{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T14:49:33Z","timestamp":1792507773252,"version":"4.5.0"},"reference-count":42,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,3,26]],"date-time":"2021-03-26T00:00:00Z","timestamp":1616716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Physiol."],"abstract":"<jats:p>Over the past 40 years, mining activities in Chile have relocated miners who normally live at sea level to work at high altitudes. This results in a form of chronic intermittent hypobaric hypoxia (CIHH) characterized by alternating periods of work at high altitude and rest periods at sea level. Previous studies performed in our laboratory showed that aerobic capacity is reduced at 3,800 m, even when oxygen content is maintained. Our study aimed to determine the corporal composition, food intake, maximum oxygen uptake, and concentration of high sensitivity C reactive protein (<jats:italic>hs<\/jats:italic>CRP) in an acclimatized miner population that work from 0 to 2,500 m with CIHH exposure over 4 years. All miners recruited for our study were operators of heavy trucks with CIHH for over 4 years (shiftwork 7*7 days), and our experimental population was composed of 54 miners at sea level, 61 at 1,600 m, and 38 at 2,500 m. All evaluations were performed on the 3rd or 4th day of diurnal shiftwork. To determine corporal composition, we measured weight and height (to calculate body mass index, BMI), skinfolds (to calculate body fatty, BF), and waist circumference (WC); maximal aerobic capacity was evaluated using a ramp-incremental cycling to exhaustion protocol and a venous blood sample before the exercise test to measure (<jats:italic>hs<\/jats:italic>CRP) <jats:italic>via<\/jats:italic> an ELISA test. We found higher values of BMI, BF, and WC, in the miners\u2019 population but observed no significant difference between populations. We found a decrease in VO<jats:sub>2<\/jats:sub> of 11.6% at 1,600 m and 25.9% at 2,500 m compared to miners at sea level. An increase in (<jats:italic>hs<\/jats:italic>CRP) at 1,600 and 2,500 m regards sea level. We observed a high prevalence of overweight and obese subjects, which was related to the <jats:italic>ad libitum<\/jats:italic> availability of food and low physical activity (sedentarism). We found that work capacity was maintained despite a decreased VO<jats:sub>2<\/jats:sub> max at moderate altitude. However, overweight and obesity support an increased risk of cardiometabolic disease in miner\u2019s which is unrelated to altitude. In contrast, an increased <jats:italic>hs<\/jats:italic>CRP level could be associated with increased inflammatory mechanisms at 1,600 and 2,500 m.<\/jats:p>","DOI":"10.3389\/fphys.2021.647976","type":"journal-article","created":{"date-parts":[[2021,3,26]],"date-time":"2021-03-26T05:55:07Z","timestamp":1616738107000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":13,"title":["Cardiovascular Risk Is Increased in Miner\u2019s Chronic Intermittent Hypobaric Hypoxia Exposure From 0 to 2,500 m?"],"prefix":"10.3389","volume":"12","author":[{"given":"Andr\u00e9s","family":"Pedreros-Lobos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rodrigo","family":"Calder\u00f3n-Jofr\u00e9","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Moraga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fernando A.","family":"Moraga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,3,26]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"S498","DOI":"10.1097\/00005768-200009001-00009","article-title":"Compendium of physical activities: an update of activity codes and MET intensities","volume":"32","author":"Ainsworth","year":"2000","journal-title":"Med. 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Nutr."},{"key":"ref5","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1089\/haam.2008.1099","article-title":"Air to muscle O2 delivery during exercise at altitude","volume":"10","author":"Calbet","year":"2009","journal-title":"High Alt. Med. Biol."},{"key":"ref6","first-page":"97","article-title":"Gas exchange at high altitude","volume-title":"Pulmonary gas exchange","author":"Cerretelli","year":"1980"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1079\/bjn19740060","article-title":"Body fat assessment from total body density and its estimation from skindfold thickness: measurements on 481 men and women aged from 16 to 72 years","volume":"32","author":"Durnin","year":"1974","journal-title":"Br. J. Nutr."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"412","DOI":"10.1089\/ham.2013.1150","article-title":"Chronic intermittent high altitude exposure, occupation, and body mass index in workers of mining industry","volume":"15","author":"Esenamanova","year":"2014","journal-title":"High Alt. Med. Biol."