Exercise Responses to Metabolic Function on High Altitude Pulmonary Edema Susceptible Individuals

Abstract

<p>The study was aimed to evaluate and compare resting and exercise induced metabolic responses between acclimatized high altitude pulmonary edema (HAPE) susceptible (HAPE-s) and HAPE resistance (HAPE-r) volunteers at sea level. A group of 14 Indian soldiers volunteered for this study, divided into two groups, (i) HAPE-s, with past history of HAPE [n<sub>1</sub> = 7; age = 33.3 ± 4.5 (M ± SD)] and (ii) HAPE-r, with prior history of repeated exposure to high altitude and without suffering HAPE [n<sub>2</sub> = 7; age = 31.9 ± 4.2 (M ± SD)]. Respiratory frequency (f<sub>R</sub>), tidal volume (<sub>T</sub>), minute ventilation (<sub>E</sub>), oxygen consumption (O<sub>2</sub>), carbon dioxide output (CO<sub>2</sub>), heart rate (HR) and respiratory quotient (RQ) were recorded on all the volunteers during resting and exercise conditions. Ventilatory equivalent for oxygen (EqO<sub>2</sub>) and oxygen pulse (O<sub>2</sub>P) were calculated. Significant differences were observed between HAPE-s and HAPE-r volunteers in f<sub>Rrest </sub>(25.3% higher), O<sub>2</sub>P<sub>rest </sub>(23.7% lower), <sub>Emax</sub> (50.9% lower) (all P<0.05), f<sub>Rmax </sub>(55.7% lower), O<sub>2max </sub>(55.5% lower), O<sub>2</sub>P<sub>max </sub>(34.2% lower) (all P<0.01) and CO<sub>2max</sub> (42.1% lower, P<0.001). Rest of the parameters did not show any significant differences between the study groups. The study revealed that resting and exercise induced metabolic responses of HAPE-r volunteers was better as compared to acclimatized HAPE-s volunteers at sea level.</p>