Clinical Factors Affecting Lipid Metabolism and Optimal Dose of Heparin in Preterm Infants on Parenteral Nutrition

Abstract

PurposePreterm infants on parenteral nutrition are at a relatively high risk for hypertriglyceridemia because they have immature lipoprotein lipase activity. The purpose of this study was to analyze the clinical factors affecting lipid metabolism in preterm infants receiving parenteral nutrition and to evaluate the influence of intravenous heparin on serum triglycerides to determine the adequate heparin dose to prevent hypertriglyceridemia in preterm infants.MethodsA single-center retrospective review was conducted among preterm infants receiving parenteral nutrition between January 2006 and February 2011. In 75 patients, 110 determinations were performed within 28 days postnatal age. Demographic and clinical data, including laboratory parameters, the dose and the duration of lipid administration, and the amount of intravenous heparin, were analyzed.ResultsSerum triglycerides were higher in the small for gestational age (SGA) infants than in the appropriate for gestational age infants (185.5±134.9 mg/dL vs. 126.9±101.9 mg/dL, p=0.019). Birth weight, gestational age, and body weight were negatively correlated with serum triglyceride level (r=-0.289, p=0.002; r=-0.208, p=0.029; r=-0.287, p=0.002, respectively). The serum triglyceride level was statistically lower in preterm infants receiving 1 U/mL of heparin than in those receiving 0.5 U/mL heparin or no heparin.ConclusionPreterm infants receiving parenteral nutrition, particularly SGA and extremely low birth weight infants, tend to have hypertriglyceridemia. Thus, administration of 1 U/mL of heparin rather than 0.5 U/mL or none may be helpful to prevent hypertriglyceridemia in preterm infants.

Hypertriglyceridemia and Intravenous Lipid Titration During Routine Parenteral Nutrition in Small Preterm Infants

“…There are a few studies in preterm infants that reported significant associations between HiTG and disease/sickness (1,5,17). Some physicians consider HiTG to be associated with short‐term illness, but our data did not support this notion.…”

“…About 85% of the study infants with HiTG, however, had plasma TG >265 mg/dL. Our case‐control design did not consider a part of patients at high risk to develop HiTG (4,17). Plasma TGs were not measured at all time points: in several circumstances when the assay was not successful and there was no need to repeat other determinations than the TG, the caring physician often decided that it was not in the interest of the patients to repeat the test.…”

Dietary Implications of Polyunsaturated Fatty Acids during Pregnancy and in Neonates

“…However, in preterm infants, LPL activity is low, as seen in small for gestational age infants [ 147 ], who have low LPL levels, little adipose tissue and low tissue levels of carnitine. Therefore, the inability to clear TAGs effectively could be associated with lipid intolerance and an increase in the probability of complications involved with the administration of lipid infusions [ 148 ]. The fact that recent studies have shown that dietary DHA from TAGs or from natural phosphatidylcholine ( sn -2 position) is not suitable for brain enrichment, whereas DHA from lysophosphatidylcholine efficiently enriches the brain and is functionally effective [ 149 ], invites us to investigate how fatty acid carriers in dietary lipid emulsions can be improved.…”

Three‐in‐One Parenteral Nutrition in Neonates and Pediatric Patients

“…However, heparin is added at a dose of 0.5-1 unit/mL to neonatal PN solutions, at many centers, primarily to maintain catheter patency, with potential secondary benefits in decreasing infection and hypertriglyceridemia. [51][52][53][54][55] While the literature suggests that low doses of heparin are unlikely to destabilize PN solutions, additional studies are warranted to validate this finding. 50,56 Compatibility of other medications with 3-in-1 PN solutions in the neonatal population due to limited intravenous access in this population may also be problematic.…”

“…Heparin causes solution destabilization through binding of divalent cations. However, heparin is added at a dose of 0.5–1 unit/mL to neonatal PN solutions, at many centers, primarily to maintain catheter patency, with potential secondary benefits in decreasing infection and hypertriglyceridemia 51 – 55 . While the literature suggests that low doses of heparin are unlikely to destabilize PN solutions, additional studies are warranted to validate this finding 50 , 56 .…”