Table 2—

Associations between pulmonary function and parameters of the timed walk test

Variable	DL,CO		Pa,O₂		PA–a,O₂ difference
Variable	r	p-value	r	p-value	r	p-value
End-exercise SP,O₂	0.80	<0.001	0.57	0.001	−0.57	0.005
Change in SP,O₂ with exercise	−0.63	0.001	−0.33	0.129	0.33	0.129
Walk distance	0.77	<0.001	0.67	<0.001	−0.67	<0.001
Walk velocity	0.73	<0.001	0.73	<0.001	−0.70	<0.001

DL,CO: diffusing capacity for carbon monoxide; Pa,O₂: arterial oxygen tension; PA–a,O₂: alveolar–arterial oxygen tension; SP,O₂: arterial oxygen saturation measured by pulse oximetry.