Lung function and blood gas of rats after different protocols of hypobaric exposure.

High-altitude pulmonary edema (HAPE) is a common disease observed in climbers, skiers and soldiers who ascend to high altitudes without previous acclimatization. Thus, a reliable and reproducible animal model that can mimic the mechanisms of pathophysiologic response in humans is crucial for successful investigations. Our results showed that exposure to 4500 m for 2 days had little influence on lung function or blood gas, and exposure to 6000 m for 2 or 3 days could change lung function and blood gas, but most parameters returned to nearly normal levels within 48 hours. This study indicates that exposure to 6000 m for 3 days may induce evident lung edema and significantly alter lung function and blood gas, which may mimic HAPE in clinical practice. Thus, this animal model of HAPE may be used in future studies on HAPE.

High altitude impact on serum bicarbonate in healthy Mexican children: concerning the overdiagnosis of renal tubular acidosis.

BACKGROUND: Altitude influences bicarbonate levels, it is a variable that is hardly considered in diagnosing Renal Tubular Acidosis (RTA), so it should be a factor to consider when diagnosing this pathology, especially at 2250 mts over the sea level as it is the case of Mexico City. RTA is most often misdiagnosed. Regarding of this, the present study established reference limits for bicarbonate levels in healthy children without pathologies associated with alterations in the acid-base balance in Mexico City and it´s metropolitan area. METHODS: A total of 267 healthy pediatric patients were included, within normal estimated glomerular filtration rate (eGFR), and without any associated pathology of any alteration in the acid-base balance. RESULTS: Compared to older children, children younger than two years of age showed statistically higher levels of calcemia and cystatin C. On the other hand, this same group showed lower values of creatininemia, pCO2, and HCO3-. Percentile 50 of bicarbonate in children under two years of age were 19.9 mEq/L and 21.9 mEq/L in those over that age. A correlation was identified between HCO3- levels and pCO2 (r = 0.68; p < 0.001). CONCLUSIONS: In the study population, an effect of altitude on blood levels of pCO2 and HCO3- was observed.

Brain Magnetic Resonance Imaging Responses to Nonhypoxic Hypobaric Decompression.

INTRODUCTION: The pathophysiological basis of neurological decompression sickness and the association between cerebral subcortical white matter (WM) change and nonhypoxic hypobaria remain poorly understood. Recent study of altitude decompression sickness risk evaluated acute WM responses to intensive hypobaric exposure using brain magnetic resonance imaging. METHODS: Six healthy men (20 to 50 yr) completed 6 h of hyperoxic hypobaria during three same-day altitude chamber decompressions to pressure altitudes ≥ 22,000 ft (6706 m). Research magnetic resonance imaging sequences, conducted on the days preceding and following decompression, evaluated subcortical WM integrity, cerebral blood flow, neuronal integrity (fractional anisotropy), and neurometabolite concentrations. RESULTS: No subcortical lesions were evident on diffusion weighted imaging and WM fractional anisotropy was unaffected. Mean WM blood flow was upregulated by 20% to over 25 mL · 100 g-1 · min-1. Gray matter flow was unchanged. There were no changes in gray matter or cerebellar neurometabolites. In parietal subcortical WM, levels of γ-aminobutyric acid (GABA) fell from (mean ± SD) 1.68 ± 0.2 to 1.35 ± 0.3 institutional units while glutathione (GSH) fell from 1.71 ± 0.4 to 1.25 ± 0.3 institutional units. Lactate increased postexposure in five subjects. CONCLUSIONS: Postexposure decrements in GABA and GSH imply WM insult with loss of neuroprotection and oxidative stress. An association between decrements in GABA and GSH support a common origin, while GSH decrements also correlate with WM blood flow responses. WM lactate increments are prone to error but suggest dysregulation of subcortical microvascular flow. WM neurometabolite and blood flow indices did not normalize by 24 h postexposure. Connolly D, Davagnanam I, Wylezinska-Arridge M, Mallon D, Wastling S, Lee VM. Brain magnetic resonance imaging responses to nonhypoxic hypobaric decompression. Aerosp Med Hum Perform. 2024; 95(10):733-740.

Menstrual cycle does not impact the hypoxic ventilatory response and acute mountain sickness prediction.

