and obesity. Results of this systematic review will be submitted for dissemination in abstract and manuscript form.

Inflammatory Factors: Nonobese Pediatric Obstructive Sleep Apnea and Adenotonsillectomy

Background: Inflammation is often considered relating to pediatric obstructive sleep apnea (OSA). We conducted a study investigating cytokines, including Il-17 and Il-23, in children with OSA before and after adenotonsillectomy (T&A), compared with controls. Methods: Children with OSA between age 4 and 12 receiving T&A were prospectively followed. Evaluation before and reevaluation six months after the treatment were done, including polysomnography (PSG), blood tests, and questionnaires. Blood samples were obtained to determine the values of high-sensitivity-C-reactive-protein (HS-CRP); tumor-necrosis-factor-alpha (TNF-α); and interleukin (IL)-1, 6, 10, 12, 17, and 23. We compared the results with an age-matched control group. Results: We included 55 OSA children and 32 controls. Children with OSA presented significant improvement after T&A in complaints, signs, apnea hypopnea index (AHI) (p < 0.001), mean oxygen desaturation index (p < 0.001), and mean oxygen saturation (p = 0.010). Upon entering this study, children with OSA had significantly higher cytokine levels than the controls and significant changes in HS-CRP (p = 0.013), TNF-α (p = 0.057), IL-1β (p = 0.022), IL-10 (p = 0.035), and IL-17 (p = 0.010) after T&A. Children with improved but persistently abnormal AHI did not have all cytokine levels normalized, particularly IL-23 and HS-CRP. Conclusion: Sleep-disordered breathing can persist after T&A and can continue to have a negative inflammatory effect. HS-CRP and IL-23 may serve as blood markers for the persistence of sleep-disordered breathing after T&A.

The cardiovascular risk in paediatrics: the paradigm of the obstructive sleep apnoea syndrome

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) describes a spectrum of abnormal breathing patterns during sleep characterised by snoring, increased upper airway resistance and pharyngeal collapsibility, with alteration of normal oxygenation and ventilation. Intermittent desaturations during sleep have multi-organ implications. Adults with OSAS have an increased risk of developing a dysfunctional endothelium that is characterised by greater adherence of inflammatory mediators to endothelial cells and hypercoagulability. There is increasing evidence to show that risk factors for comorbid cardiovascular disease (CVD) can develop during childhood and adolescence and are likely to continue over time. Risk factors for CVD include both modifiable factors and factors that cannot be changed.

MATERIALS AND METHODS

Using the MEDLINE^® electronic database, we reviewed the scientific literature for published studies evaluating the association between sleep-disordered breathing and cardiovascular damage in children.

RESULTS

In this review, we show the role of blood markers in demonstrating the inflammation caused by intermitted oxygen desaturations during sleep in both healthy and obese children. Several instrumental techniques, in addition to serum biomarkers, can be used to assess vascular endothelial damage and its deterioration in the form of a pre-atherosclerotic condition. The confirmation of their role as markers of inflammation and vascular damage is supported by normalisation after resolution or improvement of the sleep-disordered breathing with surgery.

DISCUSSION

Great attention should be given to this condition in infants and children as it will significantly affect their present and future well-being as they grow into adulthood. Healthcare professionals, especially paediatricians, should be trained to recognise the signs and symptoms of the disease in order to send children forward for specialist care in centres dealing with sleep-disordered breathing.

Matrix metalloproteinase 9 (MMP9) level and MMP9 -1562C>T in patients with obstructive sleep apnea: a systematic review and meta-analysis of case-control studies

BACKGROUND

The peripheral level of matrix metalloproteinase (MMP)-9 and polymorphism of MMP9 -1562C>T in patients with obstructive sleep apnea (OSA) remains controversial. Therefore, the aims of this systemic review and meta-analysis are to assess the MMP9 level in OSA patients and identify the relationship between MMP9 -1562C>T and OSA susceptibility.

METHODS

This systematic review was performed following the PRISMA guideline. We searched for studies in major databases, identifying those indexed from inception to July 3, 2019 which related to MMP9 level, MMP9 -1562C>T and OSA. The pooled standardized mean differences (SMDs) and 95% confidence interval (CI) of MMP9 levels were calculated. In addition, the relationship between MMP9 -1562C>T and OSA susceptibility was assessed by three genetic models. The heterogeneity analysis and calculation of the pooled odds ratio (OR) were also performed, followed by quality assessment using the Newcastle-Ottawa Scale (NOS).

