Women at Altitude: Effects of Menstrual Cycle Phase and Alpha-Adrenergic Blockade on High Altitude Acclimatization.

摘要

Background. The fluctuating levels of ovarian steroid hormones that characterize the phases of a women's menstrual cycle have metabolic effects that may significantly impact upon the physiologic process of acclimatization to hypobaric hypoxia in military women deployed to high mountain terrain. The state of altitude acclimatization affects physical performance and altitude-related casualties. Purpose and Scope. Because no previous information exists, the first year of this three-year study was designed to characterize the effects of menstrual cycle phase on altitude acclimatization in women. The mechanism(s) mediating the effects will be investigated in the subsequent years. Progress. The first-year studies were completed in late August 1996. Biochemical and statistical analyses are in progress. Results and Significance. Preliminary findings suggest that women have greater effective alveolar ventilation, less plasma volume contraction and greater fat loss with altitude acclimatization during the luteal phase of the menstrual cycle. Although many results are pending, these initial data appear to Support the hypothesis that ovarian steroid hormone fluctuations can affect altitude acclimatization. This data may serve as a basis for devising interventions and strategies to maximize the performance and well-being of military women deployed to high mountain environments.