Oxidative stress in chronic obstructive pulmonary disease patients submitted to a rehabilitation program

Abstract

Pulmonary rehabilitation (PR) improves physical capacity and health quality in patients with chronic obstructive pulmonary disease (COPD). However, the effect of exercise on oxidative stress markers in COPD patients is only partially known. This study was designed to evaluate the oxidative stress response to long-term exercise in patients with COPD enrolled in a PR program. Fifteen COPD patients (FEV1 < 60%), age between 50 and 60 years, ex-smokers, were separated in two groups: exercise-trained (n=8) and sedentary group (n=7). Exercise consisted of an 8-week conditioning program using a cycle ergometer (three times a week, 1h session). An endurance test (60% of maximal load in an incremental cycle test) was performed before and after PR. Blood samples were obtained at baseline and immediately after each endurance test. We measured the index of lipid peroxidation, thiobarbituric acid reactive species (TBARS), total radical-trapping antioxidant parameter (TRAP) and xanthine oxidase (XO) activity. TRAP was significantly different between the exercise-trained group and sedentary group of COPD patients. Baseline TBARS values were increased after the exercise training program but decreased after the endurance test. XO decrease after effort in the trained and untrained groups. The results suggest that patients with COPD are characterized by increased systemic and pulmonary oxidative stress markers both at rest as well as induced by cardiopulmonary exercise test and that PR program was associated with decreased systemic exercise-induced oxidative damage.

Comparação do treinamento físico de quatro e oito semanas sobre atividade da cadeia transportadora de elétrons e marcadores de estresse oxidativo em fígado de camundongos

“…Essas alterações são observadas no envelhecimento e em situações patológicas (5,15) . Prejuízos na atividade do complexo IV, por exemplo, estão relacionados com a doença de Alzheimer (16) e do complexo I, com Parkinson (17) .…”

“…Uma das hipóteses, de acordo com Nakamoto et al (29) para explicar a redução de estresse oxidativo no fígado é que exercício ativa fatores de transcrição que se ligam ao DNA mitocondrial e nuclear, causando adaptações que protegem as células contra o ataque das ERO. Segundo Pinho et al (5) , outro fator que poderia explicar esse fenômeno é a exposição crônica do tecido às ERO, induzida pelo treinamento, tornando o órgão mais resistente ao estresse oxidativo. Uma terceira hipótese sustentada por Gonzalez et al (29) é o aumento das proteínas da choque (HSP) induzidas pelo exercício.…”

“…Por outro lado, outros estudos têm reportado que o treinamento regular tem sido eficaz, na diminuição do estresse oxidativo provocado por diversas doenças (5,6) . Entretanto a comparação dos efeitos do treinamento de quatro e oito semanas sobre a atividade mitocondrial e marcadores de estresse oxidativo em fígados de camundongos permanece obscura.…”

Urinary 8-Hydroxydeoxyguanosine Is a Potential Indicator for Estimating Pulmonary Rehabilitation-Induced Oxidative Stress in COPD Patients

“…However, several studies have suggested that acute exercise may increase oxidative stress (OS), such as the increase in plasma thiobarbituric acid-reactive substance (TBARS) in COPD patients (Heunks et al 1999;Couillard et al 2002;Agacdiken et al 2004). In addition, Pinho et al (2007) reported that chronic exercise training can induce OS at baseline in COPD patients, and Barreiro et al (2009) demonstrated that nitrosative stress in severe COPD had increased after chronic endurance exercise. To our knowledge, however, there is little information on the relationship between PR in COPD patients and OS.…”

COPD: Is there evidence to support a role for resistance training in improving measurable health-related quality of life in pulmonary rehabilitation?

“…41 Exerciseinduced elevations in cytokines (particularly interleukin-6) have been implicated as potential role players involved in inducing the anti-inflammatory effect associated with exercise. 15 Whether resistance training promotes a downregulation in oxidative/inflammatory responses remains to be elucidated.…”