Anti-oxidant profiles and markers of oxidative stress in preterm neonates.

BACKGROUND

Preterm birth is associated with an increased oxidant burden which places these infants at a higher risk of injury.

AIMS

This prospective study aimed to assess levels of antioxidants and a marker of oxidative stress in preterm neonates.

OBJECTIVES

(i) To compare levels of anti-oxidants [vitamin A, vitamin E, catalase, total anti-oxidant status (TAS)] as well as malondialdehyde level (MDA) (a marker of lipid peroxidation) between preterm and full-term neonates; (ii) to determine changes in the values of measured vitamins at birth and at discharge among preterm neonates; and (iii) to compare levels of anti-oxidants with MDA levels in relation to complications of prematurity and outcome.

METHODS

The study was undertaken in 100 preterm neonates and 100 full-term neonates as a control group. MDA was estimated by a thiobarbituric acid-reactive technique; TAS was determined using a Randox assay kit; catalase activity was measured spectrophotometrically and vitamin A and E levels were estimated by high performance liquid chromatography.

RESULTS

The plasma levels of vitamin A, vitamin E, TAS and catalase were significantly lower in the preterm than in the full-term group (P < 0.01), and the plasma level of MDA was significantly higher in preterm than full-term neonates (P < 0.01). Vitamin A and E levels in preterm neonates were significantly higher at discharge than at birth (P < 0.01). Vitamin A, vitamin E and catalase levels at birth were significantly lower in patients who developed necrotizing enterocolitis or bronchopulmonary dysplasia than in those who did not.

CONCLUSION

Preterm neonates are exposed to increased oxidant stress at birth and are susceptible to anti-oxidant deficiencies. A higher dose of enteral vitamin A supplementation in preterm neonates might reduce morbidity and improve outcome. Further studies are warranted to evaluate the appropriate dose of oral vitamin E supplementation for preterm neonates.