ObjectiveTo investigate whether Huanglian Jiedutang can inhibit neutrophil infiltration in the brains of middle cerebral artery occlusion （MCAO） mice by regulating the expression of neutrophil-related chemokines in exosomes， thereby achieving therapeutic effects. MethodsA total of 130 male specific pathogen-free （SPF） C57BL/6J mice were randomly divided into four groups： Sham-operated group， MCAO model group， Huanglian Jiedutang group （6 g·kg^-1）， and Ginaton group （21.6 mg·kg^-1）， with 10 mice in the Ginaton group and 40 mice in each of the remaining three groups. Mice in the Huanglian Jiedutang group and the Ginaton group were administered the corresponding drugs by oral gavage once daily at a volume of 0.15 mL·（10 g）^-1 for 7 consecutive days， while the sham-operated and model groups received an equal volume of saline via the same route. After 7 days， MCAO surgery was performed. The distal and proximal ends of the right common carotid artery （CCA） were ligated， a small incision was made between the two ligatures， and a silicone rubber-coated monofilament with a rounded tip was inserted into the lumen to occlude the CCA. The filament was left in place for 1 h to establish a focal cerebral ischemia model. At 24 h after modeling， mice were evaluated. Neurological function was assessed using the Longa score. Cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Cerebral blood flow was observed by laser speckle imaging. Hematoxylin and eosin （HE） staining and Nissl staining were used to observe pathological changes in brain tissues. Exosomes were isolated from mouse plasma and brain tissues by ultracentrifugation and molecular size exclusion and identified by electron microscopy， particle size analysis， and protein blotting. Long-chain RNA libraries of exosomes were constructed and sequenced. Real-time quantitative reverse transcription polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of inflammatory factors and neutrophil-related chemokines in exosomes from plasma and brain tissues of each group. Enzyme-linked immunosorbent assay （ELISA） was used to detect the protein expression of inflammatory factors and neutrophil-related chemokines in exosomes from brain tissues of each group. Immunohistochemistry was used to detect the expression of the neutrophil-specific protein myeloperoxidase （MPO） in the brains of mice in each group. ResultsCompared with the sham-operated group， the model group showed decreased neurological function scores （P<0.01）， obvious cerebral infarction （P<0.01）， reduced cerebral blood flow （P<0.01）， neuronal necrosis in the brain， and decreased numbers of Nissl bodies （P<0.01）. The mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were significantly increased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were increased （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were elevated （P<0.01）. Compared with the model group， the Huanglian Jiedutang group and the Ginaton group showed increased neurological function scores （P<0.05）， reduced cerebral infarct volume （P<0.01）， restored cerebral blood flow （P<0.01）， reduced necrotic cells in the brain， and increased numbers of Nissl bodies （P<0.01）. In the Huanglian Jiedutang group， the mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were decreased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were reduced （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were decreased （P<0.01）. ConclusionHuanglian Jiedutang can effectively regulate the expression of neutrophil-related chemokines in exosomes from plasma and brain tissues of MCAO mice， thereby reducing neutrophil infiltration in the brain and achieving therapeutic effects.

