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Chen Y, Zhang X, Ye Q, Zhang X, Cao N, Li SY, Yu J, Zhao ST, Zhang J, Xu XM, Shi YK, Yang LX. Machine learning-based prediction model for myocardial ischemia under high altitude exposure: a cohort study. Sci Rep 2024; 14:686. [PMID: 38182722 PMCID: PMC10770400 DOI: 10.1038/s41598-024-51202-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024] Open
Abstract
High altitude exposure increases the risk of myocardial ischemia (MI) and subsequent cardiovascular death. Machine learning techniques have been used to develop cardiovascular disease prediction models, but no reports exist for high altitude induced myocardial ischemia. Our objective was to establish a machine learning-based MI prediction model and identify key risk factors. Using a prospective cohort study, a predictive model was developed and validated for high-altitude MI. We consolidated the health examination and self-reported electronic questionnaire data (collected between January and June 2022 in 920th Joint Logistic Support Force Hospital of china) of soldiers undergoing high-altitude training, along with the health examination and second self-reported electronic questionnaire data (collected between December 2022 and January 2023) subsequent to their completion on the plateau, into a unified dataset. Participants were subsequently allocated to either the training or test dataset in a 3:1 ratio using random assignment. A predictive model based on clinical features, physical examination, and laboratory results was designed using the training dataset, and the model's performance was evaluated using the area under the receiver operating characteristic curve score (AUC) in the test dataset. Using the training dataset (n = 2141), we developed a myocardial ischemia prediction model with high accuracy (AUC = 0.86) when validated on the test dataset (n = 714). The model was based on five laboratory results: Eosinophils percentage (Eos.Per), Globulin (G), Ca, Glucose (GLU), and Aspartate aminotransferase (AST). Our concise and accurate high-altitude myocardial ischemia incidence prediction model, based on five laboratory results, may be used to identify risks in advance and help individuals and groups prepare before entering high-altitude areas. Further external validation, including female and different age groups, is necessary.
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Affiliation(s)
- Yu Chen
- Department of Cardiology, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Xin Zhang
- Department of Pulmonary and Critical Care Medicine, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Qing Ye
- Department of Radiation Oncology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xin Zhang
- Department of Radiology, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Ning Cao
- Department of Neurosurgery, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Shao-Ying Li
- Department of Pulmonary and Critical Care Medicine, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Jie Yu
- Department of Thoracocardiac Surgery, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Sheng-Tao Zhao
- Department of Pulmonary and Critical Care Medicine, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Juan Zhang
- Department of Pulmonary and Critical Care Medicine, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China
| | - Xin-Ming Xu
- Department of Quality Control, 920th Hospital of Joint Logistics Support Force, PLA, No. 212 Daguan Rd, Kunming, 650032, Yunnan, China.
| | - Yan-Kun Shi
- Department of Cardiology, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China.
| | - Li-Xia Yang
- Department of Cardiology, 920th Hospital of Joint Logistics Support Force, PLA, Kunming, China.
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Mouliou DS. C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians. Diseases 2023; 11:132. [PMID: 37873776 PMCID: PMC10594506 DOI: 10.3390/diseases11040132] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/25/2023] Open
Abstract
The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.
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Özbek M, Toy HI, Takan I, Asfa S, Arshinchi Bonab R, Karakülah G, Kontou PI, Geronikolou SA, Pavlopoulou A. A Counterintuitive Neutrophil-Mediated Pattern in COVID-19 Patients Revealed through Transcriptomics Analysis. Viruses 2022; 15:104. [PMID: 36680144 PMCID: PMC9866184 DOI: 10.3390/v15010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/25/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023] Open
Abstract
The COVID-19 pandemic has persisted for almost three years. However, the mechanisms linked to the SARS-CoV-2 effect on tissues and disease severity have not been fully elucidated. Since the onset of the pandemic, a plethora of high-throughput data related to the host transcriptional response to SARS-CoV-2 infections has been generated. To this end, the aim of this study was to assess the effect of SARS-CoV-2 infections on circulating and organ tissue immune responses. We profited from the publicly accessible gene expression data of the blood and soft tissues by employing an integrated computational methodology, including bioinformatics, machine learning, and natural language processing in the relevant transcriptomics data. COVID-19 pathophysiology and severity have mainly been associated with macrophage-elicited responses and a characteristic "cytokine storm". Our counterintuitive findings suggested that the COVID-19 pathogenesis could also be mediated through neutrophil abundance and an exacerbated suppression of the immune system, leading eventually to uncontrolled viral dissemination and host cytotoxicity. The findings of this study elucidated new physiological functions of neutrophils, as well as tentative pathways to be explored in asymptomatic-, ethnicity- and locality-, or staging-associated studies.
