Diagnosis and Treatment of Sleep Apnea in Children: A Future Perspective Is Needed

Molecular Mechanisms, Diagnoses, and Treatments of Respiratory Diseases

The Special Issue "Molecular Mechanisms, Diagnoses, and Treatments of Respiratory Diseases" in the journal Biomedicines compiles critical advancements in the understanding of respiratory diseases, focusing on their molecular mechanisms, diagnostic approaches, and therapeutic strategies [...].

Impact of Chronic Intermittent Hypoxia on Cognitive Function and Hippocampal Neurons in Mice: A Study of Inflammatory and Oxidative Stress Pathways

Purpose

Chronic intermittent hypoxia (CIH) is considered one of the main pathophysiological mechanisms of obstructive sleep apnea (OSA). CIH can further lead to cognitive dysfunction by inducing processes such as neuroinflammation and oxidative stress. The hippocampus is primarily associated with cognitive functions such as learning and memory. This study aimed to explore the effects of CIH on cognitive function and hippocampal neurons in mice and to reveal its potential molecular mechanisms.

Methods

SPF-grade C57BL/6J mice (n=36) were selected as subjects and divided into control, mild CIH, and severe CIH groups (12 mice per group). Cognitive function was assessed using the Morris water maze test, and hippocampal neuron numbers and morphological changes were observed using HE staining and Nissl staining. Additionally, differential genes and pathways were revealed through RNA sequencing (RNA-seq) and bioinformatics analysis. We examined oxidative stress-related biochemical markers in the hippocampal tissue and used Western Blot to verify changes in the expression of potential key genes. Statistical analyses were performed using ANOVA and post hoc tests to ensure robust comparisons between groups.

Results

CIH mice exhibited significant cognitive impairment, including decreased learning and memory abilities. The severe CIH group had a longer escape latency compared to the mild CIH group (p < 0.001) and the control group (p < 0.01), while the mild CIH group took longer than the control group (p < 0.01). In the probe test, the severe CIH group showed a significant decrease in platform crossings (p < 0.01) and target quadrant dwell time (p < 0.05), while the mild CIH group exhibited a reduction in target quadrant dwell time (p < 0.05). Abnormal hippocampal neuron morphology was observed, with a significant reduction in hippocampal neurons (p < 0.05). RNA-seq analysis revealed numerous differentially expressed genes, mainly enriched in biological processes such as inflammation and oxidative stress, as well as multiple signaling pathways. Specifically, downregulated LepR, SIRT1, and Nrf2 genes were found to exacerbate oxidative stress and neuroinflammation, impairing neuronal integrity and cognitive function. Further validation showed increased oxidative stress levels in hippocampal tissue and downregulation of key gene expression. Western blot analysis confirmed significantly reduced expression of LepR (p < 0.01), SIRT1 (p < 0.001), and Nrf2 (p < 0.001) in the severe CIH group.

Conclusion

While oxidative stress and inflammation are well-established mechanisms in CIH-induced cognitive impairment, our study provides novel insights by identifying the specific roles of LepR, SIRT1, and Nrf2 in this process. The downregulation of these key genes suggests potential new targets for therapeutic intervention. Importantly, the differential expression patterns observed in varying degrees of hypoxia severity highlight the potential for tailored therapeutic strategies that modulate these pathways in response to the intensity of hypoxic exposure. These findings offer unique opportunities for developing targeted therapies aimed at mitigating CIH-related cognitive decline and neural damage. However, a key limitation of this study is the exclusive use of animal models, which may not fully replicate human pathophysiology. Further studies are needed to validate these findings in clinical settings and to explore the regulatory relationships between the key genes involved.

Impact of asthma and allergic rhinitis control on sleep disordered breathing in pediatrics

Aim

The aim of our study is to assess the quality of sleep in children with asthma and/or allergic rhinitis, as well as the impact of the control of allergic respiratory diseases on sleep disturbances.

Materials and methods

It is an observational cross-sectional study on children attending pediatric allergy appointments at a portuguese tertiary hospital (G1), and compared to a control population (G2). The asthma and rhinitis control was determined using the Control of Allergic Rhinitis and Asthma Test (CARAT/CARATKids) questionnaires. Sleep was evaluated using the Pediatric Sleep Questionnaire (PSQ). G1 included 61 patients and G2 included 100 children.

Results

About a third of the children in the study group had sleep-related breathing disorders (SDB), compared to 9 % on the control group (p-value <0.05). There was a significant positive correlation between uncontrolled asthma and allergic rhinitis, and SDB (p-value <0.05).

Conclusion

SDB is more prevalent among children with asthma and/or allergic rhinitis. The absence of control of the allergic respiratory diseases has a negative impact on sleep. We recommend large cross-sectional studies to better comprehend the exact relationship between the two conditions, as well as the use of objective diagnostic tools. We believe it is essential to implement early screening for sleep disorders in children with allergic respiratory diseases, through validated questionnaires.