ObjectiveTo evaluate the therapeutic effects of Huanglian Jiedutang on cerebral infarction injury in a mouse model of middle cerebral artery occlusion （MCAO） and to explore its mechanism of action on oligodendrocytes， particularly its potential in myelin repair. MethodsMultiple experimental approaches were used to evaluate cerebral ischemic injury and the effects of drug intervention. Laser speckle imaging was used to detect changes in cerebral blood flow， 2，3，5-Triphenyltetrazolium chloride （TTC） staining was used to measure infarct volume， and neurological function was scored according to the Zea-Longa criteria. Brain tissues were routinely embedded in paraffin and subjected to HE and Nissl staining to observe tissue structure and neuronal damage. Animals were divided into a sham group （n=24）， model group （n=24）， Huanglian Jiedutang group （n=24）， and Ginkgo biloba extract （GBE） group （n=18）. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 g·L^-1 solution. All groups were treated for 5 consecutive days at a dose of 0.2 mL·（10 g）^-¹·d^-¹. The MCAO model was established after the final administration on day 6. Single-cell RNA sequencing was used to analyze brain tissue cellular composition and changes in oligodendrocyte subpopulations. Distinct subpopulations were identified by Uniform manifold approximation and projection （UMAP） dimensionality reduction and unsupervised clustering， and marker gene expression was analyzed. Pathway enrichment and causal inference were further performed using IPA. Finally， real-time quantitative PCR was used to verify mRNA expression changes of myelin-related genes. ResultsCompared with the sham group， the model group showed significantly increased neurological function scores （P<0.01）， significantly impaired blood flow （P<0.01）， significantly enlarged cerebral infarct area （P<0.01）， and pathological changes including disordered cortical structural arrangement， aggravated cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased neurological function scores （P<0.01）， markedly restored blood flow levels （P<0.01）， significantly reduced cerebral infarct area （P<0.01）， and improvement in cortical structural disorder， alleviation of cytoplasmic vacuolization， and a reduction in Nissl bodies. Single-cell data showed that a myelin-associated oligodendrocyte （Mye-OL） subpopulation existed among oligodendrocytes， which was closely related to myelin generation. Compared with the sham group， the number of Mye-OL cells decreased in the model group. Compared with the model group， the number of Mye-OL cells increased in the Huanglian Jiedutang group. This subpopulation promoted the expression of myelin-related genes， including MOG， MBP， and MAG， via transcription factors such as OLIG1， OLIG2， NKX2-2， and SOX10， thereby regulating myelin generation， restoring cognition， and exerting therapeutic effects on acute cerebral infarction. Compared with the sham group， the mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 were significantly downregulated in the model group （P<0.01）， and the mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG， were also significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly upregulated mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 （P<0.01）， and significantly upregulated mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG （P<0.01）. ConclusionHuanglian Jiedutang exerts therapeutic effects on acute cerebral infarction by regulating the OLIG1/2-NKX2-2-SOX10 signaling pathway to promote myelin generation by Mye-OL cells.

ObjectiveTo investigate the characteristics of metabolic reprogramming during cerebral ischemia-reperfusion injury using single-cell transcriptome sequencing， analyze the heterogeneity of microglial populations， and evaluate the interventional effects of Huanglian Jiedutang on metabolic abnormalities and neuroinflammation. MethodsA transient middle cerebral artery occlusion （tMCAO） model was used to establish ischemic stroke in mice. Local cerebral blood flow changes were monitored by laser speckle imaging. Neurological impairment was evaluated using the Zea-Longa score， and histopathological damage in brain tissue was observed by HE and Nissl staining. Animals were divided into a sham group， model group， Huanglian Jiedutang group， and Ginkgo biloba extract （GBE） group. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 mg/mL solution. All groups were treated for 5 consecutive days （0.2 mL/10 g/day）， and the tMCAO model was established on day 6 after the final administration. At the molecular level， single-cell RNA sequencing was performed on ischemic hemisphere tissue. Non-negative matrix factorization （NMF） was used to cluster microglial subpopulations， combined with differential expression analysis， metabolic reprogramming assessment， and inflammatory factor correlation analysis to elucidate their functional characteristics in ischemia-reperfusion injury. Transcription factor enrichment analysis was further conducted to identify key regulatory nodes. Finally， PCR was used to detect mRNA expression changes of relevant genes to validate the single-cell sequencing results. ResultsCompared with the sham