PMID- 26011291
OWN - NLM
STAT- MEDLINE
DCOM- 20160520
LR  - 20220309
IS  - 1469-445X (Electronic)
IS  - 0958-0670 (Linking)
VI  - 100
IP  - 8
DP  - 2015 Aug
TI  - Cerebral oxygenation in highlanders with and without high-altitude pulmonary 
      hypertension.
PG  - 905-14
LID - 10.1113/EP085200 [doi]
AB  - What is the central question of this study? Cerebral hypoxia impairs cognitive 
      function and exercise performance and may result in brain damage. Residents at 
      high altitude, in particular those with high-altitude pulmonary hypertension, are 
      prone to hypoxaemia due to the exposure to reduced barometric pressure and 
      impaired pulmonary gas exchange. Whether highlanders have a reduced cerebral 
      oxygenation has not been studied. What is the main finding and its importance? We 
      found that despite a reduced arterial oxygen saturation, healthy highlanders and 
      even those with pulmonary hypertension have a similar cerebral oxygenation to 
      healthy lowlanders, suggesting that compensatory mechanisms protect long-term 
      residents at high altitude from cerebral hypoxia. Abstract High-altitude 
      pulmonary hypertension (HAPH), a chronic altitude-related illness, causes 
      hypoxaemia and impaired exercise performance. We evaluated the hypothesis that 
      haemodynamic limitation and hypoxaemia in patients with HAPH are associated with 
      impaired cerebral tissue oxygenation (CTO) compared with healthy highlanders (HH) 
      and lowlanders (LL). We studied 36 highlanders with HAPH and 54 HH at an altitude 
      of 3250 m, and 34 LL at 760 m. Mean(+/-SD) pulmonary artery pressures were 34(+/-3), 
      22(+/-5) and 16(+/-4) mmHg, respectively (P < 0.05, all comparisons). The CTO was 
      monitored by near-infrared spectroscopy along with pulse oximetry (peripheral 
      arterial oxygen saturation, SpO2) during quiet breathing of room air (RA) and 
      oxygen for 20 min each, and during hyperventilation with RA and oxygen, 
      respectively. In HAPH, HH and LL breathing RA, SpO2 was 88(+/-4), 92(+/-2) and 
      95(+/-2)%, respectively (P < 0.001, all comparisons), and CTO was similar in the 
      three groups, at 68(+/-3), 68(+/-4) and 69(+/-4)%, respectively (n.s., all 
      comparisons). Breathing oxygen increased SpO2 and CTO significantly more in HAPH 
      than in HH and LL. Hyperventilation (RA) did not reduce CTO in HAPH but did in HH 
      and LL; hyperventilation (oxygen) increased CTO in HAPH only. Highlanders with 
      and without HAPH studied at 3250 m had a similar CTO to healthy lowlanders at 
      760 m even though highlanders were hypoxaemic. The physiological response to 
      hyperoxia and hypocapnia assessed by cerebral near-infrared spectroscopy suggests 
      that healthy highlanders and even highlanders with HAPH effectively maintain an 
      adequate CTO. This adaptation may be of particular relevance because adequate 
      cerebral oxygenation is essential for vital brain functions.
CI  - (c) 2015 The Authors. Experimental Physiology (c) 2015 The Physiological Society.
FAU - Furian, M
AU  - Furian M
AD  - Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, 
      Zurich, Switzerland.
AD  - Institute of Human Movement Sciences and Sport, Swiss Federal Institute of 
      Technology, Zurich, Switzerland.
FAU - Latshang, T D
AU  - Latshang TD
AD  - Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, 
      Zurich, Switzerland.
FAU - Aeschbacher, S S
AU  - Aeschbacher SS
AD  - Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, 
      Zurich, Switzerland.
FAU - Ulrich, S
AU  - Ulrich S
AD  - Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, 
      Zurich, Switzerland.
FAU - Sooronbaev, T
AU  - Sooronbaev T
AD  - National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.
FAU - Mirrakhimov, E M
AU  - Mirrakhimov EM
AD  - National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.
FAU - Aldashev, A
AU  - Aldashev A
AD  - Research Institute for Molecular Biology and Medicine, Bishkek, Kyrgyzstan.
FAU - Bloch, K E
AU  - Bloch KE
AD  - Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, 
      Zurich, Switzerland.
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150705
PL  - England
TA  - Exp Physiol
JT  - Experimental physiology
JID - 9002940
RN  - Pulmonary edema of mountaineers
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - *Altitude
MH  - Altitude Sickness/*diagnosis/*metabolism
MH  - Cerebral Cortex/*metabolism
MH  - Female
MH  - Humans
MH  - Hypertension, Pulmonary/*diagnosis/*metabolism
MH  - Male
MH  - Middle Aged
MH  - Oxygen Consumption/*physiology
MH  - Pulmonary Gas Exchange
MH  - Spectroscopy, Near-Infrared/methods
MH  - Young Adult
EDAT- 2015/05/27 06:00
MHDA- 2016/05/21 06:00
CRDT- 2015/05/27 06:00
PHST- 2015/03/11 00:00 [received]
PHST- 2015/05/20 00:00 [accepted]
PHST- 2015/05/27 06:00 [entrez]
PHST- 2015/05/27 06:00 [pubmed]
PHST- 2016/05/21 06:00 [medline]
AID - 10.1113/EP085200 [doi]
PST - ppublish
SO  - Exp Physiol. 2015 Aug;100(8):905-14. doi: 10.1113/EP085200. Epub 2015 Jul 5.