Oxidative stress and lung function profiles of male smokers free from COPD compared to those with COPD: a case-control study

Abstract

BackgroundThe mechanisms of smoking tobacco leading to chronic obstructive pulmonary disease (COPD) are beginning to be understood. However, conclusions about the role of blood or lung oxidative stress markers were disparate.AimsTo investigate the oxidative stress in blood or lung associated with tobacco smoke and to evaluate its effect on pulmonary function data and its relation with physical activity.MethodsIt is a case-control study. Fifty-four male-smokers of more than five pack-years (PY) and aged 40–60 years were included (29 Non-COPD, 16 COPD). Physical activity score was determined. Blood sample levels of malondialdehyde (MDA), protein-cys-SH (PSH), and Glutathione (GSH) were measured. Fractional exhaled nitric oxide (FeNO) and plethysmographic measurements were performed. Correlation coefficients (r) evaluated the association between oxidative stress markers and independent variables (plethysmographic data and physical activity score).ResultsNon-COPD (48±6 years) and COPD (49±5 years) groups had similar tobacco consumption patterns, that is, 27±14 PY versus 30±19 PY, respectively. Compared to the Non-COPD group, the COPD group had significantly lower levels of GSH and PSH, that is, mean±SE were 40±6 versus 25±5 µg/mL and 54±10 versus 26±5 µg/g of hemoglobin, respectively. However, MDA level and FeNO values were similar. In the COPD group, none of the oxidative stress markers was significantly correlated with plethysmographic data or physical activity score. In the Non-COPD group, GSH was significantly correlated with physical activity score (r = 0.47) and PSH was significantly correlated with total lung capacity (TLC) (r=−0.50), residual volume (r = 0.41), and physical activity score (r = 0.62). FeNO was significantly correlated with TLC of the COPD group (r=−0.48).ConclusionCompared to the Non-COPD group, the COPD group had a marked decrease in blood antioxidant markers (GSH and PSH) but similar blood oxidant (MDA) or lung (FeNO) burden.

Incapacity, Handicap, and Oxidative Stress Markers of Male Smokers With and Without COPD

“…A part of the present study methodology was previously published in another study 3 that aimed to investigate oxidative stress in the blood or lungs associated with tobacco smoke and to evaluate its effect with pulmonary function data and its relation to physical activity.…”

“…More information about the city and the prevalence of smoking and COPD in that region was published previously. 3 In brief, 7.8% of the local population Ն40 y old had COPD. 3 The study was conducted in accordance with the Declaration of Helsinki.…”

“…3 In brief, 7.8% of the local population Ն40 y old had COPD. 3 The study was conducted in accordance with the Declaration of Helsinki. Participants provided written consent, and the study protocol was approved by the ethics committee of the hospital (approval 2204/2013).…”

“…2 To better investigate this chronic disease, it would be wise to refer to the World Health Organization's most recent categorization of its natural history (http:// www.who.int/classifications/icf/en/, Accessed October 9, 2015), reporting 3 evolutionary phases: deficiency, incapacity, and handicap. Although mechanisms of COPD de-ficiency have already been extensively explored, [3][4][5] those of the remaining 2 phases are understudied. 6 The assessment of incapacity is considered important, because it alone can predict the prospective functioning of the subject.…”

“…7,8 The handicap, which is the psychosocial impact of the chronic disease, can be objectively evaluated by the assessment of QOL 9 and/or physical activity status. 10 In a previous local study, 3 aiming to investigate the oxidative stress associated with tobacco smoke, the authors recommended evaluating its effects with submaximal exercise capacity and QOL. Finally, an integrative vision was advanced to evaluate subjects with COPD, through the BODE index, which is a simple multidimensional grading system predicting the risk of death.…”