Serum cholesterol concentrations in early infancy.

Sixteen healthy term infants were followed from birth to the age of 3-6 months. Total cholesterol, VLDL-LDL-cholesterol and HDL-cholesterol were determined in cord serum, in serum obtained 3-10 days after birth (mean age 4.6 days) and at the age of 3-6 months (mean 4.1 months). Mean total cholesterol increased by 1.5 mmol/l during the first 3-10 days and by an additional 1.1 mmol/l during the following 3-6 months. Mean VLDL-LdL-cholesterol increased by 1.0 mmol/l and 0.9 mmol/l, respectively, and mean HDL-cholesterol by 0.4 mmol/l and 0.3 mmol/l, respectively, during the same periods. The HDL-cholesterol: VLDL-LDL-cholesterol ratio thus fell from 1.5 at birth to 0.8 at the age of 3-10 days and to 0.6 at 3-6 months. In eight breast-fed infants, the mean total cholesterol level increased by 2.9 mmol/l from birth to the age of 3-6 months. This increase was significantly higher than the increase found in eight infants who received a cow's milk formula--i.e. 2.3 mmol/l. Free and esterified cholesterol were determined in 10 infants. Free cholesterol accounted for about one-third of the total cholesterol from birth to the age of 3-6 months.