Diagnostic value of markers of oxidative stress and metabolic disorders in preterm infants in the early neonatal period

Abstract

The aim of the study was to evaluate the markers of oxidative stress and metabolic disorders in  preterm infants and to examine their association with short-term outcomes in the early neonatal period to identify the predictors of  unfavourable outcome. The study included 46 preterm infants, gestational age ≤32 weeks, in the  early neonatal period, i.e. group 1 of 12 infants with lethal outcome and group 2 of 34 preterm  infants with favourable outcome. Markers of metabolic disorders, oxidative stress and antioxidant  system were analysed in cord blood and urine on the first/second day of life. Evaluation of  oxidative (8-isoprostane) and antioxidant system (catalase and superoxide dismutase (SOD) activity)  and metabolic (lactate, pyruvate, lactate to pyruvate ratio (LPR), NAD+/NADH) stress parameters  confirmed energy imbalance  and presence of tissue hypoxia in preterm newborns with adverse  outcomes. The following risk factors of unfavourable prognosis in preterm infants in the early  neonatal period were identified: asphyxia (p=0.038), early-onset sepsis (p=0.003), intraventricular  haemorrhage (p=0.029), hyperlactatemia (p=0.013), increased pyruvate level (p=0.002), increased LPR  (p=0.008), decreased catalase (p=0.003) and SOD (p=0.001) activity. Logistic regression indicated  that mortality rate was positively related to asphyxia, early-onset sepsis and lactate level, and  negatively related to SOD activity. In conclusion, intensive oxidative and metabolic stress in  preterm infants is associated with adverse outcomes in the early neonatal period. A combination of  asphyxia and early-onset sepsis together with high lactate level and decreased SOD activity is a  predictor of unfavourable out- come in the early neonatal period.