Exploring the Interplay of Gut Microbiota and Systemic Inflammation in Pediatric Obstructive Sleep Apnea Syndrome and Its Impact on Blood Pressure Status: A Cross-Sectional Study

Obstructive sleep apnea syndrome (OSAS) is prevalent among children and is associated with elevated blood pressure (BP), posing a risk for future hypertension and cardiovascular diseases. While the roles of gut microbiota and systemic inflammation in OSAS pathogenesis are recognized in adults and animal models, their impact on pediatric BP remains less understood. This cross-sectional study explored the relationships between polysomnographic parameters, gut microbiota, systemic inflammation, and BP in 60 children with OSAS. Significant associations between specific microbial profiles-including beta diversity and 31 marker microbes-and BP variations were observed. These microbial profiles correlated with significant alterations in systemic inflammation markers like interleukin-17 and tumor necrosis factor-α. Notably, the relative abundance of Acinetobacter was related to fluctuations in these inflammatory markers and BP levels. The research further highlighted the unique microbial and cytokine profiles exhibited by children with different BP levels, indicating a substantial role of gut microbiota and systemic inflammation in influencing pediatric cardiovascular health. The findings suggest integrating gut microbiota management into comprehensive cardiovascular risk strategies for children with OSAS. This initiative underscores the need for further investigations to decode the mechanisms behind these associations, which could lead to innovative treatments for pediatric OSAS.

Development and validation of a predictive model (CHASE-OSA) for preoperative assessment of moderate-to-severe pediatric obstructive sleep apnea

PURPOSE

Undetected obstructive sleep apnea (OSA) in children increases the likelihood of perioperative respiratory complications. Current screening tools for OSA often lack sensitivity or are overly complex. This study aimed to develop and validate a simplified preoperative predictive model for moderate-to-severe pediatric OSA.

METHODS

The study included children aged 1 to 18 years who underwent either polysomnography or nocturnal pulse oximetry from January 2013 to December 2020. OSA severity was categorized using these tests, and potential predictors were identified using multivariable logistic regression. The outcomes of the tests were used to create a risk-based scoring system. Internal validation was performed using bootstrapping procedures.

RESULTS

Out of the 1,327 participants, 882 individuals (66.5%) were diagnosed with moderate-to-severe OSA. Predictors considered for developing the scoring system included Craniofacial abnormalities, adenotonsillar Hypertrophy, Age 1-5 years, Snoring > 5 nights/week, Excessive daytime sleepiness, Obesity, Stopping breathing, and Awakening during sleep (CHASE-OSA). The scoring system developed demonstrated an area under the receiver operating characteristic curve of 0.85 (95% CI: 0.83-0.88). The CHASE-OSA score, ranging from 0 to 14, classified scores < 6 as low-risk and ≥ 6 as high-risk for moderate-to-severe pediatric OSA. This cutoff demonstrated a sensitivity of 86%, specificity of 70%, and positive and negative predictive values of 85% and 71%, respectively.

CONCLUSION

The CHASE-OSA predictive model provides a concise and user-friendly preoperative screening tool for identifying moderate-to-severe pediatric OSA. It facilitates risk assessment, enhances perioperative care optimization, and informs postoperative management planning. Further research is needed to comprehensively validate its clinical utility.

Obstructive Sleep Apnea in Pediatrics and Adolescent Women: A Systematic Review of Sex-Based Differences Between Girls and Boys

BACKGROUND/OBJECTIVES

Obstructive sleep apnea (OSA) is marked by repetitive occurrences of upper airway (UA) obstruction during sleep. Morbidities impacting the metabolic, cardiovascular (CV) and neurological systems are correlated with OSA. Only a few studies have described the existence of different characteristics depending on sex and, to date, the girl phenotype in OSA pediatrics is not well known. The objective of this systematic review is to identify the specific phenotype of OSA in pediatric and adolescent females compared to males.

METHODS

A systematic review was performed. The terms "pediatric sleep apnea" and "sex differences" were used to look for publications using PubMed, the Cochrane Library and Web of Science.

INCLUSION CRITERIA

(1) peer-reviewed journal articles written in English; (2) investigations conducted on individuals diagnosed with OSA; and (3) investigations providing information about sex differences.

EXCLUSION CRITERIA

(1) studies carried out with individuals aged 18 years and older; (2) studies involving a sample size of fewer than 10 patients; and (3) editorials, letters and case reports.

RESULTS

Fifteen studies were included and classified in sections related to sex-based differences.

CONCLUSIONS

Limited information related to sex-based OSA differences in the pediatric population exists. These differences are conditioned by hormonal status, and are minimal in the premenarcheal period. Moreover, adolescent women present a lower prevalence of obesity and craniofacial alterations, lower OSA severity related to higher UA area and earlier tonsil regression. Hyperactivity is more frequent in boys. Some studies pointed to a higher risk of high diastolic blood pressure in girls than in boys.

