Chronic Mountain Sickness (CMS) is an often fatal condition characterized by poor breathing, low blood oxygen levels, too many red blood cells, and high pressure in blood vessels of the lung. People develop CMS after years of life at altitudes above 9000 ft. This study is designed to determine whether sex hormones (testosterone, estrogen and progesterone), through their effects on red blood cell production and breathing, increase the risk for men or give women protection from developing CMS. Forty persons with CMS and an equal group of similarly-aged healthy persons living in Leadville, CO (10,150 feet) will be examined to determine: (1) whether blood oxygen levels are lower in men and women with CMS; (2) whether the hormone, erythropoietin, which stimulates red blood cell production, is related to blood oxygen and sex hormone levels; and (3) whether blood oxygen and hormone levels relate to the numbers of red blood cells in these men and women. This information will improve our understanding of the causes of CMS, the ways in which people adapt to the stress of living at high altitudes, and permit estimates of CMS prevalence and risk in Colorado.