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Affiliation(s)
- Melih Özbek
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | - Halil Ibrahim Toy
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | - Işil Takan
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | - Seyedehsadaf Asfa
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | - Reza Arshinchi Bonab
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | - Gökhan Karakülah
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
| | | | - Styliani A. Geronikolou
- Clinical, Translational and Experimental Surgery Research Centre, Biomedical Research Foundation Academy of Athens, 11527 Athens, Greece
- University Research Institute of Maternal and Child Health and Precision Medicine, UNESCO on Adolescent Health Care, National and Kapodistrian University of Athens, Aghia Sophia Children’s Hospital, 11527 Athens, Greece
| | - Athanasia Pavlopoulou
- Izmir Biomedicine and Genome Center, Balcova, Izmir 35340, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, Balcova, Izmir 35220, Turkey
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Del Valle-Mendoza J, Tarazona-Castro Y, Merino-Luna A, Carrillo-Ng H, Kym S, Aguilar-Luis MA, Del Valle LJ, Aquino-Ortega R, Martins-Luna J, Peña-Tuesta I, Silva-Caso W. Comparison of cytokines levels among COVID-19 patients living at sea level and high altitude. BMC Infect Dis 2022; 22:96. [PMID: 35090394 PMCID: PMC8795933 DOI: 10.1186/s12879-022-07079-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 01/17/2022] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND At the end of 2019, a novel coronavirus denominated SARS-CoV-2 rapidly spread through the world causing the pandemic coronavirus disease known as COVID-19. The difference in the inflammatory response against SARS-CoV-2 infection among people living at different altitudes is a variable not yet studied. METHODS A descriptive cross-sectional study was performed in two Peruvian cities at different altitudes for comparison: Lima and Huaraz. Five important proinflammatory cytokines were measured including: IL-6, IL-2, IL-10, IFN-γ and TNF-α using ELISA assays. RESULTS A total of 35 COVID-19 patients and 10 healthy subjects were recruited from each study site. The mean levels of IL-6 (p < 0.03) and TNF-α (p < 0.01) were significantly different among the study groups. In the case of IL-6, patients from Lima had a mean level of 16.2 pg/ml (healthy) and 48.3 pg/ml (COVID-19), meanwhile, patients from Huaraz had levels of 67.3 pg/ml (healthy) and 97.9 pg/ml (COVID-19). Regarding TNF-α, patients from Lima had a mean level of 25.9 pg/ml (healthy) and 61.6 pg/ml (COVID-19), meanwhile, patients from Huaraz had levels of 89.0 pg/ml (healthy) and 120.6 pg/ml (COVID-19). The levels of IL-2, IL-10 and IFN-γ were not significantly different in the study groups. CONCLUSION Patients with COVID-19 residing at high-altitude tend to have higher levels of inflammatory cytokines compared to patients living at sea level, particularly IL-6 and TNF-α. A better understanding of the inflammatory response in different populations can contribute to the implementation of therapeutic and preventive approaches. Further studies evaluating more patients, a greater variety of cytokines and their clinical impact are required.
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Affiliation(s)
- Juana Del Valle-Mendoza
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru.
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru.
- Universidad Peruana de Ciencias Aplicadas, Av. San Marcos Cuadra 2, Chorrillos, Lima, Peru.
| | - Yordi Tarazona-Castro
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | | | - Hugo Carrillo-Ng
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | - Sungmin Kym
- Korea International Cooperation for Infectious Diseases, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Miguel Angel Aguilar-Luis
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | - Luis J Del Valle
- Barcelona Research Center for Multiscale Science and Engineering, Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Ronald Aquino-Ortega
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | - Johanna Martins-Luna
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | - Isaac Peña-Tuesta
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru
| | - Wilmer Silva-Caso
- School of Medicine, Research Center of the Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru.
- Laboratorio de Biologia Molecular, Instituto de Investigación Nutricional, Lima, Peru.
- Universidad Peruana de Ciencias Aplicadas, Av. San Marcos Cuadra 2, Chorrillos, Lima, Peru.
