Michael Furian1,2, Sara E Hartmann3, Tsogyal D Latshang1, Deborah Flueck1, Christian Murer1, Philipp M Scheiwiller1, Batyr Osmonov4, Silvia Ulrich1, Malcolm Kohler1, Marc J Poulin3, Konrad E Bloch1. 1. Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland. 2. Institute of Human Movement Sciences and Sport, Swiss Federal Institute of Technology, Zurich, Switzerland. 3. Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. 4. Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.
Abstract
BACKGROUND: Effects of hypobaric hypoxia at altitude on exercise performance of lowlanders with chronic obstructive pulmonary disease (COPD) have not been studied in detail. OBJECTIVES: To quantify changes in exercise performance and associated physiologic responses in lowlanders with COPD travelling to moderate altitude. METHODS: A total of 31 COPD patients with a median age (quartiles) of 66 years (59; 69) and FEV1 of 56% predicted (49; 69) living below 800 m performed a constant-load bicycle exercise to exhaustion at 60% of the maximal work rate at 490 m (Zurich) and at an identical work rate at 2,590 m (Davos) in randomized order. Pulmonary gas exchange, pulse oximetry (SpO2), cerebral tissue oxygenation (CTO; near-infrared spectroscopy), and middle cerebral artery peak blood flow velocity (MCAv) by Doppler ultrasound during 30 s at end exercise were compared between altitudes. RESULTS: With ascent from 490 to 2,590 m, the median endurance time (quartiles) was reduced from 500 s (256; 795) to 205 s (139; 297) by a median (95% CI) of 303 s (150-420) (p < 0.001). End exercise SpO2 decreased from 92% (89; 94) to 81% (77; 84) and CTO from 62% (56; 66) to 55% (50; 60); end exercise minute ventilation increased from 40.6 L/min (35.5; 47.8) to 47.2 L/min (39.6; 58.7) (p < 0.05; all comparisons 2,590 vs. 490 m). MCAv increased similarly from rest to end exercise at 490 m (+25% [17; 36]) and at 2,590 m (+21% [14; 30]). However, the ratio of MCAv increase to SpO2 drop during exercise decreased from +6%/% (3; 12) at 490 m to +3%/% (2; 5) at 2,590 m (p < 0.05). CONCLUSIONS: In lowlanders with COPD travelling to 2,590 m, exercise endurance is reduced by more than half compared to 490 m in association with reductions in systemic and cerebral oxygen availability.
RCT Entities:
BACKGROUND: Effects of hypobaric hypoxia at altitude on exercise performance of lowlanders with chronic obstructive pulmonary disease (COPD) have not been studied in detail. OBJECTIVES: To quantify changes in exercise performance and associated physiologic responses in lowlanders with COPD travelling to moderate altitude. METHODS: A total of 31 COPDpatients with a median age (quartiles) of 66 years (59; 69) and FEV1 of 56% predicted (49; 69) living below 800 m performed a constant-load bicycle exercise to exhaustion at 60% of the maximal work rate at 490 m (Zurich) and at an identical work rate at 2,590 m (Davos) in randomized order. Pulmonary gas exchange, pulse oximetry (SpO2), cerebral tissue oxygenation (CTO; near-infrared spectroscopy), and middle cerebral artery peak blood flow velocity (MCAv) by Doppler ultrasound during 30 s at end exercise were compared between altitudes. RESULTS: With ascent from 490 to 2,590 m, the median endurance time (quartiles) was reduced from 500 s (256; 795) to 205 s (139; 297) by a median (95% CI) of 303 s (150-420) (p < 0.001). End exercise SpO2 decreased from 92% (89; 94) to 81% (77; 84) and CTO from 62% (56; 66) to 55% (50; 60); end exercise minute ventilation increased from 40.6 L/min (35.5; 47.8) to 47.2 L/min (39.6; 58.7) (p < 0.05; all comparisons 2,590 vs. 490 m). MCAv increased similarly from rest to end exercise at 490 m (+25% [17; 36]) and at 2,590 m (+21% [14; 30]). However, the ratio of MCAv increase to SpO2 drop during exercise decreased from +6%/% (3; 12) at 490 m to +3%/% (2; 5) at 2,590 m (p < 0.05). CONCLUSIONS: In lowlanders with COPD travelling to 2,590 m, exercise endurance is reduced by more than half compared to 490 m in association with reductions in systemic and cerebral oxygen availability.
Authors: Lu Tan; Tsogyal D Latshang; Sayaka S Aeschbacher; Fabienne Huber; Deborah Flueck; Mona Lichtblau; Stefanie Ulrich; Elisabeth D Hasler; Philipp M Scheiwiller; Silvia Ulrich; Konrad E Bloch; Michael Furian Journal: JAMA Netw Open Date: 2020-06-01
Authors: Michael Furian; Deborah Flueck; Tsogyal D Latshang; Philipp M Scheiwiller; Sebastian Daniel Segitz; Séverine Mueller-Mottet; Christian Murer; Adrian Steiner; Silvia Ulrich; Thomas Rothe; Malcolm Kohler; Konrad E Bloch Journal: Int J Chron Obstruct Pulmon Dis Date: 2018-10-26
Authors: Esther I Schwarz; Tsogyal D Latshang; Michael Furian; Deborah Flück; Sebastian Segitz; Severine Müller-Mottet; Silvia Ulrich; Konrad E Bloch; Malcolm Kohler Journal: Int J Chron Obstruct Pulmon Dis Date: 2019-03-14
Authors: Martina Meszaros; Tsogyal D Latshang; Sayaka S Aeschbacher; Fabienne Huber; Deborah Flueck; Mona Lichtblau; Stefanie Ulrich; Elisabeth D Hasler; Philipp M Scheiwiller; Lukas Reinhard; Silvia Ulrich; Konrad E Bloch; Michael Furian; Esther I Schwarz Journal: Int J Chron Obstruct Pulmon Dis Date: 2021-12-24
Authors: Sophia Gutweniger; Tsogyal D Latshang; Sayaka S Aeschbacher; Fabienne Huber; Deborah Flueck; Mona Lichtblau; Stefanie Ulrich; Elisabeth D Hasler; Philipp M Scheiwiller; Silvia Ulrich; Konrad E Bloch; Michael Furian Journal: Sci Rep Date: 2021-10-13 Impact factor: 4.379
Authors: Simon R Schneider; Laura C Mayer; Mona Lichtblau; Charlotte Berlier; Esther I Schwarz; Stéphanie Saxer; Lu Tan; Michael Furian; Konrad E Bloch; Silvia Ulrich Journal: ERJ Open Res Date: 2021-10-11
Authors: Mona Lichtblau; Tsogyal D Latshang; Sayaka S Aeschbacher; Fabienne Huber; Philipp M Scheiwiller; Stefanie Ulrich; Simon R Schneider; Elisabeth D Hasler; Michael Furian; Konrad E Bloch; Stéphanie Saxer; Silvia Ulrich Journal: Front Physiol Date: 2021-07-07 Impact factor: 4.566