Effects of fish oil in parenteral nutrition

Parenteral nutrition with fish oil-based lipid emulsion reduces the risk of cholestasis in preterm infants

OBJECTIVE

Preterm infants receive long-term parenteral nutrition (PN) for gastrointestinal immaturity. This study aimed to determine if mixed lipid emulsions containing fish oil decrease the incidence of PN-associated cholestasis by reducing oxidative stress and providing an anti-inflammatory effect.

METHODS

This retrospective cohort study enrolled 399 very low birth weight premature infants (gestational age ≤32 weeks) between January 2009 and November 2017 at a single neonatal intensive care unit. Preterm infants received total PN with either mixed lipid emulsion including fish oil (SMOFlipid®, n = 195) or soybean oil-based lipid emulsion (Lipovenoes®, n = 204) for at least 7 days. We compared the outcomes of PN-associated cholestasis, comorbidities, and mortality between the groups.

RESULTS

The incidence of PN-associated cholestasis was significantly lower in the SMOFlipid group than in the Lipovenoes group. The duration to full feeding days was significantly shorter in the SMOFlipid group compared with the Lipovenoes group. Relevant complications, such as severe retinopathy of prematurity and bronchopulmonary dysplasia, were also significantly reduced in the SMOFlipid group compared with the Lipovenoes group.

CONCLUSION

In premature infants, PN with fish oil-based lipid emulsions is associated with a lower incidence of PN-associated cholestasis compared with soybean oil-based lipid emulsions.

Dietary n-3 but not n-6 fatty acids modulate anthropometry and fertility indices in high-fat diet fed rats: a two-generation study

The present study assessed the modulatory potentials of dietary n-3 [α-linolenic acid (ALA, 18:3n-3, eicosapentaenoic acid (EPA, 20:5n-3 + docosahexaenoic acid (DHA) 22:6n-3), and n-6 fatty acid (LA, 18:2n-6)] on anthropometric parameters and fertility indices in high-fat-fed rats. Weanling female Wistar rats were fed with control diet (7% lard), high-fat diet (35% lard, HFL), high-fat with fish oil (21% fish oil + 14% lard, HFF), high-fat with canola oil (21% canola oil + 14% lard, HFC) and high-fat with sunflower oil (21% sunflower oil + 14% lard, HFS) for 2 months, mated and continued on their diets during pregnancy. At gestation day 18-20, the intra-uterine environment was examined in representative rats, and the rest were allowed for delivering pups. The pups after lactation were subjected to mating and feeding trials as above. Growth parameters (body weight, body length (BL), abdominal circumference (AC), thoracic circumference (TC), and Lee index and fertility parameters (litter size and sex ratio) were studied. Feeding HFL diet increased BL (16%), AC (33%) and TC (21%) compared to control (p < 0.05). Adipose tissue accumulation was 11% higher in the HFL group compared to control and was lowered with n-3 fatty acid incorporation in the diet. HFL group exhibited a lower percentage of fertility, pregnancy, and delivery indices. Litter size was decreased by 20%, and litter weight was increased by 23% in HFL group compared to control with more male pups. Our study indicated that n-3 to a larger extent than n-6 fatty acids modulated high-fat induced changes in the anthropometric parameters and fertility indices.

Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

Parenteral nutrition-associated liver disease (PNALD) is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE) are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE) are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER) and mitochondrial damage, ultimately resulting in lipid droplets accumulation and ER stress. While these deleterious events induce hepatocyte injury, FOLE at high doses cause only minor ER and mitochondrial damage, which has no effect on hepatic function. SOLE also significantly upregulated glucose-regulated protein 94 mRNA and protein expression. These data indicate that SOLE, but not FOLE, damage the ER and mitochondria, resulting in lipid droplets accumulation and ER stress and, finally, hepatocyte injury. This likely contributes to the differential impacts of SOLE and FOLE on PNALD development and progression.

Intestinal failure-associated liver disease: a position paper of the ESPGHAN Working Group of Intestinal Failure and Intestinal Transplantation

Intestinal failure-associated liver disease is the most prevalent complication affecting children with intestinal failure receiving long-term parenteral nutrition. This paper reviews the definition, diagnostic criteria, pathogenesis, and risk factors. The authors discuss the role of enteral nutrition, parenteral nutrition, and its components, especially lipid emulsions. The authors also discuss the surgical treatment, including intestinal transplantation, its indications, technique, and results, and emphasise the importance of specialised intestinal failure centres.

