Sodium Glycerophosphate vs. Inorganic Phosphate Use in Parenteral Nutrition for Preterm Infants: A Retrospective Study.

Background/objectives: Sodium glycerophosphate improves the adverse side effects of parenteral nutrition. Therefore, this study aimed to evaluate different outcomes, including metabolic bone disease and electrolyte imbalance, associated with the use of sodium glycerophosphate or inorganic phosphate in parenteral nutrition for preterm neonates.

Methods: This retrospective cohort study enrolled 402 newborns admitted to the neonatal intensive care unit of one medical center between January 2019 and September 2021. Of them, 205 received sodium glycerophosphate as parenteral nutrition, while the other 197 received inorganic phosphate. Baseline characteristics and growth parameters, including body weight, body length, and head circumference in the first year of life; calcium and phosphate content of parenteral nutrition in the first 4 weeks; calcium, phosphorus, alkaline phosphatase (ALP), and creatinine levels; and morbidities were compared.

Results: During the first 4 weeks, the calcium and phosphate contents of parenteral nutrition were significantly higher in the sodium glycerophosphate vs. inorganic phosphate group. Growth parameters did not differ significantly between groups. The sodium glycerophosphate group showed a higher mean serum phosphate level (4.0 ± 1.2 mg/dL vs. 3.5 ± 1.3 mg/dL, = 0.001), lower serum ALP level (402.8 ± 202.8 U/L vs. 466.4 ± 228.6 U/L, = 0.004), lower seizure incidence (4.9% vs. 13.2%, = 0.003), and higher hypocalcemia incidence (41.5% vs. 31.5%, = 0.038). However, there were no significant intergroup differences in other common morbidities such as metabolic bone diseases of prematurity, bronchopulmonary dysplasia, electrolyte imbalance, hypoglycemia, retinopathy of prematurity, or intraventricular hemorrhage.

Conclusions: Compared to inorganic phosphate, sodium glycerophosphate is associated with higher serum phosphate levels, lower ALP levels, and reduced seizure incidence in premature infants. However, as the study was retrospective and single-center, further randomized controlled trials are needed to confirm these findings.