Airflow and resistance
Group | Subjects n | LA | HA1 | HA2 | HA3 | pt | pgroup | pt×group | |
FEV1 % FVC | All | 30 | 75±8 | 79±7*** | 78±7*** | 77±7 | <0.01 | ||
No AMS | 10 | 74±10 | 78±8*** | 75±9** | 76±9**,# | <0.001 | 0.50 | 0.75 | |
AMS | 14 | 76±8 | 79±7*** | 78±6** | 78±5**,# | ||||
FEF25–75 L·s−1 | All | 30 | 3.3±1.3 | 4.2±1.5*** | 3.8±1.4** | 3.8±1.2*,# | 0.001 | ||
No AMS | 10 | 3.3±1.4 | 4.2±1.6*** | 3.7±1.6*** | 3.6±1.4**,# | <0.001 | 0.712 | 0.85 | |
AMS | 14 | 3.2±1.3 | 3.9±1.5*** | 3.7±1.2*** | 3.7±1.1**,# | ||||
Reff kPa·s·L−1 | All | 30 | 0.13±0.07 | 0.12±0.04 | 0.15±0.06 | 0.15±0.05 | 0.09 | ||
No AMS | 10 | 0.14±0.09 | 0.12±0.06 | 0.18±0.06# | 0.18±0.06*,# | 0.01 | 0.31 | 0.19 | |
AMS | 14 | 0.13±0.06 | 0.12±0.04 | 0.13±0.05# | 0.14±0.04*,# | ||||
sRaw kPa·s·L−1 | All | 30 | 0.72±0.30 | 0.64±0.19 | 0.73±0.25 | 0.74±0.21 | 0.14 | ||
No AMS | 10 | 0.79±0.43 | 0.70±0.27 | 0.89±0.34# | 0.89±0.28 | 0.04 | 0.10 | 0.24 | |
AMS | 14 | 0.71±0.20 | 0.61±0.14 | 0.65±0.11# | 0.69±0.12 |
Data are presented as mean±sd for all subjects without high-altitude pulmonary oedema (All) and the subgroups of subjects who suffered from acute mountain sickness (AMS) and who clearly remained healthy (No AMS). p-values were determined by ANOVA. There were no significant differences between HA2 and HA3. LA: low-altitude measurement (baseline); HA: high altitude measurement (HA1: 4 h after arrival; HA2: morning of day 2; and HA3: morning of day 3); pt: p-value for time; pgroup: p-value for group; pt×group: p-value for time×group; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FEF25–75: forced mid-expiratory flow (when 25–75% of FVC has been exhaled); Reff: effective airway resistance; sRaw: total specific airway resistance. *: p<0.05; **: p<0.01; ***: p<0.001 versus LA; #: p<0.05 versus HA1.