They also found that preventive use of ACZ resulted in a 44 percent reduction in the risk of developing SHAI.
"Although it was not double-blinded and placebo-controlled, this study confirms in a large number of subjects the efficacy of the preventive use of ACZ in high-altitude-related illness," Dr. Richalet said. "These results indicate that preventive use of ACZ may reduce the risk of SHAI in susceptible subjects to the same level as that of non-susceptible subjects."
The study also linked frequent physical activity to an increased risk of SHAI, a result which Dr. Richalet said supports the common belief among mountaineering experts that increasing the body's ability to absorb oxygen during exercise is not a predictor of success in high-altitude expeditions.
"Of course, that does not mean that those who visit high altitudes should stop training before an expedition, but they should realize that intense aerobic training is not a protective factor against altitude-related disorders," he said.
The study is the first to suggest an independent association between the geographical location of ascent and SHAI.
"When adjusted for all other risk factors, especially rate of ascent, one location Ladakh remained associated with a higher risk of SHAI in both ACZ and non-ACZ users," Dr. Richalet said. "No clear explanation, linked to the climate or the difficulty of the terrain, is available, although many informal reports mention the higher risk of this location."
Dr. Richalet said that although previous episodes of SHAI are still the best predictor of new episodes, results of the study support the use of hypoxic exercise testing, especially in individuals who are planning their first hi
|Contact: Brian Kell|
American Thoracic Society