The Untargeted Metabolomics Reveals Differences in Energy Metabolism in Patients with Different Subtypes of Ischemic Stroke.

AIMS: Ischemic stroke (IS) is the most common subtype of stroke. The risk factors and pathogenesis of IS are complex and varied due to different subtypes. Therefore, we used metabolomics technology to investigate the biomarkers and potential pathophysiological mechanisms of different subtypes of IS. METHODS: We included 126 IS patients and divided them into two groups based on the TOAST classification: large-artery atherosclerosis (LAA) group (n = 87) and small-vessel occlusion (SVO) group (n = 39). Plasma metabolomics analysis was performed using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to identify metabolic profiles in LAA and SVO subtype IS patients and to determine metabolic differences between patients with the two subtypes of IS. RESULTS: We identified 26 differential metabolites between LAA and SVO subtype IS. A multiple prediction model based on the plasm metabolites had good predictive ability for IS subtyping (AUC = 0.822, accuracy = 77.8%), with 12,13-DHOME being the most important differential metabolite in the model. The differential metabolic pathways between the two subtypes of IS patients included tricarboxylic acid (TCA) cycle, alanine, aspartate and glutamate metabolism, and pyruvate metabolism, mainly focused on energy metabolism. CONCLUSION: 12,13-DHOME emerged as the primary discriminatory metabolite between LAA and SVO subtypes of IS. In LAA subtype IS patients, energy metabolism, encompassing pyruvate metabolism and the TCA cycle, exhibited lower activity levels when compared to patients with the SVO subtype IS. The utilization of targeted metabolomics holds the potential to improve diagnostic accuracy for distinguishing stroke subtypes.

3D bioprinted endothelial cell-microglia coculture for diabetic retinopathy modeling.

Diabetic retinopathy (DR) is a common diabetes complication leading to vision impairment or blindness due to retinal vasculature alterations. Hyperglycemia induces structural alterations, inflammation, and angiogenic factor upregulation. Current treatments targeting vascular endothelial growth factor are insufficient for approximately 20% of DR patients, necessitating alternative approaches. Microglia (MG), essential for retinal homeostasis, remains underexplored in DR. This study used digital light processing bioprinting to construct a 3D coculture model of endothelial cells (ECs) and MG under varying glucose conditions, with a hydrogel stiffness of 4.6-7.1 kPa to mimic the extracellular matrix property of retina plexiform. Our results showed that high glucose levels influenced both EC and microglial phenotypes, gene expression, and angiogenic potential. Increasing glucose from 5 mM to 25 mM reduces drug efficacy by 17% for Aflibercept in EC monoculture, and 25% and 30% for Aflibercept and Conbercept in EC-MG coculture, respectively, suggesting that diabetic condition and MG presence could interfere with drug responses. In conclusion, our findings emphasize the importance of cellular interactions and microenvironmental factors in DR therapy, aiming to identify novel strategies and improve understanding of MG's role in disease pathogenesis.

The association between neutrophil counts and neutrophil-to-lymphocyte ratio and stress hyperglycemia in patients with acute ischemic stroke according to stroke etiology.

Background and purpose: Stress hyperglycemia ratio (SHR), which is used to assess stress hyperglycemia, is associated with the functional outcome of ischemic stroke (IS). IS can induce the inflammatory response. Neutrophil counts and neutrophil-to-lymphocyte ratio (NLR) as good and easily available inflammatory biomarkers, the relationship between neutrophil counts and NLR and SHR were poorly explored in IS. We aimed to systemically and comprehensively explore the correlation between various blood inflammation markers (mainly neutrophil counts and NLR) and SHR. Methods: Data from 487 patients with acute IS(AIS) in Xiangya Hospital were retrospectively reviewed. High/low SHR groups according to the median of SHR (≤1.02 versus >1.02). Binary logistic regression analysis was used to evaluate the correlation between neutrophil counts and NLR and high SHR group. Subgroup analyses were performed in the TOAST classification and functional prognosis. Results: The neutrophil counts and NLR were all clearly associated with SHR levels in different logistic analysis models. In the subgroup analysis of TOAST classification, the higher neutrophil counts and NLR were the independent risk factors for high SHR patients with large-artery atherosclerosis (LAA) (neutrophil: adjusted OR:2.047, 95% CI: 1.355-3.093, P=0.001; NLR: adjusted OR:1.315, 95% CI: 1.129-1.530, P<0.001). The higher neutrophil counts were the independent risk factor for high SHR patients with cardioembolism (CE) (adjusted OR:2.413, 95% CI: 1.081-5.383, P=0.031). ROC analysis showed that neutrophil counts was helpful for differentiating high SHR group with CE and low SHR group with CE (neutrophil: AUC =0.776, P=0.002). However, there were no difference in levels of neutrophil counts and NLR between patients with SVO and without SVO. The higher neutrophil counts and NLR independently associated with high SHR patients with mRS ≤2 at 90 days from symptom onset, (neutrophil: adjusted OR:2.284, 95% CI: 1.525-3.420, P<0.001; NLR: adjusted OR:1.377, 95% CI: 1.164-1.629, P<0.001), but not in patients with mRS >2. Conclusions: This study found that the neutrophil counts and NLR are positively associated with SHR levels in AIS patients. In addition, the correlation between neutrophil counts and NLR and different SHR levels are diverse according to TOAST classification and functional prognosis.

