Early Hypertriglyceridemia and Respiratory Outcomes in Preterm Neonates

Background: Hypertriglyceridemia (HiTG) is a frequent metabolic complication in preterm neonates receiving parenteral nutrition (PN), with potential implications for respiratory outcomes. However, predisposing factors and the clinical impact of HiTG in this population remain poorly defined. Objectives: To identify factors predisposing preterm neonates to HiTG development and to assess the association between HiTG and neonatal respiratory morbidity. Methods: A retrospective matched cohort study was conducted, nested within a single-center cohort of neonates receiving routine parenteral nutrition (PN) and on respiratory support, with gestational age ≤ 32 weeks and/or a birth weight ≤ 1500 g, consecutively admitted between January 2015 and May 2023 into the Neonatal Intensive Care Unit (NICU) of 'Umberto I' University Hospital, Sapienza University of Rome. HiTG was defined as at least one serum triglyceride (TG) value > 180 mg/dL during the first 7 days of life. TG levels were measured from morning samples collected alongside routine laboratory draws; for borderline values (180-200 mg/dL), a confirmatory sample was obtained after a 4 h lipid-free interval. Neonates with HiTG were classified as cases; newborns without HiTG served as controls, matched 1:1 for gestational age and birth weight. Results: A total of 110 neonates were enrolled (55 cases, 55 controls). HiTG was independently associated with bronchopulmonary dysplasia (BPD) (OR 29.46; 95% CI 5.82-149.07; p < 0.001) and prolonged invasive mechanical ventilation (pIMV) (OR 4.85; 95% CI 1.69-13.89; p = 0.003), after adjustment for surfactant administration and extremely low birth weight. Time to achieve full enteral feeding (FEF) was independently associated with HiTG development (β = +0.153; p < 0.001), whereas parenteral lipid intake during the first week of life was inversely associated (β = -0.081; p = 0.039). Conclusions: HiTG is independently associated with BPD and prolonged invasive mechanical ventilation in preterm neonates. Parenteral lipid intake during the first week was not higher in infants who developed HiTG. Delayed achievement of FEF was also associated with HiTG, but it occurred after the exposure window and cannot therefore be regarded as a predisposing factor. These findings are hypothesis-generating. Randomized trials are needed to assess whether closer monitoring of triglyceride levels and early advancement of enteral feeding in preterm neonates may help reduce BPD.