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Siebenmann C, Dempsey JA. Hypoxic Training Is Not Beneficial in Elite Athletes. Med Sci Sports Exerc 2020; 52:519-522. [PMID: 31939915 DOI: 10.1249/mss.0000000000002141] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
| | - Jerome A Dempsey
- Department Population Health Sciences, University of Wisconsin-Madison, Madison, WI
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6
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Torlasco C, Bilo G, Giuliano A, Soranna D, Ravaro S, Oliverio G, Faini A, Zambon A, Lombardi C, Parati G. Effects of acute exposure to moderate altitude on blood pressure and sleep breathing patterns. Int J Cardiol 2020; 301:173-179. [DOI: 10.1016/j.ijcard.2019.09.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 08/11/2019] [Accepted: 09/16/2019] [Indexed: 11/16/2022]
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Schwarz EI, Latshang TD, Furian M, Flück D, Segitz S, Müller-Mottet S, Ulrich S, Bloch KE, Kohler M. Blood pressure response to exposure to moderate altitude in patients with COPD. Int J Chron Obstruct Pulmon Dis 2019; 14:659-666. [PMID: 30936690 PMCID: PMC6421900 DOI: 10.2147/copd.s194426] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Patients with COPD might be particularly susceptible to hypoxia-induced autonomic dysregulation. Decreased baroreflex sensitivity (BRS) and increased blood pressure (BP) variability (BPV) are markers of impaired cardiovascular autonomic regulation and there is evidence for an association between decreased BRS/increased BPV and high cardiovascular risk. The aim of this study was to evaluate the effect of short-term exposure to moderate altitude on BP and measures of cardiovascular autonomic regulation in COPD patients. Materials and methods Continuous morning beat-to-beat BP was noninvasively measured with a Finometer® device for 10 minutes at low altitude (490 m, Zurich, Switzerland) and for 2 days at moderate altitude (2,590 m, Davos Jakobshorn, Switzerland) – the order of altitude exposure was randomized. Outcomes of interest were mean SBP and DBP, BPV expressed as the coefficient of variation (CV), and spontaneous BRS. Changes between low altitude and day 1 and day 2 at moderate altitude were assessed by ANOVA for repeated measurements with Fisher’s exact test analysis. Results Thirty-seven patients with moderate to severe COPD (mean±SD age 64±6 years, FEV1 60%±17%) were included. Morning SBP increased by +10.8 mmHg (95% CI: 4.7–17.0, P=0.001) and morning DBP by +5.0 mmHg (95% CI: 0.8–9.3, P=0.02) in response to altitude exposure. BRS significantly decreased (P=0.03), whereas BPV significantly and progressively increased (P<0.001) upon exposure to altitude. Conclusion Exposure of COPD patients to moderate altitude is associated with a clinically relevant increase in BP, which seems to be related to autonomic dysregulation. Clinical trial registration ClinicalTrials.gov (NCT01875133).
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Affiliation(s)
- Esther I Schwarz
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Tsogyal D Latshang
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Michael Furian
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Deborah Flück
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Sebastian Segitz
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Severine Müller-Mottet
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Silvia Ulrich
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Konrad E Bloch
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland, .,Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland,
| | - Malcolm Kohler
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland, .,Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland,
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Mahat B, Chassé É, Lindon C, Mauger JF, Imbeault P. No effect of acute normobaric hypoxia on plasma triglyceride levels in fasting healthy men. Appl Physiol Nutr Metab 2018; 43:727-732. [PMID: 29466682 DOI: 10.1139/apnm-2017-0505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Circulating fatty acids are a major systemic energy source in the fasting state as well as a determinant of hepatic triglycerides (TG)-rich very-low-density lipoprotein production. Upon acute hypoxia, sympathetic arousal induces adipose tissue lipolysis, resulting in an increase in circulating nonesterified fatty acids (NEFA). Animal studies suggest that TG clearance may also be strongly reduced under hypoxia, though this effect has been shown to be dependent on temperature. Whether the hypoxia-induced rise in blood fatty acid concentrations affects fasting TG levels in humans under thermoneutral conditions remains unknown. TG, NEFA, and glycerol levels were measured in fasted healthy young men (n = 10) exposed for 6 h to either normoxia (ambient air) or acute hypoxia (fraction of inspired oxygen = 0.12) in a randomized, crossover design. Participants were casually clothed and rested in front of a fan in an environmental chamber maintained at 28 °C during each trial. Under hypoxia, a significantly greater increase in NEFA occurred (condition × time interaction, p = 0.049) and glycerol levels tended to be higher (condition × time, p = 0.104), suggesting an increase in adipose tissue lipolysis. However, plasma TG levels did not change over time and did not differ between the normoxia and hypoxia conditions. In conclusion, acute exposure to normobaric hypoxia under thermoneutral condition in healthy men during fasting state increased lipolysis without affecting circulating TG.
