Plasma vitamin E and selenium and breath pentane in home parenteral nutrition patients

Abstract

Because both vitamin E and selenium protect against lipid peroxidation, we evaluated the relationship between breath pentane, evolved from the peroxidation of linoleic acid, and plasma levels of alpha-tocopherol (vitamin E), Se, and Se-dependent glutathione peroxidase (Se-GSHPx). Nine home parenteral-nutrition (HPN) patients received added Se in intravenous solutions and were compared with 10 normal control subjects. The excretion of pentane (pmol.kg-1.min-1, means +/- SEM) in control subjects (6.34 +/- 0.96) was significantly lower than in HPN patients (15.02 +/- 1.12, p less than 0.001). alpha-Tocopherol (mumol/L), Se (mumol/L), and Se-GSHPx (U) values were, respectively, 18.13 +/- 1.70, 1.70 +/- 0.05, and 5.34 +/- 0.27 in control subjects and 10.21 +/- 1.66, 1.35 +/- 0.14, and 7.01 +/- 0.31 in HPN patients. All differences were statistically significant. Significant negative correlations were observed between plasma alpha-tocopherol levels and HPN duration and between pentane output and plasma alpha-tocopherol levels (r = -0.58, p less than 0.01). In HPN patients with reduced plasma alpha-tocopherol levels associated with increased pentane output, there is, inferentially, increased lipid peroxidation despite normal plasma Se and Se-GSHPx levels.

Effects of intravenous supplementation with α-tocopherol in patients receiving total parenteral nutrition containing medium- and long-chain triglycerides

“…They may be neccessary to combat the a-tocopherol deficiency which can appear during the course of TPN (Lemoyne et al, 1988). It has also been shown in patients on long-term TPN that adequate a-tocopherol levels in plasma sometimes coexist with deficiencies in adipose tissue relative to cholesterol (Steephen et al, 1991).…”

“…However, these lipid infusions have been implicated in complications such as impaired function of the clotting and immunological systems (Babineau et al, 1994) as well as increased lipid peroxidation in vivo. Indeed, patients receiving total parenteral nutrition (TPN) have increased levels of some endproducts of lipid peroxidation such as breath alkanes (Lemoyne et al, 1988;Pitkanen et al, 1991). Since lipid peroxidation has been identified as a major event in degenerative processes such as ageing, atherosclerosis, cancer, inflammatory diseases and diabetes (Pincemail et al, 1996), serious efforts should be made to prevent it in all clinical situations including parenteral nutrition.…”

Utility of Breath Ethane as a Noninvasive Biomarker of Vitamin E Status in Children

“…Contamination of the expired air sample with environmental hydrocarbons was minimized by the washout period using HCFA (5,14). The breath samples were analyzed on the same day of collection to avoid any change in ethane concentration with sample storage (5).…”

“…In the inpatient studies, before vitamin E therapy, breath ethane was obtained before (fasting) and 2 h after a breakfast high in carbohydrate (60% of total calories) or in fat (40% of total calories). Breath ethane and serum vitamin E (12), total lipids (9, 10) and erythrocyte peroxide hemolysis (1 1 [1][2][3][4][5] or PBS (tubes 6 and 7) was added to the erythrocyte suspension, and the mixture was incubated for 3 h at 37°C. PBS (4.5 mL) was added to tubes 1-3 (test) and tubes 6 and 7 (blank).…”

“…These gases are the major volatile hydrocarbons that are generated through 3 peroxidation of n-3 and n-6 fatty acids, respectively. Lemoyne et al (5) have shown that treatment of vitamin E-deficient adults with i.v. vitamin E is associated with decreased pentane content of expired air.…”