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Su R, Peng P, Zhang W, Huang J, Fan J, Zhang D, He J, Ma H, Li H. Dose-effect of exercise intervention on heart rate variability of acclimatized young male lowlanders at 3,680 m. Front Physiol 2024; 15:1331693. [PMID: 38606008 PMCID: PMC11007668 DOI: 10.3389/fphys.2024.1331693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 03/14/2024] [Indexed: 04/13/2024] Open
Abstract
This study investigated whether exercise could improve the reduced HRV in an environment of high altitude. A total of 97 young, healthy male lowlanders living at 3,680 m for >1 year were recruited. They were randomized into four groups, of which three performed-low-, moderate-, and high-intensity (LI, MI, HI) aerobic exercise for 4 weeks, respectively. The remaining was the control group (CG) receiving no intervention. For HI, compared to other groups, heart rate (p = 0.002) was significantly decreased, while standard deviation of RR intervals (p < 0.001), SD2 of Poincaré plot (p = 0.046) and the number of successive RR interval pairs that differ by > 50 ms divided by total number of RR (p = 0.032), were significantly increased after intervention. For MI, significantly increase of trigonometric interpolation in NN interval (p = 0.016) was observed after exercise. Further, a decrease in systolic blood pressure (SBP) after high-intensity exercise was found significantly associated with an increase in SD2 (r = - 0.428, p = 0.042). These results indicated that there was a dose effect of different intensities of aerobic exercise on the HRV of acclimatized lowlanders. Moderate and high-intensity aerobic exercise would change the status of the autonomic nervous system (ANS) and decrease the blood pressure of acclimatized lowlanders exposed to high altitude.
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Affiliation(s)
- Rui Su
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| | - Ping Peng
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Wenrui Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Jie Huang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Jing Fan
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Delong Zhang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Jiayuan He
- National Clinical Research Center for Geriatric, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Med-X Center for Manufacturing, Sichuan University, Chengdu, Sichuan, China
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
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Guo Y, Liu X, Zhang Q, Shi Z, Zhang M, Chen J. Can acute high-altitude sickness be predicted in advance? REVIEWS ON ENVIRONMENTAL HEALTH 2024; 39:27-36. [PMID: 36165715 DOI: 10.1515/reveh-2022-0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
In high-altitude environments, the oxygen and air density are decreased, and the temperature and humidity are low. When individuals enter high-altitude areas, they are prone to suffering from acute mountain sickness (AMS) because they cannot tolerate hypoxia. Headache, fatigue, dizziness, and gastrointestinal reactions are the main symptoms of AMS. When these symptoms cannot be effectively alleviated, they can progress to life-threatening high-altitude pulmonary edema or high-altitude cerebral edema. If the risk of AMS can be effectively assessed before people enter high-altitude areas, then the high-risk population can be promptly discouraged from entering the area, or drug intervention can be established in advance to prevent AMS occurrence and avoid serious outcomes. This article reviews recent studies related to the early-warning biological indicators of AMS to provide a new perspective on the prevention of AMS.
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Affiliation(s)
- Yan Guo
- Medical College of Soochow University, Suzhou, Jiangsu Province, China
- Department of Pathology, Qinghai Provincial People's Hospital, Xining, Qinghai Province, China
| | - Xiao Liu
- Department of Basic Medical Sciences, The 960th Hospital of PLA, Jinan, Shandong Province, China
| | - Qiang Zhang
- Department of Neurosurgery, Qinghai Provincial People's Hospital, Xining, Qinghai Province, China
| | - Zhongshan Shi
- Department of Intensive Care Medicine, Ge er mu People's Hospital, Ge er mu, Qinghai Province, China
| | - Menglan Zhang
- Department of Pathology, Qinghai Provincial People's Hospital, Xining, Qinghai Province, China
| | - Jie Chen
- Department of Pathology, Qinghai Provincial People's Hospital, Xining, Qinghai Province, China
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Zhao S, Jia N, Shen Z, Pei C, Huang D, Liu J, Wang Y, Shi S, Wang X, Wang M, He Y, Wang Z. Pretreatment with Notoginsenoside R1 attenuates high-altitude hypoxia-induced cardiac injury via activation of the ERK1/2-P90RSK-Bad signaling pathway in rats. Phytother Res 2023; 37:4522-4539. [PMID: 37313866 DOI: 10.1002/ptr.7923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/19/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
High-altitude cardiac injury (HACI) is one of the common tissue injuries caused by high-altitude hypoxia that may be life threatening. Notoginsenoside R1 (NG-R1), a major saponin of Panax notoginseng, exerts anti-oxidative, anti-inflammatory, and anti-apoptosis effects, protecting the myocardium from hypoxic injury. This study aimed to investigate the protective effect and molecular mechanism of NG-R1 against HACI. We simulated a 6000 m environment for 48 h in a hypobaric chamber to create a HACI rat model. Rats were pretreated with NG-R1 (50, 100 mg/kg) or dexamethasone (4 mg/kg) for 3 days and then placed in the chamber for 48 h. The effect of NG-R1 was evaluated by changes in Electrocardiogram parameters, histopathology, cardiac biomarkers, oxidative stress and inflammatory indicators, key protein expression, and immunofluorescence. U0126 was used to verify whether the anti-apoptotic effect of NG-R1 was related to the activation of ERK pathway. Pretreatment with NG-R1 can improve abnormal cardiac electrical conduction and alleviate high-altitude-induced tachycardia. Similar to dexamethasone, NG-R1 can improve pathological damage, reduce the levels of cardiac injury biomarkers, oxidative stress, and inflammatory indicators, and down-regulate the expression of hypoxia-related proteins HIF-1α and VEGF. In addition, NG-R1 reduced cardiomyocyte apoptosis by down-regulating the expression of apoptotic proteins Bax, cleaved caspase 3, cleaved caspase 9, and cleaved PARP1 and up-regulating the expression of anti-apoptotic protein Bcl-2 through activating the ERK1/2-P90RSK-Bad pathway. In conclusion, NG-R1 prevented HACI and suppressed apoptosis via activation of the ERK1/2-P90RSK-Bad pathway, indicating that NG-R1 has therapeutic potential to treat HACI.
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Affiliation(s)
- Sijing Zhao
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
- School of Traditional Chinese Medicine, Chongqing Medical and Pharmaceutical College, Chongqing, China
| | - Nan Jia
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Zherui Shen
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Caixia Pei
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Demei Huang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Junling Liu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Yilan Wang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Shihua Shi
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Xiaomin Wang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Mingjie Wang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Yacong He
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Zhenxing Wang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
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Ebihara T, Shimizu K, Mitsuyama Y, Ogura H, Oda J. Association between high cardiac output at altitude and acute mountain sickness: preliminary study on Mt. Fuji. J Physiol Anthropol 2023; 42:6. [PMID: 37055843 PMCID: PMC10099929 DOI: 10.1186/s40101-023-00322-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 03/29/2023] [Indexed: 04/15/2023] Open
Abstract
BACKGROUND Acute mountain sickness (AMS) affects around 30% of people climbing Mt. Fuji, but its pathogenesis is incompletely understood. The influence of a rapid ascent to high altitude by climbing and summiting Mt. Fuji on cardiac function in the general population is unknown, and its association with altitude sickness has not been clarified. METHODS Subjects climbing Mt. Fuji were included. Heart rate, oxygen saturation, systolic blood pressure, cardiac index (CI) and stroke volume index were measured multiple times at 120 m as baseline values and at Mt. Fuji Research Station (MFRS) at 3,775 m. Each value and its difference from the baseline value (Δ) of subjects with AMS (defined as Lake Louise Score [LLS] ≥ 3 with headache after sleeping at 3,775 m) were compared with those of non-AMS subjects. RESULTS Eleven volunteers who climbed from 2,380 m to MFRS within 8 h and stayed overnight at MFRS were included. Four suffered AMS. Compared with the non-AMS subjects, CI in the AMS subjects was significantly higher than that before sleeping (median [interquartile range]: 4.9 [4.5, 5.0] vs. 3.8 [3.4, 3.9] mL/min/m2; p = 0.04), and their ΔCI was significantly higher before sleeping (1.6 [1.4, 2.1] vs. 0.2 [0.0, 0.7] mL/min/m2; p < 0.01) and after sleeping (0.7 [0.3, 1.7] vs. -0.2 [-0.5, 0.0] mL/min/m2; p < 0.01). ΔCI in the AMS subjects dropped significantly after sleeping versus before sleeping (3.8 [3.6, 4.5] vs. 4.9 [4.5, 5.0] mL/min/m2; p = 0.04). CONCLUSIONS Higher values of CI and ΔCI were observed at high altitude in the AMS subjects. A high cardiac output might be associated with the development of AMS.
