Oxidative stress and cystic fibrosis-related diabetes: a pilot study in children.

BACKGROUND

Cystic fibrosis (CF) is characterized by chronic inflammation with increased oxidative stress. We evaluated the relationship between glucose tolerance and oxidative stress in CF children.

METHODS

Patients 10-18 years old underwent oral glucose tolerance testing (n=31). At 2-h, we assessed blood glutathione and 4-hydroxynonenal-protein adducts (HNE-P), and urine 1,4-dihydroxynonane-mercapturic acid conjugate (DHN-MA). Plasma fatty acid (FA) profile was performed. Patients with impaired glucose tolerance (IGT) were retested 6 to 24 months later and received additional nutritional recommendations (NR) when possible.

RESULTS

Fifty-two percent of patients had normal glucose tolerance (NGT), 42% IGT and 6% cystic fibrosis-related diabetes (CFRD). HNE-P concentrations significantly increased with diabetes (109%). Two-h BG correlated positively with HNE-P and negatively with DHN-MA. FA profile was modified with IGT. Of retested IGT patients, 25% received no NR; they remained IGT at 6 months and progressed to CFRD. Of those who received NR, 67% normalized, 11% remained intolerant and 22% developed CFRD. HNE-P levels dropped (88%) in IGT patients reverting to NGT, increased (94%) in the IGT patients with NR developing CFRD, decreased (90%) with persistent IGT.

CONCLUSION

CF children showed evidence of increased oxidative stress with worsening of glucose metabolism. NR may delay the appearance of CFRD.