Levels of lipids in preterm infants fed breast milk

Actual recommendations in preterm infants limit parenteral fat intake to 3-4 g/kg/d. This is based on clinical studies where fat administration was adjusted to achieve levels close to those recommended in adults for atherosclerosis prevention. Data about lipid profiles of breast fed preterm infants who may have fat intakes of up to 7 g/kg/d and could serve as reference are not available.

To establish full lipid profiles in healthy fully breast fed preterm infants and to test the hypothesis that breast milk fat intake leads to serum triglycerides higher than those achieved under full parenteral fat administration.

Serum triglycerides, cholesterol, VLDL, LDL, HDL (all pre- and postprandial), as well as triglycerides in breast milk were measured in 65 healthy, fully breast fed, stable growing preterm infants stratified in 500 g intervals (mean gestational age: 31+/-4 weeks, birth weight: 1500+/-600 g, age at study: 25+/-16 d).

Median fat intake was 7.0 g/kg/d (interquartile range: 5.8;8.1) and led to the following serum levels: triglycerides 0.9 (0.6;1.1), cholesterol 3.1 (2.6;3.5), VLDL 0.5 (0.3;0.6), LDL 1.3 (1.1;1.6), HDL 1.1 (0.8;1.4)mmol/L. Small for gestational age infants showed higher triglycerides (p=0.005). Triglycerides (r2=0.08, p=0.023), postprandial triglyceride increase (r2=0.21, p<0.001), cholesterol (r2=0.16, p<0.001) and HDL (r2=0.16, p<0.001) were correlated with weight at study.

Though higher by a factor of two, fat intake by breast milk leads to considerably lower lipid levels when compared to published values obtained under parenteral fat intake. Results suggest that either fat absorption is reduced in preterm infants, or the composition of breast milk supports a lower profile of fat levels when compared to commercially available parenteral fat emulsions.