Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 313
Filtrar
1.
Physiol Rep ; 8(24): e14615, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33340275

RESUMO

Recent reports suggest that high-altitude residence may be beneficial in the novel coronavirus disease (COVID-19) implicating that traveling to high places or using hypoxic conditioning thus could be favorable as well. Physiological high-altitude characteristics and symptoms of altitude illnesses furthermore seem similar to several pathologies associated with COVID-19. As a consequence, high altitude and hypoxia research and related clinical practices are discussed for potential applications in COVID-19 prevention and treatment. We summarize the currently available evidence on the relationship between altitude/hypoxia conditions and COVID-19 epidemiology and pathophysiology. The potential for treatment strategies used for altitude illnesses is evaluated. Symptomatic overlaps in the pathophysiology of COVID-19 induced ARDS and high altitude illnesses (i.e., hypoxemia, dyspnea…) have been reported but are also common to other pathologies (i.e., heart failure, pulmonary embolism, COPD…). Most treatments of altitude illnesses have limited value and may even be detrimental in COVID-19. Some may be efficient, potentially the corticosteroid dexamethasone. Physiological adaptations to altitude/hypoxia can exert diverse effects, depending on the constitution of the target individual and the hypoxic dose. In healthy individuals, they may optimize oxygen supply and increase mitochondrial, antioxidant, and immune system function. It is highly debated if these physiological responses to hypoxia overlap in many instances with SARS-CoV-2 infection and may exert preventive effects under very specific conditions. The temporal overlap of SARS-CoV-2 infection and exposure to altitude/hypoxia may be detrimental. No evidence-based knowledge is presently available on whether and how altitude/hypoxia may prevent, treat or aggravate COVID-19. The reported lower incidence and mortality of COVID-19 in high-altitude places remain to be confirmed. High-altitude illnesses and COVID-19 pathologies exhibit clear pathophysiological differences. While potentially effective as a prophylactic measure, altitude/hypoxia is likely associated with elevated risks for patients with COVID-19. Altogether, the different points discussed in this review are of possibly some relevance for individuals who aim to reach high-altitude areas. However, due to the ever-changing state of understanding of COVID-19, all points discussed in this review may be out of date at the time of its publication.


Assuntos
Aclimatação , Doença da Altitude/fisiopatologia , Altitude , /fisiopatologia , Doença da Altitude/epidemiologia , Doença da Altitude/terapia , Animais , /terapia , Humanos , Prevalência , Prognóstico , Fatores de Proteção , Medição de Risco , Fatores de Risco
2.
Wilderness Environ Med ; 31(2): 157-164, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32205041

RESUMO

INTRODUCTION: A history of preexisting hypertension is common in people participating in mountain activities; however, the relationship between blood pressure (BP), preexisting hypertension, and acute mountain sickness (AMS) is not well studied. We sought to determine these relationships among trekkers in the Everest region of Nepal. METHODS: This was a prospective observational cohort study of a convenience sample of adult, nonpregnant volunteers trekking in the Everest Base Camp region in Nepal. We recorded Lake Louise Scores for AMS and measured BP at 2860 m, 3400 m, and 4300 m. The primary outcome was AMS. RESULTS: A total of 672 trekkers (including 60 with history of preexisting hypertension) were enrolled at 2860 m. We retained 529 at 3400 m and 363 at 4300 m. At 3400 m, 11% of participants had AMS, and 13% had AMS at 4300 m. We found no relationship between AMS and measured BP values (P>0.05), nor was there any relation of BP to AMS severity as measured by higher Lake Louise Scores (P>0.05). Preexisting hypertension (odds ratio [OR] 0.16; 95% CI 0.025-0.57), male sex (OR 0.59; 95% CI 0.37-0.96), and increased SpO2 (OR 0.93; 95% CI 0.87-0.98) were associated with reduced rates of AMS in multivariate analyses adjusting for known risk factors for AMS. CONCLUSIONS: AMS is common in trekkers in Nepal, even at 3400 m. There is no relationship between measured BP and AMS. However, a medical history of hypertension may be associated with a lower risk of AMS. More work is needed to confirm this novel finding.