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Affiliation(s)
- Bimit Mahat
- a Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Étienne Chassé
- a Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Clare Lindon
- a Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jean-François Mauger
- a Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Pascal Imbeault
- a Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.,b Institut du savoir Montfort, Hôpital Montfort, Ottawa, ON K1K 0T2, Canada
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Simpson EJ, Debevec T, Eiken O, Mekjavic I, Macdonald IA. PlanHab: the combined and separate effects of 16 days of bed rest and normobaric hypoxic confinement on circulating lipids and indices of insulin sensitivity in healthy men. J Appl Physiol (1985) 2016; 120:947-55. [PMID: 26769956 DOI: 10.1152/japplphysiol.00897.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/11/2016] [Indexed: 01/03/2023] Open
Abstract
PlanHab is a planetary habitat simulation study. The atmosphere within future space habitats is anticipated to have reduced Po2, but information is scarce as to how physiological systems may respond to combined exposure to moderate hypoxia and reduced gravity. This study investigated, using a randomized-crossover design, how insulin sensitivity, glucose tolerance, and circulating lipids were affected by 16 days of horizontal bed rest in normobaric normoxia [NBR: FiO2 = 0.209; PiO2 = 133.1 (0.3) mmHg], horizontal bed rest in normobaric hypoxia [HBR: FiO2 = 0.141 (0.004); PiO2 = 90.0 (0.4) mmHg], and confinement in normobaric hypoxia combined with daily moderate intensity exercise (HAMB). A mixed-meal tolerance test, with arterialized-venous blood sampling, was performed in 11 healthy, nonobese men (25-45 yr) before (V1) and on the morning ofday 17of each intervention (V2). Postprandial glucose and c-peptide response were increased at V2 of both bed rest interventions (P< 0.05 in each case), with c-peptide:insulin ratio higher at V2 in HAMB and HBR, both in the fed and fasted state (P< 0.005 in each case). Fasting total cholesterol was reduced at V2 in HAMB [-0.47 (0.36) mmol/l;P< 0.005] and HBR [-0.55 (0.41) mmol/l;P< 0.005]. Fasting HDL was lower at V2 in all interventions, with the reduction observed in HBR [-0.30 (0.21) mmol/l] greater than that measured in HAMB [-0.13 (0.14) mmol/l;P< 0.005] and NBR [-0.17 (0.15) mmol/l;P< 0.05]. Hypoxia did not alter the adverse effects of bed rest on insulin sensitivity and glucose tolerance but appeared to increase insulin clearance. The negative effect of bed rest on HDL was compounded in hypoxia, which may have implications for long-term health of those living in future space habitats.
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Affiliation(s)
- Elizabeth J Simpson
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom;
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Igor Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Ian A Macdonald
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom
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Lefferts WK, Hughes WE, Heffernan KS. Effect of acute nitrate ingestion on central hemodynamic load in hypoxia. Nitric Oxide 2016; 52:49-55. [DOI: 10.1016/j.niox.2015.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/03/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022]
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11
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Dynamic microvesicle release and clearance within the cardiovascular system: triggers and mechanisms. Clin Sci (Lond) 2015; 129:915-31. [PMID: 26359252 DOI: 10.1042/cs20140623] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Interest in cell-derived microvesicles (or microparticles) within cardiovascular diagnostics and therapeutics is rapidly growing. Microvesicles are often measured in the circulation at a single time point. However, it is becoming clear that microvesicle levels both increase and decrease rapidly in response to certain stimuli such as hypoxia, acute cardiac stress, shear stress, hypertriglyceridaemia and inflammation. Consequently, the levels of circulating microvesicles will reflect the balance between dynamic mechanisms for release and clearance. The present review describes the range of triggers currently known to lead to microvesicle release from different cellular origins into the circulation. Specifically, the published data are used to summarize the dynamic impact of these triggers on the degree and rate of microvesicle release. Secondly, a summary of the current understanding of microvesicle clearance via different cellular systems, including the endothelial cell and macrophage, is presented, based on reported studies of clearance in experimental models and clinical scenarios, such as transfusion or cardiac stress. Together, this information can be used to provide insights into potential underlying biological mechanisms that might explain the increases or decreases in circulating microvesicle levels that have been reported and help to design future clinical studies.
