2007, Piran, Slovenia

Altitude Physiology
CARBOHYDRATE INGESTION IMPROVES OXYGEN
SATURATION AT HIGH ALTITUDE
Polona Flander 1 , Matjaz Klemenc 2 , Jerica Maver 2 , Tanja Princi 3 , Petra Golja 1
1 University of Nova Gorica, Centre for Environmental and Sports Physiology,
Vipavska 13, SI-5000 Nova Gorica, Slovenia
2 General Hospital Dr. Franc Derganc, Padlih borcev 13, SI-5290 Sempeter pri
Gorici, Slovenia.
3 University of Trieste, Department of Physiology and Pathology, Via Fleming 22, I-
34127 Trieste, Italy.
Contact person: petra.golja@p-ng.si
INTRODUCTION
To improve oxygen uptake, mountaineers often use supplemental oxygen during
climbing at high altitude. Oxygen-enrichment in the rooms has also been advised to
improve cognitive and motor function of people working at high altitude. Besides
oxygen enrichment of inspired air, oxygen availability at altitude may also be
improved by increasing ventilation. The latter, however, is associated with
hypocapnia and respiratory alkalosis.
During carbohydrate metabolism, a larger amount of CO2 is produced than during
metabolism of lipids or proteins. As CO2 is a respiratory stimulant, it would be
reasonably to assume that ingestion of carbohydrates may increase CO2 production to
a level which would stimulate ventilation, consequently increase oxygen uptake, and
potentially alleviate some of the symptoms of hypoxia.
The aim of the present study was to test whether carbohydrate ingestion can increase
CO2 production enough to stimulate ventilation and improve oxygen saturation at high
altitude.
METHODS
The subjects provided their informed consent for voluntary participation in the study
and gained physicians approval. The protocol of the study was approved by the
National Ethics Committee of the Republic of Slovenia.
Fourteen subjects (8 females, 6 males) participated in two trials, which consisted of
two normoxic and an acute hypoxic period (FiO2 = 12.86 %). All females were tested
in the follicular phase of the menstrual cycle. Both trials were performed at the same
time of the day and the order of the two trials was balanced between the subjects.
Following the first control normoxic period of 15 minutes, the subjects ingested either
a 10 % water solution of sucrose (CHO; 4 kcal per kg body mass), or an equal volume
of water (control). Following a 40-minute rest, the second normoxic period was
recorded, and was followed by a 30-minute hypoxic interval. The subjects rested
supine throughout the experiments.
Ambient data were recorded for each trial. Hemoglobin saturation (SaO2, %), heart
rate (HR, bt/min) and ventilation parameters (FeO2, %; FeCO2, %; V, L/min) were
monitored throughout the experiment. Tympanic temperature (Tty, °C) was measured
at the beginning and end of each test. Glucose concentration in capillary blood
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