Asthma and obstructive sleep apnoea in adults and children - an up-to-date review

Genetic overlap and immunological pathways in asthma-obstructive sleep apnea coexistence

PURPOSE

Obstructive sleep apnea (OSA) and asthma are connected through similar epidemiology, clinical symptoms, pathophysiological features, and risk factors. However, the shared genetic basis of these conditions remains poorly understood. This study sought to identify risk genes that contribute to both OSA and asthma and to explore their associated biological pathways.

METHODS

This study was conducted using an in silico approach based on publicly available Genome-Wide Association Studies (GWAS) data. Gene sets associated with OSA (2,159 genes) and asthma (786 genes) were manually curated from GWAS results. These lists were subsequently compared to identify intersecting genes, and their statistical significance was assessed using Fisher's Exact Test. Pathway enrichment analysis was conducted utilizing the Benjamini-Hochberg test with a significance threshold set at an adjusted p-value < 0.05.

RESULTS

A total of 187 genes overlapped between OSA and asthma, indicating a significantly higher occurrence than expected by chance. The pathway overrepresentation analysis of these intersecting genes identified processes associated with immune system functions, encompassing human leucocyte antigen (HLA), antigen presentation, cell differentiation, cell signaling, and positive regulation of inflammatory mediators.

CONCLUSION

This study unveils shared genetic mechanisms associated with OSA and asthma risks, highlighting intricate interactions within pathways governing immune response and inflammation. These findings provide a preliminary step toward understanding the genetic basis of this association; however, their clinical significance remains to be established. Further functional studies and validation in independent cohorts are needed to determine their potential relevance for biomarker development and immune-targeted therapeutic strategies.

Association of obstructive sleep apnea risk with allergic asthma: A systematic review and meta-analysis

BACKGROUND

There is a close relationship between asthma and obstructive sleep apnea (OSA), and the mechanisms of these 2 diseases are overlapped. However, the relationship between OSA and allergic asthma remains to be analyzed through systematic review and meta-analysis.

METHODS

A systematic search was conducted using Scopus, PubMed, ISI, Google Scholar, and Cochrane Library by utilizing the keywords Allergic asthma, Obstructive sleep apnea, and OSA. Hazard ratio, odds ratio (OR), and risk ratio with 95% confidence interval, fixed and Mantel-Haenszel methods were calculated. Statistical software Stata was used for the evaluation of this meta-analysis.

RESULTS

Finally, 19 articles were included in this study. The prevalence of OSA in allergic asthma patients was 35.25% (19.92%, 50.57%), which was statistically significant, and pooled analysis of ORs observed in individual studies showed that the odds of OSA prevalence were 2.24 (1.32, 3.12) (P < 0.001). Also, the prevalence of OSA risk in allergic asthma patients was 30.08% (19.73%, 40.43%), which was statistically significant, and pooled analysis of ORs observed in individual studies showed that the odds of OSA risk were 3.46 (2.96, 4.94) (P < 0.001).

CONCLUSION

The present meta-analysis showed that the prevalence of OSA as well as the OSA risk in patients with asthma were significantly higher compared with healthy people.

What is the role of asthma in obstructive sleep apnea? A narrative review

INTRODUCTION

Asthma and obstructive sleep apnea (OSA) are two of the most prevalent respiratory diseases in the world. Their high prevalence increases the probability of the two diseases coexisting by chance in a single individual, but in recent years, various studies have also shown a real one-to-one association between them.

DATA SOURCES

PubMed. Keywords: asthma (title) and OSA (title) and apnea (title) and positive airway pressure and CPAP (title).

STUDIES SELECTION

All manuscript related to the relationship between asthma an OSA as well as its treatments in terms of pathophysiological, diagnostic, etiological, epidemiological and treatment points.

RESULTS

50% of asthmatic patients suffer from OSA and the adjusted risk of developing OSA in asthmatics is 2.5 times higher than in non-asthmatic individuals, especially in poorly controlled, more severe or longer-standing asthmatics. Several mechanisms have been postulated to explain this increase in OSA in asthmatics: obesity, gastro-esophageal reflux, rhinitis, nasal polyps, increased pharyngeal collapsibility due to mechanical, inflammatory or dynamic causes and, finally, the upper airway deposition of inhaled corticosteroids (IC) generating myopathy in the pharyngeal muscles (as occurs in the vocal cord muscles, resulting in dysphonia).

CONCLUSIONS

Although both asthma and OSA are common diseases that can coexist in the same individual, a one-to-one association between the two diseases has been observed. The presence of asthma could generate or exacerbate a preexisting OSA. Caution is recommended in IC inhalation techniques in patients with OSA. The use of ultrafine particles with less pharyngeal deposition is recommended.

Global burden of asthma attributable to high body mass index in older adults 1990-2021 and prediction to 2050: An analysis of Global Burden of Disease Study 2021

Background

Previous studies have shown that high body mass index was a primary risk factor for asthma, particularly impacting older adults. This study aimed to assess the spatial and temporal trends for asthma burden attributable to high body mass index in older adults from 1990 to 2021 and to project trends up to 2050.

Method

We extracted data from the Global Burden of Disease Study 2021 for population aged over 60 years with asthma attributable to high BMI. Relevant indicators included number of deaths, disability-adjusted life years, mortality, and disability-adjusted life years rates and the rates were directly standardized. Spearman rank correlation test tested the burden against the Socio-demographic Index (SDI). Decomposition analysis was used to decompose changes in burden according to population structure, population growth, and epidemiologic changes. The Bayesian age-period-cohort model was used to predict the burden.