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Xu C, Qiao X, Zhao Y, Sun R, Shang X, Niu W. Resveratrol ameliorates chronic high altitude exposure-induced oxidative stress and suppresses lipid metabolism alteration in rats. EUR J LIPID SCI TECH 2015. [DOI: 10.1002/ejlt.201400426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Chunlan Xu
- The Key Laboratory for Space Bioscience and Biotechnology; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi; P. R. China
| | - Xiangjin Qiao
- The Key Laboratory for Space Bioscience and Biotechnology; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi; P. R. China
| | - Yanfei Zhao
- Department of Agriculture and Medicine; The Open University of China, Beijing; P. R. China
| | - Rui Sun
- The Key Laboratory for Space Bioscience and Biotechnology; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi; P. R. China
| | - Xiaoya Shang
- The Key Laboratory for Space Bioscience and Biotechnology; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi; P. R. China
| | - Weining Niu
- The Key Laboratory for Space Bioscience and Biotechnology; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi; P. R. China
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Gutwenger I, Hofer G, Gutwenger AK, Sandri M, Wiedermann CJ. Pilot study on the effects of a 2-week hiking vacation at moderate versus low altitude on plasma parameters of carbohydrate and lipid metabolism in patients with metabolic syndrome. BMC Res Notes 2015; 8:103. [PMID: 25885799 PMCID: PMC4383206 DOI: 10.1186/s13104-015-1066-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 03/18/2015] [Indexed: 02/08/2023] Open
Abstract
Background Hypoxic and hypobaric conditions may augment the beneficial influence of training on cardiovascular risk factors. This pilot study aimed to explore for effects of a two-week hiking vacation at moderate versus low altitude on adipokines and parameters of carbohydrate and lipid metabolism in patients with metabolic syndrome. Methods Fourteen subjects (mean age: 55.8 years, range: 39 – 69) with metabolic syndrome participated in a 2-week structured training program (3 hours of guided daily hiking 4 times a week, training intensity at 55-65% of individual maximal heart rate; total training time, 24 hours). Participants were divided for residence and training into two groups, one at moderate altitude (1,900 m; n = 8), and the other at low altitude (300 m; n = 6). Anthropometric, cardiovascular and metabolic parameters were measured before and after the training period. Results In study participants, training overall reduced circulating levels of total cholesterol (p = 0.024), low-density lipoprotein cholesterol (p = 0.025) and adiponectin (p < 0.001). In the group training at moderate altitude (n = 8), lowering effects on circulating levels were significant not only for total cholesterol, low-density-lipoprotein cholesterol and adiponectin (all, p < 0.05) but also for triglycerides (p = 0.025) and leptin (p = 0.015), whereas in the low altitude group (n = 6), none of the lipid parameters was significantly changed (each p > 0.05). Hiking-induced relative changes of triglyceride levels were positively associated with reductions in leptin levels (p = 0.006). As compared to 300 m altitude, training at 1,900 m showed borderline significant differences in the pre-post mean reduction rates of triglyceride (p = 0.050) and leptin levels (p = 0.093). Conclusions Preliminary data on patients with metabolic syndrome suggest that a 2-week hiking vacation at moderate altitude may be more beneficial for adipokines and parameters of lipid metabolism than training at low altitude. In order to draw firm conclusions regarding better corrections of dyslipidemia and metabolic syndrome by physical exercise under mild hypobaric and hypoxic conditions, a sufficiently powered randomized clinical trial appears warranted. Trial registration ClinicalTrials.gov ID NCT02013947 (first received November 6, 2013).
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Affiliation(s)
- Ivana Gutwenger
- Department of Anesthesiology, Hospital of Bressanone
- Brixen, Bressanone
- Brixen (BZ), Italy.
| | - Georg Hofer
- Department of Anesthesiology, Hospital of Silandro, Schlanders (BZ), Italy.
| | - Anna K Gutwenger
- Department of Internal Medicine, Hospital of Silandro
- Schlanders, Silandro
- Schlanders (BZ), Italy.
| | - Marco Sandri
- Data, Methods and Systems Statistical Laboratory, University of Brescia, Brescia (BS), Italy.
| | - Christian J Wiedermann
- Department of Internal Medicine, Central Hospital of Bolzano
- Bozen, Bolzano
- Bozen (BZ), Italy. .,Interdisciplinary Medical Research Center South Tyrol (IMREST), Bolzano
- Bozen (BZ), Italy.
