Background: We hypothesized that dexamethasone induces hypertriglyceridemia (triglyceride levels >2.82 mmol/L [250 mg/dL]) and increases free fatty acid (FFA) levels and that steroid-induced hypertriglyceridemia is associated with hyperinsulinemia and elevated FFA levels.
Objective: To study the effect of dexamethasone sodium phosphate on lipid metabolism in neonates receiving intravenous lipids.
Design: A prospective cohort study with patients serving as their own controls.
Setting: Neonatal Intensive Care Unit, Children's Hospital at Strong, Rochester, NY.
Methods: All neonates younger than 29 weeks' gestational age at birth receiving 3 g/kg per day of intravenous lipids who were to start dexamethasone therapy for bronchopulmonary dysplasia were eligible. Exclusion criteria included neonates with active infection, prior hypertriglyceridemia, bleeding manifestations, recent surgery, thyroid medication, and human recombinant insulin intravenous infusion therapy. Ten neonates were studied. Blood was drawn for triglyceride, FFA, and insulin assays before initiating and at 1, 2, 3, and 5 days after starting dexamethasone therapy. On day 3, dexamethasone dosage was decreased as per protocol. Intravenous lipid intake was kept constant. Statistical analysis was done using a paired t test.
Results: Six of 10 neonates reached a state of hypertriglyceridemia (95% confidence interval, 26.2%-87.8%). The mean average increase in triglycerides, insulin, and FFA levels in neonates receiving 3 g/kg per day of intravenous lipids after initiation of dexamethasone therapy was 0.75 mmol/L (66.6 mg/dL) (P=.007), 127 pmol/L (P = .006), and 47.5 micromol/L (P = .65), respectively. Six neonates who developed hypertriglyceridemia had significantly elevated mean peak FFA levels (918.3 micromol/L) prior to developing hypertriglyceridemia compared with 4 neonates (mean peak FFA levels, 380.2 micromol/L) who had triglyceride levels lower than 2.82 mmol/L (250 mg/dL) (P = .002).
Conclusion: We conclude that dexamethasone induces hypertriglyceridemia in the presence of hyperinsulinemia and increased FFA levels.