Etiopathogenetic mechanisms of pulmonary hypertension in sleep-related breathing disorders

Cardiac Implications of Adenotonsillar Hypertrophy and Obstructive Sleep Apnea in Pediatric Patients: A Comprehensive Systematic Review

This review investigates the relationship between pediatric obstructive sleep apnea, often associated with adenotonsillar hypertrophy, and cardiovascular health, particularly pulmonary hypertension. We conducted a comprehensive literature search using electronic databases, including Medline Pub-Med, Scopus, and the Web of Science. The study analyzed a total of 230 articles and screened 48 articles, with 20 included in the final analysis, involving 2429 children. The PRISMA flowchart visually illustrates the selection process, and the ROBINS-E and -I tools help ensure the reliability and validity of the evidence produced by these studies. These studies explored various aspects, including the severity of obstructive sleep apnea, cardiac anomalies, cardiac stress markers, risk factors for pulmonary hypertension, and the impact of adenoidectomy and tonsillectomy on cardiac function. The research found that adenotonsillar hypertrophy and obstructive sleep apnea are significant risk factors for cardiovascular complications, especially pulmonary hypertension, in children. Adenoidectomy and tonsillectomy may provide effective treatments. Following adenoidectomy in relation to obstructive sleep apnea, there appears to be a reduction in mean pulmonary artery pressure during echocardiographic examination. However, the efficacy of these procedures can vary based on the severity of obstructive sleep apnea and individual cardiac conditions. The study also identified concerns regarding data bias. The authors emphasize the need for well-designed clinical studies, including both healthy patients with adenotonsillar hypertrophy and vulnerable children with genetic disorders, to ensure that clinical decisions are based on solid scientific evidence.

Idiopathic Pulmonary Comorbidities and Mechanisms

Idiopathic pulmonary fibrosis (IPF) is a disease with an unknown etiology mainly characterized by a progressive decline of lung function due to the scarring of the tissue deep in the lungs. The overall survival after diagnosis remains low between 3 and 5 years. IPF is a heterogeneous disease and much progress has been made in the past decade in understanding the disease mechanisms that contributed to the development of two new drugs, pirfenidone and nintedanib, which improved the therapeutic management of the disease. The understanding of the cofactors and comorbidities of IPF also contributed to improved management of the disease outcome. In the present review, we evaluate scientific evidence which indicates IPF as a risk factor for other diseases based on the complexity of molecular and cellular mechanisms involved in the disease development and of comorbidities. We conclude from the existing literature that while much progress has been made in understating the mechanisms involved in IPF development, further studies are still necessary to fully understand IPF pathogenesis which will contribute to the identification of novel therapeutic targets for IPF management as well as other diseases for which IPF is a major risk factor.

Sanjad Sakati syndrome and sleep-disordered breathing: an undisclosed association

BACKGROUND

Sanjad Sakati syndrome (SSS) is a rare autosomal recessive genetic disorder caused by mutation in TBCE (tubulin folding cofactor E) gene. Reported cases were almost exclusively of Middle-Eastern and Arabian children of consanguineous parents. We report the clinical manifestations, outcome, and an observed new association of sleep-disordered breathing (SDB) among children with Sanjad Sakati syndrome.

METHODS

Clinical and routine laboratory data of SSS cases attending Sultan Qaboos University Hospital, Oman, were collected from the electronic patient records or through direct clinic interviews. In-lab polysomnography (PSG) and echocardiography were carried out for all the cases. SDB diagnosis was based on the guidelines of the American Academy of Sleep Medicine.

RESULTS

Of 12 patients with SSS, 5 males (42%), all of them (100%) had obstructive sleep apnea (OSA) and 4 of them (33%) had additional significant central apnea and sleep-related hypoventilation. Eight patients (67%) had severe SDB with mean apnea-hypopnea index (AHI) of 26.5 events/h. Age at time of diagnosis with SDB ranged from 2 to 17 years with mean of 8.9 [Formula: see text] Two patients had severe pulmonary hypertension as a complication of severe SDB and died from type 2 respiratory failure.