RESULTS

In sum, our review included 15 eligible studies regarding MMP9 level and three regarding MMP9 -1562C>T. The pooled results showed that peripheral level of MMP9 was increased in OSA patients (SMD = 1.37; 95% CI = 1.15-1.59). Furthermore, significant difference of MMP9 level can be found between severe and mild-to-moderate OSA patients (SMD = 28.17; 95% CI = 4.23-52.11) or between moderate-severe and mild OSA (SMD = 36.62; 95% CI = 12.19-61.04). However, no relationship was observed between MMP9 -1562C>T and OSA susceptibility in three genetic models (Homozygote model, OR = 1.37; 95% CI = 0.87-2.18); (Recessive model, OR = 1.42; 95% CI = 0.83-2.42); (Allele model, OR = 1.07; 95% CI = 0.96-1.18).

CONCLUSIONS

This systemic review and meta-analysis indicated that the level of MMP9 was increased in patients with OSA and this increase is relevant to OSA severity. Moreover, the relationship between MMP9 -1562 C>T and OSA susceptibility has currently not been proven by current merging values. Further analyses with larger sample size are required to verify these associations.

Impact of adenotonsillectomy on the evolution of inflammatory markers

BACKGROUND

Tonsils are first-line host defence organs against pathogenic agents and participate in local and systemic immunity. Persistent increases in systemic inflammatory responses may contribute to associated morbidity. The aim of this study was to verify the short- and long-term impact of adenotonsillectomy on the evolution of inflammatory markers in 3- to 9-year-old children.

METHODS

A prospective and longitudinal study was conducted over 1 year in 29 children who underwent tonsillectomy due to either chronic tonsillitis or adenotonsillar hypertrophy. Measurements of high-sensitivity C-reactive protein (hs-CRP) levels were taken. Levels of Th1-type cytokines [interleukin-1, interferon-γ, and tumor necrosis factor-α (TNF-α)] and anti-inflammatory Th2-type cytokines [interleukin-4, -5, -6, -10 and -13] were measured. Levels of transforming growth factor-beta (TGF-β) and intercellular adhesion molecule-1 (ICAM-1) were also determined. The results were compared to those of 29 control children.

RESULTS

At baseline, children with surgery indications presented with higher levels of hs-CRP, interleukin-1 and -10, interferon-γ, TNF-α and ICAM-1, whereas values of interleukin-4 were significantly lower than in control children. Children with severe tonsillar obstruction had higher values of interleukin-1, -4, and -5 and lower values of interleukin-10 compared with children with recurrent tonsillitis. One year after surgery, the levels except IL-4 did not show a significant difference from those obtained in the control group. The levels of hs-CRP and TNF-α decreased significantly in the first month.

CONCLUSION

Children with chronic tonsillitis and/or adenotonsillar hypertrophy have significantly elevated levels of proinflammatory cytokines. Adenotonsillectomy restores the normal values of these parameters 1 year after surgery.

Risk Factors for Obstructive Sleep Apnea Syndrome in Children: State of the Art

The obstructive sleep apnea syndrome (OSAS) represents only part of a large group of pathologies of variable entity called respiratory sleep disorders (RSD) which include simple snoring and increased upper airway resistance syndrome (UARS). Although the etiopathogenesis of adult OSAS is well known, many aspects of this syndrome in children are still debated. Its prevalence is about 2% in children from 2 to 8 years of age, mostly related to the size of the upper airways adenoid tissue. Several risk factors linked to the development of OSAS are typical of the pediatric age. The object of this paper is to analyze the state of the art on this specific topic, discussing its implications in terms of diagnosis and management.

Study of Sleep Disorders among Young Children Using Hindi Translated and Validated Version of Pediatric Sleep Questionnaire

OBJECTIVE

The objective of this study is to assess the prevalence of sleep disorders among children aging between 4 and 9 years using Hindi version of Pediatric Sleep Questionnaire (PSQ).

METHODS

This study had two parts first, translation and validation of PSQ into Hindi language, and second, assessment of the prevalence of sleep disorders using PSQ Hindi version. Hindi PSQ was distributed in randomly chosen primary schools in a semi-urban area. The children were requested to get them filled by their parents. When the questionnaires were returned, responses were analyzed.

RESULTS

Most of the items of the Hindi version had perfect agreement with original questionnaire in a bilingual population (κ =1). Totally, 435 children were included in the field study having average age of 6.3 years. Obstructive sleep apnea was reported in 7.5% children; symptoms suggestive of restless legs syndrome were reported by 2%-3%; teeth grinding by 13.9% and sleep talking by 22.6% children.

CONCLUSION

PSQ Hindi version is a validated tool to screen for sleep disorders among children. Sleep disorders are fairly prevalent among young children in India.

