Normal QMVC | Weak QMVC | p-value | |
Subjects n | 236 | 115 | |
Age yrs | 63±9 | 63±11 | 0.487 |
Male sex % | 56 | 59 | 0.647# |
FFM index kg·m−2 | 15.7±2.1 | 15.8±2.1 | 0.583 |
DEXABODY lean mass kg | 45.6±9.2 | 43.6±8.7 | 0.057 |
DEXALEG lean mass kg | 14.1±3.2 | 13.2±3.0 | 0.013 |
QMVC/DEXALEG | 2.38±0.43 | 1.71±0.32 | <0.001 |
TwQ/DEXALEG | 0.56±0.16 | 0.46±0.14 | <0.001 |
FEV1 % pred | 46.2±18.2 | 40.6±17.0 | 0.006 |
DL,CO % pred | 59.7±11.2 | 56.3±10.8 | 0.008 |
RV/TLC % | 46.9±16.6 | 51.3±17.8 | 0.070 |
Pa,O2 kPa | 9.40±1.36 | 9.21±1.48 | 0.237 |
Pa,CO2 kPa | 5.29±0.66 | 5.39±0.76 | 0.192 |
6MWD m | 452±119 | 403±108 | <0.001 |
Wpeak W | 74±33 | 62±29 | 0.002 |
SGRQ Score | |||
Total score | 52.8±17.0 | 57.6±16.0 | 0.018 |
Symptoms | 60.2±20.3 | 65.5±19.5 | 0.033 |
Activities | 68.3±19.4 | 74.1±18.1 | 0.012 |
Impacts | 41.7±18.9 | 45.8±18.7 | 0.076 |
Data are presented as mean±sd, unless otherwise stated. QMVC: isometric quadriceps maximum voluntary contraction; FFM: fat-free mass; DEXABODY and DEXALEG, dual energy x-ray absorptiometry measurement of whole body and lower limb, respectively; TwQ: twitch quadriceps force following magnetic femoral nerve stimulation; FEV1: forced expiratory volume in 1 s; % pred: % predicted; DL,CO: diffusing capacity for carbon monoxide; RV: residual volume; TLC: total lung capacity; Pa,O2: arterial oxygen tension; Pa,CO2: arterial carbon dioxide tension; 6MWD, 6-min walk test distance; Wpeak: peak exercise capacity measured by incremental cycle ergometry; SGRQ: St George’s Respiratory Questionnaire (lower score denotes improvement). p-values were derived from ANOVA unless indicated and significant values are shown in bold. #: Fishers exact test was used.