Heterogeneity of high-density lipoprotein in cord blood and its postnatal change

Several subclasses of HDL are demonstrated to have different roles in atherosclerosis based on adult studies, but the significance of HDL heterogeneity in the fetus and neonate has not been clarified. It has been described that the cholesterol supply from apoE-rich HDL is essential for central nerve system neuron growth.

Sixty-five healthy, term, appropriate for gestational age neonates (38 males and 27 females) were included in the study. Serum lipoprotein analyses were performed by HPLC with gel permeation columns, which classified HDL into 5 subgroups (i.e., very large, large, medium, small, and very small) on the basis of particle size. Apolipoprotein A-I, B, and E were also determined by turbidimetric immunoassay.

Cord blood has higher very large and very small HDL-cholesterol levels. Cord blood apolipoprotein E was not uniformly distributed in the HDL subclasses, with a strong association with very large HDL-cholesterol levels (males, r=0.548, p<0.001; females, r=0.631, p<0.01). However, the association disappeared by 1 month of age in males; in females, the association remained during the neonatal period.

These results suggest that HDL may play the role of a dominant cholesterol carrier in the human fetus, and very large HDL-cholesterol have some contribution to the neurodevelopment in the fetus and neonates because of the close relationship with apolipoprotein E levels.