The relationship between the variations in ovarian hormones (i.e., estrogens and progesterone) and the hypoxic ventilatory response (HVR) remains unclear. HVR is a key adaptive mechanism to high altitude and has been proposed as a predictor for acute mountain sickness (AMS). This study aimed to explore the effects of hormonal changes across the menstrual cycle on HVR. Additionally, it assessed the predictive capacity of HVR for AMS and examined whether a particular menstrual phase could enhance its predictive accuracy. Thirteen eumenorrheic women performed a pure nitrogen breathing test near sea level, measuring HVR and cerebral oxygenation in early follicular, late follicular, and mid-luteal phases. Oxidative stress and ovarian hormone levels were also measured. AMS symptoms were evaluated after spending 14 h, including one overnight, at an altitude of 3,375 m. No differences in HVR, ventilation, peripheral oxygen saturation, or cerebral oxygenation were observed between the three menstrual cycle phases. Moreover, these parameters and the oxidative stress markers did not differ between the women with or without AMS (31% vs 69%), regardless of the menstrual cycle phase. In conclusion, ventilatory responses and cerebral oxygenation in normobaric hypoxia were consistent across the menstrual cycle. Furthermore, these parameters did not differentiate women with or without AMS.

Exploring spontaneous brain activity changes in high-altitude smokers: Insights from ALFF/fALFF analysis.

INTRODUCTION: This study aims to explore the impact of smoking on intrinsic brain activity among high-altitude (HA) populations. Smoking is associated with various neural alterations, but it remains unclear whether smokers in HA environments exhibit specific neural characteristics. METHODS: We employed ALFF and fALFF methods across different frequency bands to investigate differences in brain functional activity between high-altitude smokers and non-smokers. 31 smokers and 31 non-smokers from HA regions participated, undergoing resting-state functional magnetic resonance imaging (rs-fMRI) scans. ALFF/fALFF values were compared between the two groups. Correlation analyses explored relationships between brain activity and clinical data. RESULTS: Smokers showed increased ALFF values in the right superior frontal gyrus (R-SFG), right middle frontal gyrus (R-MFG), right anterior cingulate cortex (R-ACC), right inferior frontal gyrus (R-IFG), right superior/medial frontal gyrus (R-MSFG), and left SFG compared to non-smokers in HA. In sub-frequency bands (0.01-0.027 Hz and 0.027-0.073 Hz), smokers showed increased ALFF values in R-SFG, R-MFG, right middle cingulate cortex (R-MCC), R-MSFG, Right precentral gyrus and L-SFG while decreased fALFF values were noted in the right postcentral and precentral gyrus in the 0.01-0.027 Hz band. Negative correlations were found between ALFF values in the R-SFG and smoking years. CONCLUSION: Our study reveals the neural characteristics of smokers in high-altitude environments, highlighting the potential impact of smoking on brain function. These results provide new insights into the neural mechanisms of high-altitude smoking addiction and may inform the development of relevant intervention measures.

Curcumin-mediated enhancement of lung barrier function in rats with high-altitude-associated acute lung injury via inhibition of inflammatory response.

BACKGROUND: Exposure to a hypobaric hypoxic environment at high altitudes can lead to lung injury. In this study, we aimed to determine whether curcumin (Cur) could improve lung barrier function and protect against high-altitude-associated acute lung injury. METHODS: Two hundred healthy rats were randomly divided into standard control, high-altitude control (HC), salidroside (40 mg/kg, positive control), and Cur (200 mg/kg) groups. Each group was further divided into five subgroups. Basic vital signs, lung injury histopathology, routine blood parameters, plasma lactate level, and arterial blood gas indicators were evaluated. Protein and inflammatory factor (tumor necrosis factor α (TNF-α), interleukin [IL]-1ß, IL-6, and IL-10) concentrations in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method and enzyme-linked immunosorbent assay, respectively. Inflammation-related and lung barrier function-related proteins were analyzed using immunoblotting. RESULTS: Cur improved blood routine indicators such as hemoglobin and hematocrit and reduced the BALF protein content and TNF-α, IL-1ß, and IL-6 levels compared with those in the HC group. It increased IL-10 levels and reduced pulmonary capillary congestion, alveolar hemorrhage, and the degree of pulmonary interstitial edema. It increased oxygen partial pressure, oxygen saturation, carbonic acid hydrogen radical, and base excess levels, and the expression of zonula occludens 1, occludin, claudin-4, and reduced carbon dioxide partial pressure, plasma lactic acid, and the expression of phospho-nuclear factor kappa. CONCLUSIONS: Exposure to a high-altitude environment for 48 h resulted in severe lung injury in rats. Cur improved lung barrier function and alleviated acute lung injury in rats at high altitudes.

