title: Rate of ascent and acute mountain sickness at high altitude.
abstract: OBJECTIVE
  To examine the effect of ascent rate on the induction of acute mountain sickness (AMS) in young adults during a climb to Jiaming Lake (3350 m) in Taiwan.
  
  
  METHODS
  Prospective, nonrandomized.
  
  
  METHODS
  Climb from 2370 to 3350 m.
  
  
  METHODS
  Young adults (aged 18 to 26 years) (N = 91) chose to participate in either the fast ascent (3 days; n = 43) or slow ascent (4 days; n = 48) group (1 and 2).
  
  
  METHODS
  Two criteria were used to define AMS. A Lake Louise score ≥3 and Lake Louise criteria [in the setting of a recent gain in altitude, the presence of headache and at least 1 of gastrointestinal discomfort (anorexia, nausea, or vomiting), fatigue or weakness, dizziness or lightheadedness, or difficulty sleeping].
  
  
  METHODS
  Heart rate, blood oxygen saturation (SaO2), and symptoms of AMS were monitored each morning and evening.
  
  
  RESULTS
  Baseline characteristics were similar between groups, except for significant differences in history of alcohol consumption (P = 0.009) and climbing experience above 3000 m (P < 0.001). The incidence of AMS was not associated with the rate of ascent. Acute mountain sickness was most prevalent in group 1 on day 2 in the evening and in group 2 on day 3 in the evening. In both groups, AMS correlated with the initial reduction in SaO2. Body mass index (BMI) >24 kg/m was identified as a significant risk factor for AMS.
  
  
  CONCLUSIONS
  The development of AMS was closely associated with an initial reduction in SaO2. A BMI >24 kg/m also contributed to the occurrence of AMS.
  
  
  CONCLUSIONS
  These findings indicate that factors other than ascent rate should be considered when trying to ameliorate the risk of AMS.
authors.affiliation: *Department of Emergency Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; †Chang Gung University College of Medicine, Taoyuan, Taiwan; ‡Department of Emergency Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan; §Department of Emergency Medicine, Mackay Memorial Hospital, Taipei, Taiwan; ¶Institute of Environmental and Occupational Health Sciences, National Yang-Ming University School of Medicine, Taipei, Taiwan; ‖Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; **Department of Occupation Medicine, Chang-Gung Memorial Hospital, Keelung, Taiwan; ††Department of Emergency Medicine, Taipei Medical University Hospital, Taipei, Taiwan; ‡‡Department of Physical Education, National Taitung University, Taitung, Taiwan; and §§Department of Emergency Medicine, Taiwan Adventist Hospital, Taipei, Taiwan.
authors.forename: Tai-Yi
authors.initials: TY
authors.lastname: Hsu
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Weng
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Chiu
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Li
authors.forename: Pang-Yen
authors.initials: PY
authors.lastname: Chen
authors.forename: Shih-Hao
authors.initials: SH
authors.lastname: Wang
authors.forename: Kuo-Feng
authors.initials: KF
authors.lastname: Huang
authors.forename: Wei-Fong
authors.initials: WF
authors.lastname: Kao
authors.forename: Te-Fa
authors.initials: TF
authors.lastname: Chiu
authors.forename: Jih-Chang
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000532:Altitude Sickness / Q000453:epidemiology* / Q000503:physiopathology; D015992:Body Mass Index; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D050177:Overweight / Q000453:epidemiology*; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism*; D015995:Prevalence; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D057185:Sedentary Behavior; D013624:Taiwan; D013997:Time Factors; D055815:Young Adult
chemical_list: D010100:Oxygen