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Impaired postural control in healthy men at moderate altitude (1630 m and 2590 m): data from a randomized trial. PLoS One 2015; 10:e0116695. [PMID: 25723529 PMCID: PMC4344242 DOI: 10.1371/journal.pone.0116695] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/10/2014] [Indexed: 11/19/2022] Open
Abstract
Objectives Intact postural control is essential for safe performance of mountain sports, operation of machinery at altitude, and for piloting airplanes. We tested whether exposure to hypobaric hypoxia at moderate altitude impairs the static postural control of healthy subjects. Methods In 51 healthy men, median age 24 y (quartiles 20;28), static control was evaluated on a balance platform in Zurich, 490 m, and during a 4-day sojourn in Swiss mountain villages at 1630 m and 2590 m, 2 days each. The order of altitude exposure was randomized. Total center of pressure path length (COPL) and sway amplitude measured in two directions by a balance platform, and pulse oximetry were recorded. Data were compared between altitudes. Results Median (quartiles) COPL during standing on both legs with eyes open at 490 m and in the evenings on the first and second days at 1630 and 2590 m, respectively were: 50 (45;57), 55 (48;62), 56 (49;61), 53 (47;59), 54 (48;60) cm, P<0.001 ANOVA. Corresponding arterial oxygen saturation was 97% (96;97), 95% (94;96), 95%(94;96), 92%(90;93), 93%(91;93), P<0.001. Anterior-posterior sway amplitudes were larger at 1630 and 2590 m compared to 490 m, P<0.001. Multiple logistic regression analysis confirmed that higher altitudes (1630 and 2590m) were independently associated with increased COPL when controlled for the order of altitude exposure and age (P=0.001). Conclusions Exposure to 1630 and 2590m was associated with impaired static postural control even when visual references were available. Trial Registration ClinicalTrials.gov NCT01130948.
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15
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Tesler N, Latshang TD, Lo Cascio CM, Stadelmann K, Stoewhas AC, Kohler M, Bloch KE, Achermann P, Huber R. Ascent to moderate altitude impairs overnight memory improvements. Physiol Behav 2015; 139:121-6. [DOI: 10.1016/j.physbeh.2014.11.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/08/2014] [Accepted: 11/10/2014] [Indexed: 11/15/2022]
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Stadelmann K, Latshang TD, Tarokh L, Lo Cascio CM, Tesler N, Stoewhas AC, Kohler M, Bloch KE, Huber R, Achermann P. Sleep respiratory disturbances and arousals at moderate altitude have overlapping electroencephalogram spectral signatures. J Sleep Res 2014; 23:463-8. [PMID: 24552365 DOI: 10.1111/jsr.12131] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 01/05/2014] [Indexed: 11/30/2022]
Abstract
An ascent to altitude has been shown to result in more central apneas and a shift towards lighter sleep in healthy individuals. This study employs spectral analysis to investigate the impact of respiratory disturbances (central/obstructive apnea and hypopnea or periodic breathing) at moderate altitude on the sleep electroencephalogram (EEG) and to compare EEG changes resulting from respiratory disturbances and arousals. Data were collected from 51 healthy male subjects who spent 1 night at moderate altitude (2590 m). Power density spectra of Stage 2 sleep were calculated in a subset (20) of these participants with sufficient artefact-free data for (a) epochs with respiratory events without an accompanying arousal, (b) epochs containing an arousal and (c) epochs of undisturbed Stage 2 sleep containing neither arousal nor respiratory events. Both arousals and respiratory disturbances resulted in reduced power in the delta, theta and spindle frequency range and increased beta power compared to undisturbed sleep. The similarity of the EEG changes resulting from altitude-induced respiratory disturbances and arousals indicates that central apneas are associated with micro-arousals, not apparent by visual inspection of the EEG. Our findings may have implications for sleep in patients and mountain tourists with central apneas and suggest that respiratory disturbances not accompanied by an arousal may, none the less, impact sleep quality and impair recuperative processes associated with sleep more than previously believed.