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Affiliation(s)
- Takeshi Ebihara
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
| | - Kentaro Shimizu
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita City, Osaka, 565-0871, Japan
| | - Yumi Mitsuyama
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita City, Osaka, 565-0871, Japan
| | - Hiroshi Ogura
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita City, Osaka, 565-0871, Japan
| | - Jun Oda
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita City, Osaka, 565-0871, Japan
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Night-Time Heart Rate Variability during an Expedition to Mt Everest: A Case Report. Sports (Basel) 2023; 11:sports11020048. [PMID: 36828333 PMCID: PMC9959035 DOI: 10.3390/sports11020048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/12/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Mt Everest has been gaining popularity from casual hiking athletes, climbers, and ultra-endurance marathon runners. However, living and sleeping at altitude increases the risk of injury and illness. This is because travel to high altitudes adversely affects human physiology and performance, with unfavourable changes in body composition, exercise capacity, and mental function. This is a case report of a climber who reached the summit of Mt Everest from the north side. During his 40-day expedition, we collected sleep quality data and night-time heart rate variability. During the night inside the tent, the air temperature ranged from -12.9 to 1.8 °C (-5.8 ± 4.9 °C) and the relative humidity ranged from 26.1 to 78.9% (50.7 ± 16.9%). Awake time was 17.1 ± 6.0% of every sleep-time hour and increased with altitude (r = 0.42). Sleep time (r = -0.51) and subjective quality (r = 0.89) deteriorated with altitude. Resting heart rate increased (r = 0.70) and oxygen saturation decreased (r = -0.94) with altitude. The mean NN, RMSSD, total power, LF/HF, and SD1 and SD2 were computed using the NN time series. Altitude reduced the mean ΝΝ (r = -0.73), RMSSD (r = -0.31), total power (r = -0.60), LF/HF ratio (r = -0.40), SD1 (r = -0.31), and SD2 (r = -0.70). In conclusion, this case report shows that sleeping at high altitudes above 5500 m results in progressively reduced HRV, increased awakenings, as well as deteriorated sleep duration and subjective sleep quality. These findings provide further insight into the effects of high altitude on cardiac autonomic function and sleep quality and may have implications for individuals who frequently spend time at high altitudes, such as climbers.
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Wei CY, Chen PN, Lin SS, Huang TW, Sun LC, Tseng CW, Lin KF. Using machine learning to determine the correlation between physiological and environmental parameters and the induction of acute mountain sickness. BMC Bioinformatics 2022; 22:628. [PMID: 35641924 PMCID: PMC9153088 DOI: 10.1186/s12859-022-04749-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/23/2022] Open
Abstract
Background Recent studies on acute mountain sickness (AMS) have used fixed-location and fixed-time measurements of environmental and physiological variable to determine the influence of AMS-associated factors in the human body. This study aims to measure, in real time, environmental conditions and physiological variables of participants in high-altitude regions to develop an AMS risk evaluation model to forecast prospective development of AMS so its onset can be prevented.
Results Thirty-two participants were recruited, namely 25 men and 7 women, and they hiked from Cuifeng Mountain Forest Park parking lot (altitude: 2300 m) to Wuling (altitude: 3275 m). Regression and classification machine learning analyses were performed on physiological and environmental data, and Lake Louise Acute Mountain Sickness Scores (LLS) to establish an algorithm for AMS risk analysis. The individual R2 coefficients of determination between the LLS and the measured altitude, ambient temperature, atmospheric pressure, relative humidity, climbing speed, heart rate, blood oxygen saturation (SpO2), heart rate variability (HRV), were 0.1, 0.23, 0, 0.24, 0, 0.24, 0.27, and 0.35 respectively; incorporating all aforementioned variables, the R2 coefficient is 0.62. The bagged trees classifier achieved favorable classification results, yielding a model sensitivity, specificity, accuracy, and area under receiver operating characteristic curve of 0.999, 0.994, 0.998, and 1, respectively.
Conclusion The experiment results indicate the use of machine learning multivariate analysis have higher AMS prediction accuracies than analyses utilizing single varieties. The developed AMS evaluation model can serve as a reference for the future development of wearable devices capable of providing timely warnings of AMS risks to hikers.
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Affiliation(s)
- Chih-Yuan Wei
- Graduate Institute of Life Sciences, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan
| | - Ping-Nan Chen
- Graduate Institute of Life Sciences, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan. .,Department of Biomedical Engineering, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan.
| | - Shih-Sung Lin
- Department of Computer Science and Information Engineering, Chinese Culture University, No.55, Hwa-Kang Road, Yang-Ming-Shan, Taipei, 11114, Taiwan
| | - Tsai-Wang Huang
- Division of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, No.325, Sec. 2, Chenggong Rd., Neihu Dist., Taipei, 11490, Taiwan
| | - Ling-Chun Sun
- School of Medicine, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan
| | - Chun-Wei Tseng
- School of Medicine, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan
| | - Ke-Feng Lin
- Medical Informatics Office, Tri‑Service General Hospital, National Defense Medical Center, No.325, Sec. 2, Chenggong Rd., Neihu Dist., Taipei, 11490, Taiwan.,School of Public Health, National Defense Medical Center, No.161, Sec. 6, Minquan E. Rd., Neihu Dist., Taipei, 11490, Taiwan
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Boos CJ, Mellor A, Woods DR, O’Hara JP. The Effect of High-Altitude Acclimatisation on Ultra-Short Heart Rate Variability. Front Cardiovasc Med 2022; 9:787147. [PMID: 35419439 PMCID: PMC8995742 DOI: 10.3389/fcvm.2022.787147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/28/2022] [Indexed: 11/21/2022] Open
Abstract
Introduction High-altitude (HA) exposure affects heart rate variability (HRV) and has been inconsistently linked to acute mountain sickness (AMS). The influence of increasing HA exposure on ultra-short HRV and its relationship to gold standard HRV measures at HA has not been examined. Methods This was a prospective observational study of adults aged ≥ 18 years undertaking a HA trek in the Dhaulagiri region of the Himalayas. Cardiac inter-beat-intervals were obtained from a 10-s recording of supra-systolic blood pressure (Uscom BP+ device) immediately followed by 300 s single lead ECG recording (CheckMyHeart device). HRV was measured using the RMSSD (root mean square of successive differences of NN intervals) at sea level (SL) in the United Kingdom and at 3,619, 4,600, and 5,140 m at HA. Oxygen saturations (SpO2) were measured using finger-based pulse oximetry. The level of agreement between the 10 and 300 s RMSSD values were examined using a modified Bland–Altman relative-difference analysis. Results Overall, 89 participants aged 32.2 ± 8.8 years (range 18–56) were included of which 70.8% were men. HA exposure (SL vs. 3,619 m) was associated with an initial increase in both 10 s (45.0 [31.0–82.0]) vs. 58.0 [33.0–119.0] ms) and 300 s (45.67 [33.24–70.32] vs. 56.48 [36.98–102.0] ms) in RMSSD. Thereafter at 4,600 and 5,140 m both 10 and 300 s RMSSD values were significantly lower than SL. From a total of 317 paired HRV measures the 10 and 300 s RMSSD measures were moderately correlated (Spearman r = 0.66; 95% CI: 0.59–0.72; p < 0.0001). The median difference (bias) in RMSSD values (300 s − 10 s) was −2.3 ms with a lower and upper limit of agreement of −107.5 and 88.61 ms, respectively with no differences with altitude. Overall, 293/317 (92.4%) of all paired HRV values fell within the 95% CI limits of agreement. Neither HRV method was predictive of AMS. Conclusion Increasing HA affects ultra-short HRV in a similar manner to gold-standard 300 s. Ultra-short HRV has a moderate agreement with 300 s measurements. HRV did not predict AMS.