Anti-inflammatory and anti-fibrotic profile of fish oil emulsions used in parenteral nutrition-associated liver disease

Home parenteral nutrition (PN) is associated with many complications including severe hepatobiliary dysfunction. Commercial ω-6 fatty acid-soybean based-lipid emulsions in PN may mediate long term PN associate liver disease (PNALD) whereas ω-3-fish oil parenteral emulsions have shown to reverse PNALD in children. However, its clinical effectiveness in adults has been scarcely reported. In this work, we study the role of soybean and fish oil lipid commercial emulsions on inflammatory and profibrotic liver markers in adults with long term PNALD and in in vitro cellular models. Inflammatory and profibrotic markers were measured in serum of ten adults with long term PNALD and in culture supernatants of monocytes. Liver epithelial to mesenchymal transition (EMT) was induced by transforming growth factor beta 1 (TGFβ1) to evaluate in vitro liver fibrosis. Omegaven®, a 100% fish oil commercial emulsion, was infused during four months in two patients with severe long term PNALD reversing, at the first month, the inflammatory, profibrotic and clinical parameters of PNALD. The effect was maintained during the treatment course but impaired when conventional lipid emulsions were reintroduced. The other patients under chronic soybean oil-based PN showed elevated inflammatory and profibrotic parameters. In vitro human monocytes stimulated with lipopolysaccharide induced a strong inflammatory response that was suppressed by Omegaven®, but increased by soybean emulsions. In other experiments, TGFβ1 induced EMT that was suppressed by Omegaven® and enhanced by soybean oil lipid emulsions. Omegaven® improves clinical, anti-inflammatory and anti-fibrotic parameters in adults with long-term home PNALD.

Ω-3 fatty acids prevent hepatic steatosis, independent of PPAR-α activity, in a murine model of parenteral nutrition-associated liver disease

OBJECTIVES

ω-3 Fatty acids (FAs), natural ligands for the peroxisome proliferator-activated receptor-α (PPAR-α), attenuate parenteral nutrition-associated liver disease (PNALD). However, the mechanisms underlying the protective role of ω-3 FAs are still unknown. The aim of this study was to determine the effects of ω-3 FAs on hepatic triglyceride (TG) accumulation in a murine model of PNALD and to investigate the role of PPAR-α and microsomal triglyceride transfer protein (MTP) in this experimental setting.

METHODS

129S1/SvImJ wild-type or 129S4/SvJaePparatm/Gonz/J PPAR-α knockout mice were fed chow and water (controls); oral, fat-free PN solution only (PN-O); PN-O plus intraperitoneal (IP) ω-6 FA-predominant supplements (PN-ω-6); or PN-O plus IP ω-3 FA (PN-ω-3). Control and PN-O groups received sham IP injections of 0.9% NaCl. Hepatic histology, TG and cholesterol, MTP activity, and PPAR-α messenger RNA were assessed after 19 days.

RESULTS

In all experimental groups, PN feeding increased hepatic TG and MTP activity compared with controls. Both PN-O and PN-ω-6 groups accumulated significantly greater amounts of TG when compared with PN-ω-3 mice. Studies in PPAR-α null animals showed that PN feeding increases hepatic TG as in wild-type mice. PPAR-α null mice in the PN-O and PN-ω-6 groups demonstrated variable degrees of hepatic steatosis, whereas no evidence of hepatic fat accumulation was found after 19 days of oral PN plus IP ω-3 FAs.

CONCLUSIONS

PN induces TG accumulation (steatosis) in wild-type and PPAR-α null mice. In PN-fed wild-type and PPAR-α null mice given IP ω-3 FAs, reduced hepatic TG accumulation and absent steatosis are found. Prevention of steatosis by ω-3 FAs results from PPAR-α-independent pathways.

High rates of resolution of cholestasis in parenteral nutrition-associated liver disease with fish oil-based lipid emulsion monotherapy

OBJECTIVE

To determine factors leading to resolution of cholestasis in patients with parenteral nutrition-associated liver disease treated with fish oil-based lipid emulsion (FOLE).

STUDY DESIGN

Prospective observational study of 57 infants <6 months of age with parenteral nutrition-associated liver disease who received parenteral FOLE as monotherapy.

