2007, Piran, Slovenia

Cold physiology
THE EFFECT OF ALTITUDE ACCLIMATISATION ON THE FINGER
COLD-INDUCED VASODILATATION
Ana Felicijan 2 , Petra Golja 3 , Stephen S. Cheung 4 Metka Milcinski and Igor B. Mekjavic 1
1 Jozef Stefan Institute & 2 Clinical Centre Ljubljana, Ljubljana; 3 University of Nova Gorica,
Nova Gorica, Slovenia; 4 Brock University, St. Catharines, Ontario, Canada
Contact person: igor.mekjavic@ijs.si
INTRODUCTION
We evaluated the effect of high altitude acclimatization on the cold-induced vasodilatation
(CIVD) response, which is considered a protective mechanism against nonfreezing cold injury
of peripheral tissues.
METHODS
Subjects were assigned to two groups: an experimental group, which underwent high altitude
acclimatization, and a control group. We tested the experimental group before and
immediately after a high altitude Himalayan expedition. The acclimatisation was a sevenweek
expedition to Ama Dablam (6828 m) during which most of the daily activities were
carried out at altitudes ranging from 4000 to 6000m. With few exceptions, subjects slept at
base camp at 3895m. The control group was tested on the same occasions as the experimental
group, and the interval between both tests for both groups was 7 weeks. During each test,
subjects immersed their hand in 37 °C water for 5 min., followed by a 30 min immersion of
the hand to the styloid process in 10 °C water for 30 min. Upon completion of the hand
immersion, the same procedure was followed for the foot. During the pre-heating and cold
water immersion phases of the trials, we measured the temperature of the edge of the nail
beds of all immersed digits, as well as skin temperature at four sites (arm, chest, thigh, calf),
tympanic temperature, blood pressure and heart rate. The subjects provided ratings of thermal
sensation and comfort on a numerical scale. From the responses of the temperature of the tips
of the fingers and the toes, we determined the minimum (Tmin, |Tmin|) and maximum (Tmax,
|Tmax|) temperatures, amplitude (∆T, |∆T|, ∆Trec), mean finger skin temperature (Tmean),
recovery temperature (Trec), onset time (∆tonset), peak time (∆tpeak), frequency of CIVD (FCIVD)
and the duration of the entire blood vessel opening – closing sequence (∆tCIVD).
RESULTS
After the high altitude acclimatisation, we observed significant increases in amplitude (∆T;
before: 1.8 (1.0)°C, after: 2.7 (1.9)°C) and absolute maximum temperature (|Tmax|; before:
20.3 (5.9)°C, after: 22.3 (4.2)°C) in fingers. In toes, there were significant increases in
minimum temperature (Tmin; before: 16.6 (4.3)°C, after: 19.9 (4.6) °C), maximum temperature
(Tmax; before: 18.8 (4.0)°C, after: 22.1 (4.8)°C), mean toe skin temperature (Tmean; before:
14.8°C (4.6)°C, after: 17.0 (3.5)°C after), absolute minimum temperature (|Tmin| ; before: 12.8
(4.1)°C, after: 14.3 (2.5)°C), absolute maximum temperature (|Tmax| ; before: 19.7 (4.0)°C,
after: 23.1 (4.3)°C) and absolute amplitude (|∆T| ; before: 4.7 (1.8)°C, after: 8.1 (3.9)°C).
Peak time was significantly shorter (∆tpeak; before: 3.4 min (2.5) min, after: 2.2 (1.9) min).
Tympanic and skin temperatures were similar in the pre- and post-acclimatisation trials. There
were no changes in the blood pressure response, nor on the subjective ratings of temperature
sensation and thermal comfort.
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