Evidence of oxidative stress in relation to feeding type during early life in premature infants
James K Friel1, Bill Diehl-Jones, Kevin A Cockell
1Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada. frielj@ms.umanitoba.ca
Insights
Feeding premature infants with high levels of fortified mother's milk may increase oxidative stress. This study investigated how formula and fortified mother's milk impact redox status in preterm infants, suggesting further research on fortifier content is needed.
Area of Science:
- Neonatal nutrition
- Pediatric oxidative stress research
- Premature infant adaptation
Background:
- Premature infant morbidity can be linked to challenges in oxygen adaptation.
- Nutritional strategies, including formula and mother's milk, may influence infant redox status.
Purpose of the Study:
- To investigate the impact of formula feeding (F) and mother's milk (HM) with varying human milk fortifier (HMF) content on the redox status of premature infants.
- To quantify oxidative stress markers in preterm infants receiving different feeding regimens.
Main Methods:
- Sixty-five premature infants were monitored biweekly after oral feeds were initiated.
- Feeding groups were categorized as formula (F) or mother's milk (HM) based on >75% intake.
- Subgroups were defined by HMF content: 0-19%, 20-49%, and ≥50% of feeds.
- Oxidative stress was assessed using urinary F2-isoprostanes (F2-IsoPs), plasma protein carbonyls, and plasma oxygen radical absorbance capacity (ORAC).
Main Results:
- Urinary F2-IsoPs showed variability over time, peaking between 7-10 weeks.
- No significant difference in protein carbonyls was observed between the highest and lowest F2-IsoP groups.
- Plasma ORAC levels remained relatively stable from baseline to discharge, but were lower than in full-term infants.
- The highest F2-IsoP levels were found in infants receiving ≥50% fortified mother's milk.
Conclusions:
- Higher fortification levels in mother's milk may be associated with increased oxidative stress in premature infants.
- The findings suggest a need for further investigation into the effects of human milk fortifier concentration on infant redox balance.
- Nutritional management of premature infants requires careful consideration of fortifier content to mitigate potential oxidative stress.
Abstract:
Morbidity in the premature (PT) infant may reflect difficult adaptation to oxygen. We hypothesized that feeding including formula feeding (F) and feeding mother's milk (HM) with added fortifier would affect redox status. Therefore, 65 PT infants (birth weight: 1146 ± 261 g; GA: 29 ± 2.5 wk; mean ± SD) were followed biweekly, once oral feeds were introduced. Feeding groups: F (>75% total feeds) and HM (>75% total feeds) were further subdivided according to human milk fortifier (HMF) content of 0-19, 20-49, and ≥ 50%. Oxidative stress was quantified by F2-isoprostanes (F2-IsoPs) in urine, protein carbonyls, and oxygen radical absorbance capacity (ORAC) in plasma. F2-IsoPs (ng/mg creatinine): 0-2 wk, 125 ± 63; 3-4 wk, 191 ± 171; 5-6 wk, 172 ± 83; 7-8 wk, 211 ± 149; 9-10 wk, 222 ± 121; and >10 wk, 183 ± 67. Protein carbonyls from highest [2.41 ± 0.75 (n = 9)] and lowest [2.25 ± 0.89 (n = 12) pmol/μg protein] isoprostane groups did not differ. ORAC: baseline, 6778 ± 1093; discharge, 6639 ± 735 [full term 4 and 12 M, 9010 ± 600 mg (n = 12) TE]. Highest isoprostane values occurred in infants with >50% of their mother's milk fortified. Further research on HMF is warranted.
