EFFECTS OF PARENTERAL L-CARNITINE SUPPLEMENTATION ON FAT-METABOLISM AND NUTRITION IN PREMATURE NEONATES

The effects of parenteral L-carnitine supplementation on fat metabolis m, nutrient intake, and plasma and erythrocyte carnitine concentration s were studied in 43 very low birth weight infants. Infants were rando mly assigned to control or carnitine-supplemented (50 mu mol/kg per da y) groups within two weight categories: group 1, 750 to 1000 gm, and g roup 2, 1001 to 1500 gm. Plasma total, free, and acyl carnitine levels , erythrocyte carnitine levels, serum beta-hydroxybutyrate and triglyc eride levels, and total fat intake were monitored weekly until 50% of total caloric intake was met enterally. Neonates receiving carnitine h ad higher plasma carnitine levels than control groups (total carnitine : group 1, 75.2 +/- 22.9 vs 9.6 +/- 2.7 mmol/ml; group 2, 61.6 +/- 31. 2 vs 13.0 +/- 9.2 nmol/ml). Levels of beta-OH-butyrate decreased from baseline in control neonates (group 1, 0.12 +/- 0.06 to 0.03 +/- 0.02 mmol/L; group 2, 0.11 +/- 0.03 to 0.05 +/- 0.02 mmol/L); they remained unchanged in supplemented groups. Thus ketogenesis appeared less impa ired in infants receiving supplements. Supplemented group 2 tolerated more fat than control group 2; triglyceride levels remained acceptable in all groups. Carnitine group 2 had greater weight gain than control group 2 during the first 2 weeks of life. We Conclude that very low b irth weight infants requiring prolonged parenteral nutrition have carn itine deficiency with impaired ketogenesis. Parenteral administration of carnitine appears to alleviate this metabolic disturbance.