Ketogenesis in hypoglycemic neonates. Carnitine and dicarboxylic acids in neonatal hypoglycemia

Since hypoglycemic neonates do not exhibit compensative ketosis, we investigated the possible involvement of carnitine deficiency or omega-oxidation in neonatal hypoglycemia. In a first group of 49 neonates, serum free fatty acid, acetoacetate and beta-hydroxybutyrate concentrations were similar in hypoglycemic and normoglycemic neonates. Serum free carnitine concentrations did not show any difference in the hypoglycemic small-for-date infants (median 40 mumol/l, range 16-92 mumol/l) compared to the normoglycemic small-for-date infants (median 30 mumol/l, range 8-64 mumol/l). In a second group of 45 neonates, urinary excretion of dicarboxylic acids (adipic, suberic, sebaric and succinic acids) was similar in hypoglycemic infants compared to normoglycemic neonates. Despite the limitations of interpretation of free carnitine determination, these data do not suggest an impaired beta-oxidation by carnitine depletion or an enzymatic defect in hypoglycemic neonates.