},{"key":"ref9","year":"2004"},{"key":"ref10","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1161\/01.CIR.0000111245.75752.C6","article-title":"Clinical management of metabolic syndrome: report of the American Heart Association\/National Heart, Lung, and Blood Institute\/ American Diabetes Association conference on scientific issues related to management","volume":"109","author":"Grundy","year":"2004","journal-title":"Circulation"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"246","DOI":"10.1006\/cyto.1999.0533","article-title":"High altitude increases circulating interleukin-6, interleukin-1 receptor antagonist and C-reactive protein","volume":"12","author":"Hartmann","year":"2000","journal-title":"Cytokine"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"e0146290","DOI":"10.1371\/journal.pone.0146290","article-title":"Cognitive changes during prolonged stay at high altitude and its correlation with C-reactive protein","volume":"11","author":"Hu","year":"2016","journal-title":"PLoS One"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"S102","DOI":"10.1161\/01.cir.0000437739.71477.ee","article-title":"AHA\/ACC\/ TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology\/American Heart Association task force on practice guidelines and the Obesity Society","volume":"129","author":"Jensen","year":"2013","journal-title":"Circulation"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"156","DOI":"10.1089\/ham.2017.0155","article-title":"Appetite suppression and altered food preferences coincide with changes in appetite-mediating hormones during energy deficit at high altitude, but are not affected by protein intake","volume":"19","author":"Karl","year":"2018","journal-title":"High Alt. Med. Biol."},{"key":"ref15","first-page":"54","article-title":"Why is endurance performance decreased at high altitude?","volume":"53","author":"Kayser","year":"2005","journal-title":"Schweiz Zeitschr Sportmed Sporttraum"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"579","DOI":"10.1111\/obr.12034","article-title":"Hypoxia, energy balance and obesity: from pathophysiological mechanisms to new treatment strategies","volume":"14","author":"Kayser","year":"2013","journal-title":"Obes. Rev."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"1917","DOI":"10.1152\/jappl.1996.81.5.1917","article-title":"Evidence against an increase in capillary permeability in subjects exposed to high altitude","volume":"81","author":"Kleger","year":"1996","journal-title":"J. Appl. Physiol."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"1135","DOI":"10.1161\/hc0902.104353","article-title":"Inflammation and atherosclerosis","volume":"105","author":"Libby","year":"2002","journal-title":"Circulation"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"675","DOI":"10.1038\/oby.2009.509","article-title":"Hypobaric hypoxia causes body weight reduction in obese subjects","volume":"18","author":"Lippl","year":"2010","journal-title":"Obesity"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"11253","DOI":"10.1038\/s41598-020-68265-y","article-title":"Optimal cut-off values for anthropometric measures of obesity in screening for cardiometabolic disorders in adults","volume":"10","author":"Macek","year":"2020","journal-title":"Sci. Rep."},{"key":"ref21","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1089\/ham.2015.0084","article-title":"Increased cardiometabolic risk and worsening hypoxemia at high altitude","volume":"17","author":"Miele","year":"2016","journal-title":"High Alt. Med. Biol."},{"key":"ref22","year":""},{"key":"ref23","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1089\/ham.2017.0011","article-title":"Hemoconcentration during maximum exercise in miners with chronic intermittent exposure to hypobaric hypoxia (3800 m)","volume":"19","author":"Moraga","year":"2018","journal-title":"High Alt. Med. Biol."},{"key":"ref24","doi-asserted-by":"publisher","first-page":"1149","DOI":"10.3389\/fphys.2019.01149","article-title":"Aerobic capacity, lactate concentration, and work assessment during maximum exercise at sea level and high altitude in miners exposed to chronic intermittent hypobaric hypoxia (3,800 m)","volume":"10","author":"Moraga","year":"2019","journal-title":"Front. Physiol."},{"key":"ref25","doi-asserted-by":"publisher","first-page":"456","DOI":"10.1016\/j.pcad.2010.03.004","article-title":"Physiological adaptation of the cardiovascular system to high altitude","volume":"52","author":"Naeije","year":"2010","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref26","volume-title":"Estado nutricional, estudios de laboratorio, encuesta alimentaria, actividad f\u00edsica y consumo de tabaco en trabajadores de empresas afiliadas al INP","author":"Olivares","year":"2007"},{"key":"ref27","first-page":"67","article-title":"Regulaci\u00f3n del metabolismo de l\u00edpidos, prote\u00ednas, hidratos de carbono y otros nutrientes en trabajadores en altitud","volume-title":"Nutrici\u00f3n, fisiolog\u00eda y ejercicio en altitud","author":"Padilla","year":"1999"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"311","DOI":"10.1002\/oby.20499","article-title":"Ascent to altitude as a weight loss method: the good and bad of hypoxia inducible factor activation","volume":"22","author":"Palmer","year":"2014","journal-title":"Obesity"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"199","DOI":"10.4067\/S0717-75182018000400199","article-title":"Estado nutricional, composici\u00f3n corporal e indicadores antropom\u00e9tricos de trabajadores mineros expuestos a hipoxia hipob\u00e1rica cr\u00f3nica e intermitente a una altitud moderada (0-2500 msnm)","volume":"45","author":"Pedreros","year":"2018","journal-title":"Rev. Chil. Nutr."