CONCLUSIONS

Sleep-disordered breathing is prevalent among children with SSS, especially OSA. This is the first study to report SDB in a large cohort of patients with this extremely rare syndrome. The study results encourage the importance of screening affected patients with SSS for sleep-disordered breathing early before developing severe morbidities such as pulmonary hypertension that further compromise their quality of life.

Assessment of right ventricular remodeling and dysfunction in obstructive sleep apnea syndrome: a prospective monocentric study

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep-related disorder that has been implicated in many serious cardiovascular diseases including cardiac remodeling and dysfunction. Since most investigations have focused on the left heart, little is known on right ventricular (RV) involvement in OSA. The role of the RV in the management of cardiovascular outcomes has become increasingly recognized. Early detection of subtle signs of RV dysfunction and remodeling in patients with OSA is crucial for optimal medical care.

PURPOSE

We aimed to investigate the effect of OSA and its severity on the RV structure and function using conventional echocardiography.

METHODS

We conducted a cross-sectional analytical study including patients with OSA who did not have heart failure or chronic pulmonary disease comparing them to controls without OSA. All patients underwent respiratory polygraphy at the Pneumology Department and standard echocardiography performed by the same blinded cardiologist at the Cardiology Department of Taher Sfar University Hospital.

RESULTS

A total of 139 patients with OSA and 45 controls were enrolled in the study. Amonth the patients, there were 32% (n = 44) with mild, 20% (n = 28) with moderate, and 48% (n = 67) with severe OSA. Sixty-three percent of the study population were women. The mean age was 54.1 ± 11.0 years. Early RV dilatation was present in the mild disease stage (RVID = 42.0 ± 7.7 mm vs. 32.4 ± 5.5 mm in controls; p < 0.0001) without obvious RVH. The systolic pulmonary artery pressure was significantly higher in patients with OSA (31.2 ± 8.2 vs. 20.9 ± 9.8; p < 0.0001). Tricuspid annular plane systolic excursion was borderline normal and significantly lower in patients with OSA (17.7 ± 4.7 vs. 26.0 ± 5.7, p < 0.0001). In multivariate analysis, an OSA was independently associated with RV remodeling (OR: 0.257, 95% CI [0.114-0.582], p = 0.001) but not with RV dysfunction.

CONCLUSION

OSA was independently associated with structural alterations of RV early in the disease course, suggesting that the reversibility of these deleterious effects requires earlier detection and initiation of treatment.

Obstructive Sleep Apnea and Pulmonary Hypertension: A Review of Literature

Obstructive sleep apnea (OSA) is a disease process involving recurrent pharyngeal collapse during sleep, resulting in apneic episodes. Clinically, symptoms can include snoring, sudden awakening with a choking-like sensation, excessive somnolence, non-restorative sleep, difficulty in starting or maintaining sleep, and fatigue. It results in impaired gas exchange, subsequently causing various cardiovascular, metabolic, and neurocognitive pathologies. Historically, OSA has been underdiagnosed and undertreated, especially in women.

OSA is associated with WHO (World Health Organization) class III pulmonary hypertension (PH) or PH due to lung disease. PH is a concerning complication of OSA and thought to occur in roughly 20% of individuals with OSA. The pathogenesis of PH in OSA can include pulmonary artery vasoconstriction and remodeling. Patients suffering from OSA who develop PH tend to have worse cardiovascular and pulmonary changes. We present a thorough review of the literature examining the interplay between OSA and PH.

Relationship between Pulmonary Artery Diameter and Pulmonary to Aortic Artery Diameter Ratio in High Risk Individuals for Obstructive Sleep Apnea without Pulmonary Artery Hypertension Based on the Berlin Questionnaire

BACKGROUND

A significant association has been found between the pulmonary artery (PA) diameter and obstructive sleep apnea (OSA) in patients with pulmonary artery hypertension (PAH). We aimed to evaluate the relationship between the diameters of the PA trunk and aortic artery with their ratio as PAH markers in high risk cases for OSA based on the Berlin questionnaire without PAH.

