Increased plasma fatty acid concentrations after respiratory exacerbations are associated with elevated oxidative stress in cystic fibrosis patients.
BACKGROUND
Oxidative stress and depleted antioxidant defenses occur in stable cystic fibrosis patients. During acute infection, the balance between oxidants and antioxidants may be further disturbed.


OBJECTIVE
We examined the oxidative stress during acute infection in cystic fibrosis patients by measuring 8-iso-prostaglandin F(2 alpha) (8-iso-PGF(2 alpha)) and antioxidant defenses in relation to dietary intake, fatty acid status, immune function, and clinical status.


METHODS
Plasma concentrations of total 8-iso-PGF(2 alpha), vitamins E and C, beta-carotene, zinc, selenium, and copper; plasma fatty acid compositions; erythrocyte glutathione concentrations; glutathione peroxidase and superoxide dismutase activity; sputum glutathione and 8-iso-PGF(2 alpha) concentrations; lung function; clinical symptoms; and dietary intake were measured in 15 cystic fibrosis patients before and after 10-14 d of intravenous antibiotic treatment for a pulmonary exacerbation.


RESULTS
After treatment, respiratory status improved (percentage of forced expiratory volume in 1 s: 60 +/- 6% at baseline compared with 74 +/- 7% after treatment, P = 0.01), quality of well-being improved (P = 0.001), and total plasma 8-iso-PGF(2 alpha) concentrations increased from 469 nmol/L at baseline (interquartile range: 373-554 nmol/L) to 565 nmol/L after treatment (interquartile range: 429-689 nmol/L; P = 0.008). Total energy, fat, carbohydrate, and protein intakes per kilogram body weight also increased; however, dietary antioxidant intake was unchanged. Plasma fatty acid concentrations increased after treatment, strongly correlating with plasma 8-iso-PGF(2 alpha) concentrations (r = 0.768, P = 0.001). There were no significant changes in white cell counts or plasma concentrations of vitamins E and C or beta-carotene. Erythrocyte glutathione peroxidase activity was reduced after treatment, whereas there was no significant change in superoxide dismutase activity.


CONCLUSIONS
Oxidative stress increased after treatment for pulmonary exacerbations and was strongly linked to increased concentrations of plasma fatty acids. Although intravenous antibiotic therapy and physiotherapy improved lung function within 10-14 d of treatment, the biochemical effects of oxidation continued further. Thus, antioxidant intervention during treatment for and recovery from acute infection in cystic fibrosis should be considered.
Wood
Lisa G
LG
Discipline of Nutrition and Dietetics, the University of Newcastle, Callaghan, New South Wales, Australia.
Fitzgerald
Dominic A
DA
Gibson
Peter G
PG
Cooper
David M
DM
Garg
Manohar L
ML
D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000975:Antioxidants / Q000627:therapeutic use*; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002648:Child; D003550:Cystic Fibrosis / Q000097:blood* / Q000188:drug therapy / Q000201:enzymology; D004032:Diet; D015232:Dinoprostone / Q000031:analogs & derivatives / Q000097:blood*; D002149:Energy Intake; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D006801:Humans; D028421:Isoprostanes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012129:Respiratory Function Tests; D013183:Sputum / Q000737:chemistry; D014662:Vasoconstrictor Agents / Q000097:blood*
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001993:Bronchodilator Agents; D005227:Fatty Acids; D028421:Isoprostanes; D014662:Vasoconstrictor Agents; D015232:Dinoprostone; C011987:8-isoprostaglandin E2