title: Effects of high carnitine supplementation on substrate utilization in low-birth-weight infants receiving total parenteral nutrition.
abstract: Parenterally fed preterm neonates are known to be at risk for carnitine deficiency. We studied substrate utilization in low-birth-weight infants receiving total parenteral nutrition (TPN) with (A) and without (B) supplementation of 48 mg carnitine.kg-1.d-1 on days 4-7 (birth weights 1334 +/- 282 vs 1318 +/- 248 g, gestational age 32 +/- 2 vs 32 +/- 2 wk, A vs B, respectively). TPN consisted of 11 g glucose.kg-1.d-1 and 2.4 g.kg-1.d-1 of both protein and fat. Plasma carnitine concentrations at day 7 were for free carnitine 11.8 +/- 5.0 vs 164 +/- 56 mumol/L and for acyl carnitine 3.8 +/- 2.0 vs 33.9 +/- 15.4 mumol/L, respectively. Indirect calorimetry at day 7 showed a higher fat oxidation (0.21, -0.31 to +0.60 vs 1.18, 0.70 to 1.95 g. kg-1.d-1, respectively, P less than 0.02, median and interquartile range) in group B and a higher protein oxidation (0.37, 0.30-0.43 vs 0.63, 0.53-0.88 g.kg-1.d-1, P less than 0.001). The time to regain birth weight was also higher in group B (7, 5.5-9 vs 9, 7-14 d, P less than 0.05). Carnitine supplementation and calorie intake were the best explanatory variables for metabolic rate (R2 = 0.45, P less than 0.002). We conclude that carnitine supplementation of TPN in this dosage does not seem advisable.
authors.affiliation: Department of Pediatrics, Erasmus University Rotterdam, University Hospital/Sophia Children's Hospital, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Sulkers
authors.forename: H N
authors.initials: HN
authors.lastname: Lafeber
authors.forename: H J
authors.initials: HJ
authors.lastname: Degenhart
authors.forename: H
authors.initials: H
authors.lastname: Przyrembel
authors.forename: E
authors.initials: E
authors.lastname: Schlotzer
authors.forename: P J
authors.initials: PJ
authors.lastname: Sauer
mesh_terms: D002153:Calorimetry, Indirect; D002331:Carnitine / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D004041:Dietary Fats / Q000378:metabolism; D006801:Humans; D007230:Infant, Low Birth Weight / Q000378:metabolism*; D007231:Infant, Newborn; D010289:Parenteral Nutrition, Total; D015430:Weight Gain
chemical_list: D004041:Dietary Fats; D002331:Carnitine