[Adolescent obstructive sleep apnoea syndrome: Characteristics and treatment]

Although the prevalence of the obstructive sleep apnoea syndrome (OSAS) is high in adolescents, studies pertaining to adolescent OSAS are less numerous than childhood studies. Cases of adolescent OSAS may consist of residual OSAS after adenotonsillectomy, but most often are de novo cases. Major pathophysiological factors are weight excess or even high-grade obesity, and the association of upper airway narrowing and tonsillar hypertrophy (pharyngeal, palatal or even lingual). ENT and systematic orthodontic assessments are the main points. In case of predisposing factors such as dental, occlusal or dento-facial abnormalities, a specific orthodontic treatment can be discussed. First line treatment is surgical adenotonsillectomy; surgical reduction of the lingual tonsils is seldom required. CPAP treatment may be indicated in the case of severe comorbidities (craniofacial malformations, neuromuscular diseases…) or in obese adolescents with severe residual OSAS. Treatment of adolescent OSAS has to be comprehensive and multidisciplinary, taking into account the specific treatments of obesity and abnormal sleep/wake rhythms.

Elevated Serum Markers of Acute Kidney Injury in Patients With Obstructive Sleep Apnea

STUDY OBJECTIVES

Previous research revealed a positive correlation between endothelial cell injury (indicated by albuminuria) and obstructive sleep apnea (OSA). However, little else has been revealed about acute kidney injury (AKI) in patients with OSA.

METHODS

This prospective study recruited consecutive patients undergoing overnight polysomnography for evaluation of sleep apnea. Patients in whom any major disease or recent infection had been previously diagnosed were excluded. Ultimately, data from 75 patients with apnea-hypopnea indices of 5 or more were analyzed. Baseline values for the urinary albumin-creatinine ratio (UACR), serum levels for three markers of AKI (cystatin C, neutrophil gelatinase-associated lipocalin [NGAL], interleukin-18 [IL-18]), and polysomnography data were recorded and analyzed. Patients then were followed for 6 months of continuous positive airway pressure (CPAP) treatment.

RESULTS

At baseline, UACRs were greater in patients with more severe OSA (P = .005, r = .329). All three serum markers of AKI (cystatin C, NGAL, and IL-18) studied were positively correlated with OSA severity, and two (cystatin C and IL-18) were positively correlated with the frequency of oxygen desaturation during sleep. However, none of the AKI markers had positive correlations with UACR. After 6 months of CPAP treatment, UACR and IL-18 were decreased significantly in patients with good adherence.

CONCLUSIONS

Albuminuria and levels of three serum markers of AKI (cystatin C, NGAL, IL-18) were positively correlated with OSA severity, and good adherence with CPAP treatment decreased albuminuria and interleukin-18 levels. These results may provide additional tools for assessing early renal injury in patients with OSA.

Obstructive Sleep Apnea and Inflammation: Proof of Concept Based on Two Illustrative Cytokines

Obstructive sleep apnea syndrome (OSAS) is a markedly prevalent condition across the lifespan, particularly in overweight and obese individuals, which has been associated with an independent risk for neurocognitive, behavioral, and mood problems as well as cardiovascular and metabolic morbidities, ultimately fostering increases in overall mortality rates. In adult patients, excessive daytime sleepiness (EDS) is the most frequent symptom leading to clinical referral for evaluation and treatment, but classic EDS features are less likely to be reported in children, particularly among those with normal body-mass index. The cumulative evidence collected over the last two decades supports a conceptual framework, whereby sleep-disordered breathing in general and more particularly OSAS should be viewed as low-grade chronic inflammatory diseases. Accordingly, it is assumed that a proportion of the morbid phenotypic signature in OSAS is causally explained by underlying inflammatory processes inducing end-organ dysfunction. Here, the published links between OSAS and systemic inflammation will be critically reviewed, with special focus on the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), since these constitute classical prototypes of the large spectrum of inflammatory molecules that have been explored in OSAS patients.

Inflammation and asthma control in children with comorbid obstructive sleep apnea

OBJECTIVES

A bi-directional relationship exists between asthma and obstructive sleep apnea (OSA) in which presence of one is associated with increased prevalence and severity of the other. Our objective was to determine whether OSA accounted for differences in airway and systemic inflammation in asthmatic children and whether inflammation was associated with asthma control. We hypothesized that greater severity of SDB would correlate with increased upper airway and systemic inflammation and result in reduced asthma control.

METHODS

Non-obese children aged 4-12 years with persistent asthma, with or without OSA were recruited. Asthma control was measured with the Childhood Asthma Control Test. Children underwent polysomnography and blood sampling, and children with OSA underwent clinically indicated adenotonsillectomy. Tonsils and sera were analyzed for 11 cytokines.

