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Updated: Jul 12, 2026
Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Urinary metabolites of oxidative stress and nitric oxide in preterm and term infants
Christiana R Farkouh1, Jeffrey D Merrill, Phillip L Ballard
1Division of Neonatology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Insights
Premature infants show higher urinary peroxide levels, indicating oxidative stress, compared to term infants. Clinical interventions like TPN and indomethacin impact these markers, requiring careful consideration in neonatal care.
Area of Science:
- Neonatal physiology and disease
- Biomarkers of oxidative stress and nitric oxide metabolism
Background:
- Neonatal diseases are frequently linked to oxidative stress and altered nitric oxide (NO) status.
- Understanding these physiological markers is crucial for neonatal health assessment.
Purpose of the Study:
- To investigate the impact of clinical interventions on urinary peroxide and nitrate/nitrite levels in premature infants within the first 72 hours of life.
- To assess urinary peroxides as a marker of oxidative stress and urinary nitrate/nitrites as indices of NO production and metabolism.
Main Methods:
- Urine samples were collected from 82 premature and 20 term infants within 72 hours of birth.
- Urinary peroxide levels were measured using a fluorometric method.
- Urinary nitrate/nitrite levels were quantified via chemiluminescence.
Main Results:
- Premature infants exhibited significantly higher urinary peroxide levels compared to healthy term infants.
- No significant difference in urinary nitrate/nitrite levels was observed between premature and term infants.
- Infants receiving total parenteral nutrition (TPN) had higher urinary peroxide levels, while indomethacin administration was associated with lower urinary nitrate/nitrites.
Conclusions:
- Urinary peroxides and nitrate/nitrites can provide insights into neonatal oxidative stress and NO status.
- Clinical and therapeutic interventions significantly influence these urinary markers, necessitating their consideration in interpretation.
Background:
Many neonatal diseases have been associated with oxidative stress and altered nitric oxide status.
Objective:
To determine the effects of clinical interventions on the levels of urinary peroxides, a marker of oxidative stress, and urinary nitrate/nitrites, indices of nitric oxide production and metabolism, in the first 72 h of life in premature infants.
Methods:
A single, spot urine sample was collected from 82 premature and 20 healthy term infants within the first 72 h of life. The peroxide levels were quantified using a fluorometric method, and nitrate/nitrite levels were quantified by chemiluminescence.
Results:
Premature infants had a median peroxide level of 10.0 micromol/mmol creatinine (Cr) (interquartile range 4.8-20.0 micromol/mmol Cr). These values were significantly higher than term infants (median 5.0 micromol/mmol Cr, interquartile range 2.7-10.0 micromol/mmol Cr). Urinary nitrate/nitrite levels were not significantly different between preterm (220.5 micromol/mmol Cr, interquartile range 161-287 micromol/mmol Cr) and healthy term infants (244 micromol/mmol Cr, interquartile range 194-316 micromol/mmol Cr). For urinary peroxides, infants on TPN had significantly higher urinary peroxide levels than infants who were not on TPN at the time of urine collection (p = 0.006). Administration of indomethacin was associated with lower levels of urinary nitrate/nitrites (p = 0.0003). Both effects remained significant after controlling for gestational age, degree of respiratory distress and day of urine collection.
Conclusion:
Monitoring the level of both peroxides and nitrate/nitrite may offer added information about the degree of oxidative stress experienced by a newborn but needs to account for clinical and therapeutic interventions.
