Table 4

Pulmonary function for SMO versus CON

 Parameters Low altitude After arrival Day 3 3 months 6 months Pa Pb VC (l) SMO 4.48±0.46 SMO 4.36±0.63 SMO 4.24±0.60 SMO 4.12±0.62 SMO 4.10±0.38 0.046 G: 0.110 CON 4.54±0.44 CON 4.43±0.45 CON 4.12±0.63 CON 4.52±0.32* CON 4.50±0.26† 0.013 I: 0.027 FEV1 (l) SMO 3.92±0.82 SMO 3.98±0.74 SMO 4.02±0.84 SMO 3.96±0.78 SMO 3.82±0.74 0.321 G: 0.164 CON 4.10±0.48 CON 4.21±0.51 CON 4.18±0.62 CON 4.28±0.46‡ CON 4.22±0.50‡ 0.388 I: 0.465 FEF25–75% (litres/s) SMO 4.08±1.05 SMO 4.01±0.85 SMO 4.06±1.06 SMO 4.02±1.12 SMO 3.92±0.92 0.465 G: 0.044 CON 4.16±0.85 CON 4.24±0.66 CON 4.28±0.72 CON 4.81±0.63§ CON 4.93±0.67¶ 0.006 I: 0.048 MVV (litres/min) SMO 108.0±4.5 SMO 110.2±4.4 SMO 111.6±4.8 SMO 106.3±5.2 SMO 107.4±5.3 0.035 G: 0.002 CON 111.3±5.2 CON 115.5±5.6** CON 117.4±4.6** CON 118.3±3.8** CON 117.8±4.5** 0.002 I: 0.001
• Data are presented as mean ± SD. Pa: ANOVA for repeated measures within each group separately. Pb: ANOVA—probabilities between groups (G), and interaction (I). Group comparisons: *SMO versus CON, p<0.001; †SMO versus CON p<0.001, ‡SMO versus CON, p=0.048 and p=0.036; §SMO versus CON, p=0.048; ¶SMO versus CON, p=0.021; **SMO versus CON, p<0.001.

• Because of technical problems only a subset of subjects had pulmonary function tests: at low altitude 40 (SMO) and 42 (CON), after arrival 36 (SMO) and 28 (CON), at 3 days 36 (SMO) and 28 (CON), at 3 months 32 (SMO) and 34 (CON) and at 6 months 28 (SMO) and 25 (CON). The measurements reported concern the same subjects over time.

• SMO, smoking group; CON, control group; VC, vital capacity; FEV1, forced expiratory volume in 1 s; FEF25-75% forced expiratory flow between 25% and 75% of vital capacity; MVV, maximal voluntary ventilation.