Results

From 1990 to 2021, despite downward trends in global mortality and disability-adjusted life-year rates, global asthma deaths, and disability-adjusted life years attributable to high body mass index increase by 69% and 46%, rising to 43,628 cases (95% CI: 18,366-71 088) and 1,223,969 years (95% CI: 526,972-1 945,426). Age-standardized mortality rates and disability-adjusted life years rates were more severe in regions with lower SDI, such as Oceania. Mortality rates and disability-adjusted life-year rates increased with age, with a higher burden observed in females compared to males. Population growth had a significant impact on the increase in deaths and disability-adjusted life years from 1990 to 2021, contributing approximately 158% and 222%, respectively. Asthma deaths and disability-adjusted life years attributable to high body mass index will continue to rise to 101,252 cases and 2,941,172 years up to 2050.

Conclusion

The global asthma burden due to high body mass index in older adults has risen significantly and is expected to continue this trend, highlighting the importance of developing public health strategies to address this issue.

Quantitative Proteomics Analysis of Serum and Urine With DIA Mass Spectrometry Reveals Biomarkers for Pediatric Obstructive Sleep Apnea

OBJECTIVES

Identification of suitable biomarkers that facilitate the screening and evaluation of pediatric obstructive sleep apnea (OSA) and its severity was explored.

METHODS

Data-independent acquisition quantitative proteomic analysis was employed to identify serum and urine proteins with differential expression patterns between children with OSA and controls. Differentially expressed proteins that gradually increased or decreased with the severity of OSA were retained as potential biomarkers and underwent ELISA validation.

RESULTS

We found that with increasing severity of OSA, there was a gradual upregulation of 34 proteins in the serum and 124 proteins in the urine, along with a respective downregulation of 10 serum proteins and 64 urinary proteins in the initial cohort of 40 children. These proteins primarily participate in immune activation, the complement pathway, oxygen transport, and reactive oxygen metabolism. Notably, cathepsin Z exhibited a positive correlation with the obstructive apnea hypopnea index, whereas sex hormone-binding globulin (SHBG) was negatively correlated. These proteins were then validated by ELISA in an independent cohort (n=21). Circulating cathepsin Z and SHBG levels displayed acceptable diagnostic performance of OSA with AUC values of 0.863 and 0.738, respectively.

CONCLUSIONS

We identified two promising circulating proteins as novel biomarkers for clinical diagnosis and assessment of pediatric OSA severity. Furthermore, the comprehensive proteomic profile in pediatric OSA should aid in exploring the underlying pathophysiological mechanisms associated with this prevalent condition.

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.

Correlation analysis of LXR and its target genes COX2 and CETP with the severity of OSAHS in obese young rats

OBJECTIVE

To analyse the relationships between the expression levels of liver X receptor (LXR), cyclooxygenase-2(COX2) and cholesterol ester transfer protein (CETP) and the severity of obstructive sleep apnoea hypopnoea syndrome (OSAHS) in obese young rats, to obtain information for basic research on OSAHS in obese children.

METHODS

Twenty-four 3-4-week-old young rats were randomly assigned to the normal control group, obesity group, OSAHS group, obesity and OSAHS group. We used polysomnography to measure the obstructive apnoea hypopnoea index (OAHI) to assess the severity of OSAHS and western blotting to test the expression levels of LXRα, COX2, and CETP in the liver, heart, kidney, and brain tissues.

RESULTS

LXR, COX2, and CETP expression levels in the remaining groups were considerably higher than those in the control group (P < 0.05). Compared with those in the obesity group, LXRα, COX2, and CETP expression levels in the obesity and OSAHS group were considerably greater in the liver, kidney, and heart tissues (P < 0.05); the brain tissues of the obesity and OSAHS group showed considerably higher expression levels of COX2 and CETP (P < 0.05). Compared with those in the OSAHS group, LXRα, COX2, and CETP expression levels in the obesity and OSAHS group were significantly greater in all tissues (P < 0.05). The expression levels of LXRα, COX2, and CETP and obesity increased with increasing OSAHS severity (r = 0.777, P < 0.01; r = 0.728, P < 0.01; r = 0.793, P < 0.01; r = 0.786, P < 0.01; and r = 0.698, P < 0.01), and the oxygen concentration increased with decreasing OSAHS severity(r=-0.576, P < 0.01).

CONCLUSIONS

LXR, COX2, and CETP expression levels were significantly increased in the liver, kidney, heart, and brain tissues of young rats with obesity and OSAHS, and were positively correlated with the severity of OSAHS.

The interaction effects between depression and sleep status on asthma: a national cross-sectional study

Background

Asthma, depression, and sleep problems are three significant public health issues that are closely interrelated. This study aims to explore the relationship between depression, sleep status and asthma, as well as the potential interaction among these conditions and their effects on asthma.

Method

This cross-sectional study utilized data from the 2005-2008 National Health and Nutritional Examination Survey, including information on asthma, depression, sleep status and confounding factors. Multivariate logistic regression analyses were conducted to investigate the relationship between depression, sleep status, and asthma. Subgroup analyses were conducted to test the p-interaction between depression and each stratified variable. Additionally, both multiplicative and additive approaches were employed to assess the interaction between depression and sleep status on asthma, as well as to quantify their combined effects.

Results

A total of 8,327 participants (mean age 46.53 years) were included in this study. Compared to the individuals without depression, those with depression have an increased risk of asthma [Odds ratio (OR) = 1.57, 95% Confidence interval (CI) = 1.22-2.03], and an increase in the severity of depressive symptoms is associated with a higher risk of developing asthma. Additionally, poor sleep quality, sleep disorders, and insufficient sleep was associated with an increased risk of asthma. Effect modification was observed between depression and PIR status, smoking status, and sleep disorders in relation to asthma (p-interaction <0.05). Moreover, we found a positive interaction between severe depression and excessive sleep (OR = 29.07, 95% CI = 3.24-260.38). Furthermore, we observed the quantitative additive interaction indicators between moderately severe depression and insufficient sleep [Relative excess risk due to interaction (RERI) = 1.63, 95%CI = 0.18-3.83; Attributable proportion (AP) = 0.51, 95%CI = 0.15-0.87; Synergy index (SI) = 3.92, 95%CI = 1.65-23.50] influencing asthma risk.