Microplastic assessment in remote and high mountain lakes of Gilgit Baltistan, Pakistan.

Microplastic (MP) pollution is a critical environmental challenge worldwide, however limited research is reported in remote lakes of Pakistan. This study assessed MPs (>5 mm) prevalence, distribution and risk perspective in water and sediment of eight remote and high-altitude lakes (>1500 m above sea level) of Gilgit Baltistan, Pakistan. The lakes exhibited an average abundance of 152.6 ± 104.6 to 12.1 ± 7 MP/kg of dry sediments and 2 ± 0.9 to 17.1 ± 17.2 MP/L of surface water. MPs <200 µm dominated in both matrices. Surface water predominantly contained polyester and polypropylene, while polypropylene and polyethylene dominated in sediments. The gradient of elevation did not show any pronounced impact on the fiber loading or MP count in both matrices. Backward air mass trajectory revealed that air masses vastly travelled from western-Asia, Arabian sea and Bay of Bengal with an average transmission distance of 2500-3500 km (500 m a.s.l) that can be a potential deposition MP source in the area. Pollution Load Index of the lakes were >1 exhibiting pollution. All other lakes except Batura and Borith manifested a moderate hazard index. Naltar lake along with aforementioned two lakes also manifested high polymer toxicity. Further research should emphasize understanding the mechanisms and biotic interactions in high-mountain ecosystems.

[Progress in multiomics research on high altitude polycythemia].

Chronic mountain sickness (CMS) or Monge syndrome is a disease that is prevalent at altitude above 2 500 meters. High altitude polycythemia (HAPC) is one subtype of CMS. EPAS1 and EGNL1 are the most critical high-altitude adaptation genes in the genome of the Tibetan population. The HIF-PHD-VHL system plays an important role in the pathogenesis of HAPC. The protease encoded by the SENP1 gene regulates hypoxia related transcription factors such as HIF and GATA to affect the expression of EPO or EPOR involved in red blood cell generation. With the development of genetic testing and omics technology, new progress in the fields of metabolomics, proteomics and metabolomics has been made in the pathogenesis of HAPC. The above new research results provide a preliminary basis for bone marrow hematoecology and hematopoietic regulation of HAPC. The diagnostic criteria for CMS have certain limitations, especially in patients with excessive erythrocytosis who should undergo genetic testing recommended for congenital and polycythemia vera. This article provides a review of the latest research on HAPC in various omics techniques, hematopoietic regulation and diagnostic processes which is more conducive to understand the pathogenesis. The clinical diagnosis of excessive erythrocytosis emphasizes the importance of genetic testing.

TNF-α and RPLP0 drive the apoptosis of endothelial cells and increase susceptibility to high-altitude pulmonary edema.

High-altitude pulmonary edema (HAPE) is a fatal threat for sojourners who ascend rapidly without sufficient acclimatization. Acclimatized sojourners and adapted natives are both insensitive to HAPE but have different physiological traits and molecular bases. In this study, based on GSE52209, the gene expression profiles of HAPE patients were compared with those of acclimatized sojourners and adapted natives, with the common and divergent differentially expressed genes (DEGs) and their hub genes identified, respectively. Bioinformatic methodologies for functional enrichment analysis, immune infiltration, diagnostic model construction, competing endogenous RNA (ceRNA) analysis and drug prediction were performed to detect potential biological functions and molecular mechanisms. Next, an array of in vivo experiments in a HAPE rat model and in vitro experiments in HUVECs were conducted to verify the results of the bioinformatic analysis. The enriched pathways of DEGs and immune landscapes for HAPE were significantly different between sojourners and natives, and the common DEGs were enriched mainly in the pathways of development and immunity. Nomograms revealed that the upregulation of TNF-α and downregulation of RPLP0 exhibited high diagnostic efficiency for HAPE in both sojourners and natives, which was further validated in the HAPE rat model. The addition of TNF-α and RPLP0 knockdown activated apoptosis signaling in endothelial cells (ECs) and enhanced endothelial permeability. In conclusion, TNF-α and RPLP0 are shared biomarkers and molecular bases for HAPE susceptibility during the acclimatization/adaptation/maladaptation processes in sojourners and natives, inspiring new ideas for predicting and treating HAPE.

