Glutathione Peroxidase in Stable Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis.

Elisabetta Zinellu,Angelo Zinellu,Barbara Piras,Alessandro G Fois,Ciriaco Carru,Arduino A Mangoni,Pietro Pirina,Maria Carmina Pau,Sabrina Mellino

doi:10.3390/antiox10111745

Elisabetta Zinellu, Angelo Zinellu + Show 7 more

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https://doi.org/10.3390/antiox10111745

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Abstract

Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by a state of persistent inflammation and oxidative stress. The presence of oxidative stress in COPD is the result of an imbalance between pro-oxidant and antioxidant mechanisms. The aim of this review was to investigate a possible association between glutathione peroxidase (GPx), a key component of antioxidant defense mechanisms, and COPD. A systematic search for relevant studies was conducted in the electronic databases PubMed, Web of Science, Scopus, and Google Scholar, from inception to June 2021. Standardized mean differences (SMDs) were used to express the differences in GPx concentrations between COPD patients and non-COPD subjects. Twenty-four studies were identified. In 15 studies assessing whole blood/erythrocytes (GPx isoform 1), the pooled results showed that GPx concentrations were significantly lower in patients with COPD (SMD = −1.91, 95% CI −2.55 to −1.28, p < 0.001; moderate certainty of evidence). By contrast, in 10 studies assessing serum/plasma (GPx isoform 3), the pooled results showed that GPx concentrations were not significantly different between the two groups (very low certainty of evidence). The concentration of GPx-1, but not GPx-3, is significantly lower in COPD patients, suggesting an impairment of antioxidant defense mechanisms in this group.

Highlights

Clinical and Interventional Pulmonology, University Hospital Sassari (AOU), 07100 Sassari, Italy; Department of Medical, Surgical and Experimental Sciences, University of Sassari, 07100 Sassari, Italy; Department of Clinical Pharmacology, College of Medicine and Public Health, Flinders Medical Centre, Abstract: Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by a state of persistent inflammation and oxidative stress
In 14 studies [25,26,27,28,29,31,32,33,34,35,36,37,38,39], COPD patients had lower blood glutathione peroxidase (GPx) concentrations when compared to non-COPD subjects
The results showed that the GPx concentrations in whole blood or erythrocytes were significantly lower in COPD patients when compared to non-COPD subjects

Summary

Introduction

In 15 studies assessing whole blood/erythrocytes (GPx isoform 1), the pooled results showed that GPx concentrations were significantly lower in patients with COPD (SMD = −1.91, 95% CI −2.55 to −1.28, p < 0.001; moderate certainty of evidence). The lungs are exposed to environmental insults, such as tobacco smoke and air pollutants, that represent important sources of reactive oxygen species (ROS) The latter directly promote lung damage, resulting from alterations of DNA, lipids, carbohydrates, and proteins, as well as activate local inflammatory responses which contribute to the development and progression of COPD [6]. Recruited inflammatory cells become activated and generate further ROS, enhancing the pro-oxidant burden [7,8] These events lead to a state of sustained inflammation and chronic oxidative stress. Several studies have reported GPx activity in the blood of stable COPD patients and non-COPD subjects, the results were not always concordant or significant

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