MATERIALS AND METHODS

This case-control study included 161 non-PAH patients admitted to a multi-slice CT scan ward. Filling out the Berlin questionnaire, the patients were divided into high and low risk cases for OSA. The diameters of the PA trunk and aortic ascending aorta and their ratio were assessed using the multi-slice CT scan.

RESULTS

The PA to aortic ratios in the case and control groups were 0.89±0.17 and 0.88±0.17, respectively, which all were non-significant. With regard to gender, the PA diameter was significantly lower among males in the control group than in the case group (P=0.034). The mean PA to aortic ratio was slightly higher but statistically non-significant in the case group than in the control group. The aortic diameter showed a statistically significant increase by age in the case group (r=0.374, P=0.003) compared to the other group. However, the PA diameter increased significantly by age in both groups (r=0.184, P=0.020).

CONCLUSION

The PA diameter can be considered as a predicting factor for future cardiovascular diseases in high risk males for OSA based on the Berlin questionnaire without PAH. More studies are required to confirm these findings.

Treatment of Obstructive Sleep Apnea-Hypopnea Syndrome With a Mandible Advanced Device Increases Nitric Oxide Release and Ameliorates Pulmonary Hypertension in Rabbits

PURPOSE

To investigate the effects of mandible advanced device (MAD) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS) on nitric oxide (NO) release and changes in pulmonary artery pressure and structure.

METHODS

Thirty male New Zealand white rabbits were randomly divided into OSAHS, MAD, and control groups (n = 10 per group). The soft palate of rabbits in the OSAHS and MAD groups was injected with hydrophilic polyacrylamide gel to induce OSAHS. The MAD group wore a MAD, and the control group was not treated. Cone-beam computed tomography scans and polysomnography recordings were performed to confirm successful model establishment. All rabbits slept in a supine position for 4 to 6 hours daily and were observed for 8 consecutive weeks. The pulmonary artery pressure was measured by right heart catheterization. Pulmonary artery morphometry was analyzed by hematoxylin and eosin staining. NO levels in plasma and lung homogenate supernatants were detected by Griess reaction assay kits.

RESULTS

The OSAHS group exhibited higher pulmonary artery pressure (57.74 ± 1.79 mm Hg) than the MAD (19.99 ± 2.04 mm Hg) and control (14.49 ± 0.54 mm Hg) groups. The media thickness percentage of the pulmonary artery was higher in the OSAHS group (46.89 ± 2.72%) than the control group (15.87 ± 1.18%) and was markedly reduced by MAD (21.64 ± 1.45%). Blood oxygen saturation was positively correlated with the NO concentration in both the lung and plasma, and the NO concentration was negatively correlated with the media thickness percentage and media section percentage.

CONCLUSIONS

OSAHS induced a decrease in NO and pulmonary hypertension, which was relieved by MAD therapy.

Idiopathic Pulmonary Fibrosis: A Review of Disease, Pharmacological, and Nonpharmacological Strategies With a Focus on Symptoms, Function, and Health-Related Quality of Life

Despite several advances in treatment, idiopathic pulmonary fibrosis (IPF) remains a progressive, symptomatic, and terminal disease in patients not suitable for lung transplantation. With disease progression, IPF often leads to a constellation of symptoms, including dyspnea, cough, anxiety, and depression. Palliative care is appropriate to support these patients. However, traditional curriculum in palliative care has often focused on supporting patients with malignant disease, and clinicians are not universally trained to manage patients with progressive nonmalignant diseases such as IPF. Current antifibrotic therapies aim to slow disease progression but are not able to reduce symptoms or improve daily function and health-related quality of life (HRQL). Palliative care in this patient group requires an understanding of the clinical characteristics of IPF, comorbidities, common medications used, and nonpharmacological strategies that can be undertaken to improve daily function and HRQL. This review focuses on IPF management strategies and their effects on symptoms, exercise tolerance, HRQL, and survival. Pharmacological interactions and considerations related to commonly used palliative care medications are also reviewed. This review highlights the needs of patients with IPF and caregivers, psychosocial function, patient-reported assessment tools, and topics related to advance care planning.