group， the model group showed increased neurological function scores （P<0.01）， decreased blood flow levels （P<0.01）， disordered cortical structure， increased cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed decreased neurological function scores （P<0.01）， increased blood flow levels （P<0.01）， alleviated cortical structural disorder， reduced cytoplasmic vacuolization， and decreased Nissl bodies. Single-cell analysis showed that microglia could be divided into five subpopulations. Among them， clusters 3 and 5 exhibited significant pro-inflammatory phenotypes， with marked activation of hypoxia and NF-κB signaling pathways， and were identified as pro-inflammatory subpopulations. Clusters 1 and 2 were enriched in Wnt/β-catenin and transforming growth factor（TGF）-β signaling pathways and exhibited prominent anti-inflammatory and reparative characteristics. Meanwhile， glycolysis-related genes， such as HK2， PFKP， and LDHA， were significantly upregulated in the pro-inflammatory subpopulations. Correlation analysis showed that the expression levels of inflammatory molecules were positively correlated with glycolysis-related gene expression levels， whereas the expression levels of reparative and anti-inflammatory molecules were negatively correlated with glycolysis-related gene expression levels， indicating that microglia rely on the glycolytic pathway for energy acquisition under ischemic conditions. Further single-cell transcriptome analysis revealed that Huanglian Jiedutang effectively downregulated key genes driving metabolic reprogramming （such as HK2， PFKP， and LDHA）， significantly reduced the proportion of microglial subpopulations accompanied by glycolytic reprogramming， and inhibited their transformation toward a damage phenotype， thereby reducing inflammatory injury. Meanwhile， compared with the sham group， the mRNA expression levels of interleukin （IL）-1β， IL-6， tumor necrosis factor（TNF）-α， CCL2， CXCL2， and CSF3 were significantly upregulated （P<0.01） in the model group， whereas the mRNA expression levels of endothelial- and pericyte-related functional genes， including RGS5， PECAM1， VEGFB， and NOS3， were significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased mRNA expression levels of IL-1β， IL-6， TNF-α， CCL2， CXCL2， and CSF3 （P<0.01）， and significantly increased mRNA expression levels of endothelial- and pericyte-related functional genes， including RGS5， PECAM1， VEGFB， and NOS3 （P<0.01）. ConclusionHuanglian Jiedutang exerts neuroprotective effects by regulating the metabolic reprogramming state of microglia and modulating their inflammatory levels， thereby inhibiting neuroinflammatory injury.

ObjectiveGastrodia elata has evolved ecological types with shortened rhizome internodes and diversified flower and fruit coloration in response to different altitudes. Studying the genetic mechanisms of different ecotype germplasm is significant for guiding variety breeding in different cultivation areas. MethodsThe bHLH gene family was identified based on the whole-genome datasets of G. elata f. elata and G. elata f. glauca. Subsequently， the gene family members were subject to analysis， including gene structure， chromosomal localization， cis-acting elements， gene synteny， and phylogeny. Combined with transcriptome data and quantitative Real-time PCR， the expression patterns of bHLH genes in the stems of the different G. elata ecotype germplasm were analyzed. Finally， correlation analysis was conducted between gene expression patterns and color to obtain the key bHLH genes regulating the color formation of stem. ResultsA total of 63 bHLH genes were identified in both G elata f. elata and G. elata f. glauca， unevenly distributed across 17 chromosomes and clustered into 16 subfamilies， with significant expansion in some family members. Obvious inversions of bHLH genes on the same chromosome and interchromosomal translocations were detected in the two ecotype germplasm. Among these genes， 12 bHLH genes （such as bHLH62-3 and bHLH74） were associated with the bright yellow color of G elata f. elata stem， while 9 bHLH genes （such as PIL13， UNE12， and bHLH130） were correlated with the red color of G. elata f. glauca stem. Compared to G. elata f. glauca， the bHLH48 expression level was significantly higher in flowers and scale leaves of G elata f. elata， and the bHLH62-3 expression level was significantly higher in all organs of G elata f. elata. ConclusionsFunctional pathway divergence of the bHLH family members has occurred across different chromosomes in G elata f. elata and G. elata f. glauca. Through synergism or antagonism with other genes， 21 bHLH genes participate in the coloration metabolic pathway regulation of stems， flowers， and fruits. Specifically， bHLH62-3 is involved in regulating stem color differentiation in the anthocyanin biosynthesis pathway of G. elata， thus relevant to the color formation of stem. Additionally， GebHLH48 positively regulates flowering-related pathways to promote the early-flowering phenotype of G. elata f. elata. These findings have laid the foundation for analyzing the genetic regulatory mechanisms underlying the color formation of the G. elata stem.