RESULTS

Twenty-seven children (20 with OSA, seven without OSA) participated, mean age 7.9 years, 55.6% female, 92.6% African American. Levels did not differ for any cytokine between children with and without OSA. Lower nadir oxygen saturation was associated with higher levels of tonsil TNF-α (P < 0.001) and IL-10 (P < 0.05). Higher REM-related apnea-hypopnea index was associated with higher levels of tonsil TNF-α (P < 0.05). Children with uncontrolled asthma had significantly higher levels of serum IL-10, IL-13, and TNF-α, and tonsil TNF-α (all P < 0.05) than well-controlled asthmatic children. There was no association between OSA, or any polysomnography variable, and asthma control.

CONCLUSIONS

Despite the presence of OSA-associated airway inflammation, and asthma control-associated airway and systemic inflammation, OSA was not related to level of asthma control in this non-obese, largely minority, low income sample.

Adropin and Inflammation Biomarker Levels in Male Patients With Obstructive Sleep Apnea: A Link With Glucose Metabolism and Sleep Parameters

STUDY OBJECTIVES

The main objectives of the study were to determine plasma adropin, systemic inflammation biomarker levels, and glucose metabolism parameters in patients with moderate and severe obstructive sleep apnea (OSA) compared to healthy controls.

METHODS

In this study, we included 50 male patients with OSA (25 moderate and 25 severe) and 25 age- and sex-matched control subjects. All subjects underwent fasting sampling of peripheral blood for laboratory analyses.

RESULTS

Adropin plasma levels were significantly lower in the severe OSA group in comparison with the moderate and control groups (4.50 ± 1.45 versus 6.55 ± 1.68 versus 8.15 ± 1.79 ng/mL, P < .001). Plasma biomarkers of systemic inflammation were significantly increased in patients with moderate OSA (interleukin [IL]-6 and tumor necrosis factor alpha [TNF-α]) and severe OSA (IL-6, TNF-α, high-sensitivity C-reactive protein) when compared with controls (P < .001). Adropin levels showed a significant negative correlation with IL-6 (r = -.419, P < .001), TNF-α (r = -.540, P < .001), fasting glucose (r = -.331, P = .004), hemoglobin A1c (r = -.438, P < .001), homeostatic model assessment insulin resistance index (r = -.213, P = .046), and polysomnographic parameters including apnea-hypopnea index (r = -.615, P < .001) and oxygen desaturation index (r = -.573, P < .001). A multivariate regression analysis showed that plasma adropin remained as a significant negative predictor of severe OSA status, when adjusted for age and body mass index and computed along with other inflammatory biomarkers in the regression model (odds ratio 0.069, 95% confidence interval 0.009-0.517, P = .009).

CONCLUSIONS

Plasma adropin concentrations significantly correlate with indices of disease severity in patients with OSA, suggesting that adropin potentially plays an important role in the complex pathophysiology of the disease.

Long-Term Impact of Sleep-Disordered Breathing on Quality of Life in Children With Obesity

STUDY OBJECTIVES

(1) To determine baseline quality of life (QOL) among children with obesity and newly diagnosed moderate-severe sleep-disordered breathing (SDB) and to compare it to the reported QOL of children with obesity or SDB alone and healthy children. (2) To evaluate QOL change after 1 year.

METHODS

A prospective multicenter cohort study was conducted in children (8-16 years) with obesity, prescribed positive airway pressure (PAP) therapy for moderate-severe SDB. Outcomes included parent-proxy and self-report total and subscale scores on the PedsQL questionnaire (baseline and 1-year).

RESULTS

Total PedsQL scores were indicative of impaired QOL in 69% of cases based on parent-report and in 62% on self-report. Parents reported significantly lower QOL in our cohort than that reported in other studies for children with obesity or SDB alone or healthy children, on total PedsQL score and on social and psychosocial subscales. PedsQL total scores for participants were significantly higher (mean difference 7.3 ± 15.3, P = .03) than those reported by parents. Parents reported significant improvements in total PedsQL (mean change 7.29 ± 13.73, P = .04) and social functioning (mean change 17.65 ± 24.69, P = .04) scores after 1 year. No significant differences were found by children's self-report or by PAP adherence.

CONCLUSIONS

QOL of children with obesity and SDB is lower than in children with obesity or SDB alone or healthy children. One year later, children reported no significant changes in QOL; parents reported significant improvements in total PedsQL and social functioning scores. PAP adherence did not significantly affect QOL change in this population.

COMMENTARY

A commentary on this article appears in this issue on page 307.

Adropin: An endocrine link between the biological clock and cholesterol homeostasis

Objective

Identify determinants of plasma adropin concentrations, a secreted peptide translated from the Energy Homeostasis Associated (ENHO) gene linked to metabolic control and vascular function.

