Table 1—

Baseline characteristics by disease severity

Subjects nDisease severityp-value
Mild (MRC grade 1/2)#Moderate (MRC grade 2/3)Severe (MRC grade 5)+
Age yrs7463.6±11.467.9±9.673.2±7.90.005
BMI kg·m−2§7426.3±5.229.2±8.725.8±5.5ns
Smoking pack-yrs§7338.1±28.048.8±39.351.7±30.9ns
6MWD % pred7371.3±14.250.2±18.227.7±15.8<0.0001
Quadriceps torque (Nms/kg×100)74123.5±35.5123.0±55.083.9±36.80.003
SGRQ score§7438.0±14.861.2±12.965.5±14.2<0.0001
FEV1 % pred7365.7±20.043.0±24.438.1±16.9<0.0001
FVC % pred7383.7±20.765.6±19.766.4±23.80.008
MIP % pred6674.4±35.872.2±31.659.4±19.3ns
MEP % pred6698.2±44.087.9±32.177.4±34.6ns
V′O2,max kg·L−1·min−17116.2±7.010.9±6.07.1±1.9<0.0001
Grip % pred74109.9±17.6102.6±24.099.3±25.1ns
Borg score pre-6MWD m§720.2±0.30.7±0.71.0±1.10.009
Borg score post-6MWD m§723.1±1.43.7±0.94.5±1.50.002
Sa,O2 pre-6MWD %7395.9±2.193.8±3.092.5±3.30.001
Sa,O2 post-6MWD %7394.5±3.891.0±6.288.5±6.20.003
COPDSE723.4±1.02.9±0.92.7±0.90.03
LCADL§7419.3±10.433.6±14.346.2±16.4<0.0001
  • Differences were tested using ANOVA. Data are presented as mean (sd). A high score indicates better health, unless otherwise indicated (§: low score = better health). MRC: Medical Research Council; BMI: body mass index; 6MWD: 6-minute walk distance; SGRQ: St George's Respiratory Questionnaire; FEV1: forced expiratory volume in one second; % pred: per cent predicted; FVC: forced vital capacity; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure; VO2,max: maximal oxygen consumption; Sa,O2: arterial oxygen saturation; COPDSE: Chronic Obstructive Pulmonary Disease Self-Efficacy Scale; LCADL: London Chest Activity of Daily Living Scale. #: n = 21; : n = 29; +: n = 24; ns: nonsignificant.