Conclusion

Our study revealed distinct associations between depression, the severity of depressive symptoms, poor sleep quality, sleep disorders, and insufficient sleep with asthma. Additionally, there was an interaction between moderately severe depression and insufficient sleep on asthma. Psychological and sleep assessment are essential in asthma management. Clinicians should consider the potential risk of depression and sleep problems in asthma patients and intervene. Further longitudinal research is needed to better understand the pathophysiological mechanisms behind the interactions between asthma, depression, and sleep problems.

Assessing the importance and safety of hypoxia conditioning for patients with occupational pulmonary diseases: A recent clinical perspective

Occupational pulmonary diseases (OPDs) pose a significant global health challenge, contributing to high mortality rates. This review delves into the pathophysiology of hypoxia and the safety of intermittent hypoxic conditioning (IHC) in OPD patients. By examining sources such as PubMed, Relemed, NLM, Scopus, and Google Scholar, the review evaluates the efficacy of IHC in clinical outcomes for OPD patients. It highlights the complexities of cardiovascular and respiratory regulation dysfunctions in OPDs, focusing on respiratory control abnormalities and the impact of intermittent hypoxic exposures. Key areas include the physiological effects of hypoxia, the role of hypoxia-inducible factor-1 alpha (HIF-1α) in occupational lung diseases, and the links between brain ischemia, stroke, and OPDs. The review also explores the interaction between intermittent hypoxic exposures, mitochondrial energetics, and lung physiology. The potential of IHE to improve clinical manifestations and underlying pathophysiology in OPD patients is thoroughly examined. This comprehensive analysis aims to benefit molecular pathologists, pulmonologists, clinicians, and physicians by enhancing understanding of IHE's clinical benefits, from research to patient care, and improving clinical outcomes for OPD patients.

Obstructive Sleep Apnea Is Associated with Worsened Hospital Outcomes in Children Hospitalized with Asthma

BACKGROUND

Studies have shown a bidirectional relationship between asthma and obstructive sleep apnea (OSA). However, there is a paucity of national-level data evaluating the impact of OSA on hospital outcomes in pediatric hospitalizations for asthma.

METHODS

We analyzed the National Inpatient Sample and Kids Inpatient Database to include all pediatric hospitalizations with a primary diagnosis of asthma between 2003-2016. Using ICD codes, the pediatric asthma cohort was divided into two groups: those with and those without a concomitant diagnosis of OSA. The primary outcomes were in-hospital mortality and the need for mechanical ventilation. The secondary outcomes were the lengths of each hospital stay and total hospitalization charges.

RESULTS

We analyzed 1,606,248 hospitalizations during the 14-year study period. The overall prevalence rate of OSA was 0.7%. Patients with asthma and OSA were significantly older (8.2 versus 5.9 years) and were more often male, p < 0.001. The OSA group had several increased comorbidities. The overall mortality rate was 0.03%, and multivariate regression analysis showed that OSA was associated with 4.3 times higher odds of in-hospital mortality (95% CI: 2.4 to 7.6, p < 0.001). Furthermore, OSA was associated with a 5.2 times greater need for mechanical ventilation (95% CI: 4.8 to 5.5, p < 0.001). Linear regression analyses demonstrated that OSA independently contributed an additional 0.82 days to the hospital stay length (95% CI: 0.79 to 0.86, p < 0.001) and an extra 10,479 USD (95% CI: 10,110 to 10,848, p < 0.001) in hospitalization charges.

CONCLUSION

OSA in children admitted with asthma is associated with poor hospital outcomes such as increased mortality risk, the need for mechanical ventilation, and increased healthcare utilization.

Exploring the Relationship between Inhaled Corticosteroid Usage, Asthma Severity, and Sleep-Disordered Breathing: A Systematic Literature Review

(1) Background: Sleep-disordered breathing and asthma are often interrelated. Children and adults with asthma are more susceptible to sleep apnea. Inhaled corticosteroids effectively reduce inflammation and prevent structural changes in the airways. Objective: to explore the existing literature to determine whether inhaled corticosteroids play a role in sleep-disordered breathing in patients with asthma. (2) Methods: We conducted a thorough search of the PubMed, Scopus, and Web of Science databases for English-language articles published up to 12 May 2024. We utilized the ROBINS-E tool to assess the risk of bias. (4) Conclusions: 136 articles were discerned upon conducting the literature search. A total of 13 articles underwent exhaustive full-text scrutiny, resulting in 6 being considered non-relevant. The remaining seven articles, assessed for eligibility, were incorporated into the final analysis. Five studies were identified in adults and two in children. In adult patients, inhaled corticosteroids, especially at high doses, appear to increase the risk of sleep apnea in a dose-dependent manner. Moreover, the properties of inhaled corticosteroids, such as particle size, may impact the risk of developing sleep apnea. In children, the severity of asthma is a key factor affecting the prevalence of sleep apnea, whereas inhaled corticosteroids appear to be a less significant risk factor compared to adults. All of the studies reviewed were classified as having a high risk of bias or some concerns regarding bias. Each study revealed at least one type of bias that raised notable concerns. This research highlights a complex interaction between the use of inhaled corticosteroids, the severity of asthma, and the onset of sleep apnea. Additional research is necessary to investigate these relationships further.

Comparison of sleep quality between outpatient and hospitalized children with respiratory tract dysfunction

OBJECTIVES

The main objective of the study to compare the effect of hospitalized and outpatient settings on quality of sleep in children with respiratory tract dysfunction.

METHODOLOGY

A descriptive correlational study was carried out at Dhi-Qar Health Directorate pediatric hospitals. The period of the study was from the November 19, 2023 to March 10, 2024. Purposive sample (non-probability) of 250 children (male and female). A total of (125) children were chosen from the children whose admitted to the hospitals, and a total of (125) children were chosen from the outpatient settings. The study instrument consisted of three parts: the sociodemographic sheet, clinical diagnosis sheet, and sleep quality scale. The questionnaire was modified according to experts' recommendation to use it for children with respiratory tract dysfunction. The questionnaire was evaluated by a panel of 15 experts from diverse medical and nursing professions. Both descriptive and inferential statistics were used to analyze the data.