RESULTS

Median gestational age of subjects at birth was 28 weeks (range 22.7-39.5). Median conjugated bilirubin level at initiation of therapy with FOLE was 7.5 mg/dL (range 2.1-25). Resolution of hyperbilirubinemia (conjugated bilirubin <2.0 mg/dL) and survival to hospital discharge occurred in 47 (82.5%) infants. Median number of days to resolution of cholestasis was 35 (range 7-129). Ten infants (17.5%) died. Non-survivors showed a trend towards being more premature than survivors at birth (25.9 vs 29.1 weeks, P = .056). Infants with higher conjugated bilirubin at initiation of therapy (>10.0 compared with <5.0 mg/dL) had longer times to resolution (98 vs 56 days, P < .005). Time to resolution correlated inversely with gestational age at birth (r(2) = 0.14, P = .02) and directly with time to receive 100% calories enterally (r(2) = 0.12, P = .03).

CONCLUSIONS

Younger gestational age infants demonstrated higher degree of cholestasis, longer time to resolution of cholestasis, and increased mortality. Higher levels of cholestasis were associated with longer time to resolution. FOLE monotherapy led to resolution of cholestasis in all surviving infants.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil

PURPOSE

The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated.

METHODS

A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering.

RESULTS

SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C.

CONCLUSION

PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Improved outcome in neonatal short bowel syndrome using parenteral fish oil in combination with ω-6/9 lipid emulsions

BACKGROUND

Newborn infants with short bowel syndrome (SBS) represent a high-risk group of developing intestinal failure-associated liver disease (IFALD), which may be fatal. However, infants have a great capacity for intestinal growth and adaptation if IFALD can be prevented or reversed. A major contributing factor to IFALD may be the soybean oil-based intravenous lipid emulsions used since the introduction of parenteral nutrition (PN) 40 years ago.

METHODS

This retrospective study compares the outcome in 20 neonates with SBS treated with parenteral fish oil (Omegaven) in combination with ω-6/9 lipid emulsions (ClinOleic) with the outcome in a historical cohort of 18 patients with SBS who received a soybean oil-based intravenous lipid emulsion (Intralipid).

RESULTS

Median gestational age was 26 weeks in the treatment group and 35.5 weeks in the historical group. All patients were started on PN containing Intralipid that was switched to ClinOleic/Omegaven in the treatment group at a median age of 39 gestational weeks. In the treatment group, direct bilirubin levels were reversed in all 14 survivors with cholestasis (direct bilirubin >50 umol/L). Median time to reversal was 2.9 months. Only 2 patients died of liver failure (10%). In the historical cohort, 6 patients (33%) died of liver failure, and only 2 patients showed normalization of bilirubin levels.

CONCLUSIONS

Parenteral fish oil in combination with ω-6/9 lipid emulsions was associated with improved outcome in premature neonates with SBS. When used instead of traditional soybean-based emulsions, this mixed lipid emulsion may facilitate intestinal adaptation by increasing the IFALD-free period.

A defect in the activities of Δ and Δ desaturases and pro-resolution bioactive lipids in the pathobiology of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a low-grade systemic inflammatory condition, since liver and adipose tissue tumor necrosis factor-α (TNF-α) and TNF receptor 1 transcripts and serum TNF-α levels are increased and IL-6(-/-) mice are less prone to NAFLD. Fatty liver damage caused by high-fat diets is associated with the generation of pro-inflammatory prostaglandin E(2) (PGE(2)). A decrease in the levels of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the usefulness of EPA and DHA both in the prevention and management of NAFLD has been reported. AA, EPA and DHA and their anti-inflammatory products lipoxins (LXs), resolvins and protectins suppress IL-6 and TNF-α and PGE(2) production. These results suggest that the activities of Δ(6) and Δ(5) desaturases are reduced in NAFLD and hence, the dietary essential fatty acids, linoleic acid (LA) and α-linolenic acid (ALA) are not metabolized to their long-chain products AA, EPA and DHA, the precursors of anti-inflammatory molecules, LXs, resolvins and protectins that could pre vent NAFLD. This suggests that an imbalance between pro- and anti-inflammatory bioactive lipids contribute to NAFLD. Hence, it is proposed that plasma and tissue levels of AA, EPA, DHA and LXs, resolvins and protectins could be used as predictors and prognostic biomarkers of NAFLD. It is suggested that the synthesis and use of more stable analogues of LXs, resolvins and protectins need to be explored in the prevention and management of NAFLD.

