Long-Term Consequences of Parenteral Nutrition on Indicators of Oxidative Stress

Parenteral nutrition (PN) is the intravenous administration of all daily nutritional requirements in elemental form. PN bypasses first pass intestinal metabolism as it is delivered directly into the bloodstream. Newborn infants are a population that often require this mode of nutritional support due to the co-morbidities that preclude enteral feeding. The contraindication of enteral feeding may be due to extreme prematurity or functional failure of the gastrointestinal tract. PN has been a major advancement in the nutritional support of low birth weight infants who cannot tolerate enteral feedings. However, the use of parenteral nutrition can lead to many adverse health effects, including altered hepatic metabolism. Neonatal exposure to the oxidant load in PN may program metabolism to raise the risk of chronic disease in later in life such as metabolic syndrome. This research study aims to investigate the long-term consequences of parenteral nutrition and low birth weight on indicators of oxidative stress. Tissue samples in this research are from a previously completed study using Yucatan miniature piglets. The treatment groups included: sow-fed control, PN control, PN with betaine and creatine supplementation, and PN-fed runts. The effects of receiving parenteral nutrition using SMOFlipid for a duration of 2 weeks at the beginning of life will be compared to piglets that were sow-fed. Complications that may arise into adulthood impacted by the mode of nutrition at early life will be investigated through markers of oxidative stress. Creatine and betaine were supplemented to the PN to increase creatine stores within the body, as creatine plays an important role in neurological development in neonates. Sufficient levels of creatine may serve to minimize oxidative DNA damage. The objective of this study is to determine if early exposure to parenteral nutrition will alter the capacity to handle oxidative stress in adulthood. We hypothesize that the sow-fed control group will have less oxidative stress when compared to the parenterally-fed groups. We also predict that the PN group supplemented with betaine and creatine will have the lowest indices of oxidative stress compared to the other PN groups. We expect the PN-fed runts to have the highest markers of oxidative stress. Total antioxidant capacity was measured using the ferric reducing antioxidant power (FRAP) assay. Markers of oxidative stress have been determined using the thiobarbituric acid reactive substance (TBARS) assay. As well, vitamin E concentrations were evaluated in the plasma using ultra performance liquid chromatography (UPLC). Future directions will include analyzing antioxidant enzyme activity and myeloperoxidase (MPO) activity in the liver.