HEMATOLOGICAL CHANGES IN RESPONSE TO EXPOSURE TO MODERATE ALTITUDES (HEMOGLOBIN, RED BLOOD CELLS, SYSTEMIC BLOOD PRESSURE

The purpose of this investigation was to determine differences in cardiovascular adjustments following exposure to an altitude of 2,300 meters, 2,560 meters or 2,900 meters. Specific purposes of this investigation were to determine the effects of exposure to one of the above altitudes on the following variables: hemoglobin concentration, red blood cell count, systolic blood pressure, diastolic blood pressure and resting heart rate.;Subjects for this investigation were 14 male members of the "Glaciers of the Canadian Rockies, 82" expedition and the two principal investigators. Subjects were measured in order to determine the initial value for the physiological variables of interest prior to being taken to altitude. Subjects were measured again in order to determine final values following 12 to 14 days of exposure to altitude.;A multivariate analysis of variance was planned in order to analyze the data. This procedure was rejected, since the number of dependent variables approximated the number of subjects. An inter-correlation matrix was developed in order to determine whether univariate analysis of variance would be appropriate. Only one correlation coefficient was found to be significantly different from zero. Based on the orthogonality of the dependent variables, it was decided that a univariate analysis of variance for a groups (3) x measurement (2) factorial with repeated measures on the second factor would be used in analyzing each of the dependent variables.;Results indicated a significant difference between the two levels of measurements for each of the dependent variables. Hemoglobin concentration was found to increase significantly (p < .05) with a significant increase at 2,900 meters when compared to 2,300 meters and 2,560 meters. Red blood cell count was found to increase significantly (p < .05) with a significant increase at 2,900 meters when compared to 2,300 meters and 2,560 meters. Systolic blood pressure decreased significantly (p < .05) and diastolic blood pressure decreased significantly (p < .05). A significant increase in resting heart rate was noted (p < .05) with resting heart rate significantly higher at 2,900 meters when compared to 2,300 meters.