Antioxidant status of surgical patients receiving TPN with an omega-3-fatty acid-containing lipid emulsion supplemented with alpha-tocopherol

BACKGROUND: LCT lipid emulsions and even more fish oil-containing lipid emulsions are under debate regarding their tocopherol and PUFA content as well as their effect on the antioxidative status especially in patients with oxidative stress. METHODS: Thirty-three patients undergoing major abdominal surgery were randomly assigned to receive either an alpha-tocopherol-supplemented (562 micromol/l) MCT/LCT/omega-3-acid triglycerides (MLF, 5/4/1 w/w/w, 20%) emulsion or a soybean oil-based LCT emulsion (20%). The TPN regimen continuously provided 1.4 g fat kg bw(-1)d(-1)over 5 days. RESULTS: Plasma antioxidant concentrations were strongly reduced by surgical treatment. Following 5 days of TPN with the MLF emulsion, mean plasma alpha-tocopherol increased by 20.0 micromol/l (1.98 micromol/mmol lipid), while nearly no change was observed in the LCT emulsion group. In both groups, plasma concentrations of all non-supplemented antioxidants (vitamin C, carotenoids, selenium) as well as serum total antioxidant capacity further decreased during TPN. The concentrations of plasma cholesterol oxidation products as a measure of in vivo lipid peroxidation revealed no changes over the TPN period in either group. CONCLUSION: In contrast to the LCT emulsion, administration of the a-tocopherol supplemented MLF lipid emulsion normalized a-tocopherol plasma concentrations. Despite its high long-chain PUFA content, no hint for increased lipid peroxidation was found.