Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m)

Abstract

Context: High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels. Objectives: Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL). Results: Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these variables. Conclusions: Leptin levels appear unaffected at HA, whereas nocturnal hypoxic stress may affect plasma VEGF. Future HA studies should investigate the possible role of nocturnal intermittent hypoxemia on metabolism.

• Hypoxia
• maximal exercise test
• metabolism
• periodic breathing
• sleep

Acknowledgements

This study was carried out within the framework of the Ev-K²-CNR “Scientific and Technological Research in Himalaya and Karakorum” Project with support from the Ev-K²-CNR Committee in collaboration with the Nepal Academy of Science and Technology (NAST) as foreseen by the Memorandum of Understanding between the Government of the Kingdom of Nepal and the Government of the Republic of Italy. The research conducted was also made possible thanks to contributions from the Italian National Research Council and the Italian Ministry of Foreign Affairs. We thank Giorgio Agrifoglio for his precious help in analysis of SaO2 data.