RESUMO
OBJECTIVE: Newborn infants, particularly preterm infants, are at greater risk of oxidative stress because of an imbalance between high oxidant loads and immature antioxidant defenses. In several studies, the activities of serum paraoxonase (PON) and arylesterase (ARE) have been found to decline in patients under increased oxidative stress. We investigated the relationships between PON-1 and ARE with fasting and postprandial in premature newborns in this study. PATIENTS AND METHODS: Serum paraoxonase-1 and arylesterase levels were investigated in premature infants less than 37 weeks, after birth while they were fasting and postprandial. RESULTS: The paraoxonase-1 and arylesterase values of infants in fasting were significantly lower than the values in postprandial (for paraoxonase-1, p = 0.034, 0.002, and 0.002, respectively; for arylesterase, p < 0.001, 0.002, and p < 0.001, respectively). CONCLUSIONS: In premature infants, paraoxonase-1 and arylesterase values are increased in postprandial and reduced in fasting, showing that these neonates are subjected to oxidative stress. Thus, starting feeding as soon as possible in premature newborns is vital to protect them from oxidative damage.