Identification and Validation of STC1 Act as a Biomarker for High-Altitude Diseases and Its Pan-Cancer Analysis.

High-altitude diseases, including acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE), are closely related to an individual's ability to adapt to hypoxic environments. However, specific research in this field is relatively limited, and further biomarker research and clinical trials are needed to clarify the exact role and potential therapeutic applications of key genes in high-altitude diseases. This study focuses on the role of the STC1 gene in high-altitude diseases and explores its expression patterns in different types of cancer. By using gene expression data analysis and functional experiments, we identified STC1 as a key gene affecting the development of altitude sickness. In addition, we also conducted expression and mutation analysis on STC1 in various cancer samples and found significant differences in the expression of this gene in 13 types of malignant tumors, which is associated with the hypoxic state in the tumor microenvironment. In addition, STC1 is significantly associated with patient prognosis and influences tumor immunity by mediating six types of immune cells (CD8+T cells, CD4+T cells, neutrophils, macrophages, monocytes, and B cells) in the tumor microenvironment. The expression and diagnostic value of STC1 were confirmed through GEO datasets and qPCR testing, indicating consistency with the results of bioinformatics analysis. These results indicate that STC1 is not only an important factor in the adaptive response to high-altitude diseases but may also play a role in the adaptation of cancer to low-oxygen environments. Our research provides a new perspective and potential targets for the discovery of biomarkers for high-altitude diseases and cancer treatment.

Influence of shifting thermal regimes on tomato fruit borer, Helicoverpa armigera (Hubner) in the Eastern Himalaya: implications for pest management strategies.

Climate change, particularly temperature fluctuations, profoundly impacts pest populations. This study focuses on the tomato, a crucial commercial crop in the Eastern Himalayan Region of India. The study examined the impact of varying thermal regimes on tomato fruit borers. Field experiments were conducted at three locations, with altitudes ranging from < 500 to > 1500 m. At lower altitudes, fruit borer incidence commenced earlier (5th - 18th March) and peaked higher (1.47 ± 0.34 to 1.73 ± 0.37 larvae/plant), causing more damage (26-29%) as compared to the highest location (~ 9%). The generalized linear mixed model (GLMM) analysis indicated that maximum temperature had significant positive impacts on the H. armigera incidence and fruit damage. Climatic datasets indicate an increase in the temperature of the region during the tomato growing season, thereby increasing the risk of fruit borer impact. As an adaptation option, we evaluated eight different tomato varieties/genotypes and studied biochemical parameters to understand their tolerance. Results showed a strong positive association of fruit borer incidence with total soluble solids whereas negative association with acidity. Cherry tomato (7.62%) and MT-2 (10.04%) had relatively lower fruit damage; MT-3 (50.92 t/ha) and MT-2 (50.57 t/ha) consistently yielded the highest across all locations. Hence, the selection of appropriate genotypes and the development of varieties with suitable characteristics hold the key to fruit borer management. This insight is crucial for developing effective pest management strategies and ensuring sustainable agricultural practices in the region.

High-altitude aquatic ecosystems offer faster aging rate of plastics.

