@article {Ulrich00937-2020, author = {S. Ulrich and S. Saxer and M. Furian and P.R. Bader and P. Appenzeller and P.M. Scheiwiller and M. Mademilov and U. Sheraliev and F. Tanner and T.M. Sooronbaev and K.E. Bloch and M. Lichtblau}, title = {Pulmonary hemodynamic response to exercise in highlanders versus lowlanders}, elocation-id = {00937-2020}, year = {2021}, doi = {10.1183/23120541.00937-2020}, publisher = {European Respiratory Society}, abstract = {The question addressed by the study To investigate the pulmonary hemodynamic response to exercise in Central Asian high- and lowlanders (HL\&LL).Patients and methods Cross-sectional study in Central Asian HL (living \>2500 m) compared to LL (living \<800 m), assessing cardiac function, including tricuspid regurgitation pressure gradient (TRPG), cardiac index and tricuspid annular plane systolic excursion (TAPSE) by echocardiography combined with heart rate (HR) and SpO2 during submaximal stepwise cycle exercise (10 W increase/3 min) at their altitude of residence (at 760 m/3250 m, respectively).Results 52 HL (26 females; age 47.9{\textpm}10.7 years; BMI 26.7{\textpm}4.6 kg{\textperiodcentered}m-2; HR 75{\textpm}11 bpm; SpO2 91{\textpm}5\%;) and 22 LL (8 females; age 42.3{\textpm}8.0 years; BMI 26.9{\textpm}4.1 kg{\textperiodcentered}m-2; HR 68{\textpm}7 bpm; SpO2 96{\textpm}1\%) were studied. HL had a lower resting SpO2 compared to LL but change during exercise was similar between groups (HL versus LL. -1.4{\textpm}2.9\% versus -0.4{\textpm}1.1\%, p=0.133). HL had a significantly elevated TRPG and exercise induced increase was significantly higher (13.6{\textpm}10.5 mmHg versus 6.1{\textpm}4.8 mmHg, difference 7.5 [2.8 to 12.2]mmHg, p=0.002), whereas cardiac index increase was slightly lower in HL (2.02{\textpm}0.89 L{\textperiodcentered}min-1 versus 1.78{\textpm}0.61 L{\textperiodcentered}min-1, difference 0.24 [-0.13 to 0.61]L{\textperiodcentered}min-1, p=0.206) resulting in a significantly steeper pressure-flow ratio (ΔTRPG/Δcardiac index) in HL 9.4{\textpm}11.4 WU and LL 3.0{\textpm}2.4 WU (difference 6.4 [1.4 to 11.3]WU, p=0.012). Right ventricular-arterial coupling (TAPSE/TRPG) was significantly lower in HL but no significant difference in change with exercise in between groups was detected (-0.01 [-0.20 to 0.18] p=0.901).The answer to the question In highlanders, chronic exposure to hypoxia leads to higher pulmonary artery pressure and a steeper pressure-flow relation during exercise.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Prof. Dr. Ulrich reports grants from Zurich Lung League, grants from Swiss National Science Foundation, during the conduct of the study; grants and personal fees from Actelion SA, personal fees from Bayer SA, personal fees from MSD, grants and personal fees from Orpha Swiss, outside the submitted work.Conflict of interest: Dr. Saxer has nothing to disclose.Conflict of interest: Dr. Furian has nothing to disclose.Conflict of interest: Dr. Bader has nothing to disclose.Conflict of interest: Ms. Appenzeller has nothing to disclose.Conflict of interest: Dr. Scheiwiller has nothing to disclose.Conflict of interest: Dr. Mademilov has nothing to disclose.Conflict of interest: Dr. Sheraliev has nothing to disclose.Conflict of interest: Prof. Dr. Tanner has nothing to disclose.Conflict of interest: Dr. Sooronbaev has nothing to disclose.Conflict of interest: Prof. Dr. Bloch reports grants from Zurich Lung League, grants from Swiss National Science Foundation, during the conduct of the study.Conflict of interest: Dr. Lichtblau has nothing to disclose.}, URL = {https://openres.ersjournals.com/content/early/2021/01/14/23120541.00937-2020}, eprint = {https://openres.ersjournals.com/content/early/2021/01/14/23120541.00937-2020.full.pdf}, journal = {ERJ Open Research} }