RESULTS

The study findings that effect outpatient settings have more effect from hospitalized settings on quality of sleep in children with respiratory tract dysfunction (M ± SD = 1.322 ± 0.1522).

CONCLUSION

A study showed that the quality of sleep in children with respiratory tract dysfunction was generally average, whether in hospitalized or outpatient settings, outpatient settings had greater difficulties falling asleep and waking than children in hospitalized.

The Causal Association Between Obstructive Sleep Apnea and Child-Onset Asthma Come to Light: A Mendelian Randomization Study

Purpose

Obstructive sleep apnea (OSA) had been associated with asthma in observational studies, but the effect of OSA on the onset of asthma in childhood or adulthood remains unclear, and the causal inferences have not been confirmed. This study aims to investigate the potential causal association between OSA with asthma, including different age-of-onset subtypes, providing reliable basis for the clinical treatment of OSA and asthma.

Patients and Methods

Causality between OSA and asthma was assessed using a two-sample bi-directional Mendelian randomization (MR) analysis. OSA data were obtained from the FinnGen consortium R9, while asthma and its subtypes (adult-onset asthma, child-onset asthma, and moderate-to-severe asthma) were sourced from the IEU OpenGWAS project. The inverse-variance weighted (IVW) method was chosen as the primary analysis and was complemented by various sensitivity analyses. The MR-PRESSO outlier test was employed to systematically identify and remove outlier variants, mitigating heterogeneity and potential effects of horizontal pleiotropy.

Results

The MR analyses provided evidence of genetically predicted OSA having a promoting effect on child-onset asthma (OR,1.49; 95% CI, 1.05-2.11; P=0.025) and moderate-to-severe asthma (OR,1.03; 95% CI, 1.00-1.06; P=0.046). However, no causal association between OSA with asthma and adult-onset asthma was observed.

Conclusion

Our study revealed a causal association between OSA and child asthma, but not in adults. Moderate-to-severe asthma may have a potential promoting effect on OSA. These findings underscore the importance of age-specific considerations in managing asthma and suggests the need for personalized approaches in clinical practice.

Effects of Obstructive Sleep Apnea on Airway Immunity and Susceptibility to Respiratory Infections

Obstructive sleep apnea is a prevalent sleep disorder characterized by recurrent episodes of partial or complete upper airway collapse during sleep, leading to disrupted breathing patterns and intermittent hypoxia. OSA results in systemic inflammation but also directly affects the upper and lower airways leading to upregulation of inflammatory pathways and alterations of the local microbiome. These changes result in increased susceptibility to respiratory infections such as influenza, COVID-19, and bacterial pneumonia. This relationship is more complex and bidirectional in individuals with chronic lung disease such as chronic obstructive lung disease, interstitial lung disease and bronchiectasis.

Endoplasmic reticulum stress drives macrophages to produce IL-33 to favor Th2 polarization in the airways

Interleukin (IL)-33 is a key driver of T helper 2 (Th2) cell polarization. Endoplasmic reticulum (ER) stress plays a role in the skewed T cell activation. The objective of this project is to elucidate the role of IL-33 derived from macrophages in inducing Th2 polarization in the airways. In this study, bronchoalveolar lavage fluids (BALF) were collected from patients with asthma and healthy control subjects. Macrophages were isolated from the BALF by flow cytometry cell sorting. An asthmatic mouse model was established using the ovalbumin/alum protocol. The results showed that increased IL33 gene activity and ER stress-related molecules in BALF-derived M2a macrophages was observed in asthmatic patients. Levels of IL33 gene activity in M2a cells were positively correlated with levels of asthma response in asthma patients. Sensitization exacerbated the ER stress in the airway macrophages, which increased the expression of IL-33 in macrophages of airway in sensitized mice. Conditional ablation of Il33 or Perk or Atf4 genes in macrophages prevented induction of airway allergy in mice. In conclusion, asthma airway macrophages express high levels of IL-33 and at high ER stress status. Inhibition of IL-33 or ER stress in macrophages can effectively alleviate experimental asthma.

Role of bronchial hyperresponsiveness in patients with obstructive sleep apnea with asthma-like symptoms

BACKGROUND

Obstructive sleep apnea (OSA) is one of the major co-morbidities and aggravating factors of asthma. In OSA-complicated asthma, obesity, visceral fat, and systemic inflammation are associated with its severity, but the role of bronchial hyperresponsiveness (BHR) is unclear. We investigated the involvement of BHR and mediastinal fat width, as a measure of visceral fat, with OSA severity in patients with OSA and asthma-like symptoms.

METHODS

Patients with OSA who underwent BHR test and chest computed tomography scan for asthma-like symptoms were retrospectively enrolled. We evaluated the relationship between apnea-hypopnea index (AHI) and PC20 or anterior mediastinal fat width, stratified by the presence or absence of BHR.

RESULTS

OSA patients with BHR (n = 29) showed more obstructive airways and frequent low arousal threshold and lower mediastinal fat width, and tended to show fewer AHI than those without BHR (n = 25). In the overall analysis, mediastinal fat width was significantly positively correlated with AHI, which was significant even after adjustment with age and gender. This was especially significant in patients without BHR, while in OSA patients with BHR, there were significant negative associations between apnea index and airflow limitation, and hypopnea index and PC20.

CONCLUSIONS

Risk factors for greater AHI differed depending on the presence or absence of BHR in OSA patients with asthma-like symptoms. In the presence of BHR, severity of asthma may determine the severity of concomitant OSA.