Assuntos
Doença da Altitude/epidemiologia , Altitude , Hipertensão/complicações , Montanhismo , Doença Aguda/epidemiologia , Adulto , Idoso , Doença da Altitude/etiologia , Doença da Altitude/fisiopatologia , Pressão Sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Prevalência , Estudos Prospectivos , Fatores de Risco
3.
J. health med. sci. (Print) ; 6(1): 9-16, ene.-mar. 2020.
Artigo em Espanhol | LILACS | ID: biblio-1096527

RESUMO

Evidencias en textos históricos Chinos de los años 403 AC y de la Conquista Española en 1590, muestran de las condiciones singulares que afectaban tanto a hombres como a animales al ascender por sectores montañosos por sobre 4000 m., y que ahora reconocemos como mal agudo de montaña. Ya desde el siglo XIX, se ha reconocido que es la falta de oxígeno (hipoxia) el factor determinante de la respuesta aclimatatoria como de la desaclimatización a la hipoxia de altura. El objetivo de la actual revisión fue una puesta al día de definiciones, factores que inciden en una mayor incidencia de mal agudo de montaña, mecanismo fisiológico propuesto, el desarrollo de estrategias farmacológicas para la prevención y/o tratamiento y por último, se ha revisado respecto de las distintas estrategias que se han desarrollado para la evaluación de la susceptibilidad individual, conocido comúnmente como test de hipoxia.


Some Chinese historical text from 403 BC and the Spanish Conquest in 1590 indicates unique conditions that affected both men and animals when climbing mountainous areas over 4000 m. and that is currently known as Acute Mountain Sickness (MAM). Since the XIX century, the lack of oxygen (hypoxia), has been recognized as the main factor of the acclimatization and declimatization to the high altitude hypoxia. The aim of the current revision is an update of definitions, factors that contribute the Acute Mountain Sickness, the proposed physiological mechanism, the development of pharmacological strategies for the prevention and/or treatment, and finally, we reviewed the different strategies developed for the individual susceptibility assessment, generally known as hypoxia test.


Assuntos
Humanos , Doença da Altitude/fisiopatologia , Doença da Altitude/tratamento farmacológico , Doença da Altitude/epidemiologia , Fatores de Risco , Suscetibilidade a Doenças , Doença da Altitude/etiologia
4.
Am J Physiol Regul Integr Comp Physiol ; 318(1): R49-R56, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31617751

RESUMO

Excessive erythrocytosis (EE) is the main sign of chronic mountain sickness (CMS), a maladaptive clinical syndrome prevalent in Andean and other high-altitude populations worldwide. The pathophysiological mechanism of EE is still controversial, as physiological variability of systemic respiratory, cardiovascular, and hormonal responses to chronic hypoxemia complicates the identification of underlying causes. Induced pluripotent stem cells derived from CMS highlanders showed increased expression of genes relevant to the regulation of erythropoiesis, angiogenesis, cardiovascular, and steroid-hormone function that appear to explain the exaggerated erythropoietic response. However, the cellular response to hypoxia in native CMS cells is yet unknown. This study had three related aims: to determine the hypoxic proliferation of native erythroid progenitor burst-forming unit-erythroid (BFU-E) cells derived from CMS and non-CMS peripheral blood mononuclear cells; to examine their sentrin-specific protease 1 (SENP1), GATA-binding factor 1 (GATA1), erythropoietin (EPO), and EPO receptor (EPOR) expression; and to investigate the functional upstream role of SENP1 in native progenitor differentiation into erythroid precursors. Native CMS BFU-E colonies showed increased proliferation under hypoxic conditions compared with non-CMS cells, together with an upregulated expression of SENP1, GATA1, EPOR; and no difference in EPO expression. Knock-down of the SENP1 gene abolished the augmented proliferative response. Thus, we demonstrate that native CMS progenitor cells produce a larger proportion of erythroid precursors under hypoxia and that SENP1 is essential for proliferation. Our findings suggest a significant intrinsic component for developing EE in CMS highlanders at the cellular and gene expression level that could be further enhanced by systemic factors such as alterations in respiratory control, or differential hormonal patterns.


Assuntos
Doença da Altitude/epidemiologia , Altitude , Células Precursoras Eritroides/metabolismo , Oxigênio/metabolismo , Oxigênio/farmacologia , Doença Crônica , Eritropoetina/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Homeostase , Humanos , Hipóxia , Ferro/metabolismo , Leucócitos Mononucleares , Transcriptoma
5.
Mil Med Res ; 6(1): 38, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31813379

