Metabolomic, oxidative, and inflammatory responses to acute exercise in chronic obstructive pulmonary disease

Background There is currently a need to identify metabolomic responses to acute exercise in chronic obstructive pulmonary disease (COPD). Objective We investigated the metabolomic, oxidative, and inflammatory responses to constant (CE) and intermittent (IE) work rate exercises in COPD. Methods Sixteen males with COPD performed a symptom-limited incremental cycle exercise test (ICE). Metabolomic, oxidative, and inflammatory responses to CE and IE (based on the performance of ICE) were analyzed in the plasma. Results Fructose-6-phosphate, 3-phosphoglyceric acid, l-carnitine, and acylcarnitines levels were significantly decreased, whereas alpha-ketoglutaric, malic, 2-hydroxybutyric, and 3-hydroxybutyric acids were increased, after CE and IE (p<0.05). Increases in citric, isocitric, and lactic acids, as well as decreases in pyruvic and oxalic acids, were only present with IE (p<0.05). Isoleucine was decreased after both exercises (p<0.05). We observed an increase in inosine-5′-diphosphate, uric acid, ascorbic acid, and pantothenic acid, as well as a decrease in 5-hydroxymethyluridine, threonic acid, and dehydroascorbic acid, after IE (p<0.05). Catalase, reduced glutathione, and total antioxidant status difference values for both exercises were similar (p>0.05). The change in glutathione peroxidase (GPx) with CE was more significant than that with IE (p = 0.004). The superoxide dismutase change was greater with IE than with CE (p = 0.015). There were no significant changes in inflammatory markers after exercise (p>0.05). Conclusion CE and IE cause isoleucine, l-carnitine, and acylcarnitine levels to decrease, whereas ketone bodies were increased, thus indicating the energy metabolism shift from carbohydrates to amino acid utilization and lipid metabolism in COPD. Compared with CE, IE produces significant changes in more metabolomics in terms of carbohydrates, lipids, amino acids, nucleotides, and vitamins. Acute CE and IE alter circulating GPx levels in COPD.