Potential applications of fish oils rich in n-3 fatty acids in the palliative treatment of advanced pancreatic cancer

The palliative treatment of patients with advanced pancreatic cancer (APC) has undergone little advancement in the last 15 years. Novel therapies that have been investigated to extend survival have shown little benefit over existing chemotherapy regimens. Patients with APC often experience significant weight loss, which is one of the primary factors involved in declining quality of life. Recently, the ability of n-3 fatty acid rich oral preparations to attenuate or reverse tumour-related weight loss has been investigated in this patient group with encouraging results. Laboratory investigation has also yielded promising results suggesting a potential direct tumouricidal effect of n-3 fatty acids as well as the putative potentiation of existing chemotherapy regimes. The present review aims to examine the potential applications of fish oils rich in n-3 fatty acids in patients with APC, present a selection of the studies carried out to date and outline avenues of possible further clinical investigation.

Prevention and reversal of intestinal failure-associated liver disease in premature infants with short bowel syndrome using intravenous fish oil in combination with omega-6/9 lipid emulsions

Although premature infants with short bowel syndrome are at the highest risk of developing intestinal failure-associated liver disease (IFALD), they have great capacity for intestinal growth and adaptation if IFALD can be prevented. Conventional soybean oil-based intravenous lipid emulsions have been associated with IFALD. This study presents data on 5 premature neonates with short bowel syndrome treated with a combination of parenteral fish oil- and olive/soybean-based lipid emulsion for periods ranging between 7 and 17 months. Despite an enteral tolerance of less than 50% in 4 of these patients during their first year of life, direct bilirubin levels normalized while on this combination of ClinOleic (Baxter, Maurepas, France)/Omegaven (Fresenius Kabi, Bad Homburg, Germany) at a 1:1 ratio. None of our patients developed irreversible IFALD even though all of them were premature, had undergone multiple major surgical procedures, and had experienced several episodes of sepsis. Thus far, we have not seen any adverse effects of this mixed lipid emulsion in these preterm infants. All 5 patients are growing and developing well and have normal liver function.

Safety and efficacy of a lipid emulsion containing a mixture of soybean oil, medium-chain triglycerides, olive oil, and fish oil: a randomised, double-blind clinical trial in premature infants requiring parenteral nutrition

OBJECTIVES

Safety, tolerability, and efficacy of a novel lipid emulsion containing a mixture of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOFlipid 20%) with reduced n-6 fatty acids (FA), increased monounsaturated and n-3 FA, and enriched in vitamin E were evaluated in premature infants compared with a soybean oil-based emulsion.

PATIENTS AND METHODS

Sixty (30/30) premature neonates (age 3-7 days, gestational age ≤ 34 weeks, birth weights 1000-2500 g) received parenteral nutrition (PN) with either SMOFlipid 20% (study group) or a conventional lipid emulsion (Intralipid 20%, control group) for a minimum of 7 up to 14 days. Lipid supply started at 0.5 g · kg body weight(-1) · day(-1) on day 1 and increased stepwise (by 0.5 g) up to 2 g · kg body weight(-1) · day(-1) on days 4 to 14. Safety and efficacy parameters were assessed on days 0, 8, and 15 if PN was continued.

RESULTS

Adverse events, serum triglycerides, vital signs, local tolerance, and clinical laboratory did not show noticeable group differences, confirming the safety of study treatment. At study end, γ-glutamyl transferase was lower in the study versus the control group (107.8 ± 81.7 vs 188.8 ± 176.7 IU/L, P < 0.05). The relative increase in body weight (day 8 vs baseline) was 5.0% ± 6.5% versus 5.1% ± 6.6% (study vs control, not significant). In the study group, an increase in n-3 FA in red blood cell phospholipids and n-3:n-6 FA ratio was observed. Plasma α-tocopherol (study vs control) was increased versus baseline on day 8 (26.35 ± 10.03 vs 3.67 ± 8.06 μmol/L, P < 0.05) and at study termination (26.97 ± 18.32 vs 8.73 ± 11.41 μmol/L, P < 0.05).

CONCLUSIONS

Parenteral infusion of SMOFlipid was safe and well tolerated and showed a potential beneficial influence on cholestasis, n-3 FA, and vitamin E status in premature infants requiring PN.

Prevention of parenteral nutrition-associated liver disease: role of omega-3 fish oil

PURPOSE OF REVIEW

Parenteral nutrition-associated liver disease (PNALD) is the most severe complication of long-term parenteral nutrition. Its cause remains unclear, although recent studies suggest that the omega-6 polyunsaturated fatty acids in plant oil-based lipid emulsions and the associated phytosterols contribute to the development of hepatotoxicity. In contrast, fish oil-based lipid emulsions are composed mainly of omega-3 polyunsaturated fatty acids and are hypothesized to be hepatoprotective. This review will discuss fish oil-based lipid emulsions in the prevention of PNALD.

