Effects of an olive oil-based lipid emulsion (ClinOleic) versus LCT/MCT-based lipid emulsions upon the inflammatory markers of critically ill patients (EPICOS Study)

Introduction

Olive oil-based lipid emulsions have been used for more than a decade to reduce the polyunsaturated fatty acid (PUFA) content in TPN, thus preventing the deleterious effects associated with PUFA excess. MCT/LCT-based lipid emulsions were recently associated with deleterious effects such as lipotoxicity, activation of inflammatory cascade and increased risk of cardiovascular disease [1]. This study aims to compare the effects of these two lipid emulsions upon several inflammatory markers in critically ill patients using TPN.

Methods

Serum samples were collected in a prospective multicenter and open-label study (NCT#00798681) from 100 critical care patients receiving TPN with an olive oil-based lipid emulsion using either a premixed ready-to-use system (G1, n = 50, OliClinomel; Baxter) or a compounded system (G2, n = 25, ClinOleic; Baxter), and the results were compared with those from patients receiving a compounded TPN made with an LCT/MCT lipid emulsion (G3, n = 25). All samples were collected at baseline, day 4 and day 7 (three samples in each time point). Changes in the levels of inflammatory markers from baseline to day 7 were compared using analysis of covariance and P < 0.05 was considered statistically significant.

Results

At baseline, demographic characteristics of the patients were balanced between the groups. Regardless of the delivery system used, patients receiving TPN with an olive oil-based lipid emulsion presented at day 4 lower levels of: IL-8 (54.4 vs 67.8 vs 120.7 pg/ml), TNFα (3.4 vs 3.5 vs 13.0 pg/ml), lymphocyte phosphatidylserine externalization (PS) (5.2 vs 4.8 vs 14.7%), and resistin (R) (9.1 vs 9.2 vs 15.4 ng/ml) (all G1 vs G2 vs G3 and P < 0.05). No differences were observed in the levels of IL-10 and CRP. Statistically significant differences were maintained throughout day 7 for IL-8, TNFα, PS and R.

Conclusions

The administration of an olive oil-based lipid emulsion within the TPN regimen led to a significant reduction in the inflammatory response when compared with a LCT/MCT-based lipid emulsion. Particularly relevant are the differences for resistin (an indicator of insulin resistance) and PS (an indicator of apoptosis).