Table 4.

Correlation coefficients between ${\dot{\text{V}}\text{O}}_2$ at peak exercise and clinical parameters of COPD including skeletal muscle area.

	${\dot{\text{V}}\text{O}}_2$ (ml/min/kg) at peak exercise
	ρ	p value
Age (years)	− 0.22	0.08
BMI (kg/m2)	0.08	0.54
COPD assessment test	− 0.35	0.02
%VC (%)	0.19	0.11
%FVC (%)	0.16	0.2
FEV1 (L)	0.39	0.0009
FEV1/FVC (%)	0.33	0.006
%FEV1 (%)	0.24	0.05
DLco (%)	0.26	0.05
PMCSA (cm2)	0.36	0.007
ECMCSA (cm2)	0.39	0.003

CPET Cardiopulmonary exercise testing, ${\dot{V}O}_2$ oxygen uptake, BMI; body mass index, COPD chronic obstructive pulmonary disease, VC vital capacity, FVC forced vital capacity, FEV₁ forced expiratory volume in 1 s, DLco diffusing capacity of lung for carbon monoxide, PM_CSA cross-sectional area of pectoralis muscles, ECM_CSA cross-sectional area of erector spinae muscles.