Heterogeneity of Systemic Oxidative Stress Profiles in COPD: A Potential Role of Gender

Abstract

Oxidative stress (OS) plays a key role in the muscle impairment and exercise capacity of COPD patients. However, the literature reveals that systemic OS markers show great heterogeneity, which may hinder the prescription of effective antioxidant supplementation. This study therefore aimed to identify OS markers imbalance of COPD patients, relative to validated normal reference values, and to investigate the possibility of systemic OS profiles. We measured systemic enzymatic/nonenzymatic antioxidant and lipid peroxidation (LP) levels in 54 stable COPD patients referred for a rehabilitation program. The main systemic antioxidant deficits in these patients concerned vitamins and trace elements. Fully 89% of the COPD patients showed a systemic antioxidant imbalance which may have caused the elevated systemic LP levels in 69% of them. Interestingly, two patient profiles (clusters 3 and 4) had a more elevated increase in LP combined with increased copper and/or decreased vitamin C, GSH, and GPx. Further analysis revealed that the systemic LP level was higher in COPD women and associated with exercise capacity. Our present data therefore support future supplementations with antioxidant vitamins and trace elements to improve exercise capacity, but COPD patients will probably show different positive responses.

Circulating biomarkers of oxidative stress in chronic obstructive pulmonary disease: a systematic review

“…To a lesser extent than MDA, other biomarkers of lipid peroxidation have been studied in plasma of COPD patients of which have been described increased levels compared to controls (Table 1): lipid peroxides, determined spectrophotometrically either using their ability to convert iodide to iodine in a solution containing cholesterol-iodide [59] or following their reaction with peroxidase and a subsequent color production [62]; conjugated dienes, that are formed in the process of lipid peroxidation as a result of a reconfiguration of double bonds and yield a characteristic absorbance peak [27, 59]; oxidized LDL, determined spectrophotometrically with a competitive enzyme-linked immunosorbent assay (ELISA) kit [62] and 8-isoprostane, assayed with a specific enzyme immunoassay kit [63]. …”

“…A decreased level of vitamin C [25, 28, 62] and E [25, 28, 30], as well as no difference in the levels of vitamin A [27], C [40, 48, 95] and E [27] has been described in COPD compared to healthy controls. No differences have also been found in the different stages of severity of disease [96].…”

“…In particular, the plasma levels of selenium (Se) and zinc (Zn), determined by inductively coupled plasma-mass spectroscopy, have been evaluated, finding decreased levels in COPD compared to controls [62]. Measuring Se, Zn, iron (Fe), copper (Cu), potassium (K), rubidium (Rb) and calcium (Ca) by particle-induced X-ray emission, a reduction of K and Se and an increase of Fe, Ca, Cu, Zn and Rb has been described in plasma, while in the blood cells of the same COPD patients a reduction of K and Rb and an increase of the other elements studied has been described [69].…”

Determination of Relationship Between Lipid Peroxidation, Antioxidant Defence, Trace Elements and Hemorheology in COPD

“…Maury et al found increased lipid peroxidation and copper levels combined with decreased levels of GSH, and Glutathione peroxidase (Gpx) activity suggesting an antagonist relationship between Cu and Zn. They claim that higher Cu levels are a result of increased lipid peroxidation, whereas decreased Zn levels are due to consumption of Zn by antioxidant mechanisms which are trying to prevent oxidant damage [8].…”

“…In COPD, excessive amounts of free radicals and reactive oxygen metabolites are produced as a result of impaired inflammatory response due to progressive airway obstruction. Oxidant molecules react with proteins, lipids and nucleic acids, leading to cell dysfunction or death [8].…”