Stroke-associated infection in patients with co-morbid diabetes mellitus is associated with in-hospital mortality.

Background and objective: The association between infection and acute ischemic stroke (AIS) with diabetes mellitus (DM) remains unknown. Therefore, this study aimed to explore the effect of infection on AIS with DM. Materials and methods: The data of patients with AIS and DM were extracted from the Chinese Stroke Center Alliance (CSCA) database from August 2015 to July 2019. The association between infections [pneumonia or urinary tract infection (UTI)] and in-hospital mortality was analyzed. Logistic regression models were used to identify the risk factors for in-hospital mortality of patients with infection. Results: In total, 1,77,923 AIS patients with DM were included in the study. The infection rate during hospitalization was 10.5%, and the mortality rate of infected patients was 3.4%. Stroke-associated infection was an independent risk factor for an early poor functional outcome [odds ratio (OR) = 2.26, 95% confidence interval (CI): 1.97-2.34, P < 0.0001] and in-hospital mortality in AIS patients with DM. The in-hospital mortality after infection was associated with age (OR = 1.02, 95% CI: 1.01-1.03, P < 0.0001), male (OR = 1.39, 95% CI: 1.13-1.71, P = 0.0018), reperfusion therapy (OR = 2.00, 95% CI: 1.56-2.56, P < 0.0001), and fasting plasma glucose at admission (OR = 1.05, 95% CI: 1.03-1.08, P < 0.0001). In contrast, antiplatelet drug therapy (OR = 0.63, 95% CI: 0.50-0.78, P < 0.0001) and hospital stay (OR = 0.96, 95% CI: 0.94-0.97, P < 0.0001) were independent protecting factors against in-hospital mortality of patients with infection. Conclusion: Infection is an independent risk factor of in-hospital mortality for patients with AIS and DM, and those patients require strengthening nursing management to prevent infection.

Alterations in the gut microbiome with hemorrhagic transformation in experimental stroke.

OBJECTIVE: Hemorrhagic transformation (HT) is a life-threatening complication of stroke. Whether changes in gut microbial composition underlie the development of HT remains unknown. This study aimed to investigate whether the gut microbiota is altered in HT rats and examine the association between these changes and inflammatory responses. METHODS: HT was successfully established in rats injected with 50% glucose (6 ml/Kg, i.p.) 15 min before middle cerebral artery occlusion (MCAO, 90 min occlusion) with reperfusion. After 5 days, rats were euthanized, and their brains used to estimate infarct volume. The inflammatory factors, the analysis of gut microbiota, and short-chain fatty acids (SCFA) were assessed. RESULTS: In contrast with non-HT rats, gut microbiota sequencing showed an elevation in the relative abundance of Proteobacteria and Actinobacteria in HT rats. Total SCFAs, especially butyrate and valeric acid, were significantly lower in the cecal contents of HT rats than in those of non-HT rats. Hyperglycemia-induced HT exacerbation was not observed when rats were treated with antibiotics, suggesting that altered microbiota play a critical role in hyperglycemic HT pathogenesis. Furthermore, rats whose gut was colonized with HT rat microbiota showed increased susceptibility to HT. CONCLUSION: This study provides important information about the gut microbiota profiles and SCFA levels of MCAO rats with HT or non-HT. The susceptibility to HT in MCAO rats is associated with inflammation and gut microbiota modulation.

Association of Plasma Metabolic Biomarker Sphingosine-1-Phosphate With Cerebral Collateral Circulation in Acute Ischemic Stroke.