Methods

Associations between plasma adropin concentrations, demographics (sex, age, BMI) and circulating biomarkers of lipid and glucose metabolism were assessed in plasma obtained after an overnight fast in humans. The regulation of adropin expression was then assessed in silico, in cultured human cells, and in animal models.

Results

In humans, plasma adropin concentrations are inversely related to atherogenic LDL-cholesterol (LDL-C) levels in men (n = 349), but not in women (n = 401). Analysis of hepatic Enho expression in male mice suggests control by the biological clock. Expression is rhythmic, peaking during maximal food consumption in the dark correlating with transcriptional activation by RORα/γ. The nadir in the light phase coincides with the rest phase and repression by Rev-erb. Plasma adropin concentrations in nonhuman primates (rhesus monkeys) also exhibit peaks coinciding with feeding times (07:00 h, 15:00 h). The ROR inverse agonists SR1001 and the 7-oxygenated sterols 7-β-hydroxysterol and 7-ketocholesterol, or the Rev-erb agonist SR9009, suppress ENHO expression in cultured human HepG2 cells. Consumption of high-cholesterol diets suppress expression of the adropin transcript in mouse liver. However, adropin over expression does not prevent hypercholesterolemia resulting from a high cholesterol diet and/or LDL receptor mutations.

Conclusions

In humans, associations between plasma adropin concentrations and LDL-C suggest a link with hepatic lipid metabolism. Mouse studies suggest that the relationship between adropin and cholesterol metabolism is unidirectional, and predominantly involves suppression of adropin expression by cholesterol and 7-oxygenated sterols. Sensing of fatty acids, cholesterol and oxysterols by the RORα/γ ligand-binding domain suggests a plausible functional link between adropin expression and cellular lipid metabolism. Furthermore, the nuclear receptors RORα/γ and Rev-erb may couple adropin synthesis with circadian rhythms in carbohydrate and lipid metabolism.

•

In male humans, plasma adropin concentrations are inversely related to low-density circulating cholesterol (LDL-C) levels.

•

Adropin expression is regulated by core elements of the biological clock (RORA/G, Rev-Erb).

•

Sterol-sensing by the ROR ligand-binding domain provides a plausible link between adropin expression and lipid metabolism.

•

In mouse liver, adropin expression is rhythmic and suppressed by exogenous (dietary) cholesterol.

Assessment of weight gain following adenotonsillectomy in children with Down syndrome

INTRODUCTION

Adenotonsillectomy (T&A) has been associated with postoperative weight gain in children. The purpose of this study is to determine whether a similar association exists in children with Down syndrome (DS).

METHODS

The medical records of 311 DS patients were reviewed. Subjects were classified into either a control group or surgical group based on whether they had undergone adenotonsillectomy (T&A). Subjects were excluded if they only had one recorded BMI. Cases were analyzed in a pairwise fashion to maximize available data. 113 total patients with DS were identified: 84 (74.3%) in the control group and 29 (25.7%) in the T&A group. Height, weight, BMI, and Z-score data were compared between the control and T&A groups at 6-month intervals over a 24-month period.

RESULTS

Children with DS who underwent T&A were comparable by demographics to children with DS who did not undergo T&A. Mean weight gain at 24 months for the T&A group was 8.07 ± 5.66 kg compared with 5.76 ± 13.20 kg in controls. The median Z-score at 24 months for the T&A group was 1.11 (0.10-1.88) compared with 1.17 (0.80-1.75) in controls. Children undergoing T&A had a stable median Z-score change of 0.09 at 24 months (p = 0.861, compared to baseline) while children who did not undergo T&A had a significantly increased median Z-score of 0.52 (p = 0.035, compared to baseline). Despite this, there were no significant intergroup differences between weight change, BMI, nor Z-score at any interval (p > 0.05).

CONCLUSIONS AND RELEVANCE

Children with DS did not have an increased rate of weight gain or increased BMI after T&A. BMI Z-scores were shown to stabilize over 24 months in the T&A group and increase in the control group. While this suggests that T&A provides an added benefit of weight control in patients with DS, the results should be interpreted with caution due to the small sample size and the fact that not all patients had complete follow up across a 24-month period.

Association Between Cytokines and Liver Histology in Children with Nonalcoholic Fatty Liver Disease

Background

Reliable non-invasive markers to characterize inflammation, hepatocellular ballooning, and fibrosis in nonalcoholic fatty liver disease (NAFLD) are lacking. We investigated the relationship between plasma cytokine levels and features of NAFLD histology to gain insight into cellular pathways driving NASH and to identify potential non-invasive discriminators of NAFLD severity and pattern.

Methods

Cytokines were measured from plasma obtained at enrollment in pediatric participants in NASH Clinical Research Network studies with liver biopsy-proven NAFLD. Cytokines were chosen a priori as possible discriminators of NASH and its components. Minimization of Akaike Information Criterion (AIC) was used to determine cytokines retained in multivariable models.

