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Acute Hypoxia Decreases Systemic Blood Pressure at Exercise in Hypertensive and Normotensive Subjects
Author(s) -
Richalet JeanPaul,
Winkler Laurent,
Lhuissier François J
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.709.3
Subject(s) - medicine , hypoxia (environmental) , blood pressure , vasodilation , cardiology , acetazolamide , heart rate , effects of high altitude on humans , anesthesia , oxygen , chemistry , organic chemistry , anatomy
This study aimed to determine whether acute hypoxia associated with exercise induces an increase in systemic blood pressure (SBP) in normotensive and hypertensive subjects, and whether hypertensive subjects are more prone to develop Severe High Altitude Illnesses (SHAI). Finally, to determine if SBP and ECG changes at exercise in hypoxia in hypertensive subjects are predictive factors for SHAI. From 2012 to 2015, 1113 sea‐level natives went through a hypoxia exercise test before a sojourn at high altitude, allowing the calculation of a SHAI prediction score. A total of 958 subjects were enrolled in the study, including 106 hypertensive subjects. From 272 subjects who sent back a questionnaire evaluating their tolerance to high altitude, 52 suffered from SHAI. When compared to normoxia, for the same heart rate, acute hypoxia induced a decrease in SBP at exercise in normotensive and hypertensive subjects. Hypertensive subjects treated by beta‐blockers showed a lower arterial oxygen saturation (vs other treatments) and blunted cardiac and ventilatory responses to hypoxia at exercise. Hypertensive subjects were not more prone than normotensive subjects to develop SHAI. Hypertensive subjects suffering from SHAI although taking acetazolamide showed similar SBP and ECG characteristics than hypertensive subjects without SHAI and without acetazolamide. In conclusion, hypoxia induces a peripheral vasodilation that balances vasoconstriction and tachycardia centrally induced through the adrenergic system. Hypertensive and normotensive subjects behave similarly during exercise in acute hypoxia. Hypoxia does not exacerbate the exercise‐induced increase in SBP. Systemic arterial pressure is not a useful predictor of intolerance to high altitude.