Background: The contribution of metabolic profile to the cerebral collateral circulation in acute ischemic stroke (AIS) has not been fully outlined. In this study, we conducted a metabolomic study to assess the relationship between the metabolic biomarkers and the collateral status of AIS. Methods: A two-stage study was conducted from September 2019 to June 2021 in our hospital. There were 96 subjects including 66 patients with AIS and 30 healthy controls in the discovery stage and 80 subjects including 53 patients with AIS and 27 healthy controls in the validation stage. Collateral circulation was assessed by the Tan score based on computed tomographic angiography (CTA). Liquid chromatography-tandem mass spectrometry was used to identify differential metabolic markers. Then, an ELISA was employed to detect the plasma levels of sphingosine-1-phosphate (S1P). Results:There were 114 differential metabolites between patients with AIS and control groups and 37 differential metabolites between good collateral circulation (GCC) and poor collateral circulation (PCC) groups. The pathway enrichment analysis revealed that arginine biosynthesis was the only statistically significant pathway between AIS and control groups and sphingolipid metabolism was the only statistically significant pathway between GCC and PCC groups. The differential metabolites sphinganine-1-phosphate (SA1P) and S1P belong to the sphingolipid metabolism. In the discovery stage, when the GCC group was compared with the PCC group, the receiver operating characteristic (ROC) analysis showed that plasma SA1P relative levels demonstrated an area under the curve (AUC) of 0.719 (95% CI: 0.582-0.834), and S1P levels demonstrated an AUC of 0.701 (95% CI: 0.567-0.819). In addition, both plasma SA1P and S1P relative levels showed significant negative correlations with the 90-day modified Rankin Scale (mRS) score. In the validation sample, higher plasma S1P levels were independent predictors of GCC (p = 0.014), and plasma S1P levels demonstrated an AUC of 0.738 (95% CI: 0.599-0.849) to differentiate patients with GCC from patients with PCC. In addition, plasma S1P levels also showed significant negative correlations with the 90-day mRS score. Conclusion: We first illustrated the association between plasma metabolic profiles and cerebral collateral circulation in patients with AIS. Plasma S1P levels might be a potential diagnostic biomarker for predicting collateral circulation status in patients with AIS.

Serum Bilirubin Levels and Extent of Symptomatic Intracranial Atherosclerotic Stenosis in Acute Ischemic Stroke: A Cross-Sectional Study.

Background: Bilirubin plays a paradoxical role in the pathological mechanism of stroke. To date, few clinical studies have investigated the effect of serum bilirubin on symptomatic intracranial atherosclerotic stenosis (sICAS). This study aims to evaluate the connection between serum bilirubin and sICAS. Methods: From September 2015 to May 2020, 1,156 sICAS patients without hepatobiliary diseases admitted to our hospital were included. Patients were distributed into none-mild (0-49%), moderate (50-69%) and severe-occlusion sICAS groups (70-100%) by the degree of artery stenosis. Moderate and severe-occlusion sICAS patients were classified into three groups by the number of stenotic arteries (single-, two- and multiple-vessel stenosis). The relationship between serum bilirubin levels and sICAS was analyzed by logistic regression analysis. Results: In univariable analyses, sICAS patients with severe and multiple atherosclerotic stenoses had lower levels of total bilirubin (Tbil), direct bilirubin (Dbil), and indirect bilirubin (Ibil). In multinomial logistic regression analyses, when compared with the highest tertile of bilirubin, lower levels of Tbil, Dbil, and Ibil showed higher risks of severe-occlusion sICAS (95% CI: 2.018-6.075 in tertile 1 for Tbil; 2.380-7.410 in tertile 1 for Dbil; 1.758-5.641 in tertile 1 for Ibil). Moreover, the logistic regression analyses showed that lower levels of Tbil, Dbil, and Ibil were related to multiple (≥3) atherosclerotic stenoses (95% CI: 2.365-5.298 in tertile 1 and 2.312-5.208 in tertile 2 for Tbil; 1.743-3.835 in tertile 1 and 1.416-3.144 in tertile 2 for Dbil; 2.361-5.345 in tertile 1 and 1.604-3.545 in tertile 2 for Ibil) when compared with tertile 3. Conclusions: Our findings suggest that lower bilirubin levels may indicate severe and multiple intracranial atherosclerotic stenoses.

Gut-Derived Metabolite Phenylacetylglutamine and White Matter Hyperintensities in Patients With Acute Ischemic Stroke.

