The Role of Redox Balance
- Stephen J. Ives*,
- Ryan A. Harris*,
- Melissa A.H. Witman,
- Anette S. Fjeldstad,
- Ryan S. Garten,
- John McDaniel,
- D. Walter Wray,
- Russell S. Richardson
- From the Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT (S.J.I., M.A.H.W., R.S.G., D.W.W, R.S.R.); Department of Internal Medicine, Division of Geriatrics (S.J.I., M.A.H.W., R.S.G., D.W.W., R.S.R.) and Department of Neurology (A.S.F.), University of Utah, Salt Lake City; Department of Health and Exercise Sciences, Skidmore College, Saratoga Springs, NY (S.J.I.); Institute of Preventative and Public Health, Georgia Prevention Center, Medical College of Georgia, Augusta (R.A.H.); Sport and Exercise Science Research Institute, University of Ulster, Jordanstown, Co. Antrim, Northern Ireland, United Kingdom (R.A.H.); Department of Exercise and Sport Science, Kent State University, OH (J.M.D.); Louis Stokes VA Medical Center, Cleveland VA Medical Center, OH (J.M.D.); and Department of Exercise and Sport Science, University of Utah, Salt Lake City (D.W.W., R.S.R.).
- Correspondence to Russell S. Richardson, VA Medical Center Bldg 2, Rm 1D25, 500 Foothill Dr, Salt Lake City, UT 84148. E-mail r.richardson{at}hsc.utah.edu
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↵* These authors contributed equally to this work.
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by low pulmonary function, inflammation, free radical production, vascular dysfunction, and subsequently a greater incidence of cardiovascular disease. By administering an acute oral antioxidant cocktail to patients with COPD (n=30) and controls (n=30), we sought to determine the role of redox balance in the vascular dysfunction of these patients. Using a double-blind, randomized, placebo-controlled, crossover design, patients with COPD and controls were ingested placebo or the antioxidant cocktail (vitamin C, vitamin E, α-lipoic acid) after which brachial artery flow-mediated dilation and carotid-radial pulse wave velocity were assessed using ultrasound Doppler. The patients exhibited lower baseline antioxidant levels (vitamin C and superoxide dismutase activity) and higher levels of oxidative stress (thiobarbituic acid reactive species) in comparison with controls. The patients also displayed lower basal flow-mediated dilation (P<0.05), which was significantly improved with antioxidant cocktail (3.1±0.5 versus 4.7±0.6%; P<0.05; placebo versus antioxidant cocktail), but not controls (6.7±0.6 versus 6.9±0.7%; P>0.05; placebo versus antioxidant cocktail). The antioxidant cocktail also improved pulse wave velocity in patients with COPD (14±1 versus 11±1 m·s−1; P<0.05; placebo versus antioxidant cocktail) while not affecting controls (11±2 versus 10±1 m·s−1; P>0.05; placebo versus antioxidant). Patients with COPD exhibit vascular dysfunction, likely mediated by an altered redox balance, which can be acutely mitigated by an oral antioxidant. Therefore, free radically mediated vascular dysfunction may be an important mechanism contributing to this population’s greater risk and incidence of cardiovascular disease.
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- Received August 17, 2013.
- Revision received August 28, 2013.
- Accepted October 28, 2013.
- © 2013 American Heart Association, Inc.