RESUMO

BACKGROUND: When lowlanders rapidly ascend to altitudes > 2500 m, they may develop acute mountain sickness (AMS). The individual susceptibility, ascending velocity, time spent at altitude, activity levels and altitude reached are considered risk factors for AMS. However, it is not clear whether sex is a risk factor. The results have been inconclusive. We conducted a meta-analysis to test whether there were sex-based differences in the prevalence of AMS using Lake Louise Scoring System. METHODS: Systematic searches were performed in August 2019 in EMBASE, PubMed, and Web of Science for prospective studies with AMS data for men and women. The titles and abstracts were independently checked in the primary screening step, and the selected full-text articles were independently assessed in the secondary screening step by the two authors (YPH and JLW) based on pre-defined inclusion criteria. The meta-analysis was performed using by the STATA 14.1 software program. A random-effects model was employed. RESULTS: Eighteen eligible prospective studies were included. A total of 7669 participants (2639 [34.4%] women) were tested. The results showed that there was a statistically significant higher prevalence rate of AMS in women than in men (RR = 1.24, 95%CI 1.09-1.41), regardless of age or race. Howerver, the heterogeneity was significant in the analysis (Tau2 = 0.0403, Chi2 = 50.15, df = 17; I2 = 66.1%, P = 0.000), it was main caused by different numbers of subjects among the studies (coefficient = - 2.17, P = 0.049). Besides, the results showed that there was no evidence of significant publication bias in the combined studies on the basis of Egger's test (bias coefficient = 1.48, P = 0.052) and Begg's test (P = 0.130). CONCLUSIONS: According to this study, the statistically significant finding emerging from this study was that women have a higher prevalence of AMS. However, the authors could not exclude studies where patients were on acetazolamide. Our analysis provided a direction for future studies of the relationship of sex and the risk of AMS, such as the pathological mechanism and prevention research.


Assuntos
Doença da Altitude/epidemiologia , Fatores Sexuais , Doença Aguda , Altitude , Feminino , Humanos , Masculino , Prevalência , Fatores de Risco
6.
Dis Markers ; 2019: 5946461, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827636

RESUMO

Background: The hypoxic conditions at high altitudes are great threats to survival, causing pressure for adaptation. More and more high-altitude denizens are not adapted with the condition known as high-altitude polycythemia (HAPC) that featured excessive erythrocytosis. As a high-altitude sickness, the etiology of HAPC is still unclear. Methods: In this study, we reported the whole-genome sequencing-based study of 10 native Tibetans with HAPC and 10 control subjects followed by genotyping of selected 21 variants from discovered single nucleotide variants (SNVs) in an independent cohort (232 cases and 266 controls). Results: We discovered the egl nine homologue 3 (egln3/phd3) (14q13.1, rs1346902, P = 1.91 × 10-5) and PPP1R2P1 (Protein Phosphatase 1 Regulatory Inhibitor Subunit 2) gene (6p21.32, rs521539, P = 0.012). Our results indicated an unbiased framework to identify etiological mechanisms of HAPC and showed that egln3/phd3 and PPP1R2P1 may be associated with the susceptibility to HAPC. Egln3/phd3b is associated with hypoxia-inducible factor subunit α (HIFα). Protein Phosphatase 1 Regulatory Inhibitor is associated with reactive oxygen species (ROS) and oxidative stress. Conclusions: Our genome sequencing conducted in Tibetan HAPC patients identified egln3/phd3 and PPP1R2P1 associated with HAPC.


Assuntos
Doença da Altitude/diagnóstico , Biomarcadores/análise , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Policitemia/diagnóstico , Polimorfismo de Nucleotídeo Único , Proteína Fosfatase 1/genética , Sequenciamento Completo do Genoma/métodos , Adulto , Idoso , Doença da Altitude/epidemiologia , Doença da Altitude/genética , Estudos de Casos e Controles , Feminino , Seguimentos , Genoma Humano , Genótipo , Humanos , Hipóxia , Masculino , Pessoa de Meia-Idade , Policitemia/epidemiologia , Policitemia/genética , Prognóstico , Tibet/epidemiologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-31683707

RESUMO

Since little is known about the detailed situations of falls on Mount Fuji, the aim of this study was to clarify the risk factors of falls on Mount Fuji in Japan. We conducted a questionnaire survey of 556 participants who had climbed Mount Fuji and collected the following information: fall situation, mental status, fatigue feeling, sex, age, climbing experience on Mount Fuji and other mountains, summit success, whether staying at a lodge, use of a tour guide, and symptoms of acute mountain sickness. Among the 556 participants, 167 had a fall (30%). Among 167 participants who had experienced a fall, 30 had fallen more than three times (18%). The main cause (>60%) of fall were slips. The most optimal model using multiple logistic regression (no fall = 0, and fall = 1) found eight significant risk factors, including sex, prior climbing experience on Mount Fuji, staying overnight at a lodge, subjective feeling of relaxation, sleepiness, emotional stability, dullness, and eyestrain. These results suggest that females, people who have no prior climbing experience on Mount Fuji, and people who did not stay at a lodge should pay attention to an increased risk of falls on Mount Fuji.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Adulto , Doença da Altitude/complicações , Doença da Altitude/epidemiologia , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Inquéritos e Questionários
8.
High Alt Med Biol ; 20(4): 331-336, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31479310

