The study of high altitude pulmonary hypertension at the Chilean Andean Altiplano

PVRI Member Authors: Emilio Herrera, German Ebensperger

Non-communicable diseases (NCD) account for more than 65% of worldwide deaths, and are determined by a mix of environmental, genetic and epigenetic factors. (1). One important NCD is pulmonary hypertension that may be triggered by environmental hypoxia. An increased risk of developing cardiovascular and pulmonary diseases has been linked with in utero adverse conditions such as chronic hypoxia (2-5). Furthermore, hypoxia in postnatal life determines cardiovascular and pulmonary responses that may turn mal-adaptive and induce chronic disease (6-8). All of the above are particularly relevant in human populations exposed to high altitude, either in chronic continuous (permanent inhabitants) or intermittent fashion (high altitude workers, mountaineers and tourists). Worldwide, it is estimated that over 140 million people live in altitudes above 2,500 m. (9). The densest populations above 3,000 m. are in the South American Andean Mountains (9). In Central and South America alone, it is estimated that more than 35,000,000 people live at high-lands (10) and in Chile more than 30,000 work in high-altitude shifts (11).

The Andean Altiplano, or Alto Andino, is a ~4,000 m. high plateau located in the Central Andean Range. It has two types of human population: a permanent one consisting mainly of quechua and aymara groups (pure and caucasic-mixed), and an intermittent one composed of mining workers and staff, tourists, mountaineers, military soldiers and customs workers . The area is rich in endemic and introduced animals permanently living under hypobaric hypoxia. All of these characteristics offer an exceptional opportunity for the study of humans and animals exposed to chronic or intermittent hypobaric hypoxia. Therefore, the Altiplano becomes a fundamental natural laboratory, where unique scientific data can be obtained from species adapted or mal-adapted to chronic hypoxia.

Currently, the Andean plateau enjoys good ground and air travelling accesibility. Given this, University of Chile created the International Center for Andean Studies (INCAS) in the early 2000s in Putre (at 3,600 m), a town located in the very north of Chile and adjacent to Peruvian and Bolivian borders. Since then, several researchers have been working on animal and human cardiovascular and pulmonary adaptations to high altitude in this Center. Dr. Anibal J. Llanos, as one of the founders of this Center, developed a pulmonary hypertensive lamb model (Ovis aries) (12-16). He and his group have extensively characterized this non-adapted neonatal model, and compared the pulmonary physiology with the llama (Lama glama), a high-altitude adapted mammal gestated, born and raised above 4,000 m. with no pulmonary hypertension, offering exclusive evolutionary selections to cope with high-altitude (14,17-23).

The Putre Research Station-INCAS is open all year long to be used by Chilean and foreign researchers interested in any scientific discipline related to high altitude environments. The Center has housed research projects in diverse areas such as physiological and molecular adaptations of the pulmonary circulation to hypoxia in fetus, newborns and adults in animals raised at high altitude. 


Figure 1 Facilities of the International Center for Andean Studies (INCAS). The picture show an expedition by the authors of this manuscript. At the back is the housing area that can easily accommodate 4-6 persons. Further there are several hotels and hostels in town.

The Station has separated house and laboratory facilities, which can lodge comfortably 4 to 6.

 It is located in Putre, the capital of the Chilean Andean region of Arica and Parinacota, 140 km from Arica at sea level connected by a paved road. This same road can take you in only 5 h to the capital of Bolivia, La Paz, at 3,600 m (Figure 2).


Figure 2. Location of the International Center for Andean Studies (INCAS). The research station is located in Putre, at 3,600 m. in the north of Chile with expeditious accesses.

Putre has access to basic services such as surgery-house, school, restaurants, hotels and several shops. Several studies have shown that hypoxia at high altitude should be considered a health risk during development and adulthood (24-25) and it should be taken as a public health issue. Hence, establishing the impact of oxygen restriction throughout the lifespan represent a substantial advantage in understanding the role of hypoxia in determining cardiopulmonary diseases in the highlands. Scientists must access high-altitude areas to be able to understand the physiology and pathophysiology under chronic hypoxia. The INCAS research station is available to serve this need as a unique natural Laboratory of hypobaric hypoxia.


Authors are funded by the National Fund for Scientific and Technological Development (FONDECYT-Chile) grants nº 1110595, 1120605, 1130424, 1140647 and 1151119.



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High Altitude and Hypoxia
Pulmonary Hypertension

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July 2015

PVRI Chronicle Vol 2: Issue 2

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