THE IMPORTANCE OF HYPOXIA INDUCIBLE FACTOR (HIF-1) IN DETECTING HYPOXIA AT HIGH ALTITUDE: A REVIEW

Abstract

The conventional definition of hypobaric hypoxia (HH) is that arterial blood O2 saturation (SaO2) in the body measurably begins to fall at altitudes >2500 m It is one of the hypoxemic types, which is due to a decrease in the amount of breathable oxygen caused by the low atmospheric pressure of high altitudes, and in turn low maximal oxygen uptake (VO2 max), and the arterial partial pressure of O2 (PaO2) in the body . The higher the elevation attained and the longer the duration of space flight, the greater the drop in PO2 in the human body. These declines in oxygen tensions trigger a variety of physiologic responses in the cardiovascular system after the initial altitude hypoxia exposure that enable the individual to adapt to or compensate for the hypoxic environment. However, air crashes due to hypoxia while handling aircrafts and several detrimental health effects are the risk associated with high altitude exposures. Hence, a convenient biomarker that could detect hypoxia at high altitude could be lifesaving. This review highlights the usefulness of salivary HIF-1α (hypoxia-inducible factor 1 alpha) as a biomarker that could help detect high altitude hypoxia rapidly.