Supplemental oxygen prevents exercise-induced oxidative stress in muscle-wasted patients with chronic obstructive pulmonary disease.
BACKGROUND
Although oxygen therapy is of clear benefit in patients with severe chronic obstructive pulmonary disease (COPD), recent studies have shown that short-term supplementary oxygen may increase oxidative stress and inflammation within the airways.


OBJECTIVE
We investigated whether systemic inflammation and oxidative stress at rest and during exercise in patients with COPD are influenced by supplemental oxygen.


METHODS
Nine normoxemic, muscle-wasted patients with moderate to very severe COPD were studied. Plasma markers of systemic inflammation (leukocyte counts, interleukin 6 [IL-6]) and oxidative stress (lipid peroxidation, protein oxidation, antioxidant capacity) were measured after treatment with either supplemental oxygen (nasal, 4 L . min(-1)) or compressed air, both at rest (1 h treatment) and after submaximal exercise (40 W, constant work rate). In addition, free-radical production by neutrophils and ATP-degradation products were determined before and after exercise.


RESULTS
Short-term oxygen breathing at rest did not influence systemic low-grade inflammation and oxidative stress. The IL-6 response to exercise was attenuated during cycling with supplemental oxygen. Exercise-induced lipid and protein oxidation were prevented by treatment with supplemental oxygen. This was associated with both decreased free-radical production by neutrophils and reduced formation of (hypo)xanthine and uric acid.


CONCLUSIONS
Short-term supplementary oxygen does not affect basal systemic inflammation and oxidative stress but prevents exercise-induced oxidative stress in normoxemic, muscle-wasted patients with COPD, and attenuates plasma IL-6 response. Inhibition of neutrophil activation and ATP degradation appears to be involved in this effect.
van Helvoort
Hanneke A C
HA
Radboud University Nijmegen Medical Centre, Department of Pulmonary Diseases (454), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Heijdra
Yvonne F
YF
Heunks
Leo M A
LM
Meijer
Patty L M
PL
Ruitenbeek
Wim
W
Thijs
Hub M H
HM
Dekhuijzen
P N Richard
PN
D000368:Aged; D001784:Blood Gas Analysis; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007773:Lactates / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000209:etiology / Q000503:physiopathology*; D018384:Oxidative Stress / Q000502:physiology*; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011336:Probability; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D011659:Pulmonary Gas Exchange; D012016:Reference Values; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome
D007773:Lactates