After-Effects of a High Altitude Expedition on Blood

Abstract

The aim of the study was to investigate blood alterations caused by altitude acclimatization which last more than few days after return and might play a role for exercise performance at sea level. Measurements were performed in 12 mountaineers before, during and either 7/8 or 11/12 days after a Himalaya expedition (26-29 days at 4900 to 7600 m altitude). [Erythropoietin] rose only temporarily at altitude (max. +11 +/- 1 [SE] mu/ml serum). After return hemoglobin mass (initially 881 +/- 44 g, CO-Hb method) was increased by 14% (p < 0.01); aspartate aminotransferase activity in erythrocytes (initially 682 +/- 25 U/l) was augmented (day 7: +964 +/- 152 U/l, day 11: +533 +/- 107 U/l) indicating reduced mean cell age. Calculated blood volume (+14%) was influenced by red cell formation at altitude but also by plasma expansion at sea level. The half saturation pressure for Hb-O2 (pH 7.4, 37 degrees C) as well as the 2.3-diphosphoglycerate concentration were already initially high (32.1 +/- 0.5 mmHg, 20.5 +/- 0.7 mumol/g Hb) and showed only a nonsignificant tendency to increase after return. Also Hill's n was consistently high in the mountaineers, whereas the Bohr coefficients were slightly increased only after descent. Probably the preparatory physical training, partly in the Alps, and the stay in the Himalaya influenced O2-affinity for a prolonged time. The adaptations might reduce the loss of physical performance capacity at altitude and be part of altitude training effects.

Control of erythropoiesis after high altitude acclimatization

“…Nevertheless, decreased plasma osmolality and plasma total proteins observed in our study after the sojourn (P<0.05) suggest, indirectly, an increased plasma volume after the sojourn and consequently a lesser haemoconcentration. Identical conclusions were reached by Bo¨ning et al (1997), who showed that calculated plasma volume was increased at sea level after a high altitude stay. From our results, it seems that renal function is not involved, since osmolar and freewater clearances appeared unchanged after the sojourn.…”

Austrian Moderate Altitude Study (AMAS 2000) – fluid shifts, erythropoiesis, and angiogenesis in patients with metabolic syndrome at moderate altitude (≅1700 m)

“…Changes in plasma volume and/or red cell mass have to be considered when [Hb] or PCV increases at altitude. During a 3-month stay at an altitude above 5000 m, Bo¨ning et al (1997) documented an increase of total body haemoglobin of 123 g, equivalent to a volume of 360 ml of erythrocytes. At moderate altitude (2300 m), an increase of the total body haemoglobin of 107 g was measured in swimmers of the German national team after a sojourn of 3 weeks (Schmidt et al 1994).…”

Physical activity at moderate and high altitudes. Cardiovascular and respiratory morbidit

“…Erythropoietin -A few hours after exposure to hypobaric hypoxia, the secretion of renal erythropoietin increases [34][35][36][37] . As it stimulates the synthesis of red blood cells, in approximately one week it significantly increases the concentration of hemoglobin and, therefore, the capacity of transporting O 2 in the blood 38 .…”

“…The physiological mechanisms are the following: 1) increase in the pulmonary ventilation 39 ; 2) reduction in the HR previously increased in the acute response 22,39 ; 3) decrease in the plasmatic volume 39,40 ; 4) reduction of the accumulation of lactate in the blood during submaximal exercise in relation to the more elevated levels of acute response 39 ; 5) improvement of the cardiorespiratory capacity for exercise, also related to the initial exposure to the hypobaric hypoxia 23,41 ; 6) increase in the secretion of renal erythropoietin, in the hemoglobin mass and in the hematocrit 34,36,37,42 .…”