Subacute Effects of Hematological and Ventilatory Adaptations on Maximal Oxygen Uptake after Expedition to Peak Lenin

登山隊員攀登勒寧峰前後其運動能力及血球變化影響

陳洸艟(Kung-Tung Chen) ； 張振崗(Chen-Kang Chang) ； 吳慧君(Huey-June Wu) ； 蔡宇柔(Yu-Zou Tsai) ； 楊榮森(Rong-Sen Yang) ； 林正常(Jung-Charng Lin)

《明新學報》 34卷1期 (2008/02) Pp. 41-50

https://doi.org/10.29688/MHJ.200802.0004

摘要

The adaptations to high altitudes or hypoxia have mixed effects on the maximal oxygen uptake VO(subscript 2max) at sea level. This study investigated the change of VO(subscript 2max), and the possible hematological and ventilatory adaptation mechanisms, after returning from a 17-day expedition to Peak Lenin (7134m). Four mountaineers (three males and one female) were recruited. Hematological parameters, serum erythropoietin (EPO), VO(subscript 2max), and maximal ventilation were measured by Bruce protocol at baseline (20 days before arriving at the base camp) and eight days after their return. Serum EPO was also measured immediately after returning from the summit. The results were shown that absolute VO2(subscript) max did not change, while VO(subscript) 2max relative to body weight, maximal ventilation, and ventilation threshold increased significantly (p＜.05) after the expedition. Serum EPO marginally increased by 36.52±22.36% (p=0.053) during the expedition, then significantly decreased by 39.78±5.78% (p＜.05) after return to sea level. Hematocrit and mean corpuscular volume (MCV) significantly elevated, while mean corpuscular hemoglobin concentration (MCHC) significantly (p＜.05) decreased after the expedition. Hemoglobin was shown a trend of increase (15.0±1.6 vs 15.8±1.5g/dl, p=0.085) after the expedition. The two subjects have higher serum concentration in EPO than others. It showed the elevation in hemoglobin levels and VO(subscript 2max). This study suggested that relative VO(subscript 2max) increased after returning from a high-altitude expedition. The increase in VO(subscript 2max) at least partially resulted from hematological and ventilatory adaptations.

關鍵字

最大攝氧量 ； 紅血球生成素

並列摘要

The adaptations to high altitudes or hypoxia have mixed effects on the maximal oxygen uptake VO(subscript 2max) at sea level. This study investigated the change of VO(subscript 2max), and the possible hematological and ventilatory adaptation mechanisms, after returning from a 17-day expedition to Peak Lenin (7134m). Four mountaineers (three males and one female) were recruited. Hematological parameters, serum erythropoietin (EPO), VO(subscript 2max), and maximal ventilation were measured by Bruce protocol at baseline (20 days before arriving at the base camp) and eight days after their return. Serum EPO was also measured immediately after returning from the summit. The results were shown that absolute VO2(subscript) max did not change, while VO(subscript) 2max relative to body weight, maximal ventilation, and ventilation threshold increased significantly (p＜.05) after the expedition. Serum EPO marginally increased by 36.52±22.36% (p=0.053) during the expedition, then significantly decreased by 39.78±5.78% (p＜.05) after return to sea level. Hematocrit and mean corpuscular volume (MCV) significantly elevated, while mean corpuscular hemoglobin concentration (MCHC) significantly (p＜.05) decreased after the expedition. Hemoglobin was shown a trend of increase (15.0±1.6 vs 15.8±1.5g/dl, p=0.085) after the expedition. The two subjects have higher serum concentration in EPO than others. It showed the elevation in hemoglobin levels and VO(subscript 2max). This study suggested that relative VO(subscript 2max) increased after returning from a high-altitude expedition. The increase in VO(subscript 2max) at least partially resulted from hematological and ventilatory adaptations.

並列關鍵字

maximal oxygen uptake ； erythropoietin

參考文獻

Ashenden MJ,Gore CJ,Dobson GP,Boston TT,Parisotto R,Emslie KR,Trout GJ,Hahn AG(2000).Simulated moderate altitude elevates serum erythropoietin but does not increase reticulocyte production in well-trained runners.Eur J Appl Physiol.81,428-435.

Bernardi L,Schneider A,Pomidori L,Paolucci E,Cogo A.(2006).Hypoxic ventilatory response in successful extreme altitude climbers.Eur Respir J.27,165-171.

Casas M,Casas H,Pages T,Rama R,Ricart A,Ventura JL,Ibanez J,Rodriguez FA,Viscor G.(2000).Intermittent hypobaric hypoxia induces altitude acclimation and improves the lactate threshold.Aviat Space Environ Med.71,125-130.

Cerretelli P.(1976).Limiting factors to oxygen transport on Mount Everest.J Appl Physiol.40,658-667.

Ferretti G,Boutellier U,Pendergast DR,Moia C,Minetti AE,Howald H,di Prampero PE(1990).Oxygen transport system before and after exposure to chronic hypoxia.Int J Sports Med.11,15-20.