Oral antioxidants improve leg blood flow during exercise in patients with chronic obstructive pulmonary disease

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 309; no. 5; pp. H977 - H985
• Main Authors: Rossman, Matthew J., Trinity, Joel D., Garten, Ryan S., Ives, Stephen J., Conklin, Jamie D., Barrett-O'Keefe, Zachary, Witman, Melissa A. H., Bledsoe, Amber D., Morgan, David E., Runnels, Sean, Reese, Van R., Zhao, Jia, Amann, Markus, Wray, D. Walter, Richardson, Russell S.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.09.2015
• Subjects: Administration, Oral; Aged; Antioxidants - administration & dosage; Antioxidants - therapeutic use; Blood pressure; Chronic obstructive pulmonary disease; Exercise; Female; Human subjects; Humans; Integrative Cardiovascular Physiology and Pathophysiology; Leg - blood supply; Male; Middle Aged; Oxidative stress; Oxygen; Physiology; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - drug therapy; Pulmonary Disease, Chronic Obstructive - physiopathology; Regional Blood Flow; Veins & arteries; oxygen transport; exercise; chronic bronchitis; oxidative stress; chronic obstructive pulmonary disease; emphysema
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00184.2015

The consequence of elevated oxidative stress on exercising skeletal muscle blood flow as well as the transport and utilization of O 2 in patients with chronic obstructive pulmonary disease (COPD) is not well understood. The present study examined the impact of an oral antioxidant cocktail (AOC) on leg blood flow (LBF) and O 2 consumption during dynamic exercise in 16 patients with COPD and 16 healthy subjects. Subjects performed submaximal (3, 6, and 9 W) single-leg knee extensor exercise while LBF (Doppler ultrasound), mean arterial blood pressure, leg vascular conductance, arterial O 2 saturation, leg arterial-venous O 2 difference, and leg O 2 consumption (direct Fick) were evaluated under control conditions and after AOC administration. AOC administration increased LBF (3 W: 1,604 ± 100 vs. 1,798 ± 128 ml/min, 6 W: 1,832 ± 109 vs. 1,992 ± 120 ml/min, and 9W: 2,035 ± 114 vs. 2,187 ± 136 ml/min, P < 0.05, control vs. AOC, respectively), leg vascular conductance, and leg O 2 consumption (3 W: 173 ± 12 vs. 210 ± 15 ml O 2 /min, 6 W: 217 ± 14 vs. 237 ± 15 ml O 2 /min, and 9 W: 244 ± 16 vs 260 ± 18 ml O 2 /min, P < 0.05, control vs. AOC, respectively) during exercise in COPD, whereas no effect was observed in healthy subjects. In addition, the AOC afforded a small, but significant, improvement in arterial O 2 saturation only in patients with COPD. Thus, these data demonstrate a novel beneficial role of AOC administration on exercising LBF, O 2 consumption, and arterial O 2 saturation in patients with COPD, implicating oxidative stress as a potential therapeutic target for impaired exercise capacity in this population.