Results

Of 235 subjects, 31% had "Definite NASH" on liver histology, 43% had "Borderline NASH", and 25% had NAFLD but not NASH. Total plasminogen activator inhibitor 1 (PAI1) and activated PAI1 levels were higher in pediatric participants with Definite NASH and with lobular inflammation. Interleukin-8 (IL-8) was higher in those with stage 3-4 fibrosis and lobular inflammation. sIL-2rα was higher in children with stage 3-4 fibrosis and portal inflammation. In multivariable analysis, PAI1 variables were discriminators of Borderline/Definite NASH, definite NASH, lobular inflammation and ballooning. IL-8 increased with steatosis and fibrosis severity; sIL-2rα increased with fibrosis severity and portal inflammation. IL-7 decreased with portal inflammation and fibrosis severity.

Conclusions

Plasma cytokines associated with histology varied considerably among NASH features, suggesting promising avenues for investigation. Future, more targeted analysis is needed to identify the role of these markers in NAFLD and to evaluate their potential as non-invasive discriminators of disease severity.

Sleep and the Cardiovascular System in Children

Subspecialty pediatric practice provides comprehensive medical care for a range of ages, from premature infants to children, and often includes adults with complex medical and surgical issues that warrant multidisciplinary care. Normal physiologic variations involving different body systems occur during sleep and these vary with age, stage of sleep, and underlying health conditions. This article is a concise review of the cardiovascular (CV) physiology and pathophysiology in children, sleep-disordered breathing (SDB) contributing to CV morbidity, congenital and acquired CV pathology resulting in SDB, and the relationship between SDB and CV morbidity in different clinical syndromes and systemic diseases in the expanded pediatric population.

When and why to treat the child who snores?

Obstructive sleep-disordered breathing (SDB) can result in cardiovascular and neurocognitive morbidity as well as adversely affect behavior, growth, quality of life, and nocturnal continence. This article summarizes the latest evidence regarding the morbidity related to obstructive SDB, commenting on the impact of severity of obstruction, that is, the difference in effects seen of moderate to severe obstructive sleep apnea syndrome (OSAS) compared to those of mild OSAS or primary snoring. The impact of therapy is discussed, focusing on which children are likely to benefit from treatment interventions; namely those with moderate or severe OSAS irrespective of the presence of morbidity, children with mild OSAS with associated morbidity or predictors of SDB persistence such as obesity, and children with complex conditions accompanied by upper airway obstruction like craniosynostosis and Prader-Willi syndrome. The co-existing conditions which may improve when treatment for obstructive SDB is offered are reviewed, while the clinical parameters associated with spontaneous improvement or resolution of obstructive SDB are discussed. The intention being to enable clinicians to make informed decisions on who should be treated, when and why. Pediatr Pulmonol. 2017;52:399-412. © 2016 Wiley Periodicals, Inc.

Urine cysteinyl leukotriene levels in children with sleep disordered breathing before and after adenotonsillectomy

OBJECTIVES

Obstructive sleep apnea (OSA) is a common problem in children and is associated with increased cardiovascular, neurobehavioral and somatic growth consequences. Cysteinyl leukotrienes (CysLTs) play a major role with local and systemic relations to the pathophysiology of OSA. The level of CysLTs in urine, blood, exhaled breath and adenotonsillar tissue of OSA children are increased. However it remains unclear whether inflammatory marker levels are alleviated after adenotonsillectomy. Therefore, we compare the urine leukotriene E4 (uLTE4) levels in children before and after adenotonsillectomy and evaluate clinical outcomes on resolution of OSA.

METHODS

Children under 15 years who suspected OSA with planned adenotonsillectomy were recruited. Sleep questionnaires, quality of life assessment by OSA-18, physical examination, lateral neck radiographs, overnight SpO₂ monitoring and uLTE4 levels were collected. 4 ± 2 weeks post-surgery, OSA-18 was reevaluated and urine was collected again.

RESULTS

Thirty-three children with sleep disordered breathing (SDB) were included (mean age 8.1 ± 2.8 years). After adenotonsillectomy, the uLTE₄ levels decreased from 961.9 (684.8-1438.2) to 708.6 (538.2-1038.8) pg/mg Cr (P = 0.009). The post-surgery score from sleep questionnaire, OSA-18 questionnaire were significant improved (P < 0.001). Obese children demonstrated an improved quality of life post-surgery, but results were poorer than normal-weight children (P = 0.01). The uLTE4 no obvious improved in obese children.

CONCLUSIONS

Adenotonsillectomy remains an effective treatment for SDB children that not only alleviated the severity of SDB and improved quality of life; it also decreased levels of the systemic inflammatory marker, uLTE4. However, benefits were more obvious in non-obese children.

