Table 1.

Demographics and Enrollment Pulmonary Function Test Results for Control and Chronic Obstructive Pulmonary Disease (COPD) Groups

Characteristic	Control Subjects∗	COPD Subjects
		Total	Mild Obstruction†	Moderate/Severe Obstruction†
n	55	62	30	32
Baseline FEV1 (mean ± SD)	2.49 ± 0.59	1.28 ± 0.57	1.70 ± 0.45	0.89 ± 0.34
Age, yr (mean ± SD)	67.5 ± 5.3	65.4 ± 7.4	67.1 ± 6.0	63.8 ± 8.3
Sex (M/F)	24/31	26/36	13/17	13/19
Months of follow-up (mean ± SD)	35.1 ± 10.9‡	26.3 ± 14.2‡	28.1 ± 11.7	24.6 ± 13.2

FEV₁ = forced expiratory volume in 1 second.

Adapted from Am J Respir Crit Care Med.6

^∗FEV₁ at baseline >80% of predicted.

^†Baseline pulmonary function tests included spirometry; mild obstruction was defined as an enrollment FEV₁ ≥50% and <80% predicted, and moderate/severe obstruction was defined as an enrollment FEV₁ <50% predicted.

^‡P <0.001.