Wilcoxon signed-rank test. Statistical signifi-
cance was accepted at a p-value less than 0.05.
Analyses were performed using Statistica 10.0
(StatSoft Inc., Tulsa, OK) software package.
3 Results
3.1 Patient Characteristics
Basic characteristics of the study groups are
listed in Table1.
3.2 Baseline Level of TNF-a, IL-1b,
and MDA in Exhaled Breath
Condensate in COPD patients
and Healthy Smokers
There were no differences between baseline EBC
concentration of the evaluated biomarkers in
COPD patients and healthy smokers (Fig.1).
3.3 Effects of Smoking
on Biomarkers in Exhaled Breath
Condensate in COPD Patients
and Healthy Smokers
There were no differences in the concentration of
all three markers between their respective values
at baseline and 60 min after smoking a single
cigarette (Table2).
The level of TNF-αafter smoking was signif-
icantly lower in healthy smokers than that in
patients with COPD (0.27 pg/mL vs. 0.46 pg/
mL, p¼0.035). On the contrary, concentration
of MDA after smoking was higher in healthy
smokers compared with COPD patients
(20.41 nmol/mL vs.16.81 nmol/mL, p¼0.01)
(Fig.2).3.4 Correlations Between EBC
Biomarkers and Clinical DataThere was a negative correlation between base-
line TNF-αconcentration in EBC and duration of
cigarette smoking in healthy smokers
(r¼0.56, p¼0.01). Such a relationship was
not confirmed in COPD patients. The level of
TNF-αafter smoking inversely correlated with
FEV 1 /FVC in the control group (r¼0.59,
p¼0.008), but not in the group of COPD
patients. In the COPD group, we found a rela-
tionship between baseline MDA concentration in
EBC and FEV 1 and FVC (% of predicted value):
r¼0.52, p¼0.02 and r¼0.52, p¼0.02,
respectively. No other correlations between the
EBC biomarkers and the investigated variables
were demonstrated.Table 1 Basic demographic and clinical data of the patients with chronic obstructive pulmonary disease (COPD) and
healthy cigarette smokers participating in the study
COPD patients n¼ 19 Healthy smokers n¼ 19 p
Gender (F/M) 8/11 8/11 ns
Age (year) 65 (61–69) 23 (21–24) <0.0001
BMI (kg/m^2 ) 23.5 (21.2–27.8) 23.5 (21.1–26.3) ns
Number of pack-years 33 (24–44) 2.1 (0.7–4) <0.0001
Duration of smoking (year) 42 (35–47) 6 (5–7) <0.0001
FEV 1 (L) 1.71 (1.29–2.41) 4.06 (3.4–4.6) <0.0001
FEV 1 (% predicted) 61 (50–86) 101 (96–113) <0.0001
FVC (L) 3.43 (2.32–3.99) 4.95 (3.90–5.80) <0.0001
FVC (% predicted) 87 (81–109) 100 (93–108) ns
FEV 1 /FVC (%) 58 (47.5–60) 84 (81–90.5) <0.0001
Data are medians and interquartile ranges (IQR).BMIbody mass index,FEV 1 forced expiratory volume in one second,
FVCforced vital capacity,nsnot significant
76 M. Maskey-Warze ̨ chowska et al.