Adropin- A Novel Biomarker of Heart Disease: A Systematic Review Article

BACKGROUND

Heart disease is one of the most common chronic disease and leading cause of morbidity and mortality worldwide. Adropin, a newly identified protein, is important for energy homeostasis and maintaining insulin sensitivity, and has been referred to as a novel regulator of endothelial cells. Endothelial dysfunction is a key early event in atherogenesis and onset of HD. Therefore, this review gives a systematic overview of studies investigating plasma adropin level in patient with heart disease.

METHODS

Data carried out in PubMed, Scopus, Web of Science, Embase, Google scholar and MEDLINE, from the earliest available online indexing year through 2015. The search restricted to studies conducted in humans. The keyword search was adropin to apply in title, abstract and keywords. References lists of all original published articles were scanned to find additional eligible studies.

RESULTS

Heart failure (HF), coronary atherosclerosis acute myocardial infarction and Cardiac Syndrome X (CSX) were type of heart disease acknowledged in this study. Majority of evidences introduced low adropin as an independent risk factor of heart disease. In a case-control study, the plasma level of adropin increased with the severity of HF.

CONCLUSION

Adropinmay be a potential serum biomarker for early diagnosis of HD.

Pediatric OSA Syndrome Morbidity Biomarkers: The Hunt Is Finally On!

Since initial reports 40 years ago on pediatric OSA syndrome (OSAS) as a distinct and prevalent clinical entity, substantial advances have occurred in the delineation of diagnostic and treatment approaches. However, despite emerging and compelling evidence that OSAS increases the risk for cognitive, cardiovascular, and metabolic end-organ morbidities, routine assessment of such morbidities is seldom conducted in clinical practice. One of the major reasons for such discrepancies resides in the relatively labor-intensive and onerous steps that would be required to detect the presence of any of such morbidities, further adding to the already elevated cost of diagnosing the disorder. To circumvent these obstacles, the search for biomarker signatures of pediatric OSA and its cognitive and cardiometabolic consequences was launched, and considerable progress has occurred since then. Here, we review the current evidence for the presence of morbidity-related biomarkers among children with OSAS, and explore future opportunities in this promising arena.

Role of sleep quality in the metabolic syndrome

Emerging evidence has assigned an important role to sleep as a modulator of metabolic homeostasis. The impact of variations in sleep duration, sleep-disordered breathing, and chronotype to cardiometabolic function encompasses a wide array of perturbations spanning from obesity, insulin resistance, type 2 diabetes, the metabolic syndrome, and cardiovascular disease risk and mortality in both adults and children. Here, we critically and extensively review the published literature on such important issues and provide a comprehensive overview of the most salient pathophysiologic pathways underlying the links between sleep, sleep disorders, and cardiometabolic functioning.

Pediatric Sleep Apnea Syndrome: An Update

Obstructive sleep apnea syndrome (OSAS) may be central neurologic (<5%) or obstructive (>95%) in origin and is a relatively prevalent condition in children. It affects 1%-5% of children aged 2-8 years and is caused by a variety of different pathophysiologic abnormalities. Cardiovascular, metabolic, and neurocognitive comorbidities can occur in both children and adults when left untreated. It also can cause severe behavioral problems in children. The American Academy of Pediatrics recommends that all children be screened with an appropriate history and physical examination for symptoms and signs suggestive of OSAS. The diagnosis is primarily made clinically and confirmed by polysomnographic findings. Treatment depends on the child's age, underlying medical problems, polysomnography findings, and whether or not there is upper airway obstruction usually secondary to enlarged adenoids and/or tonsils, allergic and nonallergic rhinitis, acute and chronic sinusitis, and other upper airway pathology. If enlarged adenoid or tonsils or both conditions exist, an adenoidectomy, tonsillectomy, or adenotonsillectomy remains the treatment of choice. Pharmacotherapy of OSAS has shown some effect in children with mild symptoms. This paper reviews the prevalence, pathophysiology, clinical presentation, diagnosis, and treatment of OSAS.

Impact of Adenotonsillectomy on Insulin Resistance and Lipoprotein Profile in Nonobese and Obese Children

BACKGROUND

OSA associates with insulin resistance (IR), hyperglycemia, and dyslipidemia consistently in adults, but inconsistently in children. We set out to quantify the impact of OSA treatment upon obesity and metabolic outcomes and thus assess causality.

METHODS

Sixty-nine children with OSA; mean age, 5.9 years (range, 3-12.6); 55% boys; and 68% nonobese (NOB) underwent baseline overnight polysomnography, anthropometric and metabolic measurements, adenotonsillectomy (T&A), and follow-up testing a mean 7.9 months (range, 2-20) later.