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Affiliation(s)
- Christopher John Boos
- Department of Cardiology, Poole Hospital, University Hospitals Dorset, Poole, United Kingdom
- Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, United Kingdom
- Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom
- *Correspondence: Christopher John Boos,
| | - Adrian Mellor
- Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom
- Defence Medical Services, Lichfield, United Kingdom
- James Cook University Hospital, Middlesbrough, United Kingdom
| | - David Richard Woods
- Defence Medical Services, Lichfield, United Kingdom
- Northumbria NHS Foundation Trust, North Shields, United Kingdom
- Academic Department of Medicine, University of Newcastle, Newcastle upon Tyne, United Kingdom
| | - John Paul O’Hara
- Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom
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Georges T, Menu P, Le Blanc C, Ferreol S, Dauty M, Fouasson-Chailloux A. Contribution of Hypoxic Exercise Testing to Predict High-Altitude Pathology: A Systematic Review. Life (Basel) 2022; 12:life12030377. [PMID: 35330129 PMCID: PMC8950822 DOI: 10.3390/life12030377] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 11/20/2022] Open
Abstract
Altitude travelers are exposed to high-altitude pathologies, which can be potentially serious. Individual susceptibility varies widely and this makes it difficult to predict who will develop these complications. The assessment of physiological adaptations to exercise performed in hypoxia has been proposed to help predict altitude sickness. The purpose of this review is to evaluate the contribution of hypoxic exercise testing, achieved in normobaric conditions, in the prediction of severe high-altitude pathology. We performed a systematic review using the databases PubMed, Science Direct and Embase in October 2021 to collect studies reporting physiological adaptations under hypoxic exercise testing and its interest in predicting high-altitude pathology. Eight studies were eligible, concerning 3558 patients with a mean age of 46.9 years old, and a simulated mean altitude reaching of 5092 m. 597 patients presented an acute mountain sickness during their altitude travels. Three different protocols of hypoxic exercise testing were used. Acute mountain sickness was defined using Hackett’s score or the Lake Louise score. Ventilatory and cardiac responses to hypoxia, desaturation in hypoxia, cerebral oxygenation, core temperature, variation in body mass index and some perceived sensations were the highlighted variables associated with acute mountain sickness. A decision algorithm based on hypoxic exercise tests was proposed by one team. Hypoxic exercise testing provides promising information to help predict altitude complications. Its interest should be confirmed by different teams.
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Affiliation(s)
- Thomas Georges
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
| | - Pierre Menu
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
- CHU Nantes, Service de Médecine du Sport, 44093 Nantes, France
- Institut Régional de Médecine du Sport (IRMS), 44093 Nantes, France
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, F-44042 Nantes, France
| | - Camille Le Blanc
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
| | - Sophie Ferreol
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
| | - Marc Dauty
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
- CHU Nantes, Service de Médecine du Sport, 44093 Nantes, France
- Institut Régional de Médecine du Sport (IRMS), 44093 Nantes, France
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, F-44042 Nantes, France
| | - Alban Fouasson-Chailloux
- CHU Nantes, Service de Médecine Physique et Réadapatation Locomotrice et Respiratoire, 44093 Nantes, France; (T.G.); (P.M.); (C.L.B.); (S.F.); (M.D.)
- CHU Nantes, Service de Médecine du Sport, 44093 Nantes, France
- Institut Régional de Médecine du Sport (IRMS), 44093 Nantes, France
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, F-44042 Nantes, France
- Correspondence:
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Hamm W, Kassem S, von Stülpnagel L, Maier F, Klemm M, Schüttler D, Grabher F, Weckbach LT, Huber BC, Bauer A, Rizas KD, Brunner S. Deceleration Capacity and Periodic Repolarization Dynamics As Predictors of Acute Mountain Sickness. High Alt Med Biol 2020; 21:417-422. [DOI: 10.1089/ham.2020.0131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Wolfgang Hamm
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Sari Kassem
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Lukas von Stülpnagel
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Department of Medicine III, University Hospital, Medical University of Innsbruck, Innsbruck, Austria
| | - Florian Maier
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Mathias Klemm
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Dominik Schüttler
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Felix Grabher
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Ludwig T. Weckbach
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Bruno C. Huber
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Axel Bauer
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Department of Medicine III, University Hospital, Medical University of Innsbruck, Innsbruck, Austria
| | - Konstantinos D. Rizas
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Stefan Brunner
- Department of Medicine I, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
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Shen Y, Yang YQ, Liu C, Yang J, Zhang JH, Jin J, Tan H, Yuan FZY, Ke JB, He CY, Zhang LP, Zhang C, Yu J, Huang L. Association between physiological responses after exercise at low altitude and acute mountain sickness upon ascent is sex-dependent. Mil Med Res 2020; 7:53. [PMID: 33148321 PMCID: PMC7643355 DOI: 10.1186/s40779-020-00283-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 10/20/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Acute mountain sickness (AMS) is the mildest form of acute altitude illnesses, and consists of non-specific symptoms when unacclimatized persons ascend to elevation of ≥2500 m. Risk factors of AMS include: the altitude, individual susceptibility, ascending rate and degree of pre-acclimatization. In the current study, we examined whether physiological response at low altitude could predict the development of AMS. METHODS A total of 111 healthy adult healthy volunteers participated in this trial; and 99 (67 men and 32 women) completed the entire study protocol. Subjects were asked to complete a 9-min exercise program using a mechanically braked bicycle ergometer at low altitude (500 m). Heart rate, blood pressure (BP) and pulse oxygen saturation (SpO2) were recorded prior to and during the last minute of exercise. The ascent from 500 m to 4100 m was completed in 2 days. AMS was defined as ≥3 points in a 4-item Lake Louise Score, with at least one point from headache wat 6-8 h after the ascent. RESULTS Among the 99 assessable subjects, 47 (23 men and 24 women) developed AMS at 4100 m. In comparison to the subjects without AMS, those who developed AMS had lower proportion of men (48.9% vs. 84.6%, P < 0.001), height (168.4 ± 5.9 vs. 171.3 ± 6.1 cm, P = 0.019), weight (62.0 ± 10.0 vs. 66.7 ± 8.6 kg, P = 0.014) and proportion of smokers (23.4% vs. 51.9%, P = 0.004). Multivariate regression analysis revealed the following independent risks for AMS: female sex (odds ratio (OR) =6.32, P < 0.001), SpO2 change upon exercise at low altitude (OR = 0.63, P = 0.002) and systolic BP change after the ascent (OR = 0.96, P = 0.029). Women had larger reduction in SpO2 after the ascent, higher AMS percentage and absolute AMS score. Larger reduction of SpO2 after exercise was associated with both AMS incidence (P = 0.001) and AMS score (P < 0.001) in men but not in women. CONCLUSIONS Larger SpO2 reduction after exercise at low altitude was an independent risk for AMS upon ascent. Such an association was more robust in men than in women. TRIAL REGISTRATION Chinese Clinical Trial Registration, ChiCTR1900025728 . Registered 6 September 2019.
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Affiliation(s)
- Yang Shen
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Yuan-Qi Yang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Chuan Liu
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jie Yang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Ji-Hang Zhang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jun Jin
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Hu Tan
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Fang-Zheng-Yuan Yuan
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jing-Bin Ke
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Chun-Yan He
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Lai-Ping Zhang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Chen Zhang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jie Yu
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Lan Huang
- Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China. .,Department of Cardiology, the Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.
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11
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Post-Exercise Recovery of Ultra-Short-Term Heart Rate Variability after Yo-Yo Intermittent Recovery Test and Repeated Sprint Ability Test. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17114070. [PMID: 32517382 PMCID: PMC7312126 DOI: 10.3390/ijerph17114070] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 11/16/2022]
Abstract
This study aimed to examine the agreement and acceptance of ultra-short-term heart rate (HR) variability (HRVUST) measures during post-exercise recovery in college football players. Twenty-five male college football players (age: 19.80 ± 1.08 years) from the first division of national university championship voluntarily participated in the study. The participants completed both a repeated sprint ability test (RSA) and a Yo-Yo intermittent recovery test level 1 (YYIR1) in a randomized order and separated by 7 days. Electrocardiographic signals (ECG) were recorded in a supine position 10 min before and 30 min after the exercise protocols. The HR and HRV data were analyzed in the time segments of baseline 5~10 min (Baseline), post-exercise 0~5 min (Post 1), post-exercise 5~10 min (Post 2), and post-exercise 25~30 min (Post 3). The natural logarithm of the standard deviation of normal-to-normal intervals (LnSDNN), root mean square of successive normal-to-normal interval differences (LnRMSSD), and LnSDNN:LnRMSSD ratio was compared in the 1st min HRVUST and 5-min criterion (HRVcriterion) of each time segment. The correlation of time-domain HRV variables to 5-min natural logarithm of low frequency power (LnLF) and high frequency power (LnHF), and LF:HF ratio were calculated. The results showed that the HRVUST of LnSDNN, LnRMSSD, and LnSDNN:LnRMSSD ratio showed trivial to small effect sizes (ES) (−0.00~0.49), very large and nearly perfect interclass correlation coefficients (ICC) (0.74~0.95), and relatively small values of bias (RSA: 0.01~−0.12; YYIR1: −0.01~−0.16) to the HRVcriterion in both exercise protocols. In addition, the HRVUST of LnLF, LnHF, and LnLF:LnHF showed trivial to small ES (−0.04~−0.54), small to large ICC (−0.02~0.68), and relatively small values of bias (RSA: −0.02~0.65; YYIR1: 0.03~−0.23) to the HRVcriterion in both exercise protocols. Lastly, the 1-min LnSDNN:LnRMSSD ratio was significantly correlated to the 5-min LnLF:LnHF ratio with moderate~high level (r = 0.43~0.72; p < 0.05) during 30-min post-exercise recovery. The post-exercise 1-min HRV assessment in LnSDNN, LnRMSSD, and LnSDNN:LnRMSSD ratio was acceptable and accurate in the RSA and YYIR1 tests, compared to the 5-min time segment of measurement. The moderate to high correlation coefficient of the HRVUST LnSDNN:LnRMSSD ratio to the HRVcriterion LnLF:LnHF ratio indicated the capacity to facilitate the post-exercise shortening duration of HRV measurement after maximal anaerobic or aerobic shuttle running. Using ultra-short-term record of LnSDNN:LnRMSSD ratio as a surrogate for standard measure of LnLF:LnHF ratio after short-term bouts of maximal intensity field-based shuttle running is warranted.