Objective To systematically analyze the characteristics of the disease burden of hypertensive heart disease (HHD) in the elderly (≥60 years) globally and in China from 1990 to 2021, and to predict its future trends from 2022 to 2040, with the aim of providing data support for optimizing comprehensive prevention and control strategies for HHD. Methods Based on the Global Burden of Disease (GBD) 2021 database, the number of prevalent cases and disability-adjusted life years (DALYs) of HHD in the elderly were extracted for the world, China, and five regions categorized by sociodemographic index (SDI). Joinpoint regression was used to analyze the temporal trends of age-standardized prevalence rate and age-standardized DALYs rate of HHD in the elderly. A three-factor decomposition method was applied to evaluate the relative contributions of aging, population growth, and epidemiological changes to the variations in the elderly HHD burden. Additionally, a Bayesian age-period-cohort model was used to predict the elderly HHD burden from 2022 to 2040. Results In 2021, the number of prevalent elderly HHD cases reached 10 283 000 globally and 3 412 400 in China, representing increases of 179.20% and 159.20% respectively, compared with 1990. The DALYs of elderly HHD were 18 812 700 person-years globally and 4 731 400 person-years in China, rising by 76.08% and 29.45% respectively from 1990. Meanwhile, the growth rates of the number of prevalent cases and DALYs of elderly HHD varied across different SDI regions. From 1990 to 2021, the age-standardized prevalence rate of elderly HHD in China, as well as the age-standardized DALYs rate of elderly HHD both globally and in China, showed significant downward trends (all average annual percentage changes<0, all P<0.001). In 2021, the 70-74 years age group accounted for the highest proportion of prevalent cases and DALYs of elderly HHD, both globally and in China. Decomposition analysis revealed that population growth was the dominant factor driving the increase in the elderly HHD burden across all regions. The prediction model results indicated that the number of prevalent cases and DALYs of elderly HHD would continue to rise globally and in China from 2022 to 2040, with the growth rate of the elderly HHD burden in China between 2021 and 2040 expected to exceed the global average. Conclusion Over the past 32 years, although the age-standardized disease rates of elderly HHD have mainly shown a downward trend globally and in China, the absolute number of the disease burden has increased substantially. The projection model indicates a continued upward trajectory, with the growth rate in China higher than the global average. Therefore, there is an urgent need to implement precise prevention and control strategies to effectively mitigate the disease burden of elderly HHD.

From June 2002 to December 2023, there were 5 patients with criss-cross hearts admitted to the General Hospital of Northern Theater Command, including 3 males and 2 females, aged 1.5 to 25 years, and weighing 13-49 kg. There were 5 patients of atrioventricular position, 3 patients of right ventricular loop, 2 patients of left ventricular loop, 3 patients of normal atrioventricular connection, and 2 patients of inconsistent connection. Combined intracardiac malformations: 1 patient of simple ventricular septal defect combined with pulmonary hypertension, 1 patient of corrected transposition of the great arteries combined with ventricular septal defect, atrial septal defect, and pulmonary artery stenosis, 1 patient of corrected transposition of the great arteries combined with ventricular septal defect, atrial septal defect, and left atrioventricular valve insufficiency, and 2 patients of right ventricular double outlet combined with ventricular septal defect and pulmonary artery stenosis. The surgical methods included 2 patients of intracardiac anatomical correction, 1 patient of bidirectional vena cava pulmonary artery anastomosis, and 2 patients of total extracardiac ductal cava pulmonary artery anastomosis. All 5 patients were discharged smoothly.

Objective: To develop QingNangTCM, a specialized large language model (LLM) tailored for expert-level traditional Chinese medicine (TCM) question-answering and clinical reasoning, addressing the scarcity of domain-specific corpora and specialized alignment. Methods: We constructed QnTCM_Dataset, a corpus of 100 000 entries, by integrating data from ShenNong_TCM_Dataset and SymMap v2.0, and synthesizing additional samples via retrieval-augmented generation (RAG) and persona-driven generation. The dataset comprehensively covers diagnostic inquiries, prescriptions, and herbal knowledge. Utilizing P-Tuning v2, we fine-tuned the GLM-4-9B-Chat backbone to develop QingNangTCM. A multi-dimensional evaluation framework, assessing accuracy, coverage, consistency, safety, professionalism, and fluency, was established using metrics such as bilingual evaluation understudy (BLEU), recall-oriented understudy for gisting evaluation (ROUGE), metric for evaluation of translation with explicit ordering (METEOR), and LLM-as-a-Judge with expert review. Qualitative analysis was conducted across four simulated clinical scenarios: symptom analysis, disease treatment, herb inquiry, and failure cases. Baseline models included GLM-4-9B-Chat, DeepSeek-V2, HuatuoGPT-II (7B), and GLM-4-9B-Chat (freeze-tuning). Results: QingNangTCM achieved the highest scores in BLEU-1/2/3/4 (0.425/0.298/0.137/0.064), ROUGE-1/2 (0.368/0.157), and METEOR (0.218), demonstrating a balanced and superior normalized performance profile of 0.900 across the dimensions of accuracy, coverage, and consistency. Although its ROUGE-L score (0.299) was lower than that of HuatuoGPT-II (7B) (0.351), it significantly outperformed domain-specific models in expert-validated win rates for professionalism (86%) and safety (73%). Qualitative analysis confirmed that the model strictly adheres to the “symptom-syndrome-pathogenesis-treatment” reasoning chain, though occasional misclassifications and hallucinations persisted when dealing with rare medicinal materials and uncommon syndromes. Conclusion Combining domain-specific corpus construction with parameter-efficient prompt tuning enhances the reasoning behavior and domain adaptation of LLMs for TCM-related tasks. This work provides a technical framework for the digital organization and intelligent utilization of TCM knowledge, with potential value for supporting diagnostic reasoning and medical education.

