TABLE 1.

Clinical characteristics of subjects

	COPD	Controls	p-value
Age yrs	65±7	65±7	ns
Males:females n	12 : 6	9 : 7	ns
BMI kg·m−2	24.5±4.7	25.7±4.8	ns
Fat free mass index	15.8±2.3	17.4±2.5	ns
FEV1 L	0.93±0.40	3.03±0.63	<0.0001
FEV1 % pred	35±15	112±13	<0.0001
DL,CO % pred	37.9±14.3	91.3±16.1	<0.0001
TLC % pred	120±19	108±11	0.03
RV % pred	193±51	103±16	<0.0001
Quadriceps MVC kg	29.8±8.6	37.7±9.8	0.02
MVC/BMI	1.2±0.3	1.5±0.5	0.04
Quadriceps endurance# s	91±47	127±72	ns
6MWD m	362±145	630±86	<0.0001
SGRQ total score	57±11	3±4	<0.0001
Locomotion time min	48±45	106±53	0.004

Data are presented as mean± sd, unless otherwise stated. COPD: chronic obstructive pulmonary disease; BMI: body mass index; FEV₁: forced expiratory volume in 1 s; %pred.: % predicted; D_L,co: carbon monoxide diffusion capacity; TLC: total lung capacity; RV: residual volume; MVC: maximal voluntary contraction; 6MWD: 6-min walk distance; SGRQ: St George's Respiratory Questionnaire, ns: nonsignificant i.e. p>0.05.

^#defined as the time for force to fall to 80% of baseline.