According to researchers from Johns Hopkins Children's Center, an infant with low birth weight carries particles in the blood that can lower the amount of high-density lipoprotein (HDL) cholesterol that it produces. These particles in the blood contain apolipoprotein C-1, known for lowering HDL, or good cholesterol. Blood from the umbilical cords of 163 infants born at 28 or more gestational weeks and at approximately 1.3 lb less than normal weight were analyzed. Researchers found higher levels of apolipoprotein C-1 in 19% of these infants.

Low birth weight and higher-than-normal levels of this substance have been associated with the death of the heart's smooth-muscle cells. These cells are important to protecting the circulatory system from artery-clogging plaque, which can lead to a heart attack. Researchers concluded that it is important to check C-1 levels in low-birth-weight infants, and that these children should eat low-fat diets to reduce their risk of heart disease.