Objective To explore the relationship between circadian rhythm genes and the occurrence, development, prognosis, and tumor microenvironment (TME) of lung adenocarcinoma (LUAD). Methods The Cancer Genome Atlas data were used to evaluate the expression, copy number variation, and somatic mutation frequency of circadian gene sets in LUAD. Gene ontology, Kyoto encyclopedia of genes and genomes, and gene set enrichment analysis were used to explore the potential mechanisms by which circadian rhythm genes affected LUAD progression. Cox regression, least absolute shrinkage and selection operator regression, support vector machine recursive feature elimination, and random forest screened circadian genes and established prognostic models, and on this basis constructed nomogram to predict patients’ 1-, 3-, and 5-year survival rates. Kaplan-Meier survival curves, receiver operating characteristic (ROC) curves, and time-dependent ROC curves were drawn to evaluate the predictive ability of the model, and the external dataset of GEO further verified the prognostic value of the prediction model. In addition, we evaluated the association of the prognostic model with immune cells and immune checkpoint genes. Single cell RNA sequencing (scRNA-seq) analysis was used to explore the molecular characteristics between prognostically relevant circadian genes and different immune cell populations in TME. Results Differentially expressed circadian rhythm genes were mainly enriched in biological processes related to cGMP-PKG signaling pathway, lipid and atherosclerosis, and JAK-STAT signaling pathway. Seven circadian rhythm genes: LGR4, CDK1, KLF10, ARNTL2, RORA, NPAS2, PTGDS were screened out, and a RiskScore model was established. According to the median RiskScore, samples were divided into a high-risk group and a low-risk group. Compared with patients in the low-risk group, patients in the high-risk group showed a poorer prognosis (P<0.001). Immunological characterization analysis showed that there were differences in the infiltration of multiple immune cells between the low-risk group and high-risk group. Most immune checkpoint genes had higher expression levels in the high-risk group than those in the low-risk group, and RiskScore was positively correlated with the expression of CD276, TNFSF4, PDCD1LG2, CD274, and TNFRSF9, and negatively correlated with the expression of CD40LG and TNFSF15. The scRNA-seq analysis showed that RORA and KLF10 were mainly expressed in natural killer cells. Conclusion The prognostic model based on seven feature circadian rhythm genes has certain predictive value for predicting survival of LUAD patients. Dysregulated expression of circadian genes may regulate the occurrence, progression as well as prognosis of LUAD through affecting TME, which provides a possible direction for finding potential strategies for treating LUAD from the perspective of mechanism by which circadian disorder affects immune cells.