RESUMO

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a prevalent disorder that confers substantial cardiovascular morbidity and, in serious cases, death. VTE has a complex and incompletely understood etiopathogenesis with genetic, acquired, and environmental risk factors. As the focus of this review, one environmental risk factor, which may interact with other risk factors such as hereditary and/or acquired thrombophilias, is travel to high altitude (HA), although current evidence is limited. As guidelines do not directly address this topic, we will discuss the epidemiology of HA-VTE, review the putative mechanisms for thrombosis at HA, and discuss our clinical approach to both risk stratification and counseling, including specific pharmacologic and nonpharmacologic recommendations for patients with elevated VTE risk before they travel to HA.


Assuntos
Doença da Altitude/complicações , Doença Relacionada a Viagens , Tromboembolia Venosa/etiologia , Altitude , Doença da Altitude/epidemiologia , Humanos , Prevalência , Fatores de Risco , Tromboembolia Venosa/epidemiologia
9.
High Alt Med Biol ; 20(4): 337-343, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411495

RESUMO

Background: The associations among cortisol levels, body water status, and acute mountain sickness (AMS) remain unclear. We investigated associations between AMS prevalence and severity with resting saliva cortisol levels at low altitude (LA) and high altitude (HA) and with fluid balance during a HA stay. Methods: Twenty-two physically fit and healthy participants (12 women, 10 men) were transported to HA (Testa Grigia, 3480 m). In the late afternoon at LA, on the next day 3-4 hours after arrival at HA and in the morning after an overnight stay, heart rate, oxygen saturation, and systolic and diastolic blood pressures were measured in a sitting position after 10 minutes of rest; cortisol levels were quantified in saliva samples taken pre-ascent and 3-4 hours after arrival at HA. AMS was scored with the 1993 Lake Louise Score (LLS, cut-off ≥3). Urine volume and fluid and food intake were recorded during the altitude stay. Results: Pre-ascent cortisol levels were associated with fluid retention during the altitude stay (r2 = 0.33, p < 0.05) and both were positively related to the LLS (r2 = 0.49 and r2 = 0.26, p < 0.05, respectively). Conclusions: In conclusion, resting LA cortisol levels and fluid retention upon rapid exposure to altitude seem to be associated with AMS. This suggests a potential link among cortisol homeostasis, fluid balance, and AMS risk.


Assuntos
Doença da Altitude/metabolismo , Hidrocortisona/análise , Montanhismo/fisiologia , Saliva/química , Índice de Gravidade de Doença , Acetazolamida/administração & dosagem , Doença Aguda , Adulto , Altitude , Doença da Altitude/epidemiologia , Diuréticos/administração & dosagem , Exposição Ambiental/efeitos adversos , Feminino , Voluntários Saudáveis , Humanos , Masculino , Prevalência , Descanso/fisiologia , Equilíbrio Hidroeletrolítico
10.
High Alt Med Biol ; 20(4): 344-351, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31328969

RESUMO

Background: Mechanisms underlying acute mountain sickness (AMS) remain unclear. Corticosteroids are effective for prevention and treatment suggesting a role for deficient endogenous cortisol. The cortisol awakening response (CAR), the increase in cortisol secretion over the first 30-45 minutes after morning awakening, better reflects the hypothalamic-pituitary-adrenal (HPA) axis than single cortisol measurements. We hypothesized that CAR may be altered in AMS-prone persons. Methods: Upon arrival at 4554 m (high altitude [HA]), 81 mountaineers agreed to participate. The following morning, they gave three saliva samples after awakening (S1: 0 minute, S2: 30 minutes, S3: 45 minutes). AMS was scored with the 1993 Lake Louise Score (LLS, cut-off ≥5). Minimally 4 weeks after descent, saliva was recollected by 58 of 81 participants at low altitude (LA); 382 ± 309 m, mean ± standard deviation). Cortisol was quantified by immunoassay. Three cortisol indices were analyzed: first sample on awakening (S1), CAR (area under curve with respect to S1) and total post awaking cortisol (area under the curve from ground [AUC-G]). Results: AMS prevalence was 30%. At HA compared to LA, S1 (450 ± 190 vs. 288 ± 159 ng/dL, p < 0.001) and AUC-G (387 ± 137 vs. 276 ± 114 ng/dL·min, p < 0.001) were greater, but CAR was not (50 ± 100 vs. 60 ± 81 ng/dL·min, p = 0.550). AMS+ compared to AMS- participants had higher S1 both at HA (495 ± 209 vs. 384 ± 176 ng/dL, p = 0.016) and LA (354 ± 160 vs. 253 ± 142 ng/dL, p = 0.015) and lower CAR at LA (24 ± 87 vs. 79 ± 72 ng/dL·min, p = 0.013). AUC-G was similar in both groups at HA and LA. Conclusions: Some indices of salivary cortisol response upon awakening differ between AMS+ and AMS-, both at HA and LA, suggesting a link between HPA-axis homeostasis and AMS.


