dc.contributor.author | Cheung, Stephen S. | |
dc.contributor.author | Mutanen, Niina E. | |
dc.contributor.author | Karinen, Heikki M. | |
dc.contributor.author | Koponen, Anne S. | |
dc.contributor.author | Kyröläinen, Heikki | |
dc.contributor.author | Tikkanen, Heikki O. | |
dc.contributor.author | Peltonen, Juha E. | |
dc.date.accessioned | 2014-09-30T08:54:41Z | |
dc.date.available | 2014-09-30T08:54:41Z | |
dc.date.issued | 2014 | |
dc.identifier.citation | Cheung, S. S., Mutanen, N. E., Karinen, H. M., Koponen, A. S., Kyröläinen, H., Tikkanen, H. O., & Peltonen, J. E. (2014). Ventilatory Chemosensitivity, Cerebral and Muscle Oxygenation, and Total Hemoglobin Mass Before and After a 72-Day Mt. Everest Expedition. <i>High Altitude Medicine and Biology</i>, <i>15</i>(3), 331-340. <a href="https://doi.org/10.1089/ham.2013.1153" target="_blank">https://doi.org/10.1089/ham.2013.1153</a> | |
dc.identifier.other | CONVID_23866054 | |
dc.identifier.other | TUTKAID_62963 | |
dc.identifier.uri | https://jyx.jyu.fi/handle/123456789/44355 | |
dc.description.abstract | Abstract.
Cheung, Stephen S, Niina E. Mutanen, Heikki M. Karinen, Anne S. Koponen, Heikki Kyro
̈
la
̈
inen, Heikki O.
Tikkanen, and Juha E. Peltonen. Ventilatory chemosensitivity, cerebral and muscle oxygenation, and total
hemoglobin mass before and after a 72-day Mt. Everest expedition.
High Alt Med Biol
15:331–340, 2014.—
Background:
We investigated the effects of chronic hypobaric hypoxic acclimatization, performed over the
course of a 72-day self-supported Everest expedition, on ventilatory chemosensitivity, arterial saturation, and
tissue oxygenation adaptation along with total hemoglobin mass (tHb-mass) in nine experienced climbers (age
37
–
6 years,
_
VO
2peak
55
–
7mL
$
kg
-
1
$
min
-
1
).
Methods:
Exercise-hypoxia tolerance was tested using a constant treadmill exercise of 5.5 km
$
h
-
1
at 3.8%
grade (mimicking exertion at altitude) with 3-min steps of progressive normobaric poikilocapnic hypoxia.
Breath-by-breath ventilatory responses, Sp
o
2
, and cerebral (frontal cortex) and active muscle (vastus lateralis)
oxygenation were measured throughout. Acute hypoxic ventilatory response (AHVR) was determined by linear
regression slope of ventilation vs. Sp
o
2
. PRE and POST (
<
15 days) expedition, tHb-mass was measured using
carbon monoxide-rebreathing.
Results:
Post-expedition, exercise-hypoxia tolerance improved (11:32
–
3:57 to 16:30
–
2:09 min,
p
<
0.01).
AHVR was elevated (1.25
–
0.33 to 1.63
–
0.38 L
$
min
-
1.
%
-
1
Sp
o
2
,
p
<
0.05). Sp
o
2
decreased throughout
exercise-hypoxia in both trials, but was preserved at higher values at 4800 m post-expedition. Cerebral
oxygenation decreased progressively with increasing exercise-hypoxia in both trials, with a lower level of
deoxyhemoglobin POST at 2400, 3500 and 4800 m. Muscle oxygenation also decreased throughout exercise-
hypoxia, with similar patterns PRE and POST. No relationship was observed between the slope of AHVR and
cerebral or muscle oxygenation either PRE or POST. Absolute tHb-mass response exhibited great individual
variation with a nonsignificant 5.4% increasing trend post-expedition (975
–
154 g PRE and 1025
–
124 g
POST,
p
=
0.17).
Conclusions:
We conclude that adaptation to chronic hypoxia during a climbing expedition to Mt. Everest will
increase hypoxic tolerance, AHVR, and cerebral but not muscle oxygenation, as measured during simulated
acute hypoxia at sea level. However, tHb-mass did not increase significantly and improvement in cerebral
oxygenation was not associated with the change in AHVR | fi |
dc.language | eng | |
dc.language.iso | eng | |
dc.publisher | Mary AnnLiebert, Inc. Publishers; International Society for Mountain Medicine | |
dc.relation.ispartofseries | High Altitude Medicine and Biology | |
dc.subject.other | acute hypoxic ventilatory response | |
dc.subject.other | altitude adaptation | |
dc.subject.other | chronic hypoxia | |
dc.subject.other | climbers | |
dc.subject.other | extreme altitude | |
dc.subject.other | NIRS | |
dc.title | Ventilatory Chemosensitivity, Cerebral and Muscle Oxygenation, and Total Hemoglobin Mass Before and After a 72-Day Mt. Everest Expedition | |
dc.type | article | |
dc.identifier.urn | URN:NBN:fi:jyu-201409302904 | |
dc.contributor.laitos | Liikuntabiologian laitos | fi |
dc.contributor.laitos | Department of Biology of Physical Activity | en |
dc.contributor.oppiaine | Liikuntafysiologia | fi |
dc.contributor.oppiaine | Exercise Physiology | en |
dc.type.uri | http://purl.org/eprint/type/JournalArticle | |
dc.date.updated | 2014-09-30T03:30:25Z | |
dc.type.coar | http://purl.org/coar/resource_type/c_2df8fbb1 | |
dc.description.reviewstatus | peerReviewed | |
dc.format.pagerange | 331-340 | |
dc.relation.issn | 1527-0297 | |
dc.relation.numberinseries | 3 | |
dc.relation.volume | 15 | |
dc.type.version | publishedVersion | |
dc.rights.copyright | © Mary Ann Liebert, Inc. | |
dc.rights.accesslevel | openAccess | fi |
dc.rights.url | http://www.liebertpub.com/archpolicy/journal-of-womens-health/42/ | |
dc.relation.doi | 10.1089/ham.2013.1153 | |
dc.type.okm | A1 | |