While research on the aging behavior of plastics in aquatic systems is extensive, studies focusing on high-altitude ecosystems, characterized by higher solar radiation and lower temperatures, remain limited. This study investigated the long-term aging behavior of non-biodegradable plastics (non-BPs), namely polyethylene terephthalate (PET) and polypropylene (PP) and biodegradable plastics (BPs), specifically polylactic acid plus polybutylene adipate-co-terephthalate (PLA + PBAT) and starch-based plastic (SBP), in a tributary of the Yarlung Zangbo River on the high-altitude Tibetan Plateau. Over 84 days of field aging, all four types of plastics exhibited initial rapid aging followed by deceleration. This aging process can be divided into two phases: rapid surface oxidation aging and an aging plateau phase. Notably, PP aged at a rate comparable to BPs, contrary to expectations of faster aging for BPs. Compared to low-altitude aquatic ecosystems, plastics in this study showed a faster aging rate. This was primarily due to intense ultraviolet radiation causing severe photoaging. Furthermore, the lower temperatures contributed to the formation of thinner biofilms. These thinner biofilms exhibited a reduced capacity to block light, further exacerbating the photoaging process of plastics. Statistical analysis results indicated that temperature, total nitrogen TN, and total phosphorus TP were likely the main water quality parameters influencing plastic aging. The varying effects of water properties and nutrients underscore the complex interaction of water quality parameters in high-altitude environments. Given the delicate nature of the high-altitude environment, the environmental impact of plastics, especially BPs, warrants careful consideration.

The first high-altitude autotetraploid haplotype-resolved genome assembled (Rhododendron nivale subsp. boreale) provides new insights into mountaintop adaptation.

BACKGROUND: Rhododendron nivale subsp. boreale Philipson et M. N. Philipson is an alpine woody species with ornamental qualities that serve as the predominant species in mountainous scrub habitats found at an altitude of ∼4,200 m. As a high-altitude woody polyploid, this species may serve as a model to understand how plants adapt to alpine environments. Despite its ecological significance, the lack of genomic resources has hindered a comprehensive understanding of its evolutionary and adaptive characteristics in high-altitude mountainous environments. FINDINGS: We sequenced and assembled the genome of R. nivale subsp. boreale, an assembly of the first subgenus Rhododendron and the first high-altitude woody flowering tetraploid, contributing an important genomic resource for alpine woody flora. The assembly included 52 pseudochromosomes (scaffold N50 = 42.93 Mb; BUSCO = 98.8%; QV = 45.51; S-AQI = 98.69), which belonged to 4 haplotypes, harboring 127,810 predicted protein-coding genes. Conjoint k-mer analysis, collinearity assessment, and phylogenetic investigation corroborated autotetraploid identity. Comparative genomic analysis revealed that R. nivale subsp. boreale originated as a neopolyploid of R. nivale and underwent 2 rounds of ancient polyploidy events. Transcriptional expression analysis showed that differences in expression between alleles were common and randomly distributed in the genome. We identified extended gene families and signatures of positive selection that are involved not only in adaptation to the mountaintop ecosystem (response to stress and developmental regulation) but also in autotetraploid reproduction (meiotic stabilization). Additionally, the expression levels of the (group VII ethylene response factor transcription factors) ERF VIIs were significantly higher than the mean global gene expression. We suspect that these changes have enabled the success of this species at high altitudes. CONCLUSIONS: We assembled the first high-altitude autopolyploid genome and achieved chromosome-level assembly within the subgenus Rhododendron. In addition, a high-altitude adaptation strategy of R. nivale subsp. boreale was reasonably speculated. This study provides valuable data for the exploration of alpine mountaintop adaptations and the correlation between extreme environments and species polyploidization.

Rosacea Epidemiological Investigation and Etiology Exploration in the Plateau Area.

BACKGROUND: The epidemiology of 2 neighboring cities of differing altitude in Northwest China is unknown. The present study investigated the prevalence of rosacea in a high-altitude city and a low-altitude city. METHODS: The prevalence study was conducted via clinical examination of male and female participants in the following age groups: 5-17, 18-30, 31-50, and 51-70 years. Rosacea subtype was also determined as erythematotelangiectatic rosacea (ETTR) or papulopustular rosacea (PPR). RESULTS: The rosacea prevalence (RP) in the low-altitude city was 33.8% ± 1.2% (95% CI, ETTR = 1794, PPR = 174, n = 5794). RP in the high-altitude city has a notably higher reading of 47.7% ± 1.4% (95% CI, ETTR = 2090, PPR = 219, n = 4796). In both cities, the ETTR subtype predominated, and there was marked increase in RP among females. RP in low-altitude city females was steady across all age groups, while RP in low-altitude city males showed a declining trend with age. RP in high-altitude city females indicated a slightly increasing trend with age, while RP in males again showed a declining trend with age. Based on the results of this high-altitude city and low-altitude city study, there are an estimated 2.1 million people with rosacea, from 2 cities with a total population of 5.4 million. CONCLUSIONS: Due to the high altitude and accompanying increased UV radiation, cold climate, and reduced oxygen density, the greater northwest region of China is expected to experience high RP rates.

