Oxidant-Antioxidant Balance in the Blood of Patients with Chronic Obstructive Pulmonary Disease After Smoking Cessation

Table 2

Spirometric parameters in the COPD patients who had given up smoking and in the representatives of the control groups: COPD patients who had not given up smoking and healthy subjects.

Group	FEV1; (% predicted value)	Parameters FVC; (% predicted value)	FEV1/FVC (%)
Control I (healthy nonsmokers)	97.7 ± 14.0	109.1 ± 13.3	84.7 ± 5.7
COPD patients who had not given up smoking (Control II)
At the beginning of the study	73.2 ± 19.5***	94.6 ± 15.6***	62.3 ± 6.6***
After the 1st month of the study	73.3 ± 20.4***	93.5 ± 17.0***	61.9 ± 5.4***
After the 2nd month of the study	73.1 ± 14.7***	94.0 ± 18.5***	61.5 ± 7.5***
After the 3rd month of the study	73.1 ± 17.1***	93.8 ± 22.8***	61.2 ± 5.9***
COPD patients who had given up smoking (study group)
Before smoking cessation	73.5 ± 17.8***	94.6 ± 17.5***	61.9 ± 7.6***
After the 1st month of tobacco abstinence	74.0 ± 25.5***	94.1 ± 16.3***	61.2 ± 6.1***
After the 2nd month of tobacco abstinence	74.3 ± 23.6***	94.3 ± 14.6***	61.4 ± 6.4***
After the 3rd month of tobacco abstinence	74.8 ± 24.6***	94.5 ± 14.6*	62.1 ± 6.3***

COPD: chronic obstructive pulmonary disease; FEV₁: forced expiratory volume in 1 second; FVC: forced vital capacity; FEV₁/FVC: forced expiratory volume in 1 second/forced vital capacity ratio.
Data expressed as mean 𝑥±SD; *P < 0.05; ***P < 0.001 compared with Control I.