RECENT FINDINGS

In several animal models of PNALD, the use of an intravenous fish oil-based lipid emulsion improved parenteral nutrition-associated cholestasis without resultant essential fatty acid deficiency or growth impairment. Following these results and preliminary human data, an open trial for compassionate use was initiated, followed by a randomized controlled trial to evaluate the current management of pediatric PNALD. To date, at the author's institution, more than 130 children with PNALD have been treated with Omegaven, a fish oil-based emulsion, with improved liver function among most patients.

SUMMARY

PNALD remains the most severe complication of long-term parenteral nutrition with an unclear pathophysiology. However, the use of a fish oil-based emulsion appears efficacious and hepatoprotective.

Innovative parenteral and enteral nutrition therapy for intestinal failure

Children with intestinal failure (IF) suffer from insufficient intestinal length or function, making them dependent on parenteral nutrition (PN) for growth and survival. PN and its components are associated with many complications ranging from simple electrolyte abnormalities to life-threatening PN-associated liver disease, which is also called intestinal failure-associated liver disease (IFALD). From a nutrition perspective, the ultimate goal is to provide adequate caloric requirements and make the transition from PN to full enteral nutrition (EN) successful. Upon review of the literature, we have summarized the most effective and innovative PN and EN therapies for this patient population. Antibiotic-coated catheters and antibiotic or ethanol locks can be implemented, as they appear effective in reducing catheter-related infection and thus further reduce the risk of IFALD. Lipid emulsions should be given judiciously. The use of an omega-3 fatty acid-based formulation should be considered in patients who develop IFALD. Trophic feeding is important for intestinal adaptation, and EN should be initiated early to help wean patients from PN. Long-term management of children with IF continues to be an emerging field. We have entered uncharted territory as more children survive complications of IF and IFALD. Careful monitoring and individualized management to ensure maintenance of growth while avoiding complications are the keys to successful patient outcomes.

Impact of lipid emulsion containing fish oil on outcomes of surgical patients: systematic review of randomized controlled trials from Europe and Asia

OBJECTIVE

This study aimed to systematically review the clinical efficacy of lipid emulsion containing fish oil in surgical patients.

METHODS

Medline, SCI, Embase, Cochrane Library, and Chinese Biomedicine Database were searched for studies published before January 1, 2009 that were randomized controlled trials for postoperative patients. Parenteral nutrition with or without fish oil emulsion was the only difference between the intervention and control groups. Methodologic quality assessment was based on the Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1 and Jadad's score scale. RevMan 5.0 statistical software was used for meta-analysis.

RESULTS

Six trials met all inclusion criteria and were enrolled for final meta-analysis. The aggregated results of the trails showed that fish oil was associated with no mortality advantage. There was a significant reduction in infectious complications in patients receiving fish oil (relative risk 0.49, 95% confidence interval 0.26-0.93, P=0.03). The result on length of hospital stay showed a trend of shortening by 3.06 d associated with receiving fish oil. However, the difference was not significant. When excluding one obviously heterogeneous study and aggregating the other three remaining studies, results showed significantly shortening of length of hospital stay associated with receiving fish oil. Fish oil also significantly shortened length of stay in the intensive care unit by 2.07 d.

CONCLUSION

The administration of lipid emulsion containing fish oil to patients undergoing elective major operations improves outcomes. The infectious complications are significantly fewer and length of hospitalization significantly shortened for patients treated with lipid emulsion containing fish oil. Further well-designed randomized controlled trials are needed to demonstrate the cost effectiveness of lipid emulsion containing fish oil to postoperative patients.

Removal of trimethylamine by adsorption over zeolite catalysts and deodorization of fish oil

Trimethylamine (TMA) is the main agent for the odor often associated with fouling fish, some infections, and bad breath. This study focused on the adsorption of TMA over various microporous zeolites for application in the low-temperature deodorization of fishy odor from raw fish oil. The faujasite (Si/Al=3) zeolite exhibited the high adsorption ability, which, in combination with its wide surface area and pore volume, may have induced the high adsorption ability. The H-mordenite (Si/Al=10) zeolite exhibited a large TMA adsorption. It was considered to have generated more attractive adsorption with TMA ions, because TMA interacted briskly with cations of acid sites on the zeolites. The fishy odor of raw fish oil was considerably reduced by low-temperature adsorption on the zeolites. The surface area of the zeolites retained most of the TMA adsorption ability, and their acid strength further enhanced the adsorption ability.

