{"title":"Adaptation to Living at High Altitude in Patients with COPD. Comparative Study of Exercise Capacity and Ventilatory Variables between Patients Residing at High and Low Altitudes in the Andes.","authors":"Mauricio González-García, Luis Ernesto Téllez","doi":"10.1089/ham.2023.0111","DOIUrl":"10.1089/ham.2023.0111","url":null,"abstract":"<p><p>González-García, Mauricio and Luis Ernesto Téllez. Adaptation to living at high altitude in patients with COPD. Comparative study of exercise capacity and ventilatory variables between patients residing at high and low altitudes in the Andes. <i>High Alt Med Biol</i>. 25:266-273, 2024. <b><i>Introduction:</i></b> Although some variables related to oxygen transport and utilization such as ventilation, pulmonary vascular responses to hypoxia, heart rate (HR), cardiac output, hemoglobin (Hb), and oxygen saturation (SpO<sub>2</sub>) are used to compare adaptation to altitude between populations, peak oxygen consumption (VO<sub>2</sub>) constitutes an integrative measure of total oxygen transport that may reflect successful adaptation to altitude. We designed this study to make a direct comparison of VO<sub>2</sub> in a cardiopulmonary exercise test (CPET) between chronic obstructive pulmonary disease (COPD) patients residing at high altitude (Bogotá, Colombia: 2,640 m) (COPD-HA) and those living at low altitude (Bucaramanga, Colombia: 959 m) (COPD-LA). <b><i>Methods:</i></b> All patients performed a CPET with measurements of VO<sub>2</sub>, minute ventilation (V<sub>E</sub>), HR, oxygen pulse (VO<sub>2</sub>/HR), ventilatory equivalents (V<sub>E</sub>/VCO<sub>2</sub>), and SpO<sub>2</sub>. Unpaired T-test or Mann-Whitney <i>U</i> test were used for comparisons between COPD-HA and COPD-LA. <b><i>Results:</i></b> We included 71 patients with COPD, 53 COPD-HA, and 18 COPD-LA. There were no differences between groups in age, sex, or forced expiratory volume in 1 second. The means ± SD of Hb, g/dl was slightly higher in COPD-HA (15.9 ± 1.9 vs. 14.7 ± 1.8, <i>p</i> = 0.048), without differences in VO<sub>2</sub>, % pred (71.6 ± 17.9 vs. 69.0 ± 17.0, <i>p</i> = 0.584), VO<sub>2</sub>/HR, % pred (92.1 ± 22.0 vs. 89.7 ± 19.8, <i>p</i> = 0.733) or V<sub>E</sub>/MVV, % (75.5 ± 14.1 vs. 76.5 ± 14.3, <i>p</i> = 0.790) at peak exercise between groups. Median (IQR) of V<sub>E</sub>/VCO<sub>2</sub> nadir [38.0 (37.0-42.0) vs. 32.5 (31.0-39.0), <i>p</i> = 0.005] was significantly higher, and SpO<sub>2</sub>, % at rest [88.0 (86.0-91.0) vs. 95.0 (94.0-96.0), <i>p</i> < 0.001] and at peak exercise [84.0 (77.0-90.0) vs. 93.0 (92.0-95.0), <i>p</i> < 0.001] were significantly lower in COPD-HA. <b><i>Conclusions:</i></b> Despite higher desaturation at rest and during exercise in COPD-HA, there were no differences in VO<sub>2</sub> peak between COPD-HA and COPD-LA, suggesting a potential altitude adaptation in those patients chronically exposed to hypoxia.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"266-273"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140206766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Esteban Ortiz-Prado, Juan Sebastian Izquierdo-Condoy, María G Dávila-Rosero, Jorge Vásconez-González, Ana M Diaz, Carla E Moyano, Vanessa Arcos-Valle, Ginés Viscor, Joshua H West
{"title":"Reduced Violence-Related Burden and Mortality at Higher Altitudes: Examining the Association between High Altitude Living and Homicide Rates in Ecuador.","authors":"Esteban Ortiz-Prado, Juan Sebastian Izquierdo-Condoy, María G Dávila-Rosero, Jorge Vásconez-González, Ana M Diaz, Carla E Moyano, Vanessa Arcos-Valle, Ginés Viscor, Joshua H West","doi":"10.1089/ham.2024.0005","DOIUrl":"10.1089/ham.2024.0005","url":null,"abstract":"<p><p>Ortiz-Prado, Esteban, Juan Sebastian Izquierdo-Condoy, María G. Dávila-Rosero, Jorge Vásconez-González, Ana M. Diaz, Carla E. Moyano, Vanessa Arcos-Valle, Ginés Viscor, and Joshua H. West. Reduced violence-related burden and mortality at higher altitudes: examining the association between high altitude living and homicide rates in Ecuador. <i>High Alt Med Biol.