Introduction In Space, thermoregulation in humans should be altered due to i) changes in convective heat loss, ii) body composition, and iii) a diminished production and/or decreased efficiency of evaporation, especially during physical excercise. We hypothesized that in astronauts for a given absolute level of work, body core temperatures (CBT) should show a faster, higher, and longer lasting increase as compared to a similar exercise protocol on Earth. Material & Methods 11 astronauts (7 male, 4 females) were studied several times before, during, and after a physical exercise protocol on ground and in space on ISS between 2010-2012. Out of these 11 astronauts we received complete pre and post-flight anthropometric and body composition data from 10 astronauts, 6 males and 4 females with an average age of 48.5 ± 3.9 years , height 1.76 m ± 0.07 [m], weight of 77.5 ± 16.2 [kg], body mass index of 24.7 ± 3.4 (kg/[m]2), a lean body mass preflight of 59.5 ± 11.9 [kg], and a fat mass of 18.0 ± 5.3 [kg]. Results It was found that i) CBTs increased much faster in space as compared to baseline values at all time points (p<0.05), ii) during exercise the absolute peakes of CBTs reached were significantly higher than preflight (p<0.05), incidentally above 41.0 °C, and iii) the post- excercise cooling periods were significantly prolonged (p<0.05). However, most unexpected, we observed iv) that the resting CBTs were found to be elevated by 0.5-0.9 °C inflight as compared to preflight (p<0.05), and returned only gradually to control level 30 days after postflight. Discussion & Conclusions We conclude that i) in space already during a short-term physical exercise high CBTs >40.0 °C can be reached in astronauts, ii) post-exercise 'cool-down' periods inflight are prolonged, and iii) most remarkable in space the setpoint of CBT is shifted to a higher level up to 0.9 °C as compared to pre- and post baseline values. The latter shift of core temperature to a higher set- point is presumably induced by immunolological processes and might contribute to our understanding of fore-most isolated observed adaptive changes in humans during long-term space flight such as negative energy balance and peripheral vasoconstriction.

SPACE FEVER : CORE BODY TEMPERATURES IN ASTRONAUTS UNDER REST AND EXERCISE ON THE INTERNATIONAL SPACE STATION (ISS) / G. H., A. Stahn, O. O, M. Steinach, M.A. Maggioni, A. Moore, J. Koch, L. Roecker, K. K, Werner. ((Intervento presentato al 6. convegno International Congress of Medicine in Space and Extreme Environments (ICMS) tenutosi a Berlin nel 2014.

SPACE FEVER : CORE BODY TEMPERATURES IN ASTRONAUTS UNDER REST AND EXERCISE ON THE INTERNATIONAL SPACE STATION (ISS)

M.A. Maggioni;
2014-09

Abstract

Introduction In Space, thermoregulation in humans should be altered due to i) changes in convective heat loss, ii) body composition, and iii) a diminished production and/or decreased efficiency of evaporation, especially during physical excercise. We hypothesized that in astronauts for a given absolute level of work, body core temperatures (CBT) should show a faster, higher, and longer lasting increase as compared to a similar exercise protocol on Earth. Material & Methods 11 astronauts (7 male, 4 females) were studied several times before, during, and after a physical exercise protocol on ground and in space on ISS between 2010-2012. Out of these 11 astronauts we received complete pre and post-flight anthropometric and body composition data from 10 astronauts, 6 males and 4 females with an average age of 48.5 ± 3.9 years , height 1.76 m ± 0.07 [m], weight of 77.5 ± 16.2 [kg], body mass index of 24.7 ± 3.4 (kg/[m]2), a lean body mass preflight of 59.5 ± 11.9 [kg], and a fat mass of 18.0 ± 5.3 [kg]. Results It was found that i) CBTs increased much faster in space as compared to baseline values at all time points (p<0.05), ii) during exercise the absolute peakes of CBTs reached were significantly higher than preflight (p<0.05), incidentally above 41.0 °C, and iii) the post- excercise cooling periods were significantly prolonged (p<0.05). However, most unexpected, we observed iv) that the resting CBTs were found to be elevated by 0.5-0.9 °C inflight as compared to preflight (p<0.05), and returned only gradually to control level 30 days after postflight. Discussion & Conclusions We conclude that i) in space already during a short-term physical exercise high CBTs >40.0 °C can be reached in astronauts, ii) post-exercise 'cool-down' periods inflight are prolonged, and iii) most remarkable in space the setpoint of CBT is shifted to a higher level up to 0.9 °C as compared to pre- and post baseline values. The latter shift of core temperature to a higher set- point is presumably induced by immunolological processes and might contribute to our understanding of fore-most isolated observed adaptive changes in humans during long-term space flight such as negative energy balance and peripheral vasoconstriction.
Settore BIO/09 - Fisiologia
Deutschen Zentrums für Luft- und Raumfahrt (DLR)
European Space Agency (ESA)
Center for Space Medicine at Charité
Institute of Biomedical Problems (IBMP)
http://icms2014.de
SPACE FEVER : CORE BODY TEMPERATURES IN ASTRONAUTS UNDER REST AND EXERCISE ON THE INTERNATIONAL SPACE STATION (ISS) / G. H., A. Stahn, O. O, M. Steinach, M.A. Maggioni, A. Moore, J. Koch, L. Roecker, K. K, Werner. ((Intervento presentato al 6. convegno International Congress of Medicine in Space and Extreme Environments (ICMS) tenutosi a Berlin nel 2014.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/240150
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