Objective To understand the current status of low-density lipoprotein cholesterol (LDL-C) control in patients after coronary artery bypass grafting (CABG). Methods Clinical data of patients who underwent isolated CABG in Beijing Anzhen Hospital in 2023 were collected. All patients returned to our hospital approximately one year after surgery (10-13 months) for a lipid level recheck. We analyzed their LDL-C attainment status and influencing factors. Patients were categorized into two groups based on whether their LDL-C met the target: a LDL-C attainment group and a LDL-C non-attainment group. Results This study included 1456 patients who underwent CABG, including 320 females and 1136 males, with an average age of (61.41±9.12) years. One year post-surgery, 234 patients achieved the LDL-C target, with an attainment rate of 16.07%. The proportion of patients in the LDL-C attainment group who were ultra-high risk (77.35% vs. 92.06%, P＜0.001), female (16.24% vs. 23.08%, P=0.021), and those with comorbid hypertension (55.98% vs. 63.18%, P=0.038) was significantly lower than those in the LDL-C non-attainment group. Additionally, the baseline body mass index (BMI) [(25.37±3.24) kg/m2 vs. (26.03±3.56) kg/m2, P=0.017], total cholesterol levels [(3.30±0.84) mmol/L vs. (4.01±1.03) mmol/L, P＜0.001], LDL-C [(1.62±0.63) mmol/L vs. (2.25±0.85) mmol/L, P＜0.001], and high-density lipoprotein cholesterol [(0.98±0.26) mmol/L vs. (1.02±0.24) mmol/L, P=0.049] upon admission in the attainment group were all lower than those in the non-attainment group. Moreover, the lipid-lowering drug usage rate in the attainment group (100.00% vs. 96.24%, P=0.003) and the proportion using two types of drugs together (25.21% vs. 10.72%, P＜0.001) were both higher than those in the non-attainment group, while the statin monotherapy rate was lower than that in the non-attainment group (74.79% vs. 85.19%, P＜0.001). Logistic regression analysis showed that baseline BMI (OR=0.928, P=0.012) and baseline LDL-C levels (OR=0.207, P<0.001), patient cardiovascular risk stratification (OR=0.155, P<0.001) and lipid-lowering drug treatment regimen (OR=3.758, P<0.001) are significant factors affecting the LDL-C control status. Conclusion The LDL-C compliance rate of patients undergoing CABG is at a relatively low level 1 year after surgery. Patients with very high risk of atherosclerotic cardiovascular disease, high baseline LDL-C levels, and overweight or obesity should be strengthened lipid management. For these patients, the intensity of lipid-lowering drug use or combination medication should be increased upon discharge.

Objective: To investigate the prevalence of undernutrition and its associated factors among left behind and non left behind primary and secondary school students in the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) areas of central and western China, so as to provide evidence for improving the nutritional status of children and adolescents. Methods: A survey was conducted among 123 782 students selected by random cluster sampling method in grades 3-9 from NIPRCES in central (Hebei, Shanxi, Heilongjiang, Jilin, Anhui, Jiangxi, Henan, Hunan, Hubei, and Hainan) and western (Gansu, Guangxi, Inner Mongolia, Ningxia, Tibet, Shaanxi, Guizhou, Sichuan, Xinjiang, the Xinjiang Production and Construction Corps, Yunnan, Qinghai, and Chongqing) China in 2023. Anthropometric measurements and questionnaires were used to assess nutritional and dietary status. The prevalence of undernutrition was compared between left behind and non left behind students by Chi square test, and associated factors were analyzed by three level Logistic mixed effects model. Results: The prevalence of undernutrition was 8.5% (4 326) in left behind students and 8.1% (5 905) in non left behind students. Three level Logistic mixed effect model analysis showed that whether left behind or non left behind, the undernutrition rates of primary and secondary students in western regions were higher than those of students in central regions [ OR (95% CI )=1.72(1.57-1.87),2.25(2.07- 2.43 )]; the undernutrition risk was lower for those whose fathers had a cultural level of high school or above [ OR (95% CI )=0.69(0.62-0.77),0.90(0.82-0.98)] or junior high school [ OR (95% CI )=0.72(0.66-0.79),0.92(0.85-0.99)] compared to those with primary school or below; picky eating or selective eating increased the risk of undernutrition [ OR (95% CI )=2.36(2.07-2.68),2.28(2.04-2.55)], and primary and secondary school students without nutritional content in health education classes had higher rates of undernutrition [ OR (95% CI )=1.12(1.03-1.23),1.09(1.01-1.17)](all P <0.05). Conclusion The prevalence of undernutrition is slightly higher in left behind primary and secondary students than in non left behind primary and secondary students in central and western NIPRCES areas, with variations across different characteristics.