Impact of altitude on the development of low bone mineral density and osteoporosis in individuals aged 50 years and older: protocol for a multicentre prospective cohort study.

INTRODUCTION: Osteoporotic fractures are a leading cause of disability and contribute significantly to medical care costs worldwide. Variations in bone mineral density and the risk of osteoporosis are notably influenced by altitude. This study aims to longitudinally examine individuals with osteoporosis and low bone mass at three different altitudes (low, high and very high) to understand the effects of high-altitude environments on bone density. METHODS AND ANALYSIS: This multicentre, prospective cohort study will involve 893 participants divided into three groups based on altitude: low (500-1500 m), high (2500-4500 m) and very high (4500-5500 m). Participants will undergo comprehensive diagnostic assessments, including demographic data collection, structured questionnaires, medical examinations and clinical laboratory tests. Follow-up visits will occur annually for a minimum of 5 years. The primary outcome will be changes in bone mineral density values. Secondary outcomes will include the incidence of osteoporosis and osteoporotic fractures. Cox proportional hazard models will be used to calculate the risk associated with osteoporotic events and related fractures. ETHICS AND DISSEMINATION: The study has been approved by the Institutional Review Board of the Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region (No: 2024-70). The acquired insights will be disseminated via academic forums, scholarly articles and stakeholder engagement sessions. TRIAL REGISTRATIONNUMBER: ChiCTR2300078872.

[Changes of ferroptosis related pathways in hippocampus of mice exposed to high-altitude hypoxia].

The present study aimed to investigate the occurrence of ferroptosis in mouse hippocampal tissue and changes in related pathways after exposure to high-altitude hypoxia. A low-pressure hypoxia model was established using a high-altitude environment at 4 010 m. HE staining was used to observe morphological changes in mouse hippocampal tissue, immunohistochemical staining was used to observe lipid peroxidation levels in hippocampal tissue, and corresponding kits were used to measure malondialdehyde (MDA), reduced glutathione (GSH), and Fe2+ levels in hippocampal tissue. Western blot was used to detect glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), ferritin heavy chain 1 (FTH1), ferroportin 1 (FPN1), transferrin receptor 1 (TfR1), ferroptosis suppressor protein 1 (FSP1), and acyl-CoA synthase long chain family member 4 (ACSL4). The results showed that, compared with the plain control group, the mice exposed to high-altitude hypoxia for 1, 3, 7, and 14 d exhibited significant pathological damage, disordered arrangement, and obvious nuclear condensation in the dentate gyrus of the hippocampus. Compared with the plain control group, high-altitude hypoxia exposure increased 4-hydroxynonenal (4-HNE) content in the dentate gyrus and hippocampal MDA content, whereas significantly decreased hippocampal GSH content. Compared with the plain control group, the Fe2+ content in the hippocampus of mice exposed to high-altitude hypoxia for 14 d significantly increased. Compared with the plain control group, the protein expression levels of GPX4, FTH1, FPN1, TfR1, and FSP1 in the hippocampus of mice exposed to high-altitude hypoxia were significantly down-regulated (SLC7A11 was significantly down-regulated only in the 7-d high-altitude hypoxia exposure group), while the protein expression level of ACSL4 was only significantly up-regulated in the 14-d high-altitude hypoxia exposure group. These results suggest that exposure to high-altitude hypoxia for 14 d can reduce GSH synthesis in mouse hippocampus, down-regulate GPX4 expression, lead to GSH metabolism disorders, inhibit iron storage and efflux, promote lipid peroxidation reaction, and inhibit CoQ10H2's anti-lipid peroxidation effect, ultimately leading to ferroptosis.

[Analysis of the relationship between epistaxis and homocysteine and climatic factors in ultra-high altitude area].