RESULTS

Fifty-three children (77% of study cohort; 91% of obese children) had residual OSA (apnea-hypopnea index > 1 event/h) post-T&A. Fasting plasma insulin (FPI, 14.4 ± 9.4 → 12.6 ± 9.7 μIU/mL, P = .008), homeostasis model assessment-IR (3.05 ± 2.13 → 2.62 ± 2.22, P = .005), and high-density lipoprotein (HDL) (51.0 ± 12.9 → 56.5 ± 14.4 mg/dL, P = .007) improved despite increased BMI z score (1.43 ± 0.78 → 1.52 ± 0.62, P = .001); changes did not differ significantly between sexes or NOB and obese participants; however, post-T&A BMI z score rather than apnea-hypopnea index was the main predictor of levels of follow-up FPI, HDL, and other metabolic parameters. Higher baseline FPI and BMI-z predicted likelihood of residual OSA; conversely, on regression analysis, follow-up IR, HDL, and triglycerides were predicted by BMI z score, not residual OSA.

CONCLUSIONS

T&A improved IR and HDL, and residual OSA is predicted by baseline FPI and BMI z score, indicating a causal relationship; however, following T&A, residual metabolic dysfunction related to underlying adiposity rather than remaining sleep-disordered breathing. Finally, T&A cured OSA in < 25% of all children and only 10% of obese children; post-T&A polysomnography is indicated to assess which children still require treatment.

Update on paediatric obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is one of the most common causes of sleep-disordered breathing (SDB) in children. It is associated with significant morbidity, potentially impacting on long-term neurocognitive and behavioural development, as well as cardiovascular outcomes and metabolic homeostasis. The low grade systemic inflammation and increased oxidative stress seen in this condition are believed to underpin the development of these OSA-related morbidities. The significant variance in degree of end organ morbidity in patients with the same severity of OSA highlights the importance of the interplay of genetic and environmental factors in determining the overall OSA phenotype. This review seeks to summarize the current understanding of the aetiology and mechanisms underlying OSA, its risk factors, diagnosis and treatment.

Sleep Disordered Breathing in Children

Sleep-disordered breathing (SDB) refers to a group of disorders characterized by abnormalities of respiration or ventilation during sleep. It encompasses obstructive sleep apnea (OSA), central sleep apnea (CSA) syndromes, sleep-related hypoventilation and sleep-related hypoxemia disorders. This review will concentrate on the disorder most prevalent in pediatrics, i.e., OSA, highlighting the most recent developments in our understanding of the etiology, pathophysiology and treatment options of this condition. OSA morbidities primarily involve the neurocognitive, cardiovascular and metabolic systems. However, there can be significant phenotypic variation in terms of end organ morbidity for the same OSA severity. This is likely due to the interplay between genetic and environmental factors; recent developments in the fields of genomics and proteomics have the potential to shed light on these complex pathological cascades. As we enter the era of personalized medicine, phenotyping patients to enable clinicians to tailor bespoke clinical management plans will be of crucial importance.

Treatment outcomes of obstructive sleep apnoea in obese community-dwelling children: the NANOS study

The first line of treatment of obstructive sleep apnoea syndrome (OSAS) in children consists of adenotonsillectomy (T&A). The aim of the present study was to evaluate treatment outcomes of OSAS among obese children recruited from the community.A cross-sectional, prospective, multicentre study of Spanish obese children aged 3-14 years, with four groups available for follow-up: group 1: non-OSAS with no treatment; group 2: dietary treatment; group 3: surgical treatment; and group 4: continuous positive airway pressure treatment.117 obese children (60 boys, 57 girls) with a mean age of 11.3±2.9 years completed the initial (T0) and follow-up (T1) assessments. Their mean body mass index (BMI) at T1 was 27.6±4.7 kg·m(-2), corresponding to a BMI Z-score of 1.34±0.59. Mean respiratory disturbance index (RDI) at follow-up was 3.3±3.9 events·h(-1). Among group 1 children, 21.2% had an RDI ≥3 events·h(-1) at T1, the latter being present in 50% of group 2, and 43.5% in group 3. In the binary logistic regression model, age emerged as a significant risk factor for residual OSAS (odds ratio 1.49, 95% confidence interval 1.01-2.23; p<0.05) in obese children surgically treated, and RDI at T0 as well as an increase in BMI emerged as significant risk factors for persistent OSAS in obese children with dietary treatment (OR 1.82, 95% CI 1.09-3.02 (p<0.03) and OR 8.71, 95% CI 1.24-61.17 (p=0.03)).Age, RDI at diagnosis and obesity are risk factors for relatively unfavourable OSAS treatment outcomes at follow-up.

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.