High altitude medicine & biology最新文献

Objective: We aimed to determine changes in cognitive function resulting from chronic hypobaric hypoxia through proteomic analysis of hippocampal tissue. We screened cognition-related proteins to provide ideas and directions that could help prevent and treat hypoxia-associated cognitive impairment. Methods: We analyzed hippocampal tissues from mice exposed to high altitudes and control mice using 4 D label-free quantitative proteomics. The data were analyzed by protein quantitative analysis, functional annotation, differential protein screening, clustering analyses, and functional classification and enrichment. Differential protein expression was investigated using targeted quantitative omics based on parallel response monitoring. Results: We identified and quantified 20 target proteins in 12 samples, of which 18 were significant validated proteins that were or might be related to cognitive functions. Signaling pathways that were significantly enriched in differentially expressed proteins were pyrimidine metabolism, 5'-Adenosine Triphosphate-activated protein kinase signaling, phospholipase D signaling, purine metabolism, inflammatory mediator regulation of transient receptor potential channels, hedgehog signaling pathways, dilated cardiomyopathy, platelet activation, insulin resistance, mRNA surveillance pathways, drug metabolism-other enzymes, and drug metabolism-cytochrome P450. Conclusion: Chronic hypoxia alters protein expression in murine hippocampal tissues. Eighteen differentially expressed cognition-related proteins might be related to cognitive impairment in mice exposed to chronic high-altitude hypoxia.

Lankford, Harvey V, Hannah Kimberley. Supplemental Oxygen on the Annie Smith Peck Expedition of 1903 to 6,367 m (20,892 ft) Mount Sorata (Illampu). High Alt Med Biol. 00:00-00, 2024. The 1903 expedition to 6,367 m (20,892 ft) Mount Sorata (Illampu) in Bolivia that was conceived, organized, and led by American mountaineer Annie Smith Peck appears to have been the first to take a supplemental oxygen apparatus to a great mountain. The expedition did not have heavy cylinders of compressed oxygen or closed-circuit rebreathers with chemically generated oxygen but took an apparatus to produce oxygen on the mountain apparently by a 19th century heated chlorate chemical method. Oxygen was to be manufactured in camp, stored in rubber bags, and used with an open-circuit breathing set while climbing. The equipment was taken, but once in Bolivia, a late change in plans resulted in a summit attempt on 6,427 m (21,086 ft) Ancohuma rather than Illampu on the twin-peaked Sorata massif. The summit attempt ended prematurely at 4,700 m (15,350 ft), and the oxygen system was not used. The present paper reviews some of the supplemental oxygen options that were available in 1903 and examines the Sorata expedition, a little-known part of the early history of mountaineering oxygen use.

Su, Ping, Masako Taniike, Yuko Ohno, and Ikuko Mohri. The effects of high altitude on children's sleep: A community-based study on preschoolers in the Tibetan Plateau. High Alt Med Biol. 00:00-00, 2024. Objective/Background: It has been reported that high altitude affects breathing during sleep in children. To evaluate the symptoms suspected sleep-disordered breathing (SDB) and sleep quality of preschool children living in high altitude of 2,261-3,800 m above sea level (masl) in the Tibetan Plateau, we conducted the community-based survey using a questionnaire. Patients/Methods: Sleep problems were assessed in 3,113 children aged 3-6 years in Qinghai province using the Chinese version of the Japanese Sleep Questionnaire for Preschoolers (JSQ-P-C), focusing on obstructive sleep apnea (OSA) and OSA-related symptoms. The effect of altitude on these scores was analyzed. Results: The subscale scores of OSA, morning symptoms, and daytime excessive sleepiness in the JSQ-P-C were higher in children living in areas above 3,000 masl than in those living below 3,000 masl and in Japanese children. Altitude, but not family income or maternal education level, significantly affected the scores of OSA, morning symptoms, and daytime excessive sleepiness. Conclusions: Living at altitudes higher than 3,000 masl may adversely affect children's sleep quality.