Assuntos
Doença da Altitude/metabolismo , Hidrocortisona/metabolismo , Montanhismo/fisiologia , Saliva/química , Vigília/fisiologia , Adulto , Idoso , Altitude , Doença da Altitude/epidemiologia , Feminino , Humanos , Sistema Hipotálamo-Hipofisário , Masculino , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal , Prevalência , Adulto Jovem
11.
Value Health Reg Issues ; 20: 115-121, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31255923

RESUMO

BACKGROUND: Copper mining installations in Chile use a large number of workers who do their jobs at high altitudes, exposing them to the conditions of chronic intermittent hypobaric hypoxia. The Chilean Safety Association implements the surveillance program. OBJECTIVE: This organization, under the sponsorship of the Chilean Superintendency of Social Security, was interested in determining the costs involved in this program to support its decision-making processes and to improve its performance. METHODS: Direct operating costs of the Hypoxia Medical Surveillance Program were determined through on-site surveys applied to the organization's local agencies in charge. The microcosting method was used, quantifying personnel costs, consumables, and equipment and overhead costs. Time-driven activity-based costing was partially adapted for the allocation of personnel and equipment costs. Costs concerning activities, groups of activities and items, and average cost per exposed worker were determined. RESULTS: The annual costs of the program were $127 299.58. The highest costs corresponded to the assessment activities, which were $89 192.13, representing 60.06% of the total. The labor factor costs were $77 568.50, which represents 60.93% of the total. The average cost per worker in the program is $21.17. CONCLUSIONS: The partial adaptation of the time-driven activity-based costing method in combination with the microcosting method provides a suitable solution to determine the total costs of running a healthcare program of this kind. The information generated by this study will aid in the decision-making and management processes of the Hypoxia Medical Surveillance Program.


Assuntos
Doença da Altitude/economia , Cobre , Custos de Cuidados de Saúde/estatística & dados numéricos , Mineração/economia , Doenças Profissionais/economia , Medicina do Trabalho/economia , Doença da Altitude/epidemiologia , Doença da Altitude/etiologia , Doença da Altitude/prevenção & controle , Chile/epidemiologia , Humanos , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Medicina do Trabalho/métodos , Fatores de Tempo
12.
High Alt Med Biol ; 20(3): 271-278, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31259608

RESUMO

Background: Acetazolamide is the most common medication used for prevention of acute mountain sickness (AMS), usually administered the day or night before ascent. The objective of this study was to evaluate the efficacy of day of ascent dosing of acetazolamide for AMS prevention. Methods: Double-blind, randomized, controlled noninferiority trial of acetazolamide 125 mg twice daily beginning either the night before or the morning of ascent. Healthy low altitude adults ascended from 1240 m (4100 ft) to 3810 m (12,570 ft) during summer 2018 on White Mountain, California. Primary outcome was incidence of AMS with the two different dosing patterns, assessed by the 1993 Lake Louise Questionnaire (LLQ) of ≥3 with headache and a minimum of 1 for other symptom. Results: One hundred four participants completed the study, with 54 (52%) randomized to night before acetazolamide and 50 (48%) to day of ascent dosing, without differences in baseline characteristics. There was 9% greater incidence of AMS in the day of ascent acetazolamide group (48.0% vs. 39%, 95% confidence interval [CI] -11.8 to 30, p = 0.46, number needed to treat [NNT] = 5.6 vs. 3.7), with the CI just surpassing the predetermined 26% noninferiority margin. There was a lower incidence of severe AMS (1993 LLQ >5) in the day of ascent group (n = 5, 10%, NNT = 2.3) compared with night before dosing (n = 12, 22%, NNT = 3.1) (95% CI -28 to 3.6), and lower average symptom severity in the day of ascent group (3 vs. 3.5, 95% CI -0.5 to 1.4). Conclusions: Day of ascent acetazolamide demonstrated higher rates of AMS compared with traditional dosing by a small margin. With similar rates of severe AMS and overall symptom severity, the potential for improved convenience and compliance may support day of ascent use.


