EFFECT OF INTRAVENOUS L-CARNITINE ON GROWTH-PARAMETERS AND FAT-METABOLISM DURING PARENTERAL-NUTRITION IN NEONATES

To determine whether intravenous carnitine can improve nutritional indices, neonates requiring parenteral nutrition were randomized into carnitine treatment (n = 23) and control (n = 20) groups. Observed plasma lipid indices, carnitine and nitrogen balances, and plasma carnitine concentrations were not different in the prestudy period. Under standardized, steady-state conditions, 0.5 g/kg Intralipid was administered intravenously over 2 hr prior to carnitine administration, after infants received 7 days of 50 μmol/kg/day, and after a second 7 days of 100 μmol/kg/day of continuous intravenous L-carnitine as part of parenteral nutrition. Triglyceride (TGY), free fatty acid (FFA), acetoacetate (AA), β-hydroxybutyrate (BOB), and plasma carnitine concentrations were measured prior to and at 2, 4, and 6 hr after the initiation of the lipid bolus. Twenty-four-hour urine collections for nitrogen and carnitine balance were obtained on days 7 and 14. Neonates receiving carnitine had significantly greater concentrations of plasma carnitine on days 7 and 14 (p < 0.001). Greater nitrogen (p < 0.05) and carnitine (p < 0.001) balances and weight gain (week 2, p < 0.05) were found in the carnitine-supplemented group when compared with controls. On day 14, (BOB + AA)/FFA ratios were significantly higher (p < 0.05), and peak TGY concentrations and 6-hr FFA concentrations were significantly lower (p < 0.05) in the treatment group. Carnitine supplementation was associated with modest increases in growth and nitrogen accretion possibly by enhancing the neonate's ability to utilize exogenous fat for energy.