[Concentration of serum lipids and apolipoprotein B in newborns]

To determine the concentrations of serum lipids and apolipoprotein B (apo-B) in a population of normal full-term and preterm newborns in a city in Southern Brazil, and assess the impact of gestational age and birth weight on these values.

Two hundred and twelve newborns of both genders were studied, 142 of whom were full-term (>37 weeks of gestation) and 70 preterm (<37 weeks of gestation). According to their birth weights, the full-term and preterm newborns were classified as small for gestational age or appropriate for gestational age. Umbilical cord blood was collected for biochemical analysis.

The total cholesterol, LDL-C, HDL-C and apo-B values were higher in preterm newborns (79+/-34, 26+/-6, 45+/-15 and 36+/-14 mg/dL, respectively) than in full-term newborns (58+/-19, 20+/-10, 31+/-14 and 28+/-7 mg/dL, respectively; p < 0.0001). Inversely, triglyceride values were lower in preterm newborns (36+/-14 mg/dL) than in full-term newborns (43+/-25 mg/dL; p < 0.0018). Gender and size at birth did not have any impact on the values of total cholesterol and fractions, triglycerides, and apo-B.

Plasma concentrations of lipids and apo-B in the population of newborns studied are similar to those in newborns from other countries and continents reported in medical literature and, as expected, are markedly lower than the values mentioned in literature for infants over two years of age. Fetal maturity has an impact on the concentration of lipids in newborns, but birth weight does not have any effect on these parameters.