Assuntos
Acetazolamida/administração & dosagem , Doença da Altitude/prevenção & controle , Inibidores da Anidrase Carbônica/administração & dosagem , Cronoterapia Farmacológica , Montanhismo , Adulto , Doença da Altitude/epidemiologia , Método Duplo-Cego , Feminino , Humanos , Incidência , Masculino , Índice de Gravidade de Doença
13.
Int J Sports Med ; 40(7): 440-446, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31189189

RESUMO

This study aimed to evaluate the influence of physical activity on incidence of acute mountain sickness (AMS) by continuous activity monitoring in a free-living sample of South Pole workers over the initial 72 h at altitude exposure of 2,840 m (9,318 ft). Body Media activity monitors were worn by 47 healthy participants. AMS was defined by the Lake Louise symptom questionnaire. Venous blood samples were taken at sea level and approximately 48 h after high altitude exposure. AMS incidence was 34% (n=16/47) over the first 48 h and 40% (n=19/47) over 72 h. On day 2 at high altitude, individuals with AMS demonstrated a significantly greater increase in the percent change in physical activity metrics from baseline: total energy expenditure 19±13 vs. 5±7%, total steps 65±51 vs. 10±18%, metabolic equivalent of tasks 21±13 vs. 7±13%, and time spent performing moderate to vigorous physical activity 114±79 vs. 26±27% for individuals with AMS vs. no AMS, respectively, p<0.05. In addition, erythropoietin and vascular endothelial growth factor were 1.69 and 1.75 times higher, respectively, in those with AMS. In conclusion, workers who engaged in increased physical activity and activity intensity during initial exposure to the South Pole were more susceptible to developing AMS.


Assuntos
Doença da Altitude/fisiopatologia , Exercício Físico , Esforço Físico , Doença da Altitude/sangue , Doença da Altitude/epidemiologia , Regiões Antárticas/epidemiologia , Metabolismo Energético , Eritropoetina/sangue , Monitores de Aptidão Física , Humanos , Incidência , Fatores de Risco , Fator A de Crescimento do Endotélio Vascular/sangue
14.
Biomed Pharmacother ; 116: 109003, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31125823

RESUMO

Trimetazidine (TMZ) has been shown to optimize myocardial energy metabolism and is a common anti-ischemic agent. Our trial (ChiCTR-TRC-13003298) aimed to explore whether TMZ has any preventive effect on high-altitude fatigue (HAF), cardiac function and cardiorespiratory fitness upon acute high-altitude exposure and how it works on HAF. Thirty-nine healthy young subjects were enrolled in a randomized double-blinded placebo-controlled trial and were randomized to take oral TMZ (n = 20) or placebo (n = 19), 20 mg tid, 14 days prior to departure until the end of study. The 2018 Lake Louise Score questionnaire, echocardiography, assessments of physical working capacity, circulating markers of myocardial energy metabolism and fatigue were performed both before departure and arrival at highland. At follow-up, TMZ significantly reduced the incidence of HAF (p = 0.038), reversed cardiorespiratory fitness impairment, decreased left ventricular end-systolic volume (LVESV, p = 0.032) and enhanced left ventricular ejection fraction (LVEF, p = 0.015) at highland. Relative to the placebo group, the TMZ group had significantly lower LDH (p = 0.025) and lactate levels before (p < 0.001) and after (p = 0.012) physical exercise after acute high-altitude exposure. Additionally, improved left ventricular systolic function might have contributed to ameliorating HAF during TMZ treatment (LVEF, OR = 0.859, 95% CI = 0.741-0.996, p = 0.044). In conclusion, our results demonstrated that TMZ could prevent HAF, cardiorespiratory fitness impairment and improves left ventricular systolic function during acute high-altitude exposure. This trial provides new insights into the effect of TMZ and novel evidence against HAF and cardiorespiratory fitness impairment at highland.


Assuntos
Altitude , Aptidão Cardiorrespiratória/fisiologia , Fadiga/tratamento farmacológico , Fadiga/fisiopatologia , Trimetazidina/uso terapêutico , Adolescente , Doença da Altitude/sangue , Doença da Altitude/tratamento farmacológico , Doença da Altitude/epidemiologia , Doença da Altitude/fisiopatologia , Método Duplo-Cego , Metabolismo Energético/efeitos dos fármacos , Fadiga/sangue , Testes de Função Cardíaca , Humanos , Incidência , L-Lactato Desidrogenase/sangue , Lactatos/sangue , Miocárdio/metabolismo , Placebos , Análise de Regressão , Sístole/efeitos dos fármacos , Trimetazidina/farmacologia , Função Ventricular Esquerda/efeitos dos fármacos , Adulto Jovem
15.
J Physiol Anthropol ; 38(1): 4, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999951