The Hypoxic Burden, Clinical Implication of a New Biomarker in the Cardiovascular Management of Sleep Apnea Patients: A Systematic Review

Background

Obstructive sleep apnea (OSA) is a highly prevalent sleep-disordered breathing. It is associated with adverse co-morbidities, being the most scientific evidence of cardiovascular (CV) disease. Currently, OSA is measured through the apnea-hypopnea index (AHI), the total number of respiratory events per hour of sleep. However, different studies have questioned its utility in OSA management, highlighting the need to search for new parameters that better reflect the heterogeneity of the disease. Hypoxic burden (HB) has emerged as a novel biomarker that informs about the frequency, duration and depth of the desaturation related to the respiratory events. We conducted a systematic review in order to find publications about the heterogeneity of OSA measured by HB and its associations with future disease.

Methods

Systematic review was conducted using PubMed and Web of Science. The terms "sleep apne" and "hypoxic burden" were used to look for publications from the date of inception to August 15, 2023. Inclusion criteria: articles in English published in peer-reviewed journals. Exclusion criteria: (1) not available publications; (2) duplicated articles; (3) letters, editorials, and congress communications; (4) articles not including information about HB as a specific biomarker of OSA.

Results

33 studies were included. The results were classified in 2 main sections: (1) HB implication in the CV sphere: HB showed to be a better predictor of CV risk in OSA patients than traditional measures such as AHI with possible clinical management implication in OSA. (2) HB response to OSA treatment: pharmacological and nonpharmacological treatments have demonstrated to be effective in improving hypoxia measured through the HB.

Conclusions

HB could be a better and more effective parameter than traditional measurements in terms of diagnosis, risk prediction and therapeutic decisions in patients with OSA. This measure could be incorporated in sleep units and could play a role in OSA management, driving the clinic to a more personalized medicine.

Insights into Pediatric Sleep Disordered Breathing: Exploring Risk Factors, Surgical Interventions, and Physical and Scholastic Performance at Follow-Up

(1) Background: Sleep-disordered breathing represents a growing public health concern, especially among children and adolescents. The main risk factors for pediatric sleep-disordered breathing in school-age children are tonsillar and adenoid hypertrophy. Adenoidectomy, often in combination with tonsillectomy, is the primary treatment modality for pediatric sleep-disordered breathing. This study aims to comprehensively investigate various risk and protective factors in children with sleep-disordered breathing undergoing adenotonsillar or adenoidal surgeries. We also aim to explore the differences in neuropsychological profiles. (2) Methods: This is an observational, retrospective cohort study. We collected information on adenoidectomy or adenotonsillectomy in children referred to our center. We reviewed the clinical history and preoperative visits and collected data through a telephone questionnaire. The Pediatric Sleep Questionnaire (PSQ) and the Pediatric Quality of Life Inventory (PedsQL) screen sleep-disordered breathing and quality of life, respectively. The data were statistically analyzed using SPSS version 22.0 for Windows (SPSS Inc., Chicago, IL, USA). (3) Results: The study involved 138 patients, but only 100 children participated. A higher percentage of patients with sleep-disordered breathing were observed to have mothers who smoked during pregnancy. A smaller proportion of patients with sleep-disordered breathing habitually used a pacifier. A rise in physical score was associated with a reduced PSQ at follow-up (p = 0.051). An increase in the overall academic score was related to a decrease in the PSQ at follow-up (p < 0.001). A more significant proportion of patients undergoing adenotonsillectomy were observed to have a history of prematurity and cesarean birth. (4) This comprehensive study delves into the intricate interplay of risk and protective factors impacting children with sleep-disordered breathing undergoing adenotonsillectomy and adenoidectomy.

New Approaches to the Management of Cardiovascular Risk Associated with Sleep Respiratory Disorders in Pediatric Patients

Exposure to risk factors in youth can exacerbate the development of future cardiovascular disease (CVD). Obstructive sleep apnea (OSA), characterized by repetitive episodes of airway obstructions, could trigger said CVD acting as a modifiable risk factor. Measurements from echocardiography have shown impairments in the anatomy and function of the heart related to the severity of OSA. Therefore, the aim of this review was to propose a new clinical approach to the management of cardiovascular risk (CVR) in children based on treating OSA. The review includes studies assessing echocardiographic parameters for cardiac function and structure in pediatric OSA diagnosed using the apnea-hypopnea index (AHI) ≥ 1/h using polysomnography (PSG) and conducted within a year. Based on the reviewed evidence, in addition to PSG, echocardiography should be considered in OSA children in order to indicate the need for treatment and to reduce their future CVR. A follow-up echocardiography after treatment could be performed if impairments in the anatomy and function were found. Prioritizing parameters intimately connected to comorbidity could propel more effective patient-centered care. In conclusion, a reevaluation of pediatric OSA strategies should be considered, emphasizing comorbidity-related parameters in the cardiovascular field. Further studies are needed to assess this approach, potentially leading to enhanced protocols for more effective pediatric OSA treatment and CVR prevention.