</i> 25:295-307, 2024. <b><i>Background:</i></b> Homicides are a major public health concern and a leading cause of preventable deaths worldwide. The relationship between altitude and homicides remains unclear, and evidence of the possible effects of living at high altitudes on homicide rates is limited. This research aimed to investigate the mortality rates resulting from various types of aggression that culminated in homicides in Ecuador and to explore potential differences associated with altitude. <b><i>Methods:</i></b> An ecological analysis of homicide rates in Ecuador was conducted from 2001 to 2022. Homicide cases and the population at risk were categorized based on their place of residence according to two altitude classifications: a binary classification of low (<2,500 m) and high altitude (>2,500 m), and a detailed classification according to criteria by the International Society for Mountain Medicine, which includes low (<1,500 m), moderate (1,500-2,500 m), high (2,500-3,500 m), and very high altitude (3,500-5,500 m) categories. Both crude and directly age-sex standardized mortality rates were calculated for each altitude category. <b><i>Results:</i></b> We analyzed a total of 40,708 deaths attributed to aggressions (ICD-10 codes X85-Y09). The total homicide rate for men was 21.29 per 100,000 (95% confidence interval [CI]: 9.55-32.37), whereas for women, it was 2.46 per 100,000 (95% CI: 1.44-3.27). Average rates across the 22 analyzed years were higher at low altitudes (men: 13.2/100,000 and women: 1.33/100,000) as compared with high altitudes (men: 5.79/100,000 and women: 1.05/100,000). Notably, the male-to-female rate difference was more pronounced at low altitudes (898%) than at high altitudes (451%). <b><i>Conclusions:</i></b> Our study revealed a higher prevalence of homicides in certain provinces and significant disparities in mortality rates between men and women. Although we cannot establish a direct relationship between altitude and homicide rates, further research is needed to explore potential confounding factors and a better understanding of the underlying causes for these variations.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"295-307"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141283558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"8th ISMM & WMS World Congress on Mountain & Wilderness Medicine Snowbird, Utah.","authors":"","doi":"10.1089/ham.2024.18977.abstract","DOIUrl":"https://doi.org/10.1089/ham.2024.18977.abstract","url":null,"abstract":"","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":"25 4","pages":"352-355"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142768544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alba Camacho-Cardenosa, Marta Camacho-Cardenosa, Johannes Burtscher, Pedro R Olivares, Guillermo Olcina, Javier Brazo-Sayavera
{"title":"Intermittent Hypoxic Training Increases and Prolongs Exercise Benefits in Adult Untrained Women.","authors":"Alba Camacho-Cardenosa, Marta Camacho-Cardenosa, Johannes Burtscher, Pedro R Olivares, Guillermo Olcina, Javier Brazo-Sayavera","doi":"10.1089/ham.2023.0127","DOIUrl":"10.1089/ham.2023.0127","url":null,"abstract":"<p><p>Camacho-Cardenosa, Alba, Marta Camacho-Cardenosa, Johannes Burtscher, Pedro R. Olivares, Guillermo Olcina, and Javier Brazo-Sayavera. Intermittent hypoxic training increases and prolongs exercise benefits in adult untrained women. <i>High Alt Med Biol.