Background: White matter hyperintensity (WMH) burden is associated with a higher risk of ischemic stroke. Phenylacetylglutamine (PAGln) is a gut microbiota-derived metabolite that may induce cardiovascular events by activating platelets and increasing the risk of thrombosis. The relationship between plasma PAGln and WMH burden in patients with ischemic stroke is unknown. This study was designed to investigate the association between plasma PAGln and WMH burden in patients with acute ischemic stroke. Methods: A total of 595 patients with acute ischemic stroke were enrolled in this study within 14 days of symptom onset. The burden of WMH was evaluated using the Fazekas scale based on the fluid-attenuated inversion recovery sequence. The severity of overall WMH was defined as none-mild WMH (total Fazekas score 0-2) or moderate-severe WMH (total Fazekas score 3-6). Based on the severity of periventricular WMH (P-WMH) and deep WMH (D-WMH), patients were categorized into either a none-mild (Fazekas score 0-1) group or a moderate-severe (Fazekas score 2-3) group. Plasma PAGln levels were quantified using liquid chromatography-mass spectrometry. Results: We found that patients with moderate-severe overall WMH showed higher plasma PAGln levels than patients with none-mild overall WMH, and similar results were found in the analyses according to P-WMH and D-WMH. The logistic regression analysis showed that the fourth PAGln quartile was independently associated with moderate-severe overall WMH (adjusted 95% CI 1.134-4.018) and P-WMH (adjusted 95% CI 1.174-4.226). Conclusion: These findings suggest that higher plasma PAGln levels are associated with moderate-severe overall WMH and P-WMH in patients with acute ischemic stroke.

Neutrophil-to-Lymphocyte Ratio as a Predictive Biomarker for Stroke Severity and Short-Term Prognosis in Acute Ischemic Stroke With Intracranial Atherosclerotic Stenosis.

Background: Neutrophil-to-lymphocyte ratio (NLR) is an indicator of poor prognosis in acute ischemic stroke (AIS), but associations between NLR with stroke severity and prognosis of intracranial atherosclerotic stenosis (ICAS)-related ischemic events have not been well-elucidated; therefore, we aimed to evaluate whether admission NLR levels correlate with the early stroke severity and short-term functional prognosis in patients with symptomatic intracranial atherosclerotic stenosis (sICAS). Methods: This retrospective study enrolled 899 consecutive patients with AIS attributed to ICAS at Xiangya Hospital stroke center between May 2016 and September 2020. The initial stroke severity was rated by the admission National Institutes of Health Stroke Scale (NIHSS) scores, and the short-term prognosis was evaluated using the 14-day modified Rankin Scale (mRS) scores after stroke onset. A severe stroke was defined as NIHSS >8; an unfavorable functional outcome was defined as mRS scores of 3-6. Admission NLR was determined based on circulating neutrophil and lymphocyte counts. Results: The median admission NLR of all patients was 2.80 [interquartile range (IQR), 2.00-4.00]. In univariate analysis, admission NLR was significantly elevated in patients with severe stroke and poor short-term prognosis. After multivariate adjustment, admission NLR levels were significantly correlated with severe stroke [odds ratio (OR), 1.132; 95% confidence interval (95% CI), 1.038-1.234; P = 0.005] and unfavorable short-term prognosis (OR, 1.102; 95% CI, 1.017-1.195; P = 0.018) in Model 1. In Model 2, the highest NLR tertile (≥3.533) remained an independent predictor of severe stroke (OR, 2.736; 95% CI, 1.590-4.708; P < 0.001) and unfavorable functional outcome (OR, 2.165; 95% CI, 1.416-3.311; P < 0.001) compared with the lowest NLR tertile (<2.231). The receiver operating characteristic (ROC) curves showed the predictability of NLR regarding the stroke severity [area under the curve (AUC), 0.659; 95% CI, 0.615-0.703; P < 0.001] and short-term prognosis (AUC, 0.613; 95% CI, 0.575-0.650; P < 0.001). The nomograms were constructed to create the predictive models of the severity and short-term outcome of sICAS. Conclusions: Elevated admission NLR levels were independently associated with the initial stroke severity and could be an early predictor of severity and poor short-term prognosis in AIS patients with ICAS, which might help us identify a target group timely for preventive therapies.

Molecular Biomarkers Associated with Early-Onset Symptomatic Intracranial Atherosclerosis.