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12
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Niebauer JH, Niebauer J, Wille M, Burtscher M. Systemic Blood Pressure Variation During a 12-Hour Exposure to Normobaric Hypoxia (4500 m). High Alt Med Biol 2020; 21:194-199. [PMID: 32186921 DOI: 10.1089/ham.2019.0130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study was aimed at evaluating a potential association between blood pressure variation and acute mountain sickness (AMS) during acute exposure to normobaric hypoxia. A total of 77 healthy subjects (43 males, 34 females) were exposed to a simulated altitude of 4500 m for 12 hours. Peripheral oxygen saturation, heart rate, systemic blood pressure, and Lake Louise AMS scores were recorded before and during (30 minutes, 3, 6, 9, and 12 hours) hypoxic exposure. Blood pressure dips were observed at 3-hour mark. However, systolic blood pressure fell more pronounced from baseline during the initial 30 minutes in normobaric hypoxia (-17.5 vs. -11.0 mmHg, p = 0.01) in subjects suffering from AMS (AMS+; n = 56) than in those remaining unaffected from AMS (AMS-; n = 21); values did not differ between groups over the subsequent time course. Our data may suggest a transient autonomic dysfunction resulting in a more pronounced blood pressure drop during initial hypoxic exposure in AMS+ compared with AMS- subjects.
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Affiliation(s)
| | - Josef Niebauer
- University Institute of Sports Medicine, Prevention and Rehabilitation, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Maria Wille
- Department of Sports Science, University of Innsbruck, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sports Science, University of Innsbruck, Innsbruck, Austria.,Austrian Society for Alpine- and High-Altitude Medicine, Innsbruck, Austria
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13
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Estoppey J, Léger B, Vuistiner P, Sartori C, Kayser B. Low- and High-Altitude Cortisol Awakening Responses Differ Between AMS-Prone and AMS-Resistant Mountaineers. High Alt Med Biol 2019; 20:344-351. [DOI: 10.1089/ham.2019.0035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Jan Estoppey
- Institute of Sport Sciences, Synathlon, Uni-Centre, Lausanne, Switzerland
| | - Bertrand Léger
- Department of Medical Research, Romandie Clinic for Rehabilitation, Sion, Switzerland
| | - Philippe Vuistiner
- Department of Medical Research, Romandie Clinic for Rehabilitation, Sion, Switzerland
| | - Claudio Sartori
- Department of Internal Medicine, University Hospital, Lausanne, Switzerland
| | - Bengt Kayser
- Institute of Sport Sciences, Synathlon, Uni-Centre, Lausanne, Switzerland
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14
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Holmström P, Mulder E, Sundström AL, Limbu P, Schagatay E. The Magnitude of Diving Bradycardia During Apnea at Low-Altitude Reveals Tolerance to High Altitude Hypoxia. Front Physiol 2019; 10:1075. [PMID: 31507443 PMCID: PMC6714063 DOI: 10.3389/fphys.2019.01075] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/05/2019] [Indexed: 11/13/2022] Open
Abstract
Acute mountain sickness (AMS) is a potentially life-threatening illness that may develop during exposure to hypoxia at high altitude (HA). Susceptibility to AMS is highly individual, and the ability to predict it is limited. Apneic diving also induces hypoxia, and we aimed to investigate whether protective physiological responses, i.e., the cardiovascular diving response and spleen contraction, induced during apnea at low-altitude could predict individual susceptibility to AMS. Eighteen participants (eight females) performed three static apneas in air, the first at a fixed limit of 60 s (A1) and two of maximal duration (A2-A3), spaced by 2 min, while SaO2, heart rate (HR) and spleen volume were measured continuously. Tests were conducted in Kathmandu (1470 m) before a 14 day trek to mount Everest Base Camp (5360 m). During the trek, participants reported AMS symptoms daily using the Lake Louise Questionnaire (LLQ). The apnea-induced HR-reduction (diving bradycardia) was negatively correlated with the accumulated LLQ score in A1 (r s = -0.628, p = 0.005) and A3 (r s = -0.488, p = 0.040) and positively correlated with SaO2 at 4410 m (A1: r = 0.655, p = 0.003; A2: r = 0.471, p = 0.049; A3: r = 0.635, p = 0.005). Baseline spleen volume correlated negatively with LLQ score (r s = -0.479, p = 0.044), but no correlation was found between apnea-induced spleen volume reduction with LLQ score (r s = 0.350, p = 0.155). The association between the diving bradycardia and spleen size with AMS symptoms suggests links between physiological responses to HA and apnea. Measuring individual responses to apnea at sea-level could provide means to predict AMS susceptibility prior to ascent.
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Affiliation(s)
- Pontus Holmström
- Department of Health Sciences, Mid Sweden University, Sundsvall, Sweden
| | - Eric Mulder
- Department of Health Sciences, Mid Sweden University, Sundsvall, Sweden
| | | | - Prakash Limbu
- Department of Clinical Physiology, Nepalese Army Institute of Health Sciences, Kathmandu, Nepal
| | - Erika Schagatay
- Department of Health Sciences, Mid Sweden University, Sundsvall, Sweden
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15
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Huang H, Dong H, Zhang J, Ke X, Li P, Zhang E, Xu G, Sun B, Gao Y. The Role of Salivary miR-134-3p and miR-15b-5p as Potential Non-invasive Predictors for Not Developing Acute Mountain Sickness. Front Physiol 2019; 10:898. [PMID: 31379603 PMCID: PMC6646415 DOI: 10.3389/fphys.2019.00898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/27/2019] [Indexed: 01/28/2023] Open
Abstract
Background Acute mountain sickness (AMS) is a crucial public health problem for high altitude travelers. Discriminating individuals who are not developing (AMS resistance, AMS−) from developing AMS (AMS susceptibility, AMS+) at baseline would be vital for disease prevention. Salivary microRNAs (miRNAs) have emerged as promising non-invasive biomarkers for various diseases. Thus, the aim of our study was to identify the potential roles of salivary miRNAs in identifying AMS− individuals pre-exposed to high altitude. Moreover, as hypoxia is the triggering factor for AMS, present study also explored the association between cerebral tissue oxygenation indices (TOI) and AMS development after exposed to high altitude, which was the complementary aim. Methods In this study, 124 healthy men were recruited, and were exposed at simulated high altitude of 4,500 m. Salivary miR-134-3p and miR-15b-5p were measured at baseline (200 m). AMS was diagnosed based on Lake Louise Scoring System at 4,500 m. The measurements of physiological parameters were recorded at both the altitudes. Results Salivary miR-134-3p and miR-15b-5p were significantly up-regulated in AMS− individuals as compared to the AMS+ (p < 0.05). In addition, the combination of these miRNAs generated a high power for discriminating the AMS− from AMS+ at baseline (AUC: 0.811, 95% CI: 0.731−0.876, p < 0.001). Moreover, the value of cerebral TOIs at 4,500 m were significantly higher in AMS− individuals, compared to AMS+ (p < 0.01). Conclusion Our study reveals for the first time that salivary miR-134-3p and miR-15b-5p can be used as non-invasive biomarkers for predicting AMS− individuals pre-exposed to high altitude.
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Affiliation(s)
- He Huang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Huaping Dong
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Jianyang Zhang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Xianfeng Ke
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Peng Li
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China.,Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Erlong Zhang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Gang Xu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Bingda Sun
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Yuqi Gao
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
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16
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Taralov ZZ, Terziyski KV, Dimov PK, Marinov BI, Kostianev SS. Assessment of the impact of 10-day intermittent hypoxia on the autonomic control measured by heart rate variability. Physiol Int 2018; 105:386-396. [DOI: 10.1556/2060.105.2018.4.31] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Purpose
The purpose of this study is to establish the alterations in the activity of the autonomic nervous system (ANS) via heart rate variability (HRV) in subjects exposed to 1 h of exogenous hypoxia for 10 consecutive days.
