Participant demographics and lung function
| Health | Asthma | Smokers | |
| Participants (n) | 27 | 20 | 16 |
| Males/females (n) | 16/11 | 4/16 | 12/4 |
| Age (years) | 34 (19–65) | 43 (24–78)¶ | 43 (27–54)+ |
| BMI (kg·m−2) | 24.6±3.4 | 25.5±4.3 | 27.4±6.4 |
| Smoking history (pack-years) | 19.3±8.6 | ||
| Lung function | |||
| FEV1 (% predicted) | 105.0±14 | 89.2±19¶ | 98.8±11§ |
| FVC (% predicted) | 105.0±15 | 97.7±20 | 105.5±11 |
| FEV1/FVC (%) | 83±6.0 | 74±8.4¶ | 76±6.0+ |
| TLC (% predicted) | 101±23 | 103±18 | 108±11 |
| FRCpleth (% predicted) | 97.0±27 | 97.0±17 | 109.1±19 |
| DLCO (% predicted) | 102±13 | 99±15 | 90±12+ |
| FRCMBNW (L)# | 2.94±0.89 | 2.62±0.72 | 2.93±0.84 |
| LCI (TO)# | 6.49±0.47 | 7.23±1.04¶ | 7.05±0.82+ |
| Scond (L−1)# | 0.019±0.011 | 0.033±0.018¶ | 0.038±0.019§ |
| Sacin (L−1)# | 0.056±0.020 | 0.086±0.049 | 0.095±0.037+,§ |
Data are presented as mean±sd or median (interquartile range) unless otherwise stated. BMI: body mass index; DLCO: diffusing capacity of the lung for carbon monoxide; FEV1: forced expiratory volume in 1 s; FRC: functional residual capacity; FVC: forced vital capacity; LCI: lung clearance index; MBNW: multiple breath nitrogen washout; Sacin: distal/intra-acinar airways ventilation heterogeneity; Scond: conducting airways ventilation heterogeneity; TLC: total lung capacity; TO: lung turnover. #Corrected, controlled breathing protocol values used. ¶p<0.05 health versus asthma. +p<0.05 health versus smokers. §p<0.05 asthma versus smokers.