TABLE 1.

BASELINE CHARACTERISTICS OF PATIENTS WITH BASELINE o₂max ABOVE OR BELOW THE 8.3 ml/kg/min THRESHOLD

	Above Threshold	Below Threshold	P Value
n	109	8
Age, yr	64.0 ± 8.4	69.1 ± 8.6	0.10
Sex			0.044
Male	78 (78.8%)	3 (37.5%)
Female	31 (31.3%)	5 (62.5%)
Diagnosed with lung biopsy	70 (70.7%)	5 (62.5%)	0.92
Smokers			0.30
Never smokers	28 (28.3%)	4 (50%)
Former smokers	76 (76.7%)	4 (50%)
Current smokers	5 (5.0%)	0
Pack-years	39.2 ± 24.9	42.0 ± 44.4	0.84
Spirometry at baseline
FVC, L	2.8 ± 0.9	1.8 ± 0.6	0.002
FVC%	69.0 ± 17.8	53.0 ± 9.6	0.01
DlCO, ml/min/mm Hg	12.3 ± 4.4	7.1 ± 1.3	0.002
DlCO%	47.8 ± 14.9	31.9 ± 7.7	0.006
Exercise at baseline
Exercise PaO2	67.4 ± 15.0	59.4 ± 12.6	0.25
Exercise Aa gradient	41.0 ± 14.7	42.2 ± 13.3	0.85
Exercise saturation	89.5 ± 4.9	88.0 ± 5.7	0.41
Minutes of exercise	7.4 ± 1.9	4.2 ± 1.5	<0.001
Work, W	95.2 ± 35.0	40.0 ± 11.6	<0.001
o2max, ml/kg/min	14.0 ± 4.2	6.9 ± 1.4	<0.001
Exercise gas exchange score	12.4 ± 9.8	20.0 ± 14.2	0.04
6MWT at baseline
Desaturation < 88%	38 (38.4%)	5 (62.5%)	0.12
Distance, ft	1,116.6 ± 456.0	582.2 ± 386.1	0.002

Definition of abbreviations: Aa gradient = alveolar-arterial gradient; Dl_CO% = diffusion capacity for carbon monoxide percent predicted; FVC% = forced vital capacity percent predicted; o₂max = maximal oxygen consumption during cardiopulmonary exercise testing; 6MWT = 6-min-walk test.

Data are shown as mean ± standard deviation (SD) or frequency (%).