Oxidative stress in cystic fibrosis: Dietary and metabolic factors

Objective: To examine oxidative stress in CF by measuring 8-iso-PGF2 alpha and antioxidant defenses, in relation to dietary intake, immune function an d clinical status. Methods: We measured total plasma concentrations of 8-iso-PGF2 alpha and di etary antioxidants (vitamin E, vitamin C, beta -carotene), erythrocyte anti oxidant enzyme activities (glutathione peroxidase and superoxide dismutase) , lung function and dietary intake in 21 CF subjects and 21 healthy age- an d gender-matched controls. Results: Total plasma 8-iso-PGF2 alpha concentration (median [quartile 1-qu artile 3]) was significantly higher in CF subjects compared to controls (21 4 pg/mL(155-331) vs. 135 pg/mL (101-168), p = 0.001). Neutrophil, monocyte and total white cell counts were elevated in the CF group and these correla ted with 8-iso-PGF2 alpha concentration. Despite similar dietary intake, lo wer plasma antioxidant concentrations were observed in the CF group (vitami n E, p < 0.001, vitamin C, p = 0.004, <beta>-carotene, p = 0.001). 8-iso-PG F2 alpha correlated negatively with plasma vitamin E, C and beta -carotene concentrations. Conclusion: Oxidative stress is increased in CF patients, despite normal di etary antioxidant intake. The immune response appears to be a key factor ca using oxidative stress. Antioxidant intervention aimed at reducing oxidativ e stress in CF needs to be assessed.