The impact of physical fitness and body mass index in children on the development of acute mountain sickness: A prospective observational study.

Background: Acute mountain sickness (AMS) is commonly found among people traveling above 2500 m. We investigated whether the occurrence of AMS is related to differences in individual physical fitness and BMI in subjects 11-13 years of age.
Methods: This study was conducted at Xue Mountain, Taiwan (elevation of 3886 m) between June 13, 2011 and June 17, 2011. Subjects were asked to ascend from Taipei City (25 m) to the summit (3886 m) over 3 days and 2 nights. Gender, age, weight, height, and fitness index (determined using a 3-minute step test) were recorded at sea level before ascent. The Lake Louise AMS score was used to record symptoms and diagnose AMS.
Results: A total of 179 subjects (mean age: 11.8 years; 102 males, 77 females) were included in the analysis. A total of 44.7% of subjects were diagnosed with AMS. Male gender (p = 0.004) and elevated body mass index (BMI) (p < 0.001) were each associated with the development of AMS. However the physical fitness index was comparable in subjects with and without AMS (67.8 ± 10.1 vs. 68.0 ± 9.3, p = 0.9).
Conclusions: This study shows that both BMI and male gender were associated with the development of AMS in 11-13 year old children. Physical fitness was not associated with the occurrence of AMS.