Methods
Twelve healthy non-smoker males at mean age of 29.8 ± 7.4 (mean ± SD) breathed hypoxic air delivered through hypoxicator (FiО2 = 12.3% ± 1.5%) for 1 h in 10 consecutive days. Pulse oximetry and electrocardiography were monitored during the visit and HRV was calculated for the entire 1-h hypoxic period.
Results
Comparing the last hypoxic visit to the first, subjects had higher standard deviation of normal-to-normal interbeat intervals (SDNNs) (65.7 ± 32.5 vs. 81.1 ± 32.0 ms, p = 0.013) and root mean square of successive R–R interval difference (RMSSD) (58.1 ± 30.9 vs. 76.5 ± 34.6 ms, p = 0.029) as well as higher lnTotal power (8.1 ± 1.1 vs. 8.5 ± 0.9 ms2, p = 0.015) and high frequency (lnHF) (6.8 ± 1.3 vs. 7.5 ± 1.2 ms2, p = 0.05) and lower LF/HF (2.4 ± 1.4 vs. 1.5 ± 1.0, p = 0.026). Changes in saturation (87.0 ± 7.1 vs. 90.8 ± 5.0%, p = 0.039) and heart rate (67.1 ± 8.9 vs. 62.5 ± 6.0 beats/min, p = 0.040) were also observed.
Conclusions
Intermittent hypoxic training consisting of 1-h hypoxic exposure for 10 consecutive days could diminish the effects of acute exogenous hypoxia on the ANS characterized by an increased autonomic control (SDNN and total power) with augmentation of the parasympathetic nervous system activity (increased RMSSD and HF and decreased LF/HF). Therefore, it could be applied as a pre-acclimatization technique aiming at an increase in the autonomic control and oxygen saturation in subjects with upcoming sojourn to high altitude.
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Affiliation(s)
- ZZ Taralov
- 1 Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - KV Terziyski
- 1 Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - PK Dimov
- 1 Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - BI Marinov
- 1 Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - SS Kostianev
- 1 Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria
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17
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Hamm W, von Stülpnagel L, Klemm M, Baylacher M, Rizas KD, Bauer A, Brunner S. Deceleration Capacity of Heart Rate After Acute Altitude Exposure. High Alt Med Biol 2018; 19:299-302. [DOI: 10.1089/ham.2018.0041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Wolfgang Hamm
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
- German Cardiovascular Research Center (DZHK), Partner Site: Munich Heart Alliance, Munich, Germany
| | - Lukas von Stülpnagel
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
- German Cardiovascular Research Center (DZHK), Partner Site: Munich Heart Alliance, Munich, Germany
| | - Mathias Klemm
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
- German Cardiovascular Research Center (DZHK), Partner Site: Munich Heart Alliance, Munich, Germany
| | - Monika Baylacher
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
| | - Konstantinos D. Rizas
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
- German Cardiovascular Research Center (DZHK), Partner Site: Munich Heart Alliance, Munich, Germany
| | - Axel Bauer
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
- German Cardiovascular Research Center (DZHK), Partner Site: Munich Heart Alliance, Munich, Germany
| | - Stefan Brunner
- Medical Department I, Cardiology, Ludwig-Maximilian University Munich, Munich, Germany
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18
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Wu Y, Zhang C, Chen Y, Luo YJ. Association between acute mountain sickness (AMS) and age: a meta-analysis. Mil Med Res 2018; 5:14. [PMID: 29747689 PMCID: PMC5946480 DOI: 10.1186/s40779-018-0161-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 04/24/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acute mountain sickness (AMS) is a potentially lethal condition caused by acute hypoxia after ascending to altitudes higher than 2500 m in a short time. The main symptom of AMS is headache. Numerous risk factors of AMS have been examined, including gender, obesity, ascent rate, age and individual susceptibility. In previous studies, age was considered a predisposing factor for AMS. However, different opinions have been raised in recent years. To clarify the association between AMS and age, we conducted this meta-analysis. METHODS We obtained observational studies that explored risk factors for AMS by searching PubMed, Embase, China National Knowledge Internet (CNKI), the Wanfang database and CQVIP for articles published before March 2017. The studies included were required to provide the mean age and its standard deviation for subjects with and without AMS, the maximum altitude attained and the mode of ascent. The Lake Louse Score (LLS) or the Chinese AMS score (CAS) was used to judge the severity of AMS symptoms and incidence. Studies were pooled for the analysis by using a random effects model in RevMan 5.0. Meta-regression and subgroup analyses were conducted to identify sources of heterogeneity using Stata 14.2 and RevMan 5.0. RESULTS In total, 17 studies were included, and the overall number of subjects with and without AMS was 1810 and 3014, respectively. The age ranged from 10 to 76 years. Analysis of the 17 included studies showed that age was not associated with AMS (mean difference (MD) = 0.10; 95% CI: -0.38-0.58; P = 0.69). CONCLUSION This meta-analysis suggests that there is no association between age and the risk of AMS. Race, age, and ascent mode are common sources of heterogeneity, which may provide an analytical orientation for future heterogeneity analyses.
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Affiliation(s)
- Yu Wu
- Department of Military Medical Geography, Army Medical Service Training Base, Army Medical University, Chongqing, 400038, China.,Battalion 5 of Cadet Brigade, Army Medical University, Chongqing, 400038, China
| | - Chi Zhang
- Department of Military Medical Geography, Army Medical Service Training Base, Army Medical University, Chongqing, 400038, China.,Key Laboratory of High Altitude Environmental Medicine of PLA, Army Medical University, Chongqing, 400038, China
| | - Yu Chen
- Department of Military Medical Geography, Army Medical Service Training Base, Army Medical University, Chongqing, 400038, China.,Key Laboratory of High Altitude Environmental Medicine of PLA, Army Medical University, Chongqing, 400038, China
| | - Yong-Jun Luo
- Department of Military Medical Geography, Army Medical Service Training Base, Army Medical University, Chongqing, 400038, China. .,Key Laboratory of High Altitude Environmental Medicine of PLA, Army Medical University, Chongqing, 400038, China.
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19
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Boos CJ, Bye K, Sevier L, Bakker-Dyos J, Woods DR, Sullivan M, Quinlan T, Mellor A. High Altitude Affects Nocturnal Non-linear Heart Rate Variability: PATCH-HA Study. Front Physiol 2018; 9:390. [PMID: 29713290 PMCID: PMC5911497 DOI: 10.3389/fphys.2018.00390] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/28/2018] [Indexed: 01/23/2023] Open
Abstract
Background: High altitude (HA) exposure can lead to changes in resting heart rate variability (HRV), which may be linked to acute mountain sickness (AMS) development. Compared with traditional HRV measures, non-linear HRV appears to offer incremental and prognostic data, yet its utility and relationship to AMS have been barely examined at HA. This study sought to examine this relationship at terrestrial HA. Methods: Sixteen healthy British military servicemen were studied at baseline (800 m, first night) and over eight consecutive nights, at a sleeping altitude of up to 3600 m. A disposable cardiac patch monitor was used, to record the nocturnal cardiac inter-beat interval data, over 1 h (0200-0300 h), for offline HRV assessment. Non-linear HRV measures included Sample entropy (SampEn), the short (α1, 4-12 beats) and long-term (α2, 13-64 beats) detrend fluctuation analysis slope and the correlation dimension (D2). The maximal rating of perceived exertion (RPE), during daily exercise, was assessed using the Borg 6-20 RPE scale. Results: All subjects completed the HA exposure. The average age of included subjects was 31.4 ± 8.1 years. HA led to a significant fall in SpO2 and increase in heart rate, LLS and RPE. There were no significant changes in the ECG-derived respiratory rate or in any of the time domain measures of HRV during sleep. The only notable changes in frequency domain measures of HRV were an increase in LF and fall in HFnu power at the highest altitude. Conversely, SampEn, SD1/SD2 and D2 all fell, whereas α1 and α2 increased (p < 0.05). RPE inversely correlated with SD1/SD2 (r = -0.31; p = 0.002), SampEn (r = -0.22; p = 0.03), HFnu (r = -0.27; p = 0.007) and positively correlated with LF (r = 0.24; p = 0.02), LF/HF (r = 0.24; p = 0.02), α1 (r = 0.32; p = 0.002) and α2 (r = 0.21; p = 0.04). AMS occurred in 7/16 subjects (43.8%) and was very mild in 85.7% of cases. HRV failed to predict AMS. Conclusion: Non-linear HRV is more sensitive to the effects of HA than time and frequency domain indices. HA leads to a compensatory decrease in nocturnal HRV and complexity, which is influenced by the RPE measured at the end of the previous day. HRV failed to predict AMS development.