PURPOSE: Previous studies have shown a rising incidence of early-onset symptomatic intracranial atherosclerosis (sICAS), which has brought a severe economic burden to social development. This study aimed to evaluate the molecular biomarkers associated with early-onset sICAS and to seek possible intervention strategies for early prevention. PATIENTS AND METHODS: We consecutively recruited patients with sICAS and divided them into two groups based on age: early-onset sICAS group as age ≤60 years old and late-onset sICAS group as age >60 years old. We collected and compared the demographic data and laboratory results of each group. A bivariate logistic regression model was applied to evaluate the independent molecular biomarkers of early-onset sICAS. RESULTS: A total of 1007 subjects with sICAS were enrolled in this study, comprising 519 patients in the early-onset sICAS group and 488 patients in the late-onset sICAS group. Bivariate logistic regression analysis demonstrated an increased level of white blood cell, platelet, albumin globulin ratio, free triiodothyronine, and a decreased level of total bile acid, urea nitrogen, high-density lipoprotein, homocysteine, and fibrinogen in the early-onset sICAS group when compared to the late-onset group. CONCLUSION: Our study showed the relevance between early sICAS and circulating levels of different molecular biomarkers. Detection of these related molecular biomarkers may provide a simple way for early sICAS preventions in the future.

Intestinal Barrier Dysfunction Participates in the Pathophysiology of Ischemic Stroke.

The gastrointestinal tract is a major organ of the body that absorbs nutrients, water, and electrolytes. At the same time, it is a tight barrier that resists the invasion of harmful substances and maintains the homeostasis of the internal environment. Destruction of the intestinal barrier is linked to the digestive system, cardiovascular system, endocrine system, and other systemic diseases. Mounting evidence suggests that ischemic stroke not only changes the intestinal microbes but also increases the permeability of the intestinal barrier, leading to bacterial translocation, infection, and even sepsis. The intestinal barrier, as part of the gut-brain axis, has also been proven to participate in the pathophysiological process of ischemic stroke. However, little attention has been paid to it. Since ischemic stroke is a major public health issue worldwide, there is an urgent need to know more about the disease for better prevention, treatment, and prognosis. Therefore, understanding the pathophysiological relationship between ischemic stroke and the intestinal barrier will help researchers further uncover the pathophysiological mechanisms of ischemic stroke and provide a novel therapeutic target for the treatment of ischemic stroke. Here, we review the physiology and pathology between ischemic stroke and intestinal barrier based on related articles published in the past ten years about the relationship between ischemic stroke, stroke risk factors and intestinal flora, and intestinal barrier. We further discuss the following parts: the intestinal barrier, possible mechanisms of intestinal barrier destruction in ischemic stroke, intestinal barrier destruction caused by stroke-related risk factors, intestinal barrier dysfunction in ischemic stroke, targeting the intestinal barrier for improving stroke, conclusions and perspectives.

Phenylacetylglutamine, a Novel Biomarker in Acute Ischemic Stroke.

Background: To discover novel metabolic biomarkers of ischemic stroke (IS), we carried out a two-stage metabolomic profiling of IS patients and healthy controls using untargeted and targeted metabolomic approaches. Methods: We applied untargeted liquid chromatography-mass spectrometry (LC-MS) to detect the plasma metabolomic profiles of 150 acute IS patients and 50 healthy controls. The candidate differential microbiota-derived metabolite phenylacetylglutamine (PAGln) was validated in 751 patients with IS and 200 healthy controls. We evaluated the associations between PAGln levels and the severity and functional outcomes of patients with IS. Clinical mild stroke was defined as the National Institutes of Health Stroke Scale (NIHSS) score 0-5, and moderate-severe stroke as NIHSS score >5. A favorable outcome at 3 months after IS was defined as the modified Rankin Scale (mRS) score 0-2, and unfavorable outcome as mRS score 3-6. Results: In untargeted metabolomic analysis, we detected 120 differential metabolites between patients with IS and healthy controls. Significantly altered metabolic pathways were purine metabolism, TCA cycle, steroid hormone biosynthesis, and pantothenate and CoA biosynthesis. Elevated plasma PAGln levels in IS patients, compared with healthy controls, were observed in untargeted LC-MS analysis and confirmed by targeted quantification (median 2.0 vs. 1.0 µmol/L; p < 0.001). Patients with moderate-severe stroke symptoms and unfavorable short-term outcomes also had higher levels of PAGln both in discovery and validation stage. After adjusting for potential confounders, high PAGln levels were independently associated with IS (OR = 3.183, 95% CI 1.671-6.066 for the middle tertile and OR = 9.362, 95% CI 3.797-23.083 for the highest tertile, compared with the lowest tertile) and the risk of unfavorable short-term outcomes (OR = 2.286, 95% CI 1.188-4.401 for the highest tertile). Conclusions: IS patients had higher plasma levels of PAGln than healthy controls. PAGln might be a potential biomarker for IS and unfavorable functional outcomes in patients with IS.