RESUMO

BACKGROUND: High-altitude pulmonary edema (HAPE) is a life-threatening form of non-cardiogenic edema which occurs in unacclimatized individuals after rapid ascent to high altitude. NR3C1 gene encodes for glucocorticoid receptor (GR) which plays an important role in stress and inflammation. This study aimed to investigate the association of NR3C1 polymorphisms with the susceptibility to HAPE in Han Chinese. METHODS: The 30 SNPs in the NR3C1 gene were genotyped by the Sequenom MassARRAY SNP assay in 133 HAPE patients (HAPE-p) and 135 matched Han Chinese resistant to HAPE (HAPE-r). The genotypic and allele frequencies, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated, respectively. RESULTS: The 12 SNPs showed a significant difference between the HAPE-p and HAPE-r groups. In allelic model analysis, we found that the allele "A" of rs17287745, rs17209237, rs17209251, rs6877893, and rs1866388; the allele "C" of rs6191, rs6188, and rs2918417; the allele "T" of rs33388 and rs4634384; and the allele "G" of rs41423247 and rs10052957 were associated with increased the risk of HAPE. In the genetic model analysis, we found that rs17287745, rs6191, rs6188, rs33388, rs2918417, rs6877893, rs1866388, rs41423247, rs4634384, and rs10052957 were relevant to the increased HAPE risk under the dominant model. In addition, the haplotype AACACTCAAGTG of the 12 SNPs was detected to be significantly associated with HAPE risk (OR = 2.044, 95%CI = 1.339~3.120, P = 0.0008), while the haplotype GGAGCACGACCG was associated with the decreased risk of HAPE (OR = 0.573, 95% CI = 0.333~0.985, P = 0.0422). CONCLUSIONS: Our findings provide new evidence for the association between SNPs in NR3C1 and an increased risk of HAPE in the Chinese population. NR3C1 polymorphisms are associated with the susceptibility to HAPE in Han Chinese.


Assuntos
Doença da Altitude/epidemiologia , Doença da Altitude/genética , Grupo com Ancestrais do Continente Asiático/genética , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/genética , Receptores de Glucocorticoides/genética , Adulto , Altitude , China , Predisposição Genética para Doença/genética , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade
16.
Travel Med Infect Dis ; 31: 101356, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30502547

RESUMO

BACKGROUND: The study investigates the diagnoses of inpatients (tourists and Nepali workers) of Kunde Hospital (Mt.Everest region) over 15 years. METHODS: Records from January 1996 to September 2011 were analyzed concerning date, gender, age group, nationality, purpose of visit, diagnosis, length of treatment, and condition at discharge. Diagnoses were coded according to ICD-10-WHO 2010. Data were analyzed using descriptive statistics and non-parametric tests. P < 0.05 was defined as significant. RESULTS: 479 inpatients were included: 363 (75.8%) males (202 trekkers (42.2%), 277 Nepalese workers (57.8%)). Most suffered from altitude sickness (45.5%), acute gastroenteritis (10.4%) or acute respiratory infection (8.4%). Severe cases of altitude sickness amongst trekkers decreased but increased amongst workers. Severe cases of acute gastroenteritis amongst trekkers increased. Mean length of inpatient treatment was 4.6 days ±2.7 days. 573/2030 days of treatment were caused by altitude sickness. 70 patients were evacuated, 9 died. CONCLUSION: Altitude illness caused the majority of inpatient treatment and acute gastroenteritis may be an underestimated risk for both groups. Other severe problems were mostly illnesses, not trauma. Improved prevention strategies are needed for both groups. For tourists who often show pre-existing diseases this includes an individual pre-travel expert advice. Nepali workers should be instructed concerning acclimatization.


Assuntos
Doença da Altitude/terapia , Altitude , Gastroenterite/terapia , Hospitalização/estatística & dados numéricos , Montanhismo , Infecções Respiratórias/terapia , Viagem , Adulto , Doença da Altitude/epidemiologia , Feminino , Gastroenterite/epidemiologia , Humanos , Incidência , Masculino , Nepal , Infecções Respiratórias/epidemiologia , Estudos Retrospectivos
18.
High Alt Med Biol ; 19(4): 329-338, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30517038