</i> 25:274-284, 2024. <b><i>Background:</i></b> Exercising in hypoxia may confer multiple health benefits, but the evidence for specific benefits is scarce. <b><i>Methods:</i></b> We investigated effects of intermittent hypoxic training (IHT) on the quality of life and functional fitness of healthy adult women, in a double-blind, randomized, placebo-controlled study. Subjects performed 36 sessions of IHT (experimental group, <i>n</i> = 41; fraction of inspired oxygen [FIO<sub>2</sub>]: 0.17) or the same training in normoxia (control group, <i>n</i> = 41; FIO<sub>2</sub>: 0.21). Health-related quality of life, fitness tests, and hemoglobin levels were assessed before (T1), directly after (T2), and 4 weeks after (T3) cessation. <b><i>Results:</i></b> At T2, upper body strength (+14.96%), lower body strength (+26.20%), and agility (-4.94%) increased significantly in the experimental group compared to baseline but not in controls. The experimental group improved lower body strength more (by 9.85%) than controls at T2 and performed significantly better in walking (by 2.92%) and upper body strength testing (by 16.03%), and agility (by 4.54%) at T3. Perceived general health and vitality was significantly greater in the experimental group at T2 and T3 compared with T1. None of these improvements were observed in the control group. <b><i>Conclusions:</i></b> IHT is a promising strategy to induce long-lasting fitness benefits in healthy adult women.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"274-284"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140876315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>Letter to the Editor</i>: Some Considerations on the Article \"High-Altitude Renal Syndrome\".","authors":"Cristhian A Vizcarra-Vizcarra","doi":"10.1089/ham.2024.0043","DOIUrl":"10.1089/ham.2024.0043","url":null,"abstract":"","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"350-351"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140922132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Preexisting Hyperuricemia Before High-Altitude Ascent is Associated with a Slower Recovery of Estimated Glomerular Filtration Rate Following Descent.","authors":"Linggong Zhao, Yujie Huang, Xiaoling Tan","doi":"10.1089/ham.2024.0006","DOIUrl":"10.1089/ham.2024.0006","url":null,"abstract":"<p><p>Zhao, Linggong, Yujie Huang, and Xiaoling Tan. Preexisting hyperuricemia before high-altitude ascent is associated with a slower recovery of estimated glomerular filtration rate following descent. <i>High Alt Med Biol.</i> 25:308-318, 2024. <b><i>Objectives:</i></b> Hypoxia at high altitudes results in elevated uric acid (UA) and reduced estimated glomerular filtration rate (eGFR). However, the impact of a prolonged high-altitude sojourn on UA levels and renal function in patients with preexisting hyperuricemia warrants further exploration. The study was to investigate the eGFR and related factors in patients with preexisting hyperuricemia following exposure to high altitude. <b><i>Methods:</i></b> The study included 345 participants, who worked at a high altitude for 1 year. Anthropometric and laboratory indices were collected before ascent (i.e., baseline), as well as 20 and 80 days after descent. The participants were categorized into individuals with hyperuricemia (HUA) or normal uric acid (NUA) group based on the presence or absence of hyperuricemia at baseline. <b><i>Results:</i></b> No difference in baseline eGFR was observed between the two groups before ascend or on day 20 after descent (<i>p</i> > 0.05). However, on day 80, eGFR of the HUA group was lower compared with the NUA group (<i>p</i> < 0.05). Correlations existed between post-descent eGFR levels and variables, including sampling time, UA levels, total and direct bilirubin, and baseline grouping. <b><i>Conclusions:</i></b> After high-altitude exposure, the recovery of eGFR was delayed in participants with preexisting hyperuricemia. Preexisting hyperuricemia and high-altitude hypoxia jointly contribute to renal impairment.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"308-318"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141534276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brian Strickland, Elan Small, Mary Ryan, Ryan Paterson
