Accession Number : AD0756572

Title :   Effect of Fasting on Tolerance to Moderate Hypoxia,

Corporate Author : DEFENCE AND CIVIL INST OF ENVIRONMENTAL MEDICINE DOWNSVIEW (ONTARIO)

Personal Author(s) : Hartzell,W. G. ; Newberry,P. D.

Report Date : 1972

Pagination or Media Count : 6

Abstract : Blood pressure response to moderate hypoxia was compared in a fasting and a control (non-fasting) state in 10 seated subjects. End-tidal gas tensions were monitored continuously in the tests. In the control state the mean BP (MAP) was 98% (P less than 0.2) of its resting value after 45 minutes of exposure to a simulated altitude of 17,000 ft. When exposed to the same stress after fasting for 18 hours, the MAP fell to 87% (P less than 0.01) of its resting value. The mean end-tidal Po2 was significantly lower in the fasting state and the end-tidal Pco2 was unchanged. It is concluded that acute fasting significantly increases the orthostatic, hypotensive response to moderate hypoxia. This synergistic effect was sufficient to induce a syncopal attack in one normal individual during stress by moderate hypoxia while fasting, and this subject's recovery was delayed for more than 20 minutes after return to breathing room air. (Author)

Descriptors :   (*HYPOXIA, NUTRITION), OXYGEN CONSUMPTION, TOLERANCES(PHYSIOLOGY), HYPOTENSION, STRESS(PHYSIOLOGY), BLOOD PRESSURE, HIGH ALTITUDE, AVIATION MEDICINE

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE