The Physiology of Acute Mountain Sickness in Women
Abstract
The purpose of this investigation was to determine whether gender, phases of the menstrual cycle or oral contraceptive use by women are significant considerations in assigning military personnel to high altitude duty. In this reported study 18 healthy men and 33 women were exposed for 12 hours to a simulated altitude of 16,000 ft in a decompression chamber. Previous studies have shown that individuals who exhibit altitude sickness within the first half-day at high altitude also experience altitude sickness during the subsequent days at altitude. This chamber study was chosen because it allowed us to control and regulate the environment, activity level and food and fluid intake of the subjects and thereby also learn something about the early progression and development of this poorly understood disease. In two/thirds of the experiments the subjects experienced clear symptoms of altitude sickness, but the occurrence and severity were not different between men and women, menstrual cycle phase? or the use of oral contraceptives in the repeated exposures in women. In those subjects, men or women, who experienced altitude sickness, the concentrations of fluid regulating hormones changed differently while at altitude than in those subjects who showed no symptoms. These hormone changes, which began early during the exposure, were typical of a strong drive to retain body fluids and this fluid retention probably caused the subsequent headache and other symptoms in the subjects who became sick. This suggests that their body was responding to a shock- like reaction to the initial fall in oxygen levels, which caused instability in the regulation of blood pressure and other functions. This large-scale study failed to reveal any differences of significance in altitude sickness that are related to gender, menstrual cycle or oral contraceptive use.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2000
- Accession Number
- ADA385650
Entities
People
- Jack Loappky
Organizations
- Lovelace Foundation