Potential Contribution of Carotid Body-Induced Sympathetic and Renin-Angiotensin System Overflow to Pulmonary Hypertension in Intermittent Hypoxia

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA), featured by chronic intermittent hypoxia (CIH), is an independent risk for systemic hypertension (HTN) and is associated with pulmonary hypertension (PH). The precise mechanisms underlying pulmonary vascular remodeling and PH in OSA are not fully understood. However, it has been suggested that lung tissue hypoxia, oxidative stress, and pro-inflammatory mediators following CIH exposure may contribute to PH.

RECENT FINDINGS

New evidences obtained in preclinical OSA models support that an enhanced carotid body (CB) chemosensory reactiveness to oxygen elicits sympathetic and renin-angiotensin system (RAS) overflow, which contributes to HTN. Moreover, the ablation of the CBs abolished the sympathetic hyperactivity and HTN in rodents exposed to CIH. Accordingly, it is plausible that the enhanced CB chemosensory reactivity may contribute to the pulmonary vascular remodeling and PH through the overactivation of the sympathetic-RAS axis. This hypothesis is supported by the facts that (i) CB stimulation increases pulmonary arterial pressure, (ii) denervation of sympathetic fibers in pulmonary arteries reduces pulmonary remodeling and pulmonary arterial hypertension (PAH) in humans, and (iii) administration of angiotensin-converting enzyme (ACE) or blockers of Ang II type 1 receptor (ATR1) ameliorates pulmonary remodeling and PH in animal models. In this review, we will discuss the supporting evidence for a plausible contribution of the CB-induced sympathetic-RAS axis overflow on pulmonary vascular remodeling and PH induced by CIH, the main characteristic of OSA.

Sleep hygiene in patients with chronic respiratory disease

PURPOSE

This study assessed the effectiveness of patient-directed interventions for improving sleep quality in patients with cystic fibrosis and pulmonary hypertension.

METHODS

A nonrandomized, prospective pilot study was used to monitor the effectiveness of patient-initiated sleep preferences in 15 hospitalized patients.

RESULTS

During their stay, 53.3% of patients reported better sleep associated with the intervention, supporting the need for and efficacy of patient-driven sleep interventions.

CONCLUSION

Patients unanimously recognized the need for sleep interventions and were open to seeking a good sleep hygiene regimen to improve their sleep quality while in the hospital.

Chronic obstructive sleep apnea accelerates pulmonary remodeling via TGF-β/miR-185/CoLA1 signaling in a canine model

Chronic obstructive sleep apnea syndrome (OSAS) is considered to be associated with pulmonary diseases. However, the roles and mechanisms of OSA in pulmonary remodeling remain ambiguous. Thus, this study was aimed to elucidate the morphological and mechanical action of OSA in lung remodeling. In the present study, we employed a novel OSA model to mimic the OSA patient and investigate the role of OSA in pulmonary remodeling. We showed that pulmonary artery pressure of OSA group has no significant increased compared with the sham group. Nevertheless, we found that fibrotic tissue was predominantly located around the bronchi and vascular in the lung. Additionally, inflammatory cell infiltration was also detected in the peribonchial and perivascular space. The morphological change in OSA canines was ascertained by ultrastructure variation characterized by mitochondrial swelling, lamellar bodies degeneration and vascular smooth muscle incrassation. Moreover, sympathetic nerve sprouting was markedly increased in OSA group. Mechanistically, we showed that several pivotal proteins including collagen type I(CoLA1), GAP-43, TH and NGF were highly expressed in OSA groups. Furthermore, we found OSA could activated the expression of TGF-β, which subsequently suppressed miR-185 and promoted CoL A1 expression. This signaling cascade leads to pulmonary remodeling. In conclusion, Our data demonstrates that OSA can accelerate the progression of pulmonary remodeling through TGF-β/miR-185/CoLA1 signaling, which would potentially provide therapeutic strategies for chronic OSAS.