},{"key":"ref30","doi-asserted-by":"publisher","first-page":"1805","DOI":"10.1172\/JCI18921","article-title":"C-reactive protein: a critical update","volume":"111","author":"Pepys","year":"2003","journal-title":"J. Clin. Invest."},{"key":"ref31","doi-asserted-by":"publisher","first-page":"225","DOI":"10.1089\/ham.2007.8309","article-title":"Long term intermittent hypoxia increases O2 transport capacity but not VO2 max","volume":"8","author":"Prommer","year":"2007","journal-title":"High Alt. Med. Biol."},{"key":"ref32","doi-asserted-by":"publisher","first-page":"S22","DOI":"10.1055\/s-2007-1024582","article-title":"The control of cardiac chronotropic function in hypobaric hypoxia","volume":"13","author":"Richalet","year":"1992","journal-title":"Int. J. Sports Med."},{"key":"ref33","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1089\/15270290260131894","article-title":"Chilean miners commuting from sea level to 4500 m: a prospective study","volume":"3","author":"Richalet","year":"2002","journal-title":"High Alt. Med. Biol."},{"key":"ref34","doi-asserted-by":"publisher","first-page":"526","DOI":"10.1111\/j.1365-3156.2004.01220.x","article-title":"Assessing obesity and overweight in a high mountain Pakistani population","volume":"9","author":"Shah","year":"2004","journal-title":"Tropical Med. Int. Health"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"1309","DOI":"10.1152\/jappl.1988.64.4.1309","article-title":"Operation Everest II: oxygen transport during exercise at extreme simulated altitude","volume":"64","author":"Sutton","year":"1988","journal-title":"J. Appl. Physiol."},{"key":"ref36","doi-asserted-by":"publisher","first-page":"629","DOI":"10.3109\/15563650.2011.607169","article-title":"Occupational health of miners al altitude: adverse health effects, toxic exposure, pre-placement screening, acclimatization, and worker surveillance","volume":"49","author":"Vearrier","year":"2011","journal-title":"Clin. Toxicol."},{"key":"ref37","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1089\/ham.2015.0067","article-title":"Chronic intermittent hypoxia and blood pressure: is there risk for hypertension in healthy individuals?","volume":"17","author":"Vinnikov","year":"2016","journal-title":"High Alt. Med. Biol."},{"key":"ref38","doi-asserted-by":"publisher","first-page":"25","DOI":"10.1093\/icb\/icj005","article-title":"Human responses to extreme altitude","volume":"46","author":"West","year":"2006","journal-title":"Integr. Comp. Biol."},{"key":"ref39","doi-asserted-by":"publisher","first-page":"340","DOI":"10.1038\/ejcn.2016.237","article-title":"Control of energy expenditure in humans","volume":"71","author":"Westerterp","year":"2017","journal-title":"Eur. J. Clin. Nutr."},{"key":"ref40","doi-asserted-by":"publisher","first-page":"88","DOI":"10.1089\/ham.2007.1015","article-title":"Who should not go high: chronic disease and work at altitude during construction of the Qinghai-Tibet railroad","volume":"8","author":"Wu","year":"2007","journal-title":"High Alt. Med. Biol."},{"key":"ref41","doi-asserted-by":"publisher","first-page":"972","DOI":"10.1161\/01.atv.19.4.972","article-title":"C-reactive protein in healthy subjects: associations with obesity, insulin resistance, and endothelial dysfunction: a potential role for cytokines originating from adipose tissue?","volume":"19","author":"Yudkin","year":"1999","journal-title":"Arterioscler. Thromb. Vasc. Biol."},{"key":"ref42","first-page":"219","volume-title":"Food composition table","author":"Zacar\u00edas","year":"2018"}],"container-title":["Frontiers in Physiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2021.647976\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,26]],"date-time":"2021-03-26T05:55:19Z","timestamp":1616738119000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2021.647976\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,26]]},"references-count":42,"alternative-id":["10.3389\/fphys.2021.647976"],"URL":"https:\/\/doi.org\/10.3389\/fphys.2021.647976","relation":{},"ISSN":["1664-042X"],"issn-type":[{"value":"1664-042X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,26]]},"article-number":"647976"}}