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Affiliation(s)
- Christopher J Boos
- Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, United Kingdom.,Centre of Postgraduate Medical Research and Education, Bournemouth University, Bournemouth, United Kingdom.,Research Institute for Sport Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - Kyo Bye
- The Defence Medical Services, Lichfield, United Kingdom
| | - Luke Sevier
- Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, United Kingdom
| | - Josh Bakker-Dyos
- Research Institute for Sport Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - David R Woods
- Research Institute for Sport Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom.,The Defence Medical Services, Lichfield, United Kingdom.,Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.,Department of Academic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | | | - Adrian Mellor
- The Defence Medical Services, Lichfield, United Kingdom.,James Cook University Hospital, Middlesbrough, United Kingdom
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Boos CJ, Vincent E, Mellor A, O'Hara J, Newman C, Cruttenden R, Scott P, Cooke M, Matu J, Woods DR. The Effect of Sex on Heart Rate Variability at High Altitude. Med Sci Sports Exerc 2018; 49:2562-2569. [PMID: 28731986 DOI: 10.1249/mss.0000000000001384] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
There is evidence suggesting that high altitude (HA) exposure leads to a fall in heart rate variability (HRV) that is linked to the development of acute mountain sickness (AMS). The effects of sex on changes in HRV at HA and its relationship to AMS are unknown. METHODS HRV (5-min single-lead ECG) was measured in 63 healthy adults (41 men and 22 women) 18-56 yr of age at sea level (SL) and during a HA trek at 3619, 4600, and 5140 m, respectively. The main effects of altitude (SL, 3619 m, 4600 m, and 5140 m) and sex (men vs women) and their potential interaction were assessed using a factorial repeated-measures ANOVA. Logistic regression analyses were performed to assess the ability of HRV to predict AMS. RESULTS Men and women were of similar age (31.2 ± 9.3 vs 31.7 ± 7.5 yr), ethnicity, and body and mass index. There was main effect for altitude on heart rate, SD of normal-to-normal (NN) intervals (SDNN), root mean square of successive differences (RMSSD), number of pairs of successive NN differing by >50 ms (NN50), NN50/total number of NN, very low-frequency power, low-frequency (LF) power, high-frequency (HF) power, and total power (TP). The most consistent effect on post hoc analysis was reduction in these HRV measures between 3619 and 5140 m at HA. Heart rate was significantly lower and SDNN, RMSSD, LF power, HF power, and TP were higher in men compared with women at HA. There was no interaction between sex and altitude for any of the HRV indices measured. HRV was not predictive of AMS development. CONCLUSIONS Increasing HA leads to a reduction in HRV. Significant differences between men and women emerge at HA. HRV was not predictive of AMS.
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Affiliation(s)
- Christopher John Boos
- 1Department of Cardiology, Poole Hospital NHS Foundation trust, Poole, UNITED KINGDOM; 2Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, UNITED KINGDOM; 3Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UNITED KINGDOM; 4Defence Medical Services, Lichfield, UNITED KINGDOM; 5Department of Anaesthetics, James Cook University Hospital, Middlesbrough, UNITED KINGDOM; 6Department of Medicine, Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UNITED KINGDOM; and 7Department of Academic Medicine, University of Newcastle, Newcastle upon Tyne, UNITED KINGDOM
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21
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Muza SR. Wearable physiological sensors and real-time algorithms for detection of acute mountain sickness. J Appl Physiol (1985) 2018; 124:557-563. [DOI: 10.1152/japplphysiol.00367.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
This is a minireview of potential wearable physiological sensors and algorithms (process and equations) for detection of acute mountain sickness (AMS). Given the emerging status of this effort, the focus of the review is on the current clinical assessment of AMS, known risk factors (environmental, demographic, and physiological), and current understanding of AMS pathophysiology. Studies that have examined a range of physiological variables to develop AMS prediction and/or detection algorithms are reviewed to provide insight and potential technological roadmaps for future development of real-time physiological sensors and algorithms to detect AMS. Given the lack of signs and nonspecific symptoms associated with AMS, development of wearable physiological sensors and embedded algorithms to predict in the near term or detect established AMS will be challenging. Prior work using [Formula: see text], HR, or HRv has not provided the sensitivity and specificity for useful application to predict or detect AMS. Rather than using spot checks as most prior studies have, wearable systems that continuously measure SpO2 and HR are commercially available. Employing other statistical modeling approaches such as general linear and logistic mixed models or time series analysis to these continuously measured variables is the most promising approach for developing algorithms that are sensitive and specific for physiological prediction or detection of AMS.
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Affiliation(s)
- Stephen R. Muza
- Strategic Science Management Office, US Army Research Institute of Environmental Medicine, Natick, Massachusetts
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22
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Abstract
INTRODUCTION The autonomic system and sympathetic activation appears integral in the pathogenesis of acute mountain sickness (AMS) at high altitude (HA), yet a link between heart rate variability (HRV) and AMS has not been convincingly shown. In this study we investigated the utility of the smartphone-derived HRV score to predict and diagnose AMS at HA. METHODS Twenty-one healthy adults were investigated at baseline at 1400 m and over 10 days during a trek to 5140 m. HRV was recorded using the ithlete HRV device. RESULTS Acute mountain sickness occurred in 11 subjects (52.4%) at >2650 m. HRV inversely correlated with AMS Scores (r = -0.26; 95% CI, -0.38 to -0.13: P < 0.001). HRV significantly fell at 3700, 4100, and 5140 m versus low altitude. HRV scores were lower in those with both mild (69.7 ± 14.0) and severe AMS (67.1 ± 13.1) versus those without AMS (77.5 ± 13.1; effect size n = 0.043: P = 0.007). The HRV score was weakly predictive of severe AMS (AUC 0.74; 95% CI, 0.58-0.89: P = 0.006). The change (delta) in the HRV Score (compared with baseline at 1400 m) was a moderate diagnostic marker of severe AMS (AUC 0.80; 95% CI, 0.70-0.90; P = 0.0004). A fall in the HRV score of >5 had a sensitivity of 83% and specificity of 60% to identify severe AMS (likelihood ratio 1.9). Baseline HRV at 1400 m was not predictive of either AMS at higher altitudes. CONCLUSIONS The ithlete HRV score can be used to help in the identification of severe AMS; however, a baseline score is not predictive of future AMS development at HA.
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Sutherland A, Freer J, Evans L, Dolci A, Crotti M, Macdonald JH. MEDEX 2015: Heart Rate Variability Predicts Development of Acute Mountain Sickness. High Alt Med Biol 2017; 18:199-208. [DOI: 10.1089/ham.2016.0145] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Angus Sutherland
- Anaesthetic Department, Portsmouth Hospitals Trust, Queen Alexandra Hospital, Portsmouth, United Kingdom
| | - Joseph Freer
- The BMJ, BMA House, Tavistock Square, London, United Kingdom
| | - Laura Evans
- Intensive Care Department, Northern General Hospital, Sheffield, United Kingdom
| | - Alberto Dolci
- Faculty of Science and Technology, University of Westminster, London, United Kingdom
| | - Matteo Crotti
- School of Exercise and Sports Sciences, Università degli Studi di Milano, Milan, Italy
| | - Jamie Hugo Macdonald
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
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24
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Gonggalanzi, Labasangzhu, Bjertness E, Wu T, Stigum H, Nafstad P. Acute mountain sickness, arterial oxygen saturation and heart rate among Tibetan students who reascend to Lhasa after 7 years at low altitude: a prospective cohort study. BMJ Open 2017; 7:e016460. [PMID: 28698346 PMCID: PMC5726117 DOI: 10.1136/bmjopen-2017-016460] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Objectives The aim of the present study was to estimate the incidence of acute mountain sickness (AMS) and address the changes in arterial oxygen saturation (SaO2) and heart rate (HR) in native Tibetans who reascend to the high-altitude city of Lhasa (3658 m) after a 7-year stay at low altitude. Methods We followed two cohorts of students aged 17–21 years (859 Native Tibetan and 801 Han Chinese), travelling from lowland China until 3 days after their arrival in highland city of Lhasa. Questionnaire information of the symptoms of AMS using the Lake Louise Scoring System, resting SaO2 and HR were assessed both before leaving the lowland and after arriving in Lhasa. Linear regression was performed to compare changes in SaO2 and HR levels from low to high altitude in Tibetan and Han Chinese. Results New cases of AMS occurred in only 1.2% (95% CI 0.4% to 2.0%) of the Tibetan students who came to Lhasa by train compared with 32.7% (95% CI 28.0% to 37.3%) and 42.9% (95% CI 38.0% to 47.7%) of the Han Chinese students who came to Lhasa by train and by air, respectively. Tibetan students had less changes in SaO2 (−2.95 percentage points, 95% CI −3.24% to −2.65%) and HR (10.89 beats per minute (bpm), 95% CI 9.62 to 12.16 bpm) from low to high altitude compared with Han Chinese students, although measurements did not differ between the two groups when measured at low altitude. Conclusions Healthy Tibetans are mostly protected against AMS and primarily maintain their good adaptation to high altitude, even after a long period of stay at low altitude.