Pulmonary Hypertension Due to Common Respiratory Conditions: Classification, Evaluation and Management Strategies

Pulmonary hypertension (PH) due to chronic respiratory disease and/or hypoxia is classified as World Health Organization (WHO) Group III pulmonary hypertension. The patients most commonly encountered in clinical practice with group III PH include those with chronic obstructive lung disease (COPD), diffuse parenchymal lung disease, and sleep-disordered breathing. The purpose of this review is to outline the variable clinical significance of pulmonary hypertension in the most common pulmonary disease states and how a clinician may approach the management of these patients.

Model-based stability assessment of ventilatory control in overweight adolescents with obstructive sleep apnea during NREM sleep

Obstructive sleep apnea (OSA) involves the interplay of several different factors such as an unfavorable upper airway anatomy, deficiencies in pharyngeal muscle responsiveness, a low arousal threshold, and ventilatory control instability. Although the stability of ventilatory control has been extensively studied in adults, little is known about its characteristics in the pediatric population. In this study, we developed a novel experimental setup that allowed us to perturb the respiratory system during natural non-rapid eye movement (NREM) sleep conditions by manipulating the inspiratory pressure, provided by a bilevel pressure ventilator, to induce sighs after upper airway stabilization. Furthermore, we present a modeling framework that utilizes the noninvasively measured ventilatory responses to the induced sighs and spontaneous breathing data to obtain representations of the processes involved in the chemical regulation of respiration and extract their stability characteristics. After validation with simulated data, the modeling technique was applied to data collected experimentally from 11 OSA and 15 non-OSA overweight adolescents. Statistical analysis of the model-derived stability parameters revealed a significantly higher plant gain and lower controller gain in the OSA group (P = 0.046 and P = 0.007, respectively); however, no differences were found in loop gain (LG) and circulatory time delay between the groups. OSA severity and LG, within the 0.03-0.04-Hz frequency band, were significantly negatively associated (r = -0.434, P = 0.026). Contrary to what has been found in adults, our results suggest that in overweight adolescents, OSA is unlikely to be initiated through ventilatory instability resulting from elevated chemical loop gain.

Novel Therapeutic Strategies for Reducing Right Heart Failure Associated Mortality in Fibrotic Lung Diseases

Fibrotic lung diseases carry a significant mortality burden worldwide. A large proportion of these deaths are due to right heart failure and pulmonary hypertension. Underlying contributory factors which appear to play a role in the mechanism of progression of right heart dysfunction include chronic hypoxia, defective calcium handling, hyperaldosteronism, pulmonary vascular alterations, cyclic strain of pressure and volume changes, elevation of circulating TGF-β, and elevated systemic NO levels. Specific therapies targeting pulmonary hypertension include calcium channel blockers, endothelin (ET-1) receptor antagonists, prostacyclin analogs, phosphodiesterase type 5 (PDE5) inhibitors, and rho-kinase (ROCK) inhibitors. Newer antifibrotic and anti-inflammatory agents may exert beneficial effects on heart failure in idiopathic pulmonary fibrosis. Furthermore, right ventricle-targeted therapies, aimed at mitigating the effects of functional right ventricular failure, include β-adrenoceptor (β-AR) blockers, angiotensin-converting enzyme (ACE) inhibitors, antioxidants, modulators of metabolism, and 5-hydroxytryptamine-2B (5-HT2B) receptor antagonists. Newer nonpharmacologic modalities for right ventricular support are increasingly being implemented. Early, effective, and individualized therapy may prevent overt right heart failure in fibrotic lung disease leading to improved outcomes and quality of life.