Joyce, Kelsey E., Catherine A. Campbell, Arthur R. Bradwell, Samuel J.E. Lucas, Christopher T. Lewis, Rebekah A.I. Lucas, and Mark Edsell. The environmental impact of a high-altitude medical research expedition. High Alt Med Biol. 00:00-00, 2024. Introduction: Scientists must begin examining the environmental cost(s) of their research. The purpose of this study was to evaluate a component of the environmental impact of a high-altitude medical research expedition by totaling the carbon dioxide (CO₂) emissions calculated from as many direct and indirect sources as possible. Methods: Eighteen individuals flew from London to Bagdogra (via Delhi), and then drove onward to Lachung (via Gangtok) where they began their ascent on foot to 4,800 m (Kanchenjunga National Park, Sikkim). Several research experiments were conducted throughout the expedition, which required use of a laboratory centrifuge, solid CO₂ (specimen storage), rechargeable laptop computers and battery-powered oximeters. International Civil Aviation Organization calculators estimated aviation CO₂ production. Land emissions were calculated for Mahindra vehicles. Solid waste was weighed and CO₂ emissions estimated for its incineration. Results: Total CO₂ emissions equated to ∼16.7 tonnes from the following sources: air and land transportation of expedition team (87.3%); sublimation and transportation of solid CO₂ (7.7%), waste incineration (0.58%), generator transportation and gasoline (12 l) combustion (0.48%), and battery transportation (3.3%). Conclusions: Air travel contributed the most to the overall environmental cost of the research expedition. Further investigation is required to contextualize these findings in relation to lab-based alternative(s).

Yufei Wang, Qiong Meng, Jin Zhang, Bing Guo, Nanyan Li, Qian Deng, Julinling Hu, Deji Quzong, Han Guan, Danzhen Wangjiu, Hui Yu, Zhifeng Li, and Junmin Zhou. Altitude and metabolic dysfunction-associated fatty liver disease (MAFLD) in China: a population-based study. High Alt Med Biol. 00:00-00, 2024. Objectives: The epidemiological evidence for the relationship between altitude and metabolic dysfunction-associated fatty liver disease (MAFLD) is scarce. This study aims to examine the altitude-MAFLD relationship and explore the potential mediators explaining the relationship. Methods: Data were derived from the China Multi-Ethnic Cohort. The participants' altitude information was extracted from their residential addresses. MAFLD was diagnosed based on radiographically confirmed hepatic steatosis and any one of the following three items: overweight/obese status, diabetes mellitus, or metabolic dysregulation. We performed multivariable logistic regression and mediation analyses to assess the altitude-MAFLD associations and potential mediators, respectively. In the mediation analysis, mediation proportion is an estimate of the extent to which the total effect (altitude-MAFLD association) is accounted for by the pathway through the mediators. Results: In total, 87,679 participants (female: 60.7%, mean age: 51.36 years) were included. The odds ratio of MAFLD was 1.61 (95% confidence interval [CI]: 1.52-1.71) between high and low altitudes, 1.52 (95% CI: 1.43-1.62) between high and middle altitudes, and 1.06 (95% CI: 1.01-1.10) between middle and low altitudes. Of the total estimated effect between high and low altitude, physical activity and vegetable intake accounted for 15.7% (95% CI: 12.8-19.1) and 3.8% (95% CI: 1.2-6.6), respectively. Of the total estimated effect between high and middle altitude, physical activity and vegetable intake accounted for 31.4% (95% CI: 26.2-34.8) and 2.3% (95% CI: 0.6-3.8), respectively. Of the total estimated effect between middle and low altitude, vegetable intake accounted for 11.8% (95% CI: 3.2-61.5). Conclusion: Higher altitude was associated with increased odds of MAFLD, and physical activity and vegetable intake mediated such association. Multifaceted efforts should be taken in public health to promote healthy lifestyles among higher altitude residents.

