Coordinate Control of Expression of Nrf2-Modulated Genes in the Human Small Airway Epithelium Is Highly Responsive to Cigarette Smoking

Table 1 Study population demographics and biologic sample data^a

Parameter	Healthy nonsmokers	Healthy smokers	P value ^b
n	38	45
Sex, male/female	28/10	32/13	P > 0.8
Age, y	43 ± 2	43 ± 1	P > 0.4
Ancestry, B/W/H/A/O^c	16/16/4/1/1	28/11/6/0/0	P > 0.2
Smoking history, pack-year	0 ± 0	27 ± 2	P < 1 × 10⁻¹⁴
Urine nicotine, ng/mL	0 ± 0	967 ± 161	P < 4 × 10⁻⁷
Urine cotinine, ng/mL	0 ± 0	1055 ± 119	P < 4 × 10⁻¹¹
Venous carboxy hemoglobin, %	0 ± 0	2.0 ± 0.3	P < 2 × 10⁻⁶
Pulmonary function parameters^d
FVC	109 ± 2	109 ± 2	P > 0.6
FEV1	105 ± 3	108 ± 2	P > 0.5
FEV1/FVC	81 ± 1	81 ± 1	P > 0.7
TLC	103 ± 2	100 ± 2	P > 0.4
DLCO	99 ± 2	95 ± 2	P > 0.3
Epithelial cells recovered, n × 10⁶	5.8 ± 0.3	6.5 ± 0.4	P < 0.04
Epithelial cells, %	99.7 ± 0.2	99.8 ± 0.1	P > 0.4
Inflammatory cells, %	0.2 ± 0.1	0.2 ± 0.1	P > 0.8
Differential cell count
Ciliated, %	75.3 ± 1.1	72.3 ± 1.3	P > 0.06
Secretory, %	7.1 ± 0.6	7.1 ± 0.5	P > 0.4
Basal, %	10.1 ± 0.8	10.6 ± 0.7	P > 0.5
Undifferentiated, %	7.3 ± 0.6	10.0 ± 0.9	P < 0.01

^aData are presented as mean ± standard error.
^bGroup comparison with unpaired, two-tailed t test with unequal variance and chi-square test.
^cB, black; W, white; H, Hispanic; A, Asian; O, other.
^dPulmonary function testing parameters are given as percentage of predicted value, with the exception of FEV1/FVC, which is reported as percentage observed; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; TLC, total lung capacity; DLCO, diffusing capacity.

ISSN: 1528-3658