Inflammatory response mechanisms exacerbating hypoxemia in coexistent pulmonary fibrosis and sleep apnea

Mediators of inflammation, oxidative stress, and chemoattractants drive the hypoxemic mechanisms that accompany pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis commonly have obstructive sleep apnea, which potentiates the hypoxic stimuli for oxidative stress, culminating in systemic inflammation and generalized vascular endothelial damage. Comorbidities like pulmonary hypertension, obesity, gastroesophageal reflux disease, and hypoxic pulmonary vasoconstriction contribute to chronic hypoxemia leading to the release of proinflammatory cytokines that may propagate clinical deterioration and alter the pulmonary fibrotic pathway. Tissue inhibitor of metalloproteinase (TIMP-1), interleukin- (IL-) 1α, cytokine-induced neutrophil chemoattractant (CINC-1, CINC-2α/β), lipopolysaccharide induced CXC chemokine (LIX), monokine induced by gamma interferon (MIG-1), macrophage inflammatory protein- (MIP-) 1α, MIP-3α, and nuclear factor- (NF-) κB appear to mediate disease progression. Adipocytes may induce hypoxia inducible factor (HIF) 1α production; GERD is associated with increased levels of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and tumor necrosis factor alpha (TNF-α); pulmonary artery myocytes often exhibit increased cytosolic free Ca2+. Protein kinase C (PKC) mediated upregulation of TNF-α and IL-1β also occurs in the pulmonary arteries. Increased understanding of the inflammatory mechanisms driving hypoxemia in pulmonary fibrosis and obstructive sleep apnea may potentiate the identification of appropriate therapeutic targets for developing effective therapies.

Obstructive sleep apnea syndrome: An important piece in the puzzle of cardiovascular risk factors

The obstructive sleep apnea syndrome (OSA) is a clinical entity characterized by recurring episodes of apnea and/or hypopnea during sleep, due to a total or partial collapse, respectively, of the upper airway. This collapse originates a set of pathophysiological changes that determine the appearance of several cardiovascular complications. OSA contributes for the development of hypertension, heart failure, arrhythmias and coronary heart disease. Nowadays it is recognized to be an important public health problem, taking into account not just its repercussions but also its prevalence, since the main risk factor for the disease is obesity, a growing problem worldwide, both in developed and developing countries. The present review summarizes the current knowledge about OSA, as regards its definition, pathophysiology, clinical manifestations, diagnosis, cardiovascular effects and treatment.

Sleep-related breathing disorders and gait variability: a cross-sectional preliminary study

Background

Sleep-related breathing disorders (SRBDs) provoke cognitive and structural brain disorders. Because these disorders have been associated with unsafe gait characterized by an increase in stride-to-stride variability of stride time (STV), we hypothesised that SRBDs could be associated with an increased STV. The aim of this study was to examine the association between SRBDs and STV in French healthy older community-dwellers.

Methods

A total of 49 participants (mean age 69.6 ± 0.8years; 65.2% female) were included in this cross-sectional study. All participants, who were free of clinically diagnosed SRBDs before their inclusion, had a nocturnal unattended home-sleep assessment. There were separated in three group based on apnea + hypopnea index (AHI): AHI <15 defining the absence of SRBD, AHI between 15–30 defining mild SRBD, and AHI >30 defining moderate-to-severe SRBD. Coefficient of variation of stride time, which is a measure of STV, was recorded while usual walking using SMTEC® footswitches system. Digit span score was used as a measure of executive performance. Age, gender, body mass index (BMI), number of drugs daily taken, vision, proprioception, history of falls, depression symptoms, global cognitive functioning were also recorded.

Results

STV and BMI were higher in participants with mild SRBDs (P = 0.031 and P = 0.020) and moderate-to-severe SRBDs (P = 0.004 and P = 0.002) compared to non-SRBDs. STV positively correlated with AHI (P = 0.036). Lower (i.e., better) STV was associated with the absence of SRBDs (P = 0.021), while greater (i.e., worse) STV was associated with moderate-to-severe SRBD (P < 0.045) but not with mild SRBD (P > 0.06).

Conclusion

Our results show a positive association between STV and SRBDs, with moderate-to-severe SRBD being associated with greater gait variability. This association opens new perspectives for understanding gait disorders in older adults with SRBDs and opens the door to treatments options since SRBDs are potential treatable factors.