RESUMO

OBJECTIVE: To determine whether 2 days of staging at 2500-3500 m, combined with either high or low physical activity, reduces acute mountain sickness (AMS) during subsequent ascent to 4300 m. METHODS: Three independent groups of unacclimatized men and women were staged for 2 days at either 2500 m (n = 18), 3000 m (n = 16), or 3500 m (n = 15) before ascending and living for 2 days at 4300 m and compared with a control group that directly ascended to 4300 m (n = 12). All individuals departed to the staging altitudes or 4300 m after spending one night at 2000 m during which they breathed supplemental oxygen to simulate sea level conditions. Half in each group participated in ∼3 hours of daily physical activity while half were sedentary. Women accounted for ∼25% of each group. AMS incidence was assessed using the Environmental Symptoms Questionnaire. AMS was classified as mild (≥0.7 and <1.5), moderate (≥1.5 and <2.6), and severe (≥2.6). RESULTS: While staging, the incidence of AMS was lower (p < 0.001) in the 2500 m (0%), 3000 m (13%), and 3500 m (40%) staged groups than the direct ascent control group (83%). After ascent to 4300 m, the incidence of AMS was lower in the 3000 m (43%) and 3500 m (40%) groups than the 2500 m group (67%) and direct ascent control (83%). Neither activity level nor sex influenced the incidence of AMS during further ascent to 4300 m. CONCLUSIONS: Two days of staging at either 3000 or 3500 m, with or without physical activity, reduced AMS during subsequent ascent to 4300 m but staging at 3000 m may be recommended because of less incidence of AMS.


Assuntos
Aclimatação/fisiologia , Doença da Altitude/prevenção & controle , Altitude , Oxigenoterapia/métodos , Doença Aguda , Doença da Altitude/epidemiologia , Doença da Altitude/etiologia , Exercício Físico/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Incidência , Masculino , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
19.
Wilderness Environ Med ; 29(4): 488-492, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30292562

RESUMO

INTRODUCTION: The mineralocorticoid receptor is encoded by the NR3C2 gene and plays an important role in regulating vascular tone in high-altitude pulmonary edema (HAPE). This study aimed to investigate the association of the polymorphisms in the NR3C2 gene with HAPE susceptibility in Han Chinese. METHODS: We enrolled 133 HAPE patients and 131 matched healthy Han Chinese from the Yushu area in Qinghai, where the altitude is greater than 3500 m. Two single nucleotide polymorphisms (SNPs) of the NR3C2 gene, rs2070951 and rs5522, were genotyped by the Sequenom MassARRAY SNP assay. RESULTS: The genotypic distributions and allele frequencies of NR3C2 SNP rs5522 were significantly different between the HAPE and control groups (P<0.05). The frequency of the A allele of rs5522 was significantly higher in the HAPE group than in the control group (P<0.05) with an odds ratio of 1.7 (95% CI: 1.0-2.8). There were no significant differences in the genotypic distributions and allele frequencies of NR3C2 SNP rs2070951 between the HAPE and control groups. The frequencies of the C-A and C-G haplotypes were significantly higher in the HAPE group than in control group. CONCLUSIONS: The rs5522 polymorphism of the NR3C2 gene was associated with HAPE susceptibility in Chinese subjects. The A allele may contribute to the susceptibility to HAPE. The frequency of the C-A and C-G haplotypes of rs2070951 and rs5522 in the NR3C2 gene may increase the risk of HAPE.


Assuntos
Doença da Altitude/genética , Grupo com Ancestrais do Continente Asiático/genética , Hipertensão Pulmonar/genética , Receptores de Mineralocorticoides/genética , Adulto , Doença da Altitude/epidemiologia , Doença da Altitude/fisiopatologia , China/epidemiologia , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença/genética , Genótipo , Humanos , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
20.
Wilderness Environ Med ; 29(4): 431-436, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30292563

RESUMO

INTRODUCTION: Porters working at high altitude face a number of preventable health risks ranging from frostbite to potentially fatal high-altitude pulmonary and cerebral edema. Porters are often recruited from impoverished low-altitude areas, poorly equipped in terms of protective clothing, and tasked with carrying loads that equal or exceed their body mass to high elevations. Despite a large population of porters working throughout mountainous parts of the world, there is little documentation regarding knowledge levels, attitudes, and practices related to the prevention of altitude illness in this population. Much of the literature focuses on biomechanics of load carrying for porters or altitude issues for trekkers. METHODS: A cross-sectional survey was developed using a modified Delphi technique. The survey was administered to a convenience sample of porters (n=146) from diverse cultural groups between Lukla (2774 m) and Everest Base Camp (5361 m). RESULTS: Many of the porters started at a young age, carried heavy loads, and had difficulty identifying symptoms of high altitude illness, and less than 20% correctly identified preventive measures for high-altitude illness. CONCLUSIONS: Porters in the Khumbu region continue to face hazards in their working environment. Future research and health education campaigns should address knowledge deficits and help with the design of tailored interventions.


Assuntos
Doença da Altitude/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Doenças Profissionais/prevenção & controle , Adolescente , Adulto , Doença da Altitude/diagnóstico , Doença da Altitude/epidemiologia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Inquéritos e Questionários , Populações Vulneráveis , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...