Objective:To analyze the related influencing factors of epistaxis in extremely high altitude area, and to provide evidence for the prevention and treatment of epistaxis in extremely high altitude area. Methods:From January 2021 to December 2022, 206 outpatients with epistaxis, 54 inpatients with epistaxis and 69 inpatients withoutepistaxis in theDepartment of Otorhinolarygology, Naqu People's Hospital were collected. The previous history, drinking history, smoking history, serum homocysteine（Hcy）, white blood cell count（WBC）, red blood cell count（RBC）, hematocrit（HCT）, hemoglobin（HGB） and mean hemoglobin concentration（MCHC） were compared between inpatients with or without epistaxis. The factors with significant differences were analyzed by binary Logistic regression. The monthly average temperature,air pressure, humidity and 2-minute wind speed were collected from January 2021 to December 2022 in Naqu City to analyze the correlation between epistaxis and climate factors. Results:The number of patients with hypertension in the case group was more than that in the control group, and the difference was significant（P=0.013）. Serum Hcy level in the case group was higher than that in the control group（P<0.001）. RBC, HCT, HGB and MCHC were lower than that in the control group（P=0.001, 0.001, 0.001, 0.039）, and the difference was significant. History of hypertension and Hcy were risk factors for epistaxis. Patients with a history of hypertension were 3.713 times more likely to suffer from epistaxis than those without a history of hypertension（P=0.022）. Each 1 increase in Hcy concentration increased the risk of epistaxis by 13.1%（P=0.001）. Conclusion:Patients with epistaxis in Naqu area had higher serum Hcy level and lower RBC, HCT, HGB and MCHC. History of hypertension and Hcy were risk factors for epistaxis. Patients with a history of hypertension were 3.713 times more likely to suffer from epistaxis than those without a history of hypertension. Every 1 increase in Hcy concentration increased the risk of epistaxis by 13.1%. Active intervention of hypertension and serum Hcy can effectively prevent the incidence of epistaxis.

Prevalence and risk factors of deep venous thrombosis of hospitalizations in plateau: a cross-section analysis.

BACKGROUND: Deep venous thrombosis (DVT) is a serious public health issue that threatens human health and economic development. Presently, differences in the prevalence of DVT among individuals from different nationalities, residents of high-altitude areas, and those consuming any special diet are unknown. Therefore, we aimed to elucidate the prevalence of and the associated risk factors for DVT in hospitalized patients in the plateau areas. METHODS: The subjects were hospitalized patients in three grade III-a hospitals in the Qinghai Province, China, during January-October 2020. The demographic, clinical, and laboratory data were collected at admission, and ultrasonography of the bilateral lower extremities was performed. The hospital stay-duration was recorded at the time of discharge. RESULTS: A total of 3432 patients were enrolled, of which 159 (4.60%) were diagnosed with DVT. The age of > 50 years (OR = 2.434, 95% CI: 1.521-3.894252, P < 0.001), residence altitude of ≥ 3000 m (OR = 2.346, 95% CI: 1.239-4.440, P = 0.009), D-dimer level of ≥ 0.5 mg/L (OR = 2.211, 95% CI: 1.547-3.161, P < 0.001), presence of comorbidities (OR = 1.904, 95% CI: 1.386-2.705, P < 0.001), a history of varicose veins (OR = 1.990, 95% CI: 0.959-4.128, P = 0.045), and current medications (OR = 2.484, 95% CI: 1.778-3.471, P < 0.001) were identified as risk factors for DVT in these plateau areas. CONCLUSION: The prevalence of DVT in the hospitalized patients of the studied plateau areas was 4.60%. We recommend considering individualized risk stratification (age > 50 years, residence altitude ≥ 3000 m, a history of varicose veins, D-dimer level ≥ 0.5 mg/L, current medications, and comorbidities) for patients at the time of admission.

Maternal AMPK pathway activation with uterine artery blood flow and fetal growth maintenance during hypoxia.