Gastroesophageal reflux disease, obesity, bronchial asthma: simple combination or complex interaction

Gastroesophageal reflux disease (GERD) continues to be one of the most common diseases in primary health care. In recent years, the presence of several diseases in the same patient at the same time has been widely discussed. An increase in persons suffering from several chronic diseases is associated with a deterioration in the quality of life, a high risk of hospitalization and mortality, and taking into account the presence of co/poly/multimorbidity is necessary for decision-making when developing a patient management strategy in primary health care. Studies on GERD, obesity and bronchial asthma have shown that there are common and bidirectional mechanisms in the development of these diseases. And, there are many gaps in understanding these relationships, it is important to identify concomitant diseases, since they can be the cause of resistance to therapy, to form an unfavorable prognosis of their course.

Prevalence of obstructive sleep apnea (OSA) among preschool aged children in the general population: A systematic review

Untreated pediatric obstructive sleep apnea (OSA) is associated with significant morbidities affecting behavior, neurocognitive development, endocrine and metabolic health. This systematic review evaluated prevalence of OSA reported in population-based studies among preschoolers as early intervention may have positive effects on health and quality of life. Thirty studies were included. High degrees of heterogeneity in methods and definitions were observed between the studies. Seven studies confirmed OSA by implementing objective methods after screening for habitual snoring with only two studies utilizing polysomnography, the reference standard, testing 1.2% of the combined cohorts (n = 82/4575) to confirm disease. Diagnosis of OSA was based on utilizing retired thresholds of the apnea-hypopnea-index (AHI), AHI4%≥5/hour of sleep (hrSleep), reporting prevalence of 1.8% and 6.4%, respectively. The remaining five studies implemented relatively insensitive objective recording methods to confirm disease in a limited number of children (n = 449/2486; 18.0%), estimating prevalence in the range of 0.7%-13.0%. The remaining literature is based on implementing questionnaires only to evaluate OSA. Studies published before 2014 reported 3.3%-9.4% prevalence, while more recent studies published 2016-2023 report higher prevalence, 12.8%-20.4%, when excluding outliers. This trend suggests that prevalence of OSA may possibly have been increasing in preschoolers over the past decade.

Obesity and Insulin Resistance in Asthma Pathogenesis and Clinical Outcomes

Common inflammatory ground links obesity, insulin resistance, and asthma. As recognition of their interplay, one worsening the natural course of the other, is recognised, questions remain about how to adequately address them altogether to improve clinical outcomes. The present manuscript sheds light on the problem, describing possible pathophysiological links, clinical views, and therapeutic challenges, raising questions about what remains to be done, and calling for multidisciplinary treatment of these patients to detect diseases early and adequately address them before they become full-blown and deteriorate their health and quality of life.

Effects of biological therapies on patients with Type-2 high asthma and comorbid obesity

Over 20 million adults and 6 million children in the United States (US) have asthma, a chronic respiratory disease characterized by airway inflammation, bronchoconstriction, and mucus hypersecretion. Obesity, another highly prevalent disease in the US, is a major risk factor for asthma and a significant cause of diminished asthma control, increased submucosal eosinophilia, and reduced quality of life. A large subgroup of these patients experiences severe symptoms and recurrent exacerbations despite maximal dosage of standard asthma therapies. In the past two decades, the development of biological therapies has revolutionized the field and advanced our understanding of type 2 inflammatory biomarkers. However, patients with obesity and comorbid asthma are not principally considered in clinical trials of biologics. Large landmark cluster analyses of patients with asthma have consistently identified specific asthma phenotypes that associate with obesity but may be differentiated by age of asthma onset and inflammatory cell profiles in sputum. These patterns suggest that biologic processes driving asthma pathology are heterogenous among patients with obesity. The biological mechanisms driving pathology in patients with asthma and comorbid obesity are not well understood and likely multifactorial. Future research needs to be done to elicit the cellular and metabolic functions in the relationship of obesity and asthma to yield the best treatment options for this multiplex condition. In this review, we explore the key features of type 2 inflammation in asthma and discuss the effectiveness, safety profile, and research gaps regarding the currently approved biological therapies in asthma patients with obesity.

Asthma and obstructive sleep apnea: Unveiling correlations and treatable traits for comprehensive care

Asthma and obstructive sleep apnea (OSA) are common respiratory disorders. They share characteristics such as airway obstruction, poor sleep quality, and low quality of life. They are often present as comorbidities, along with obesity, gastroesophageal reflux disease (GERD), and allergic rhinitis (AR), which impacts the disease's control. In recent years, there has been discussion about the association between these conditions and their pathophysiological and clinical consequences, resulting in worse health outcomes, increased healthcare resource consumption, prolonged hospital stays, and increased morbidity and mortality. Some studies demonstrate that treatment with continuous positive airway pressure (CPAP) can have a beneficial effect on both pathologies. This review summarizes the existing evidence of the association between asthma and OSA at their pathophysiological, epidemiological, clinical, and therapeutic levels. It intends to raise awareness among healthcare professionals about these conditions and the need for further research.

Co-existence of OSA and respiratory diseases and the influence of gender

INTRODUCTION

Sleep-disordered breathing (SDB), especially obstructive sleep apnea (OSA), is commonly associated with respiratory diseases, such as COPD, asthma and interstitial lung disease.

AREAS COVERED

This narrative review aims to comprehensively synthesize the existing information on SDB in respiratory diseases, investigate the role of gender in this association, and highlight the importance of OSA management in improving sleep, quality of life, and disease prognosis in these specific patient populations.

EXPERT OPINION

Research indicates a synergistic link between OSA and chronic respiratory diseases, which leads to greater morbidity and mortality compared to each disorder alone. Given the lack of an optimal OSA screening tool for these patients, a comprehensive patient approach and overnight diagnostic sleep study are imperative. Despite the limited evidence available, it seems that gender has an impact on the prevalence, severity, and susceptibility of this coexistence. Recognizing the role of gender in the coexistence of OSA and other respiratory diseases can enhance everyday medical practice and enable clinicians to adopt a more personalized approach toward optimal screening and diagnosis of these patients.