Study on the raw fish oil purification from PCDD/F and dl-PCB-industrial tests

The results of tests for the purification of fish oils with activated carbon for industrial use are presented. The optimum parameters for the process of purification (granulation of the activated carbon, its dosage, the oil temperature, and the duration of mixing the oil with activated carbon) were previously established for the laboratory scale. The optimization of the process consisted of selecting purification parameters that would allow for maximum reduction of the toxic polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) content, while retaining the favorable high fatty acid content [C20:5 n-3, eicosapentaenoic acid (EPA) and C22:6 n-3, docosahexaenoic acid (DHA)]. The use of that optimum parameters in industrial conditions confirmed the satisfactory results obtained in laboratory tests. Five types of oil derived from various Baltic fish were purified. Reduction in the PCDD/Fs content was 77.0-93.6% on average, whereas in the dioxin-like polychlorinated biphenyls (dl-PCBs)-it was 42.7-50.5% on average, with insignificant changes in the total amount of EPA and DHA content. Furthermore, a significant reduction in the content of arsenic was noted (by about 62% on average), with insignificant changes in the content of organochlorine pesticides (OCPs), and marker polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), cadmium, lead, and mercury. Purification provided fish oil having standardized parameters that allow for its use as feed additives, whilst retaining its favorable fatty acid content.

Standard and immunomodulating enteral nutrition in patients after extended gastrointestinal surgery--a prospective, randomized, controlled clinical trial

BACKGROUND & AIM

The immunomodulating enteral diets are intended to reduce the incidence of postoperative complications in surgical patients. The aim of the study was to assess the clinical effect of such nutrition.

MATERIALS AND METHODS

Between June 2004 and September 2007 196 well-nourished patients undergoing resection for pancreatic and gastric cancer were randomized in double-blind manner to receive postoperative enteral nutrition with immunostimulating diet (IMEN group) or standard oligopeptic diet (SEN group). Outcome measures were: number and type of complications, length of hospital stay, mortality, treatment tolerance, liver and kidney function.

RESULTS

One hundred and ninety six patients were initially enrolled, finally 183 patients (91 SEN, 92 IMEN group; 69 F, 114 M, median age 61.2) were analyzed. Median postoperative hospital stay was 12.4 days (SD 5.9) in SEN and 12.9 days (SD 8.0) in IMEN group (p=0.42). Complications were observed in 21 patients (23.1%) in SEN and 23 (25.2%) in IMEN group (p>0.05). Four (4.4%) patients in SEN group and 4 (4.4%) in IMEN had surgical complications (p>0.05). There were no differences in liver and kidney function, visceral protein turnover and treatment tolerance.

CONCLUSION

Results of our study showed no benefit of immunomodulating enteral nutrition over standard enteral nutrition in patients after major gastrointestinal surgery. The Trial was registered in Clinical Trials Database--number: NCT00576940.

Anti-angiogenic effects of conjugated docosahexaenoic acid in vitro and in vivo

The anti-angiogenic effects of conjugated docosahexaenoic acid (CDHA), which was prepared by an alkaline treatment of docosahexaenoic acid and contained conjugated double bonds, were investigated in vitro and in vivo. CDHA inhibited tube formation by the bovine aortic endothelial cell (BAEC), and also inhibited the proliferation of BAEC at a concentration of CDHA that suppressed tube formation, but did not influence cell migration. The inhibition of BAEC growth caused by CDHA was accompanied by a marked change in cellular morphology. Nuclear condensation and brightness were observed in Hoechst 33342-stained cells treated with CDHA, indicating that CDHA induced apoptosis in BAEC. We also evaluated the angiogenesis inhibition of CDHA in vivo. The vessel formation which was triggered by tumor cells was clearly suppressed in mice orally given CDHA. Our findings suggest that CDHA has potential use as a therapeutic dietary supplement for minimizing tumor angiogenesis.

Evaluation of clinical safety and beneficial effects of a fish oil containing lipid emulsion (Lipoplus, MLF541): Data from a prospective, randomized, multicenter trial*

OBJECTIVE

To prove safety and effectiveness of a lipid emulsion enriched with n-3 fatty acids from fish oil (Lipoplus) within the setting of parenteral nutrition of patients after major abdominal surgery and to determine whether there are effects on outcome parameters.

