A 10-day confinement to normobaric hypoxia impairs toe, but not finger temperature response during local cold stress.
The study examined the effects of a 10-day normobaric hypoxic confinement on the finger and toe temperature responses to local cooling. Eight male lowlanders underwent a normoxic (NC) and, in a separate occasion, a normobaric hypoxic confinement (HC; FO2: 0.154; simulated altitude ~3400m). Before and after each confinement, subjects immersed for 30min their right hand and, in a different session, their right foot in 8°C water, while breathing either room air (AIR) or a hypoxic gas mixture (HYPO). Throughout the cold-water immersion tests, thermal responses were monitored with thermocouples on fingers and toes. Neither confinement influenced thermal responses in the fingers during the AIR or HYPO test. In the foot, by contrast, HC, but not NC, reduced the average toe temperature by ~1.5°C (p=0.03), both during the AIR and HYPO test. We therefore conclude that a 10-day confinement to normobaric hypoxia per se augments cold-induced vasoconstriction in the toes, but not in the fingers. The mechanism underlying this dissimilarity remains to be established.
Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia. Electronic address: skounal@phed.uoa.gr.
Stylianos N
SN
Kounalakis
Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
Michail E
ME
Keramidas
Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
Mojca
M
Amon
Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
Ola
O
Eiken
Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
Igor B
IB
Mekjavic
D000064:Acclimatization; D000293:Adolescent; D000328:Adult; D000531:Altitude; D001833:Body Temperature Regulation; D003080:Cold Temperature; D005385:Fingers / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D007035:Hypothermia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D007101:Immersion; D008297:Male; D014034:Toes / Q000098:blood supply / Q000502:physiology*; D014661:Vasoconstriction
CIVD; Foot; Hand; High altitude