Whole-blood-free choline and choline metabolites in infants Who require chronic parenteral nutrition therapy

Background and Aim: Choline deficiency is associated with hepatic dysfunction. Parenteral nutrition (PN) and lipid emulsions contain phosphatidylcholine (PtdCho) but insignificant free choline (FCho). PtdCho is sequentially degraded to glycerolphosphocholine (GPCho), phosphocholine (PCho), and finally to FCho. Biosynthesis of FCho may be insufficient during PN therapy. The aim of the study was to examine the status of FCho and related metabolites in infants on prolonged (≥4 weeks) PN. Methods: Whole blood concentrations of FCho, PtdCho, GPCho, and PCho were measured and compared in infants on PN and infants on enteral feeds (controls). Results: Infants on PN (n = 14) had higher birth weight but same postnatal age as controls (n = 14) (mean ± standard deviation) 8.3 ± 3.9 versus 7.4 ± 3.6 weeks. Parenteral nutrition was associated with increased PtdCho 1761 ± 452 versus 1471 ± 221 nmol/mL, P = 0.04. Mean whole blood FCho, GPCho, and PCho concentrations did not differ significantly in PN versus controls: 40.0 ± 15.4 versus 50.8 ± 49.7, 16.4 ± 14.5 versus 25.2 ± 29.3, and 15.3 ± 13.5 versus 22.0 ± 14.8 nmol/mL, respectively. However, PCho was positively correlated with GPCho in controls (r = 0.91, P < 0.01) but not PN (r = 0.24, P = NS), and infants receiving >90% of daily energy intake from PN (n = 6) had decreased PCho, 5.7 ± 4.1 nmol/mL, compared with those receiving <90% of daily energy intake (n = 8) 22.5 ± 13.7 nmol/mL, P < 0.05, and controls, 22.0 ± 14.8 nmol/mL, P < 0.01. Conclusions: Decreased whole-blood concentrations of choline suggest possible evidence of choline deficiency as illustrated by decreased whole-blood PCho. Choline supplementation should be investigated in infants who require prolonged PN, and whole-blood PCho can be used to monitor response.