{"title":"Effectiveness of Continuous Positive Airway Pressure in Alleviating Hypoxemia and Improving Exertional Capacity at Altitude.","authors":"Brian Strickland, Elan Small, Mary Ryan, Ryan Paterson","doi":"10.1089/ham.2024.0007","DOIUrl":"10.1089/ham.2024.0007","url":null,"abstract":"<p><p>Strickland, Brian, Elan Small, Mary Ryan, and Ryan Paterson. Effectiveness of continuous positive airway pressure in alleviating hypoxemia and improving exertional capacity at altitude. <i>High Alt Med Biol.</i> 25:319-325, 2024. <b><i>Introduction:</i></b> Decreased oxygen saturation and exercise tolerance are commonly experienced at high altitude. Continuous positive airway pressure (CPAP) devices have become increasingly portable and battery powered, providing a potentially unique new therapeutic modality for treatment of altitude-related illnesses. This study evaluated the potential use of CPAP devices to improve and maintain oxygen saturation at altitude, both at rest and with exertion, to evaluate the feasibility of using this device at altitude. <b><i>Methods:</i></b> Subjects were taken to Mount Blue Sky and monitored while they hiked to the summit (4,350 m), maintaining a consistent level of exertion. Subjects hiked for 0.7 km both with and without CPAP set to 10 cmH<sub>2</sub>O pressure. Continuous vital signs were collected during the hike and recovery period. <b><i>Results:</i></b> All subjects completed the hike wearing CPAP devices at a vigorous level of exertion. Mean oxygen saturation of the CPAP group (M = 83.8%, SD = 3.72) was significantly higher than that of the control group during exertion (M = 78.7%, SD = 2.97); <i>p</i> = 0.005. Recovery after exertion was quicker in the CPAP group than the control group. Three subjects experienced claustrophobia requiring a brief pause, but were able to complete their exercise trial without removing equipment or experiencing adverse events. When pauses from claustrophobia were excluded, there was no difference in completion time between the groups (<i>p</i> = 0.06). <b><i>Conclusion:</i></b> CPAP reliably improved oxygen saturation at rest and during vigorous exertion at high altitude. Its ability to correct hypoxemia, even with physical exertion, may prove useful after further study as a portable self-carried device to prevent and treat altitude-related illness, or to improve safety in high-altitude rescues.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"319-325"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141563296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mismanagement of Patients with High Altitude Illness Evacuated from the Mount Everest Region in Nepal.","authors":"Samriddha Raj Pant, Suraj Shrestha, Suman Acharya, Ghan Bahadur Thapa, Buddha Basnyat","doi":"10.1089/ham.2024.0034","DOIUrl":"10.1089/ham.2024.0034","url":null,"abstract":"","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"348-349"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141199627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yaqi Wan, Ri-Li Ge, Yaxin Cao, Lan Luo, Weizhong Ji
{"title":"Chronic Hypobaric Hypoxia Stimulates Differential Expression of Cognitive Proteins in Hippocampal Tissue.","authors":"Yaqi Wan, Ri-Li Ge, Yaxin Cao, Lan Luo, Weizhong Ji","doi":"10.1089/ham.2024.0105","DOIUrl":"https://doi.org/10.1089/ham.2024.0105","url":null,"abstract":"<p><p><b><i>Objective:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> 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.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142727465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Supplemental Oxygen on the Annie Smith Peck Expedition of 1903 to 6,367 m (20,892 ft) Mount Sorata (Illampu).","authors":"Harvey V Lankford, Hannah Kimberley","doi":"10.1089/ham.2024.0098","DOIUrl":"https://doi.org/10.1089/ham.2024.0098","url":null,"abstract":"<p><p>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). <i>High Alt Med Biol.</i> 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.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142727885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}