The mental health of neurological doctors and nurses in Hunan Province, China during the initial stages of the COVID-19 outbreak.

BACKGROUND: Neurological symptoms are increasingly being noted among COVID-19 patients. Currently, there is little data on the mental health of neurological healthcare workers. The aim of this study was to identify the prevalence and influencing factors on anxiety and depression in neurological healthcare workers in Hunan Province, China during the early stage of the Coronavirus Disease 2019 (COVID-19) outbreak. METHODS: An online cross-sectional study was conducted among neurological doctors and nurses in early February 2020 in Hunan Province. Symptoms of anxiety and depression were assessed by the Chinese version of the Self-Rating Anxiety Scale (SAS) (defined as a total score ≥ 50) and Self-Rating Depression Scale (SDS) (defined as a total score ≥ 53). The prevalences of probable anxiety and depression were compared between different groups, and multivariate logistic regression analysis was used to understand the independent influencing factors on anxiety and depression. RESULTS: The prevalence of probable anxiety and depression in neurological nurses (20.3 and 30.2%, respectively) was higher than that in doctors (12.6 and 20.2%, respectively). Female healthcare workers (18.4%) had a higher proportion of anxiety than males (10.8%). Probable anxiety and depression were more prevalent among nurses, younger workers (≤ 40 years), and medical staff with junior titles. Logistic regression analysis showed that a shortage of protective equipment was independently associated with probable anxiety (OR = 1.980, 95% CI: 1.241-3.160, P = 0.004), while young age was a risk factor for probable depression (OR = 2.293, 95% CI: 1.137-4.623, P = 0.020) among neurological healthcare workers. CONCLUSIONS: Probable anxiety and depression were more prevalent among neurological nurses than doctors in Hunan Province. The shortage of protective equipment led to probable anxiety, and young age led to probable depression in healthcare workers in neurology departments, which merits attention during the battle against COVID-19.

Muscle type of palatopharyngeal muscle in children with severe obstructive sleep apnea.

STUDY OBJECTIVES: To investigate the fiber-type distribution in palatopharyngeal muscle via adenosine triphosphatase and quantitative real-time polymerase chain reaction in children with severe obstructive sleep apnea (OSA). METHODS: Study participants were 12 children with severe OSA and 15 children with simple snoring as the control group. Both groups were diagnosed by polysomnography and treated with tonsillectomy. The samples of palatopharyngeus muscle were studied under adenosine triphosphatase staining and quantitative real-time polymerase chain reaction to classify the different fiber types. RESULTS: There were no differences in baseline age, body mass index, tonsil size, or sleep stage constitution between the 2 groups. Dominance (>60%) of type I fiber was observed both in children with simple snoring (3/15, 20%) and in those with severe OSA (1/12, 8.3%) via adenosine triphosphatase staining. Predominance of type II fibers was seen in 3/15 (20%) in the control group and 6/12 (50%) in the severe OSA group, respectively. Type grouping was also seen in 8/15 (53.3%) in non-OSA and 6/12 (50%) in severe OSA groups, respectively. There was no difference in distribution of subtype fibers assessed by quantitative real-time polymerase chain reaction between the 2 groups; the mean percentages of type I fibers were 25.8% ± 19.5% and 20.9% ± 16.6%, respectively (P > .05), similar to type IIa fibers (35.2% ± 23.4% and 40.9% ± 28.8%) (P > .05). There was a decrease in the percentage of type I fibers between children younger and older than 12 years (P < 0.05), although this was not due to OSA (P > 0.05). CONCLUSIONS: There were no specific changes via adenosine triphosphatase staining or a difference in distribution of subtype fibers via quantitative real-time polymerase chain reaction between children with severe pediatric OSA and those with simple snoring, whereas the percentage of type I fiber decreased dynamically due to age but not OSA. CLINICAL TRIAL REGISTRATION: Registry: Chinese Clinical Trials Registry; Name: A study of the mechanism of the conversion of upper airway expasion muscle's fiver types of OSA patient which may be mediated by estrogen-related receptor alpha; URL: https://www.chictr.org.cn/showproj.aspx?proj=6144; Identifier: ChiCTR-CCC-13003415.