ACUTE MOUNTAIN SICKNESS IN IRANIAN PILGRIMS AROUND DAMAVAND

The objective was to determine the incidence and risk factors of acute mountain sickness (AMS) in the pilgrims. Although it is known that Western trekkers suffer from AMS in other mountains, not much has been documented about the incidence of AMS in the Damavand mountains, among the Iranian population who travel to high altitudes, and its related contributing factors. The design was a cross-sectional study. During 6 weeks in the summer of 2000, a population of 459 pilgrims was studied. Symptoms of AMS were assessed by an extensively-used standard questionnaire (Lake Louise), applied at 2,900 m, after arrival at 4,200 m above sea level, and during descent from summit Damavand (at 4,200 m) at Damavand in the Iranian Alborz mountain. The study population was comprised of climbers between the ages of 13 and 71 years, and 67.8% of the study population was men. The overall incidence of AMS was 60.8%. The rate of AMS was not significantly different in men and women. The incidence was higher in those who resided at an altitude below 600 m, climbed fast, were amateur climbers, had a previous AMS experience or high altitude illness, and had a history of AMS at ascent to Damavand at night (6 pm – 6 am). It was weakly dependent on the rate of ascent (from 2,800 m to 4,200 m in less than 4 hours) and sleeping at 4,200 m. The incidence of AMS was unrelated to sex, age, body mass index , height, weight, smoking, the load and knapsack carried, and spending more than 15 hours under shelter (at 4,200 m). Therefore, it was independent of the rate of ascent in the higher altitude (from 4,200 m to 5,671 m), speed of ascent and family history of AMS. Data show a strong relation between experience in mountaineering, history of AMS, ascent time at night, and the incidence of AMS in 459 climbers studied at high altitudes that didn’t report previously.