Obstructive sleep apnea and cardiovascular comorbidities: a large epidemiologic study

Obstructive sleep apnea (OSA) is a common disorder, characterized by cyclic cessation of airflow for 10 seconds or more. There is growing awareness that OSA is related to the development and progression of cardiovascular disease. However, only a few studies have associated OSA directly to major cardiovascular events. The aim of this study was to evaluate the relationship between OSA and cardiovascular morbidity in a well defined population of patients.The electronic database of the central district of a major health management organization was searched for all patients diagnosed with OSA in 2002-2010. For each patient identified, an age- and sex-matched patient was randomly selected from the members of the same health management organization who did not have OSA. Data on demographics, socioeconomic status, and relevant medical parameters were collected as well.The study population included 2797 patients, average age 58.1, in which 76.6% were males. There was a significant correlation between OSA and the presence of ischemic heart disease (P < 0.001), pulmonary hypertension (P < 0.001), congestive heart failure (P < 0.001), cardiomyopathy (P = 0.003), and arrhythmia (P < 0.001). OSA was also significantly correlated with low socioeconomic status (P < 0.001).OSA and cardiovascular disease were strongly correlated. As such, early diagnosis and treatment of OSA may change the course of both diseases. We suggest that sleep disordered breathing should be routinely assessed in patients with cardiovascular problems. An ear-nose-throat evaluation may also be important to rule out anatomic disorders that cause upper airway obstruction.

Relationship of redundant Th17 cells and IL-17A, but not IL-17 F, with the severity of obstructive sleep apnoea/hypopnoea syndrome (OSAHS)

Background

The pathogenesis of obstructive sleep apnoea/hypopnoea syndrome (OSAHS), a highly prevalent disease, is not completely understood. The purpose of this study was to investigate the contributions of Th17 cells and the Th17-associated cytokines IL-17A and IL-17 F to OSAHS.

Methods

46 male patients with a clinical suspicion of OSAHS were enrolled and divided into four groups based on their polysomnography results: controls and mild, moderate, and severe OSAHS. The serum levels of IL-17A and IL-17 F were determined by enzyme linked immunosorbent assay (ELISA), pulmonary arterial pressure (PAP) was determined by echocardiography, and Th17 cell frequencies in peripheral blood were measured by flow cytometry.

Results

Serum IL-17A levels in the severe group were elevated (median value: control group 0.89 pg/ml, mild OSAHS 1.02 pg/ml, moderate OSAHS 1.18 pg/ml, and severe OSAHS 1.62 pg/ml; p < 0.05) and positively correlated with AHI (r = 0.52, p < 0.05) but negatively related to the mean O₂ saturation and lowest O₂ saturation (r = −0.349, p < 0.05; and r = −0.336, p < 0.05, respectively). Although the frequencies of Th17 cells in the OSAHS groups were higher than that in the control group, these differences were not significant (p = 0.275). Pulmonary arterial hypertension was not present in our patients as the median PAP of the normal control and the mild, moderate, and severe OSAHS groups were 26, 27.5, 24.5, and 25.5 mmHg, respectively (p = 0.676).

Conclusion

IL-17A may be involved in the pathogenesis of OSAHS and may represent a target for therapeutic intervention.

Obstructive sleep apnea in children: a critical update

Obstructive sleep apnea (OSA) in children is a highly prevalent disorder caused by a conglomeration of complex pathophysiological processes, leading to recurrent upper airway dysfunction during sleep. The clinical relevance of OSA resides in its association with significant morbidities that affect the cardiovascular, neurocognitive, and metabolic systems. The American Academy of Pediatrics recently reiterated its recommendations that children with symptoms and signs suggestive of OSA should be investigated with polysomnography (PSG), and treated accordingly. However, treatment decisions should not only be guided by PSG results, but should also integrate the magnitude of symptoms and the presence or absence of risk factors and signs of OSA morbidity. The first-line therapy in children with adenotonsillar hypertrophy is adenotonsillectomy, although there is increasing evidence that medical therapy, in the form of intranasal steroids or montelukast, may be considered in mild OSA. In this review, we delineate the major concepts regarding the pathophysiology of OSA, its morbidity, diagnosis, and treatment.