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Affiliation(s)
- Gonggalanzi
- Tibet University Medical College, Tibet, China
| | - Labasangzhu
- Tibet University Medical College, Tibet, China
| | - Espen Bjertness
- Tibet University Medical College, Tibet, China.,Faculty of Medicine,University of Oslo, Oslo, Norway
| | - Tianyi Wu
- Tibet University Medical College, Tibet, China.,National Key Laboratory of High-Altitude Medicine, Xining, Qinghai, China
| | - Hein Stigum
- Faculty of Medicine,University of Oslo, Oslo, Norway.,Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
| | - Per Nafstad
- Faculty of Medicine,University of Oslo, Oslo, Norway.,Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
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25
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Riley CJ, Gavin M. Physiological Changes to the Cardiovascular System at High Altitude and Its Effects on Cardiovascular Disease. High Alt Med Biol 2017; 18:102-113. [PMID: 28294639 DOI: 10.1089/ham.2016.0112] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Riley, Callum James, and Matthew Gavin. Physiological changes to the cardiovascular system at high altitude and its effects on cardiovascular disease. High Alt Med Biol. 18:102-113, 2017.-The physiological changes to the cardiovascular system in response to the high altitude environment are well understood. More recently, we have begun to understand how these changes may affect and cause detriment to cardiovascular disease. In addition to this, the increasing availability of altitude simulation has dramatically improved our understanding of the physiology of high altitude. This has allowed further study on the effect of altitude in those with cardiovascular disease in a safe and controlled environment as well as in healthy individuals. Using a thorough PubMed search, this review aims to integrate recent advances in cardiovascular physiology at altitude with previous understanding, as well as its potential implications on cardiovascular disease. Altogether, it was found that the changes at altitude to cardiovascular physiology are profound enough to have a noteworthy effect on many forms of cardiovascular disease. While often asymptomatic, there is some risk in high altitude exposure for individuals with certain cardiovascular diseases. Although controlled research in patients with cardiovascular disease was largely lacking, meaning firm conclusions cannot be drawn, these risks should be a consideration to both the individual and their physician.
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Affiliation(s)
| | - Matthew Gavin
- 2 University of Leeds School of Biomedical Sciences , Leeds, United Kingdom
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26
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Effects of rapid ascent on the heart rate variability of individuals with and without acute mountain sickness. Eur J Appl Physiol 2017; 117:757-766. [PMID: 28251400 DOI: 10.1007/s00421-017-3555-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/19/2017] [Indexed: 10/20/2022]
Abstract
PURPOSE Through time- and frequency-domain analysis, we compared the effects of acute hypobaric hypoxia on the changes in heart rate variability (HRV) following night sleeping and morning awakening in individuals with and without acute mountain sickness (AMS). METHOD Thirty-nine nonacclimatised healthy individuals were transported by bus from sea level to 3150 m within 3 h. Short-term HRV was measured two times a day-before sleeping (BS) and after awakening (AA)- at 3 days before ascent (T0), two consecutive nights at 3150 m (T1 and T2), and 2 days after descent (T3). AMS was diagnosed using the self-reported Lake Louise score questionnaire. RESULT AMS developed in 19 of 39 participants (48.7%). At sea level, individuals had higher HRV at AA than at BS, and the trend of increased HRV at AA remained unchanged at high altitude, irrespective of AMS. At T1 BS, low-frequency power in normalised unit was significantly lower in participants with AMS than in those without AMS. Compared with those at T1 BS, the square root of the mean squared differences of successive normal-normal (NN) intervals, the number of interval differences of successive NN intervals more than 50 ms (NN50), and the proportion derived by dividing NN50 by the total number of NN intervals at T1 AA significantly increased in participants without AMS but nonsignificantly decreased in those with AMS. CONCLUSION After rapid ascent, individuals with AMS did not demonstrate sympathetic hyperactivity but did exhibit withdrawal of cardiac vagal modulation in the morning following the first night's sleep.
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Liu B, Huang H, Wu G, Xu G, Sun BD, Zhang EL, Chen J, Gao YQ. A Signature of Circulating microRNAs Predicts the Susceptibility of Acute Mountain Sickness. Front Physiol 2017; 8:55. [PMID: 28228730 PMCID: PMC5296306 DOI: 10.3389/fphys.2017.00055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/23/2017] [Indexed: 12/21/2022] Open
Abstract
Background: Acute mountain sickness (AMS) is a common disabling condition in individuals experiencing high altitudes, which may progress to life-threatening high altitude cerebral edema. Today, no established biomarkers are available for prediction the susceptibility of AMS. MicroRNAs emerge as promising sensitive and specific biomarkers for a variety of diseases. Thus, we sought to identify circulating microRNAs suitable for prediction the susceptible of AMS before exposure to high altitude. Methods: We enrolled 109 healthy man adults and collected blood samples before their exposure to high altitude. Then we took them to an elevation of 3648 m for 5 days. Circulating microRNAs expression was measured by microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). AMS was defined as Lake Louise score ≥3 and headache using Lake Louise Acute Mountain Sickness Scoring System. Results: A total of 31 microRNAs were differentially expressed between AMS and Non-AMS groups, 15 up-regulated and 16 down-regulated. Up-regulation of miR-369-3p, miR-449b-3p, miR-136-3p, and miR-4791 in patients with AMS compared with Non-AMS individuals were quantitatively confirmed using qRT-PCR (all, P < 0.001). With multiple logistic regression analysis, a unique signature encompassing miR-369-3p, miR-449b-3p, and miR-136-3p discriminate AMS from Non-AMS (area under the curve 0.986, 95%CI 0.970–1.000, P < 0.001, LR+: 14.21, LR–: 0.08). This signature yielded a 92.68% sensitivity and a 93.48% specificity for AMS vs. Non-AMS. Conclusion: The study here, for the first time, describes a signature of three circulating microRNAs as a robust biomarker to predict the susceptibility of AMS before exposure to high altitude.
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Affiliation(s)
- Bao Liu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - He Huang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Gang Wu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Gang Xu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Bing-Da Sun
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Er-Long Zhang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Jian Chen
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Yu-Qi Gao
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
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28
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Giles D, Kelly J, Draper N. Alterations in autonomic cardiac modulation in response to normobaric hypoxia. Eur J Sport Sci 2016; 16:1023-31. [DOI: 10.1080/17461391.2016.1207708] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Taralov ZZ, Terziyski KV, Kostianev SS. Heart Rate Variability as a Method for Assessment of the Autonomic Nervous System and the Adaptations to Different Physiological and Pathological Conditions. Folia Med (Plovdiv) 2016; 57:173-80. [PMID: 27180343 DOI: 10.1515/folmed-2015-0036] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/07/2016] [Indexed: 01/08/2023] Open
Abstract
The autonomic nervous system controls the smooth muscles of the internal organs, the cardiovascular system and the secretory function of the glands and plays a major role in the processes of adaptation. Heart rate variability is a non-invasive and easily applicable method for the assessment of its activity. The following review describes the origin, parameters and characteristics of this method and its potential for evaluation of the changes of the autonomic nervous system activity in different physiological and pathological conditions such as exogenous hypoxia, physical exercise and sleep. The application of heart rate variability in daily clinical practice would be beneficial for the diagnostics, the outcome prognosis and the assessment of the effect of treatment in various diseases.