Poirier, Anne, Amélie Basso, Sarah Bonnet-Ducrot, Ellen Katranji, Sophia Cherif-Alami, Sophie Chateigner-Coelsch, Manon Navarre, Cécile Ricard, and Corentin Tanné. Clinical Effect of Descent in Infants with Bronchiolitis Diagnosed at Altitude: A Prospective Multicenter Study. High Alt Med Biol. 00:00-00, 2024. Objective: This study aims to assess the clinical impact of descending to a lower altitude in infants with bronchiolitis diagnosed at an altitude above 1,000 m. Methods: We performed a prospective, observational, multicenter study during two consecutive winters (2022-2023 and 2023-2024). The diagnosis was made by local general practitioners (GPs) who then sent the patients who were younger than 1 year and had a Wang respiratory score (WRS) ≥4 to any of the five emergency departments (EDs) located at lower altitudes. The WRS, peripheral oxygen saturation (SpO₂), and respiratory rate (RR) recorded by the GPs and at the EDs were compared. Results: We included 74 infants (59% females, median age 5.4 [3.6-8.0] months). Compared with the median values recorded by the GPs at altitudes above 1,000 m, the median values at the lower-altitude EDs were significantly better for the WRS (5.0 vs. 6.0, p = 0.002), RR (50/min vs. 60/min, p = 0.001), and SpO₂ (97.0% vs. 91.5%, p < 0.001). Conclusion: Descending to a lower altitude significantly improved respiratory function in infants younger than 1 year with bronchiolitis diagnosed at altitudes above 1,000 m.

Gstir, Claudia, Timo Schurr, Roxana Ehlers, Johannes Burtscher, Barbara Sperner-Unterweger, and Katharina Hüfner. Is it possible for individuals with pre-existing mental disorders to perform mountain sports at high altitude-First evidence from a pilot cross-sectional questionnaire study. High Alt Med Biol. 00:00-00, 2024. Introduction: Mountain sports at high altitude (HA) are gaining increasing popularity, but little is known about the effect of such activities on mental health, despite a great prevalence of mental disorders. Methods: Data were collected using an online self-report questionnaire assessing mental and somatic disorders in individuals performing mountain sports at HA (>2,500 m above sea level [ASL]) as well as their symptom change. Nonparametric tests were used for analyses. Results: 251 individuals without pre-existing disorders (noD), 34 with somatic disorders (somaD), and 38 with mental disorders (mentalD; mainly depressive, eating, and anxiety disorders) participated in this study. Overall, 44.7% of the mentalD group compared with 14.7% of somaD experienced ameliorated symptoms during mountain sports at HA, while 2.6% and 8.8%, respectively, reported a worsening (χ²[2] =8.13, p = 0.017). People in the mentalD compared with somaD group significantly less frequently inform tour partners (41.9% vs. 90.9%; χ²[2]=16.69, p < 0.001) about their condition or consult their physician (2.6% vs. 26.5%; χ²[1]=8.53, p = 0.003) regarding their plans to perform mountain sports at HA. 14.5% of all participants reported mental symptoms at 2,500-3,500 m ASL, 23.5% between >3,500-5,500 m ASL and 31.8% >5,500 m ASL. Conclusion: Individuals with mental disorders often report improved mental health during mountain sports at HA, possibly due to a combination of physical activity, the alpine natural environment, and/or moderate hypoxia. The fact that tour partners and physicians are rarely informed shows the need to reduce the stigma of mental disorders in the mountain sports community. The study was prospectively registered with the German Clinical Trials Registry (DRKS00024949).

There is interest among technical, expedition, commercial, and military divers in expanding diving operations to high altitude. However, altitude diving presents unique challenges including acclimatization, increased decompression sickness (DCS) risk, and logistical and equipment considerations. Divers must plan altitude acclimatization strategies conservatively to reduce risk of acute mountain sickness and dehydration before diving. Several methods of augmenting sea level diving tables to be used at altitude have been theorized and tested both in simulated dives and high-altitude expeditions. With proper acclimatization, augmentation of standard diving tables, equipment, and safety planning, diving at high altitude may be performed in many contexts safely while minimizing risk of DCS or injury.