Analysis of possible risk factors for the severity of paediatric obstructive sleep apnoea syndrome

PURPOSE

This study aimed to determine the effect of body mass index (BMI) percentile, asthma, sex, and age on the paediatric obstructive sleep apnoea (OSA) severity. Furthermore, to determine the possible predictive role of the BMI percentile and age in severe OSA.

METHODS

This retrospective study included 921 children aged 2-18 years diagnosed with OSA by polysomnography. Analysis of Covariance (ANCOVA), Spearman's correlation, Receiver Operating Characteristics (ROC) analyses were performed and area under the curve (AUC) was determined.

RESULTS

We observed a significant association between a higher BMI percentile and the severity of OSA (p < 0.001, ρ = 0.15). The correlation also was significant under (p = 0.007, ρ = 0.11) and over 7 (p = 0.0002, ρ = 0.23) years of age. There was no association between the severity of OSA and the presence of asthma (p = 0.9) or sex (p = 0.891), respectively. Age was significantly related to OSA severity (p = 0.01, ρ = 0.08). Although both the BMI percentile (0.59 AUC [0.54-0.65]) and age (0.58 AUC [0.52-0.63]) predicted severe OSA, according to the sensitivity and specificity values of the ROC curve, the association presents a slight clinical relevance.

CONCLUSIONS

OSA severity is determined by the BMI percentile and age in children; however, these factors are unsuitable for predicting severe OSA in clinical practice. Based on our results, obesity is also a significant risk factor for OSA in younger children. Our study highlights that older, overweight, and obese children have a higher risk for severe OSA.

Exogenous Ang-(1-7) inhibits autophagy via HIF-1α/THBS1/BECN1 axis to alleviate chronic intermittent hypoxia-enhanced airway remodelling of asthma

Obstructive sleep apnoea (OSA)-induced chronic intermittent hypoxia (CIH) has been considered a risk factor for severe asthma. Airway remodelling, which could be modulated by autophagy, plays a key role in severe asthma. However, the extent of autophagy's involvement in CIH-potentiated airway remodelling remains largely unexplored. Furthermore, we had found that angiotensin-(1-7) [Ang-(1-7)] has therapeutic effects on airway remodelling in asthma, but the underlying mechanism is either unclear. This study aimed to explore how CIH aggravates asthma and mechanism of protective effects of Ang-(1-7) on airway remodelling, with a focus on autophagy. We observed that CIH promoted epithelial-to-mesenchymal transition (EMT), indicated by elevated EMT and fibrotic markers such as Snail and Collagen IV, both in vitro and in vivo. CIH intensified cell autophagy, evident from increased LC3B expression and reduced p62 levels. Ang-(1-7) reversed the CIH-enhanced expression of Snail, Collagen IV, and LC3B. To explore how CIH enhanced autophagy in cellular and animal model of asthma, overexpression of hypoxia-inducible factor 1-alpha (HIF-1α) and Thrombospondin 1 (THBS1) were identified in CIH-exposure mice lung compared with normal mice lung tissues from the GEO database. Finally, through chromatin immunoprecipitation and immunoprecipitation assays, we verified that Ang-(1-7) inhibits CIH-induced binding of HIF-1α to the promoter of THBS1, and also disrupts the protein-protein interaction between THBS1 and the autophagy-associated protein Beclin 1 (BECN1), ultimately leading to autophagy inhibition. Our findings suggest that exogenous Ang-(1-7) can inhibit autophagy via HIF-1α/THBS1/BECN1 axis, thereby alleviating CIH-enhanced airway remodelling in asthma. These findings imply the potential therapeutic effect of Ang-(1-7) in asthma with OSA.

Comparison of invisalign mandibular advancement and twin-block on upper airway and hyoid bone position improvements for skeletal class II children: a retrospective study

BACKGROUND

This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT).

METHODS

32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT.

RESULTS

(1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05).

CONCLUSION

Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range.

In silico network pharmacology analysis and molecular docking validation of Swasa Kudori tablet for screening druggable phytoconstituents of asthma

Traditional medicines are impactful in treating a cluster of respiratory-related illnesses. This paper demonstrates screening active, druggable phytoconstituents from a classical Siddha-based poly-herbal formulation called Swasa Kudori Tablet to treat asthma. The phytoconstituents of Swasa Kudori are identified as Calotropis gigantea, Piper nigrum, and (Co-drug) Abies webbiana. Active chemical compounds are extracted with the Chemical Entities of Biological Interest (ChEBI) database. The gene targets of each compound are identified based on the pharmacological activity using the DIGEP-Pred database. Thirty-two genes showing Pa> 0.7 is screened, and the target markers are selected after performing gene overlap evaluation with the asthma genes reported in GeneCards and DisGeNET database. Ten markers are identified, such as ADIPOQ, CASP8, CAT, CCL2, CD86, FKBP5, HMOX1, NFE2L2, TIMP1, VDR, in common, listed as molecular targets. Pharmacokinetic assessment (ADME) revealed five natural drug compounds 2-5-7-trihydroxy-2-(4-hydroxyphenyl)-2,3-dihydro-4H-chromen-4-one, (+)-catechin-3'-methyl ether, futoenone, 5-hydroxy-4',7-dimethoxyflavanone, and pinocembrin showing better druggability. Further screening delineates the target (HMOX1) and drug (pinocembrin) for molecular docking evaluation. When docked with HO-1, Pinocembrin showed a binding affinity of -8.0 kcal/mol. MD simulation studies substantiate the docking studies as HO-1 in complex with pinocembrin remains stable in the simulated trajectory. The current findings exhibit the significance of traditional medicines as potential drug candidates against asthma.

The relationship between obstructive sleep apnea and asthma severity and vice versa: a systematic review and meta-analysis

BACKGROUND

There is a great association between the prevalence of obstructive sleep apnea (OSA) and asthma. Nonetheless, whether OSA impacts lung function, symptoms, and control in asthma and whether asthma increases the respiratory events in OSA are unknown. This meta-analysis aimed to examine the relationship between obstructive sleep apnea and asthma severity and vice versa.