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Affiliation(s)
- Katrin Stadelmann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Circulating levels of cell-derived microparticles are reduced by mild hypobaric hypoxia: data from a randomised controlled trial. Eur J Appl Physiol 2014; 114:1067-73. [PMID: 24514947 DOI: 10.1007/s00421-014-2837-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE Hypoxia is known to induce the release of microparticles in vitro. However, few publications have addressed the role of hypoxia in vivo on circulating levels of microparticles. This randomised, controlled, crossover trial aimed to determine the effect of mild hypoxia on in vivo levels of circulating microparticles in healthy individuals. METHODS Blood was obtained from 51 healthy male volunteers (mean age of 26.9 years) at baseline altitude (490 m) and after 24 and 48 h at moderate altitude (2,590 m). The order of altitude exposure was randomised. Flow cytometry was used to assess platelet-poor plasma for levels of circulating microparticles derived from platelets, endothelial cells, leucocytes, granulocytes, monocytes, red blood cells and procoagulant microparticles. RESULTS Mean (standard deviation) oxygen saturation was significantly lower on the first and second day after arrival at 2,590 m, 91.0 (2.0) and 92.0 (2.0) %, respectively, compared to 490 m, 96 (1.0) %, p < 0.001 for both comparisons. A significant decrease in the levels of procoagulant microparticles (annexin V+ -221/μl 95 % CI -370.8/-119.0, lactadherin+ -202/μl 95 % CI -372.2/-93.1), platelet-derived microparticles (-114/μl 95 % CI -189.9/-51.0) and red blood cell-derived microparticles (-81.4 μl 95 % CI -109.9/-57.7) after 48 h at moderate altitude was found. Microparticles derived from endothelial cells, granulocytes, monocytes and leucocytes were not significantly altered by exposure to moderate altitude. CONCLUSIONS In healthy male individuals, mild hypobaric hypoxia, induced by a short-term stay at moderate altitude, is associated with lower levels of procoagulant microparticles, platelet-derived microparticles and red blood cell-derived microparticles, suggesting a reduction in thrombotic potential.
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Stadelmann K, Latshang TD, Lo Cascio CM, Tesler N, Stoewhas AC, Kohler M, Bloch KE, Huber R, Achermann P. Quantitative changes in the sleep EEG at moderate altitude (1630 m and 2590 m). PLoS One 2013; 8:e76945. [PMID: 24167552 PMCID: PMC3805553 DOI: 10.1371/journal.pone.0076945] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 08/28/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Previous studies have observed an altitude-dependent increase in central apneas and a shift towards lighter sleep at altitudes >4000 m. Whether altitude-dependent changes in the sleep EEG are also prevalent at moderate altitudes of 1600 m and 2600 m remains largely unknown. Furthermore, the relationship between sleep EEG variables and central apneas and oxygen saturation are of great interest to understand the impact of hypoxia at moderate altitude on sleep. METHODS Fourty-four healthy men (mean age 25.0 ± 5.5 years) underwent polysomnographic recordings during a baseline night at 490 m and four consecutive nights at 1630 m and 2590 m (two nights each) in a randomized cross-over design. RESULTS Comparison of sleep EEG power density spectra of frontal (F3A2) and central (C3A2) derivations at altitudes compared to baseline revealed that slow-wave activity (SWA, 0.8-4.6 Hz) in non-REM sleep was reduced in an altitude-dependent manner (~4% at 1630 m and 15% at 2590 m), while theta activity (4.6-8 Hz) was reduced only at the highest altitude (10% at 2590 m). In addition, spindle peak height and frequency showed a modest increase in the second night at 2590 m. SWA and theta activity were also reduced in REM sleep. Correlations between spectral power and central apnea/hypopnea index (AHI), oxygen desaturation index (ODI), and oxygen saturation revealed that distinct frequency bands were correlated with oxygen saturation (6.4-8 Hz and 13-14.4 Hz) and breathing variables (AHI, ODI; 0.8-4.6 Hz). CONCLUSIONS The correlation between SWA and AHI/ODI suggests that respiratory disturbances contribute to the reduction in SWA at altitude. Since SWA is a marker of sleep homeostasis, this might be indicative of an inability to efficiently dissipate sleep pressure.
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Affiliation(s)
- Katrin Stadelmann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | | | | | - Noemi Tesler
- University Children's Hospital Zurich, Zurich, Switzerland
| | | | - Malcolm Kohler
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- Pulmonary Division, University Hospital Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- Pulmonary Division, University Hospital Zurich, Zurich, Switzerland
| | - Reto Huber
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- University Children's Hospital Zurich, Zurich, Switzerland
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
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