DESIGN

Prospective, randomized, double-blind, multicenter trial.

SETTING

University and surgical teaching hospitals.

PATIENTS

After obtaining informed consent, 256 patients undergoing major abdominal surgery were randomized. Parameters of safety, effectiveness, and outcome were routine laboratory parameters, complication rates, length of stay in the intensive care unit, and length of hospital stay. In addition we determined in patient subgroups of 30 patients each, the changes of the content of selected long-chain polyunsaturated fatty acids, the leukotriene synthetic capacity and the antioxidant alpha-tocopherol.

INTERVENTIONS

Participating patients were randomized to receive either Lipoplus (group I; n = 127 patients) or Intralipid (group II; n = 129 patients). Parenteral nutrition was initiated immediately after surgery and ended on day 5 after surgery.

MEASUREMENTS AND MAIN RESULTS

No significant differences between groups I and II were observed when comparing routine laboratory parameters during the perioperative period. Plasma levels of eicosapentaenoic acid, leukotriene B5, and antioxidant content were significantly increased in group I. Furthermore, there was a significantly shorter length of hospital stay of approximately 21% (17.2 vs. 21.9 days; p = .0061) in group I.

CONCLUSIONS

Our findings indicate that the administration of Lipoplus in the postoperative period after major abdominal surgery is safe and results in a significantly shorter length of hospital stay. Administration of n-3 polyunsaturated fatty acids in the postoperative period can be considered a valuable choice for patients requiring parenteral nutrition after major abdominal surgery.

In vivo and in vitro properties of an intravenous lipid emulsion containing only medium chain and fish oil triglycerides

BACKGROUND & AIMS

The triglyceride (TG) fatty acyl composition in lipid emulsions influences their metabolism. Little is known about the effects of long chain omega-3 polyunsaturated fatty acids (PUFA) on lipid emulsion metabolism. We investigated possible differences between omega-3 containing emulsions in their metabolism and tissue-targeting in vivo in a mouse model, and in vitro using lipolysis and cell culture experiments.

METHODS

Soy oil (LCT), MCT/LCT/omega-3 (5:4:1, wt/wt/wt), and MCT/omega-3 (8:2, wt/wt) emulsions were radiolabeled with nondegradable 1alpha,2alpha (n)-[3H] cholesteryl oleoyl ether to trace core particle metabolism in C57BL/6J mice following a bolus injection. Blood samples obtained over 25 min and extracted organs were used to measure the tissue distribution of lipid emulsion particles. Lipoprotein lipase (LpL)-mediated hydrolysis experiments and cell uptake studies in cultured J774 murine macrophages were also performed.

RESULTS

Blood clearance of 8:2 was 13.4% and 29.8% faster compared to 5:4:1 and LCT, respectively. LCT had greatest liver uptake. LpL-mediated hydrolysis was greatest in 8:2 and lowest in LCT. Overall, cell TG accumulation in the presence of apolipoprotein E was least with 8:2.

CONCLUSIONS

Our data shows that 8:2 had the most efficient blood clearance but less hepatic uptake in vivo. In vitro, 8:2 had both highest hydrolysis by LpL and intracellular TG utilization in the presence of apoE. Thus, an 8:2 lipid emulsion undergoes efficient blood clearance and may direct omega-3 PUFA more towards extrahepatic tissues.

Omega-3 fatty acid supplementation prevents hepatic steatosis in a murine model of nonalcoholic fatty liver disease

Prolonged use of total parenteral nutrition can lead to nonalcoholic fatty liver disease, ranging from hepatic steatosis to cirrhosis and liver failure. It has been demonstrated that omega-3 fatty acids are negative regulators of hepatic lipogenesis and that they can also modulate the inflammatory response in mice. Furthermore, they may attenuate hepatic steatosis even in leptin-deficient ob/ob mice. We hypothesized that omega-3 fatty acid supplementation may protect the liver against hepatic steatosis in a murine model of parenteral nutrition in which all animals develop steatosis and liver enzyme disturbances. For testing this hypothesis, groups of mice received a fat-free, high-carbohydrate liquid diet ad libitum for 19 d with enteral or i.v. supplementation of an omega-3 fatty acid emulsion or a standard i.v. lipid emulsion. Control mice received food alone or the fat-free, high-carbohydrate diet without lipid supplementation. Mice that received the fat-free, high-carbohydrate diet only or supplemented with a standard i.v. lipid emulsion developed severe liver damage as determined by histology and magnetic resonance spectroscopy as well as elevation of serum liver function tests. Animals that received an i.v. omega-3 fatty acid emulsion, however, showed only mild deposits of fat in the liver, whereas enteral omega-3 fatty acids prevented hepatic pathology and led to normalization of liver function tests. In conclusion, whereas standard i.v. lipid emulsions fail to improve dietary-induced steatotic injury to the liver, i.v. supplementation of omega-3 fatty acids partially and enteral supplementation completely protects the liver against such injury.