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Affiliation(s)
- Zdravko Z Taralov
- Department of Pathophysiology, Faculty of Medicine, Medical University, Plovdiv, Bulgaria
| | - Kiril V Terziyski
- Department of Pathophysiology, Faculty of Medicine, Medical University, Plovdiv, Bulgaria
| | - Stefan S Kostianev
- Department of Pathophysiology, Faculty of Medicine, Medical University, Plovdiv, Bulgaria
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30
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Boos CJ, Bakker-Dyos J, Watchorn J, Woods DR, O'Hara JP, Macconnachie L, Mellor A. A comparison of two methods of heart rate variability assessment at high altitude. Clin Physiol Funct Imaging 2016; 37:582-587. [PMID: 26769455 DOI: 10.1111/cpf.12334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 11/03/2015] [Indexed: 11/30/2022]
Abstract
Heart rate variability (HRV) is a useful index of autonomic function and has been linked to the development of high altitude (HA) related illness. However, its assessment at HA has been undermined by the relative expense and limited portability of traditional HRV devices which have mandated at least a minute heart rate recording. In this study, the portable ithlete™ HRV system, which uses a 55 s recording, was compared with a reference method of HRV which utilizes a 5 min electrocardiograph recording (CheckMyHeart™ ). The root mean squares of successive R-R intervals (RMSSD) for each device was converted to a validated HRV score (lnRMSSD × 20) for comparison. Twelve healthy volunteers were assessed for HRV using the two devices across seven time points at HA over 10 days. There was no significant change in the HRV values with either the ithlete (P = 0·3) or the CheckMyHeart™ (P = 0·19) device over the seven altitudes. There was also a strong overall correlation between the ithlete™ and CheckMyHeart™ device (r = 0·86; 95% confidence interval: 0·79-0·91). The HRV was consistently, though non-significantly higher with ithlete™ than with the CheckMyHeart™ device [mean difference (bias) 1·8 l; 95% CI -12·3 to 8·5]. In summary, the ithlete™ and CheckMyHeart™ system provide relatively similar results with good overall agreement at HA.
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Affiliation(s)
- Christopher John Boos
- Department of Cardiology, Poole Hospital NHS Foundation trust, UK.,Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, UK
| | | | | | - David Richard Woods
- Defence Medical Services, Lichfield, UK.,Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.,Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK.,University of Newcastle, Newcastle upon Tyne, UK
| | - John Paul O'Hara
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Lee Macconnachie
- Department of Cardiology, Poole Hospital NHS Foundation trust, UK
| | - Adrian Mellor
- Defence Medical Services, Lichfield, UK.,Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.,James Cook University Hospital, Middlesborough, UK
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Bian SZ, Jin J, Zhang JH, Li QN, Yu J, Yu SY, Chen JF, Yu XJ, Qin J, Huang L. Principal Component Analysis and Risk Factors for Acute Mountain Sickness upon Acute Exposure at 3700 m. PLoS One 2015; 10:e0142375. [PMID: 26554385 PMCID: PMC4640520 DOI: 10.1371/journal.pone.0142375] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/21/2015] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE We aimed to describe the heterogeneity in the clinical presentation of acute mountain sickness (AMS) and to identify its primary risk factors. METHODS The participants (n = 163) received case report form questionnaires, and their heart rate (HR), oxygen saturation (SpO2), echocardiographic and transcranial Doppler variables, ability to perform mental and physical work, mood and psychological factors were assessed within 18 to 22 hours after arriving at 3700 m from sea level (500 m) by plane. First, we examined the differences in all variables between the AMS-positive and the AMS-negative groups. Second, an adjusted regression analysis was performed after correlation and principal component analyses. RESULTS The AMS patients had a higher diastolic vertebral artery velocity (Vd; p = 0.018), a higher HR (p = 0.006) and a lower SpO2. The AMS subjects also experienced poorer sleep quality, as quantified using the Athens Insomnia Scale (AIS). Moreover, the AMS population exhibited more negative mood states, including anxiety, depression, hostility, fatigue and confusion. Five principal components focused on diverse aspects were also found to be significant. Additionally, more advanced age (p = 0.007), a higher HR (p = 0.034), a higher Vd (p = 0.014), a higher AIS score (p = 0.030), a decreased pursuit aiming capacity (p = 0.035) and decreased vigor (p = 0.015) were risk factors for AMS. CONCLUSIONS Mood states play critical roles in the development of AMS. Furthermore, an elevated HR and Vd, advanced age, elevated AIS sores, insufficient vigor and decreased mental work capacity are independent risk factors for AMS.
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Affiliation(s)
- Shi-Zhu Bian
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jun Jin
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Ji-Hang Zhang
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qian-Ning Li
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jie Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Shi-Yong Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jian-Fei Chen
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xue-Jun Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jun Qin
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Lan Huang
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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32
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Swenson ER. Pharmacology of acute mountain sickness: old drugs and newer thinking. J Appl Physiol (1985) 2015; 120:204-15. [PMID: 26294748 DOI: 10.1152/japplphysiol.00443.2015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/12/2015] [Indexed: 01/09/2023] Open
Abstract
Pharmacotherapy in acute mountain sickness (AMS) for the past half century has largely rested on the use of carbonic anhydrase (CA) inhibitors, such as acetazolamide, and corticosteroids, such as dexamethasone. The benefits of CA inhibitors are thought to arise from their known ventilatory stimulation and resultant greater arterial oxygenation from inhibition of renal CA and generation of a mild metabolic acidosis. The benefits of corticosteroids include their broad-based anti-inflammatory and anti-edemagenic effects. What has emerged from more recent work is the strong likelihood that drugs in both classes act on other pathways and signaling beyond their classical actions to prevent and treat AMS. For the CA inhibitors, these include reduction in aquaporin-mediated transmembrane water transport, anti-oxidant actions, vasodilation, and anti-inflammatory effects. In the case of corticosteroids, these include protection against increases in vascular endothelial and blood-brain barrier permeability, suppression of inflammatory cytokines and reactive oxygen species production, and sympatholysis. The loci of action of both classes of drug include the brain, but may also involve the lung as revealed by benefits that arise with selective administration to the lungs by inhalation. Greater understanding of their pluripotent actions and sites of action in AMS may help guide development of better drugs with more selective action and fewer side effects.
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Affiliation(s)
- Erik R Swenson
- Veterans Affairs Puget Sound Health Care System, Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington, Seattle
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Taralov Z, Terziyski K, Dimov P, Marinov B, Tarvainen MP, Perini R, Kostianev S. Assessment of the acute impact of normobaric hypoxia as a part of an intermittent hypoxic training on heart rate variability. COR ET VASA 2015. [DOI: 10.1016/j.crvasa.2015.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yano T, Afroundeh R, Yamanaka R, Arimitsu T, Lian CS, Shirakawa K, Yunoki T. Oscillation in O2 uptake in impulse exercise. ACTA PHYSIOLOGICA HUNGARICA 2014; 101:143-149. [PMID: 24901075 DOI: 10.1556/aphysiol.101.2014.2.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The purpose of the present study was to examine 1) whether O(2) uptake (VO(2)) oscillates during light exercise and 2) whether the oscillation is enhanced after impulse exercise. After resting for 1 min on a bicycle seat, subjects performed 5-min pre-exercise with 25 watts work load, 10-s impulse exercise with 200 watts work load and 15-min post exercise with 25 watts work load at 80 rpm. VO(2) during pre-exercise significantly increased during impulse exercise and suddenly decreased and re-increased until 23 s after impulse exercise. In the cross correlation between heart rate (HR) and VO(2) after impulse exercise, VO(2) strongly correlated to HR with a time delay of -4 s. Peak of power spectral density (PSD) in HR appeared at 0.0039 Hz and peak of PSD in VO(2) appeared at 0.019 Hz. The peak of the cross power spectrum between VO(2) and HR appeared at 0.0078 Hz. The results suggested that there is an oscillation in O(2) uptake during light exercise that is associated with the oscillation in O(2) consumption in active muscle. The oscillation is enhanced not only by change in O(2) consumption but also by O(2) content transported from active muscle to the lungs.
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Affiliation(s)
- T Yano
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - R Afroundeh
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - R Yamanaka
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - T Arimitsu
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - C S Lian
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - K Shirakawa
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - T Yunoki
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
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Kriemler S, Bürgi F, Wick C, Wick B, Keller M, Wiget U, Schindler C, Kaufmann BA, Kohler M, Bloch K, Brunner-La Rocca HP. Prevalence of Acute Mountain Sickness at 3500 m Within and Between Families: A Prospective Cohort Study. High Alt Med Biol 2014; 15:28-38. [DOI: 10.1089/ham.2013.1073] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Susi Kriemler
- Institute of Social and Preventive Medicine, University of Zürich, Zurich, Switzerland
| | - Flavia Bürgi
- Institute of Social and Preventive Medicine, University of Zürich, Zurich, Switzerland
| | - Christian Wick
- Institute of Exercise and Health Sciences, University of Basel, Basel, Switzerland
| | - Birgit Wick
- Institute of Exercise and Health Sciences, University of Basel, Basel, Switzerland
| | - Melanie Keller
- Institute of Exercise and Health Sciences, University of Basel, Basel, Switzerland
| | - Urs Wiget
- Swiss Society for Emergency Medicine, Bern, Switzerland
| | - Christian Schindler
- Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Beat A. Kaufmann
- Division of Cardiology, University Hospital Basel, Basel, Switzerland
| | - Malcolm Kohler
- Pulmonary Division, University Hospital Zürich, Zurich, Switzerland
| | - Konrad Bloch
- Pulmonary Division, University Hospital Zürich, Zurich, Switzerland
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