Frances Malone^1,2, Patric Javid^1,2, Cheryl Davis¹, Susan Jacob¹, Jorge Reyes^1,2, Patrick Healey^1,2, Simon Horslen^1,2

¹Seattle Children’s Hospital, Seattle, WA, United States; ²University of Washington, Seattle, WA, United States

Objective: Recent data demonstrate that parenteral fish oil-based lipids can reverse cholestatic liver injury from parenteral nutrition (PN) in young children. Yet, the effects of long-term fish oil supplementation on fatty acid metabolism are unknown. The objective of this study was to examine the fatty acid profiles of children receiving chronic intravenous fish oil-based supplementation as their sole fat source.

Patients and Methods: Prospectively collected data from 10 patients receiving intravenous fish oil-based lipid monotherapy were reviewed for biochemical alterations in essential fatty acid profiles. All patients demonstrated progressive liver disease at the initiation of fish-oil based lipids and received PN with fish oil-based lipid emulsion at 1 g/kg/day as their sole source of fat energy for a minimum of 3 months. Data are presented as median (range).

Results: The median age at fish-oil initiation was 7 months (1-43), and the median duration of fish oil-based lipid therapy was 99 weeks (13-152). Age-adjusted biochemical alterations began at the following times post fish-oil monotherapy: linoleic acid median= 46 weeks (3.7-96); mead acid median= 48 (23-88); and triene: tetraene ratio median= 64 (5-86). Progressive decreases in markers of essential fatty acid status began after normalization of hyperbilirubinemia in 9/10 patients [16 (9-41) weeks] and continued with fish-oil monotherapy. Other indicators of essential fatty acid deficiency (dermatitis or elevations in mead acid and triene: tetraene ratios) are not present. Furthermore patients eventually demonstrate mead acid levels and triene: tetraene ratios that are below the normal range.

Discussion: Long-term use of fish-oil based intravenous lipid monotherapy is associated with dramatic biochemical changes in elements of the essential fatty acid profile. The clinical significance of these changes remains unknown and requires further study.