Table 4

Association of maximum exercise capacity with lung function

Predictor variableChange in VO2max (mL/min)
r2 PE±SEMP values
RV/TLC (%)0.47−16±6 0.013
FEV1/FVC (%)0.46−12±70.070
FEV1 (L)0.46149±780.059
FEF25–75 (L/s)0.45−21±440.635
FEF75 (L/s)0.46−109±760.151
TLC (L)0.47113±47 0.017
RV (L)0.45−31±850.714
FRC (L)0.47−15±580.801
Slope of VFL (mL/W)*0.42−29±10 0.009
1% change in slope of %EFL (%/W)*0.40−3.52±1.39 0.017
Slope of EELV (FRC) (mL/W)*0.2716±180.390
Slope of RV (mL/W)*0.26−7±190.701
LAAexp −860 to −9500.24−9±4 0.049
  • Association of maximum exercise capacity (VO2max) with lung function was estimated using the regression analyses with adjustment for age, sex, height and weight with inclusion of one lung function at a time based on the regression model: Work=β0+β1(age)+β2(sex)+β3(height)+β4(weight)+β5(lung function). n=179 unless otherwise noted. Significant p-values are shown in bold.

  • *n=32.

  • †n=23.

  • %EFL, per cent of expiratory flow limitation; EELV, end-expiratory lung volume; FEF25–75, maximum airflow at mid-lung volume; FEF75, maximum airflow at low-lung volume; FEV1, forced expiratory volume in 1 s; FRC, functional residual capacity; FVC, forced vital capacity; LAAexp −860 to −950, per cent low attenuation area between −860 and − 950 HU on RV scan representing radiographic gas trapping; PE±SEM, parameter estimate±SEM; r2, model fit; RV, residual volume; TLC, total lung capacity; VFL, volume of the tidal breath that is flow limited on expiration; VO2max, maximum oxygen uptake.