Table 2.

Pulmonary function data

	CON (n = 20)			PRE (n = 19)			BPD (n = 25)
	Absolute values	%Predicted	Z-score	Absolute values	%Predicted	Z-score	Absolute values	%Predicted	Z-score
Spirometry
FVC, liters	4.9 ± 0.2	103 ± 2	0.34 ± 0.16	4.7 ± 0.2	95 ± 3	−0.17 ± 0.21	4.3 ± 0.3	90 ± 3*	−0.54 ± 0.24*
FEV1, liters	3.9 ± 0.2	103 ± 2	−0.13 ± 0.15	3.7 ± 0.2	92 ± 2*	−0.90 ± 0.26	3.1 ± 0.2*†	82 ± 4*	−1.61 ± 0.29*
FEV1/FVC	81 ± 1	95 ± 1	−0.76 ± 0.16	78 ± 2	92 ± 2	−1.11 ± 0.23	74 ± 2*	85 ± 3*	−1.62 ± 0.26*
PEF, l × s−1	9.1 ± 0.4	112 ± 2		7.6 ± 0.4*	88 ± 3*		6.5 ± 0.4*	78 ± 4*
FEF25, l × s−1	8.0 ± 0.3	106 ± 3		6.3 ± 0.4*	78 ± 4*		5.0 ± 0.4*†	65 ± 4*†
FEF50, l × s−1	4.7 ± 0.2	85 ± 4		3.9 ± 0.3	70 ± 5		3.1 ± 0.3*	58 ± 5*
FEF75, l × s−1	2.0 ± 0.1	88 ± 6	−0.16 ± 0.19	1.7 ± 0.2	71 ± 6	−0.95 ± 0.24	1.4 ± 0.1*	60 ± 6*	−1.41 ± 0.28*
FEF25–75, l × s−1	3.9 ± 0.2	94 ± 3	−0.46 ± 0.15	3.3 ± 0.3	75 ± 5*	−1.33 ± 0.24*	2.7 ± 0.2*†	63 ± 5*	−1.96 ± 0.28*
Lung volumes
TLC, liters	6.2 ± 0.2	103 ± 2		6.3 ± 0.3	102 ± 3		5.9 ± 0.3	102 ± 2
IC, liters	3.1 ± 0.1	108 ± 4		3.1 ± 0.1	100 ± 4		2.7 ± 2	95 ± 4*
FRC, liters	3.1 ± 0.1	99 ± 4		3.3 ± 0.2	107 ± 5		3.2 ± 0.2	109 ± 4
ERV, liters	1.8 ± 0.1	109 ± 4		1.7 ± 0.1	100 ± 6		1.6 ± 0.1	96 ± 6
RV, liters	1.2 ± 0.1	87 ± 6		1.5 ± 0.1	111 ± 9		1.6 ± 0.1	126 ± 9*

All values are expressed as means ± SD; n, number of subjects. BPD, bronchopulmonary dysplasia; CON, control; ERV, expiratory reserve volume; FEV₁, forced expiratory volume in 1 s; FEF₂₅, forced expiratory flow at 25% of FVC; FEF₅₀, forced expiratory flow at 50% of FVC; FEF₇₅, forced expiratory flow at 75% of FVC; FEF_25–75, average forced expiratory flow from 25 to 75% of FVC; FRC, functional residual capacity; FVC, forced vital capacity; IC, inspiratory capacity; PEF, peak expiratory flow; PRE, preterm without bronchopulmonary dysplasia; RV, residual volume; TLC, total lung capacity.

^*Statistically significant difference from CON, P < 0.05;

^†statistically significant difference between PRE and BPD, P < 0.05.