Triglyceride profiles in preterm infants reveal dynamic and age-specific trajectories

Triglyceride (TG) values are routinely monitored in preterm infants receiving lipid emulsion therapy, but their clinical utility remains poorly defined. The objective of this study was to define TG values and their associations with gestational age (GA), birth weight (BW), lipid dosing and postnatal age in preterm infants born <32 weeks' across two distinct academic medical centers.

We conducted a retrospective multi-centered observational study using data from the Lucile Packard Children's Hospital (LPCH) Stanford Neonatal Intensive Care Unit and the Beth Israel Deaconess Medical Center (BIDMC) Neonatal Intensive Care Unit. TG values in infants <32 weeks' GA were interrogated by GA, postnatal age, BW and in aggregate. Pre- and postnatal factors were evaluated using multivariable logistic regression in the LPCH Stanford data set for associations with hypertriglyceridemia, defined using thresholds of 200 mg/dL and 250 mg/dL. Spline regression was used to model the relationship between continuous TG values and postnatal outcomes in both data sets.

TG distributions differed significantly by GA, with the highest values observed among infants born at 22-25 weeks' gestation and/or with extremely low birth weight. In the LPCH 22-25 week cohort, TG levels peaked at approximately two weeks of postnatal age and subsequently declined. Lipid emulsion dosing <2 g/kg/day was associated with a reduced risk of hypertriglyceridemia, whereas dosing >2 g/kg/day did not significantly alter risk. Continuous TG values were not consistently associated with major neonatal outcomes, including respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), or retinopathy of prematurity (ROP) in either cohort.

TG values in preterm infants vary by developmental stage, closely reflecting GA, BW, and postnatal age, suggesting that circulating TG levels are developmentally regulated. These findings support consideration of age- or weight-based TG reference ranges, particularly for infants born at 22-25 weeks' gestation. In contrast, the limited association between TG levels and neonatal morbidities raises questions regarding the relevance of early TG measurements for predicting later disease.