Role of KRAS in regulating normal human airway basal cell differentiation

Respiratory Research

Table 1 Demographics of Nonsmokers and Smokers^a

Parameter	Nonsmokers	Smokers	Smokers vs nonsmokers p value
n	5	5
Gender (M/F)	1/4	4/1	0.06
Age (yr)	33.4 ± 11.5	48.6 ± 8.1	0.05
Race (B/W/H/O)^b	2/1/0/2	2/0/2/1	0.34
Body mass index	23.6 ± 2.0	23.4 ± 4.0	0.9
Smoking history
Age of initiation	NA	20.4 ± 4.8	NA
Duration of smoking (pk-yr)	NA	25.1 ± 15.3	NA
Urine nicotine (ng/ml)^c	< 2	640 ± 746	0.07
Urine cotinine (ng/ml)^c	< 5	925 ± 312	0.002
Carboxyhemoglobin (%)	1.6 ± 0.2	2.6 ± 0.33	0.0008
Pulmonary function parameters^d
FVC	100.4 ± 17.4	114 ± 15.3	0.23
FEV1	101.2 ± 12.6	115 ± 17.2	0.19
% Change FEV1 post-bronchodilator	3.2 ± 3.6	3.4 ± 2.2	0.92
FEV1/FVC	85.4 ± 5.0	81.6 ± 3.8	0.22
TLC	98.6 ± 15.3	98.8 ± 6.7	0.98
DLCO	86.6 ± 7.6	88.2 ± 8.4	0.76
Cough Score^e	0.6 ± 0.5	1 ± 1	0.46
Sputum Score^e	0.4 ± 0.5	1 ± 1	0.28

^aData are presented as mean ± standard deviation, p values of numeric parameters calculated using a 2-tailed Student’s t-test with unequal variance, p value of categorical parameters calculated using a chi-square test for screening date
^bAbbreviations^: B=Black, W=White, H=Hispanic, O=Other, NA = not applicable
^cUndetectable urine nicotine < 2 ng/ml; cotinine < 5 ng/ml
^dPulmonary function testing parameters are given as % of predicted value with the exception of FEV1/FVC, which is reported as % observed; FVC - forced vital capacity, FEV1 - forced expiratory volume in 1 s, TLC -total lung capacity, DLCO - diffusing capacity
^eCough and sputum score were each evaluated on a scale of 0–4: 0 = not at all; 1 = only with chest infections; 2 = a few days a month; 3 = several days per week; 4 = most days per wk. [35]

ISSN: 1465-993X