Table 2.

Disease severity values in patients with CF and control subjects

Variable	Patients with CF	Control Subjects	P Value
	Pulmonary function
FVC, liters	3.61 ± 1.24	4.54 ± 1.10	0.023*
FEV1, liters	2.78 ± 1.01	3.74 ± 0.81	0.006*
FEF25–75, l/s	2.56 ± 1.30	3.77 ± 0.99	0.007*
FEV1, %predicted	75 ± 16	97 ± 9	0.001*
FEV1/FVC, %	72 ± 8	91 ± 6	0.044*
	Exercise capacity
V̇o2peak
l/min	1.6 ± 0.5	2.3 ± 0.8	0.017*
ml·kg−1·min−1	28.4 ± 4.8	34.5 ± 7.0	0.012*
%predicted	73 ± 12	98 ± 14	0.001*
Heart rate peak, beats/min	160 ± 6	184 ± 4	0.003*
Work peak, W	139 ± 14	205 ± 13	0.001*

Values are means ± SD.

CF, cystic fibrosis; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; FEF_25–75, forced expiratory flow at 25-75% FVC; V̇o_2peak, peak O₂ consumption.

^*Statistically significant.