Phytosterolemia in parenteral nutrition patients: implications for liver disease development.

OBJECTIVE: Phytosterols present in parenteral nutrition (PN) lipid emulsions have been linked to phytosterolemia and cholestatic liver disease, although no direct relation has been established. We investigated the relation among plasma phytosterol (PY) infused, total plasma PY levels, and possible links to PN-associated liver disease.
METHODS: Twenty-seven adult patients on home PN were enrolled in the study. PYs were measured in plasma and lipid emulsions by gas chromatography. Liver function tests and blood counts were assessed to identify hepatic impairment, and biopsies were performed in eight patients.
RESULTS: Mean total plasma PY level was higher in patients than in controls (55.4 +/- 6.2 versus 14.8 +/- 2.3 microg/mL). Simple linear regression models showed a correlation among total plasma PY, liver function tests, and platelet counts, which was stronger for total bilirubin (r(2) = 0.53, P = 0.0001) and aspartate aminotransferase (r(2) = 0.50, P = 0.0001) and weaker for platelet counts (r(2) = 0.158, P = 0.04); between infused lipid and liver function tests, the correlation was significant for total bilirubin (r(2) = 0.19, P = 0.038) and aspartate aminotransferase (r(2) = 0.164, P = 0.049). In multiple linear regression analysis, a decreased oral diet (b = -52.3, P = 0.001) and infused PY (b = 2.54, P = 0.093) were risk factors for high plasma PY levels (r(2) = 0.54). Biopsies showed moderate to severe liver impairment in five patients.
CONCLUSION: Liver damage may be linked to high plasma PY levels and strengthened by lack of an oral diet in patients on home PN.