Exhaled Nitric Oxide Changes During Acclimatization to High Altitude: A Descriptive Study

• Published in: High altitude medicine & biology Vol. 19; no. 3; p. 215
• Main Authors: Summerfield, Douglas T, Coffman, Kirsten E, Taylor, Bryan J, Issa, Amine N, Johnson, Bruce D
• Format: Journal Article
• Language: English
• Published: United States 01.09.2018
• Subjects: Acclimatization - physiology; Altitude; Arterial Pressure; Breath Tests; Exhalation; Female; Humans; Male; Nitric Oxide - analysis; Oxygen - blood; Partial Pressure; Pulmonary Artery; Time Factors; exhaled nitric oxide; acclimatization; high altitude populations; systolic pulmonary artery pressure
• ISSN: 1557-8682
• DOI: 10.1089/ham.2017.0109

Summerfield, Douglas T., Kirsten E. Coffman, Bryan J. Taylor, Amine N. Issa, and Bruce D. Johnson. Exhaled nitric oxide changes during acclimatization to high altitude: a descriptive study. High Alt Med Biol. 19:215-220, 2018. This study describes differences in the partial pressures of exhaled nitric oxide (PeNO) between subjects fully acclimatized (ACC) to 5300 m and those who have just arrived to high altitude. PeNO was determined in eight subjects newly exposed and nonacclimatized (non-ACC) to high altitude and compared with that in nine subjects who had ACC to high altitude for 1 month. In addition, systolic pulmonary artery pressure (sPAP) and arterial oxygen saturation (SaO ) were measured in all participants. These measurements were repeated in the non-ACC group 5 and 9 days later. PeNO levels on day 1 were significantly higher in the non-ACC versus ACC cohort (8.7 ± 3.5 vs. 3.9 ± 2.2 nmHg, p = 0.004). As the non-ACC group remained at altitude, PeNO levels fell and were not different when compared with those of the ACC group by day 9 (5.9 ± 2.4 vs. 3.9 ± 2.2 nmHg, p = 0.095). Higher sPAP was correlated with lower PeNO levels in all participants (R = -0.50, p = 0.043). PeNO levels were not correlated with SaO . As individuals acclimatized to high altitude, PeNO levels decreased. Even after acclimatization, PeNO levels continued to play a role in pulmonary vascular tone.