Effect of simulated ascent to 3500 meter on neuro-endocrine functions.

Ascent to extreme High Altitude (HA) is in steps and it entails acclimatization at moderately HA locations. In terms of acclimatization, it is pertinent to understand the physiological changes, which occur on immediate ascent to moderate HA. The study aimed to evaluate the effect of ascent to 3500 m on neuro-endocrine responses in the first hour of induction. The plasma levels of catecholamines and cortisol were measured before and after one hour of ascent to high altitude. The peripheral oxygen saturation (SpO2), Galvanic Skin Resistance (GSR), Heart Rate (HR) and Blood Pressure (BP) were simultaneously monitored. The plasma epinephrine, norepinephrine, dopamine and cortisol were increased after one-hour exposure to 3500 m altitude as compared to before exposure. The SpO2 showed a significant decrease during and after high altitude induction. The heart rate and diastolic BP increased at 3500 m whereas the GSR did not show significant changes. There are changes in neuroendocrine responses, which reflect a sympathetic over activity in the first hour of exposure to 3500 m.