METHODS

We carried out a systematic search of PubMed, EMBASE, and Scopus from inception to September 2022. Primary outcomes were lung function, parameters of polysomnography, the risk of OSA in more severe or difficult-to-control asthmatic patients, and the risk of asthma in patients with more severe OSA. Heterogeneity was examined with the Q test and I² statistics. We also performed subgroup analysis, Meta-regression, and Egger's test for bias analysis.

RESULTS

34 studies with 27,912 subjects were totally included. The results showed that the comorbidity of OSA aggravated lung function in asthmatic patients with a consequent decreased forced expiratory volume in one second %predicted (%FEV1) and the effect was particularly evident in children. %FEV1 tended to decrease in adult asthma patients complicated with OSA, but did not reach statistical significance. Interestingly, the risk of asthma seemed to be slightly lower in patients with more severe OSA (OR = 0.87, 95%CI 0.763-0.998). Asthma had no significant effect on polysomnography, but increased daytime sleepiness assessed by the Epworth Sleepiness Scale in OSA patients (WMD = 0.60, 95%CI 0.16-1.04). More severe asthma or difficult-to-control asthma was independently associated with OSA (odds ratio (OR) = 4.36, 95%CI 2.49-7.64).

CONCLUSION

OSA was associated with more severe or difficult-to-control asthma with decreased %FEV₁ in children. The effect of OSA on lung function in adult patients should be further confirmed. Asthma increased daytime sleepiness in OSA patients. More studies are warranted to investigate the effect of asthma on OSA severity and the impact of different OSA severity on the prevalence of asthma. It is strongly recommended that people with moderate-to-severe or difficult-to-control asthma screen for OSA and get the appropriate treatment.

Obese asthma phenotypes display distinct plasma biomarker profiles

BACKGROUND

Obese asthma is a complex phenotype and further characterization of the pathophysiology is needed. This study aimed to explore inflammation-related plasma biomarkers in lean and overweight/obese asthmatics.

METHODS

We elucidated levels of inflammation-related plasma proteins in obese asthma phenotypes in the population-based cohort BAMSE (Swedish: Children, Allergy, Milieu, Stockholm, Epidemiology) using data from 2069 24-26-year-olds. Subjects were divided into lean asthma (n = 166), lean controls (n = 1440), overweight/obese asthma (n = 73) and overweight/obese controls (n = 390). Protein levels (n = 92) were analysed using the Olink Proseek Multiplex Inflammation panel.

RESULTS

Of the 92 included proteins, 41 were associated with lean and/or overweight/obese asthma. The majority of proteins associated with overweight/obese asthma also associated with overweight/obesity among non-asthmatics. Beta-nerve growth factor (BetaNGF), interleukin 10 (IL-10), and matrix metalloproteinase 10 (MMP10) were associated only with lean asthma while C-C motif chemokine 20 (CCL20), fibroblast growth factor 19 (FGF19), interleukin 5 (IL-5), leukemia inhibitory factor (LIF), tumor necrosis factor ligand superfamily member 9 (TNFRSF9), and urokinase-type plasminogen activator (uPA) were associated only with overweight/obese asthma. Overweight/obesity modified the association between asthma and 3 of the proteins: fibroblast growth factor 21 (FGF21), interleukin 4 (IL-4), and urokinase-type plasminogen activator (uPA). In the overweight/obese group, interleukin-6 (IL-6) was associated with non-allergic asthma but not allergic asthma.

CONCLUSION

These data indicate distinct plasma protein phenotypes in lean and overweight/obese asthmatics which, in turn, can impact upon therapeutic approaches.

Diagnosing sleep disordered breathing in patients with chronic pulmonary disease: which test for which patient?

Overnight polysomnography should be the first-line diagnostic test in patients with severe respiratory disease. However, if access to polysomnography is limited, overnight polygraphy can be used as an alternative first-line diagnostic. https://bit.ly/3KlmFED.

Leptin and Asthma: What Are the Interactive Correlations?

Leptin is an adipokine directly correlated with the proinflammatory obese-associated phenotype. Leptin has been demonstrated to inhibit adipogenesis, promote fat demarcation, promote a chronic inflammatory state, increase insulin sensitivity, and promote angiogenesis. Leptin, a regulator of the immune response, is implicated in the pathology of asthma. Studies involved in the key cell reaction and animal models of asthma have provided vital insights into the proinflammatory role of leptin in asthma. Many studies described the immune cell and related cellular pathways activated by leptin, which are beneficial in asthma development and increasing exacerbations. Subsequent studies relating to animal models support the role of leptin in increasing inflammatory cell infiltration, airway hyperresponsiveness, and inflammatory responses. However, the conclusive effects of leptin in asthma are not well elaborated. In the present study, we explored the general functions and the clinical cohort study supporting the association between leptin and asthma. The main objective of our review is to address the knowns and unknowns of leptin on asthma. In this perspective, the arguments about the different faces of leptin in asthma are provided to picture the potential directions, thus yielding a better understanding of asthma development.

Resolution of daytime and night-time respiratory symptoms but persistent sleep apnea in severe asthma with the add-on of benralizumab

Introduction

The relationship between asthma and obstructive sleep apnea (OSA) is a widely debated topic in the scientific literature with the controversy surrounding the bi-directional nature of the correlation.