High-altitude (HA) hypoxia lowers uterine artery (UtA) blood flow during pregnancy and birth weight. Adenosine monophosphate kinase (AMPK) activation has selective, uteroplacental vasodilator effects that lessen hypoxia-associated birth weight reductions. In this study, we determined the relationship between AMPK-pathway gene expression and metabolites in the maternal circulation during HA pregnancy as well as with the maintenance of UtA blood flow and birth weight at HA. Residents at HA (2,793 m) versus low altitude (LA; 1,640 m) had smaller UtA diameters at weeks 20 and 34, lower UtA blood flow at week 20, and lower birth weight babies. At week 34, women residing at HA versus women residing at LA had decreased expression of upstream and downstream AMPK-pathway genes. Expression of the α1-AMPK catalytic subunit, PRKAA1, correlated positively with UtA diameter and blood flow at weeks 20 (HA) and 34 (LA). Downstream AMPK-pathway gene expression positively correlated with week 20 fetal biometry at both altitudes and with UtA diameter and birth weight at LA. Reduced gene expression of AMPK activators and downstream targets in women residing at HA versus women residing at LA, together with positive correlations between PRKAA1 gene expression, UtA diameter, and blood flow suggest that greater sensitivity to AMPK activation at midgestation at HA may help offset later depressant effects of hypoxia on fetal growth.NEW & NOTEWORTHY Fetal growth restriction (FGR) is increased and uterine artery (UtA) blood flow is lower at high altitudes (HA) but not all HA pregnancies have FGR. Here we show that greater UtA diameter and blood flow at week 20 are positively correlated with higher expression of the gene encoding the α1-catalytic subunit of AMP protein kinase, PRKAA1, suggesting that increased AMPK activation may help to prevent the detrimental effects of chronic hypoxia on fetal growth.

IL-2, IL-17A and TNF-α hold potential as biomarkers for predicting acute mountain sickness prior to ascent.

BACKGROUND: Acute mountain sickness (AMS) is the most prevalent condition resulting from hypobaric hypoxia (HH) at high altitudes. Although evidence suggests the involvement of inflammatory cytokines in AMS development, there is currently a lack of reports on variations in cytokine levels between individuals susceptible to AMS and those resistant to AMS prior to ascending to high altitude. Thus our current study aims to assess the predictive capability for AMS occurrence by evaluating differences in cytokine levels at low altitudes. METHODS: The present study recruited 48 participants, who ascended from low altitude to middle high-altitude (3700 m) and further to extreme high-altitude (5000 m). Based on Lake Louise Score (LLS) at the two high altitudes, participants were categorized into severe AMS-susceptible (sAMS), moderate AMS-susceptible (mAMS), and non-AMS groups. The Bio-Plex MAGPIX System was employed to measure plasma levels of 11 inflammatory cytokines. Cytokines at low altitude and middle high-altitude were analyzed through receiver operating characteristic (ROC) analysis to obtain area under the ROC curve (AUROC), sensitivity, and specificity. RESULTS: Based on LLS at 3700 m, we initially categorized the study subjects into the sAMS group (n = 8) and the Non-AMS group (n = 40). Among individuals in the non-AMS group (n = 40) at the altitude of 3700 m, those who developed AMS at the altitude of 5000 m were assigned to the mAMS group (n = 17), whereas those who did not experience AMS were included into the non-AMS group (n = 23). The concentration of TNF-α at low altitude exhibited robust predictive performance for predicting AMS occurrence at the altitude of 3700 m. Among the non-AMS group at the altitude of 3700 m, we identified that the concentration of IL-2 and IL-17A demonstrated high efficacy in predicting the onset of AMS following ascent to 5000 m. In addition, differentially expressed cytokines including IL-17A, TNF-α and IL-2 at low altitude possessed discriminatory potential among the three groups at 5000 m.. CONCLUSION: We posited that the levels of TNF-α, IL-2, IL-17A in serum of low altitude could be considered as potential biomarkers to predict the occurrence of AMS at high altitude. NEW & NOTEWORTHY: Through the two comparisons at different two altitudes (baseline level and 3700 m), we provided a model to progressively screen individuals who are susceptible and resistant to different high altitudes (3700 m and 5000 m). TNF-α could firstly screen out the AMS susceptible individuals at the altitude of 3700 m. And through its combination with IL-2 and IL-17A, we could further screen out AMS susceptible individuals at the altitude of 5000 m.