Case presentation

We report the case of a 59-year-old male being affected by severe allergic eosinophilic asthma and severe OSA (apnea-hypopnea index [AHI] 32 ev·hr^-1). Due to a clinical worsening of asthma (aggravation of dyspnea, chest constriction and night-time respiratory symptoms), despite the optimal therapy for asthma and recurrent administration of systemic corticosteroids, we have added-on treatment with benralizumab (monoclonal anti-interleukin 5 antibody). After eight months, the patient reported an improvement in asthma control (asthma control test [ACT]= 25 points), in pulmonary function and a good control of nocturnal symptoms of both diseases (i.e., wheezing, snoring, etc.). Then, the follow up polysomnography (PSG) was performed resulting in a high reduction of OSA severity (~18% AHI) even if obstructive events persisted and almost resolution of nocturnal hypoxemia. So, a trial with positive airway pressure (PAP) was proposed to the patient, who declined.

Conclusions

In consideration of our experience, we suggest that the nocturnal profile of patients with severe asthma should be always studied by a sleep investigation to prevent the negative effects of interaction with OSA. However, further studies on larger samples are needed to better understand the pathophysiological mechanisms underlying the beneficial effects of benralizumab on obstructive events during sleep.

The Association between Asthma and OSA in Children

Obstructive sleep apnea (OSA) and asthma are two of the most prevalent and commonly co-existing respiratory conditions seen in the pediatric population. Studies linking asthma and OSA in children are limited but indicate that there is a bi-directional relationship between them with significant overlap in the symptoms, risk factors, pathophysiology, comorbidities, and management. It is suggested that there is a reciprocal association between asthma predisposing to OSA, and OSA worsening symptom control and outcomes from asthma. It stands to reason that inflammation in the upper and/or lower airways can influence each other. Most of the pediatric literature that is available evaluates each aspect of this relationship independently such as risk factors, mechanisms, and treatment indications. This article highlights the relationship between OSA and asthma in the context of shared risk factors, pathophysiology, and available management recommendations in the pediatric population. Early recognition of the co-existence and association between OSA and asthma could ideally improve the treatment outcomes for these two conditions. Gaining a better understanding of the mechanism of this relationship can help identify nuances for medical management, optimize treatment and protect this population at risk from associated morbidity.

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.

Do not forget asthma comorbidities in pediatric severe asthma!

Asthma is the most common chronic respiratory disease in childhood. The long-term goals in managing asthma aim to control symptoms and prevent exacerbations, as well as to reduce side effects of therapy and mortality disease-related. Most of patients have mild to moderate asthma and respond well to standard therapies. However, a minor proportion of children with asthma has severe disease that remains uncontrolled despite optimal adherence to prescribed therapy and treatment of contributory factors, including trigger exposures and comorbidities, which can mimic or worsen asthma and contribute to exacerbations and poor quality of life. Evaluation of comorbidities is fundamental to optimize the management of the disease in a subgroup of patients with poor responder asthma. The overall aim of this article is to describe characteristics of main pediatric severe asthma comorbidities reported in literature, giving clinicians tools to recognize and manage properly these conditions.

Effects of Intermittent Hypoxia in Training Regimes and in Obstructive Sleep Apnea on Aging Biomarkers and Age-Related Diseases: A Systematic Review

Several studies have assessed the effects of intermittent hypoxia-normoxia training (IHNT), intermittent hypoxia-hyperoxia training (IHHT), and obstructive sleep apnea (OSA) on aging and age-related diseases in humans; however, the results remain contradictory. Therefore, this review aims to systematically summarize the available studies on the effects of IHNT, IHHT, and OSA on aging and age-related diseases. Relevant studies were searched from PubMed, Google Scholar, Cochrane Library databases, and through manual searching from reference lists of eligible studies. A total of 38 eligible studies were included in this systematic review. IHHT and IHNT provide positive effects on several age-related parameters including quality of life, cognitive and physical functions, plasma level of glucose and cholesterol/LDL, systolic blood pressure, red blood cells, and inflammation. Moreover, moderate intermittent hypoxia induces telomerase reverse transcriptase (TERT) activity and telomere stabilization, delays induction of senescence-associated markers expression and senescence-associated β-galactosidase, upregulates pluripotent marker (Oct4), activates a metabolic shift, and raises resistance to pro-apoptotic stimuli. On the contrary, intermittent hypoxia in OSA causes hypertension, metabolic syndrome, vascular function impairment, quality of life and cognitive scores reduction, advanced brain aging, increase in insulin resistance, plasma hydrogen peroxide, GSH, IL-6, hsCRP, leptin, and leukocyte telomere shortening. Thus, it can be speculated that the main factor that determines the direction of the intermittent hypoxia action is the intensity and duration of exposure. There is no direct study to prove that IHNT/IHHT actually increases life expectancy in humans. Therefore, further study is needed to investigate the actual effect of IHNT/IHHT on aging in humans.

Systematic Review Registration

www.crd.york.ac.uk/prospero, identifier CRD42022298499.

The Effect of Short Sleep Duration on the Development of Asthma

Asthma is regarded as a heterogeneous disease with chronic airway inflammation and reversible airway limitation. Asthma itself and recurrent attacks of asthma can decrease sleep duration and increase the prevalence of short sleep duration. Systemic low-grade inflammation and obesity caused by short sleep duration have been known for a long time, which potentially affect the development of asthma. It would be interesting to study the interaction between short sleep duration and asthma. However, there are relatively few studies and no review about the association between short sleep duration and asthma. This article performed a review about the relationships between short sleep duration and asthmatic phenotype, laboratory tests, comorbidity, and clinical outcomes. Pooled studies about short sleep duration and asthma provided following four results: (1) compared with healthy sleep duration, short sleep duration seemingly increased the risk of central obesity in asthmatics; (2) short sleep duration potentially reduced the level of FeNO and increased lung function impairment in patients with asthma; (3) asthmatic comorbidities, mainly obesity and depression, were negatively associated with short sleep duration among asthmatics; (4) short sleep duration potentially increased the risks of asthma-related hospitalization and emergency care. However, almost all studies are based on subjective but not objective sleep duration. In addition, the study on sleep duration and cause-specific mortality in patients with asthma is relatively scant. Considering the effect of short sleep duration on the development of asthma, we recommend that periodic sleep monitoring for asthmatic management is very necessary.