Fatty liver in the intensive care unit

PURPOSE OF REVIEW

Non-alcoholic steatohepatitis is a liver disease characterized by steatosis and steatohepatitis in subjects whose alcohol consumption is negligible. The primary form is associated with insulin resistance whereas secondary non-alcoholic steatohepatitis occurs notably during total parenteral nutrition or in patients in the intensive care unit. This review is mainly focused on recent developments in the understanding of the pathogenesis of this disease.

RECENT FINDING

Pathogenesis involves the direct role of fatty acids in liver injury, oxidative stress, cytokines, genetic susceptibility or mitochondrial dysfunction. An increased delivery of free fatty acids to the liver contributes to the first hit, originating liver steatosis. The process may undergo a second hit, characterized by inflammation and hepatocellular degeneration. Mitochondrial dysfunction plays a key role by leading to abnormal generation of reactive oxygen species, which cause lipid peroxidation. The peroxidation products and cytokines favor progression from steatohepatitis to fibrosis. Fatty liver disease may also be encountered in the intensive care unit in patients receiving parenteral nutrition. However, an adapted glucose-lipid ratio as source of non-protein calories prevents the development of fatty liver. Moreover, recent evidence suggests the importance of the type of lipid infused (structured lipid emulsion or fish oils). The acute phase response associated with severe disease can also lead to the development of fatty liver in spite of adequate nutritional support.

SUMMARY

The pathogenesis of non-alcoholic steatohepatitis is multifactorial, but there is growing evidence that mitochondrial dysfunction always plays a key role. Adapted nutrition may prevent in part fatty liver in the intensive care unit.

Perioperative administration of parenteral fish oil supplements in a routine clinical setting improves patient outcome after major abdominal surgery

BACKGROUND & AIMS

It is hypothesized that provision of pre- and/or postoperative omega-3 fatty acids to surgical patients in clinical routine improves clinical outcome.

METHODS

Retrospective evaluation of a 2-year-longitudinal data base of ICU patients (n=249) elected for major abdominal surgery. Group I (n=110): postoperative standard parenteral nutrition (1.2 g amino acids, 0.3 g glutamine dipeptide, 0.6 g lipids, 4 g/kg glucose; energy ratio glucose to lipid 2:1); group II (n=86): part of postoperative lipid emulsion replaced by fish oil; group III (n=53): in addition 2-3 days preoperative fish oil supplementation (max. 100 ml/d).

RESULTS

A decrease in mortality was observed in group III compared to group I (P=0.02). The number of patients requiring mechanical ventilation was lower with perioperative fish oil (n=34 in groups I and II. 10 in III, P<0.05). The number of days in ICU was not different (group I: 7.6 days, group II: 7.0, group III: 7.3), the length of hospital stay was shorter in group I (group I: 29.2 days, group II: 24.9, group III: 22.2, P<0.05 vs I).

CONCLUSIONS

In a retrospective evaluation, perioperative provision of parenteral fish oil (ca. 10 g/day) beneficially influences patient outcome probably by modulating the immune response.

Omega-3 fatty acids and cardiovascular disease

PURPOSE OF REVIEW

Omega-3 fatty acids are gaining acceptance in the cardiovascular field. The present review describes the most recent studies and developments in the field.

RECENT FINDINGS

Marine omega-3 fatty acids, that is eicosapentaenoic and docosahexaenoic acids, prevent fatal myocardial infarction and sudden cardiac death by their antiarrhythmic effects and presumably also by their effect on infarct size, the latter mediated by plaque stabilization, improvements in endothelial function and other mechanisms. In contrast, a cardioprotective effect of alpha-linolenic acid, a plant-derived omega-3 fatty acid, remains to be clearly demonstrated in adequate intervention trials. Other forms of applications, like parenteral use or other indications, like in the psychiatric field, are currently being actively investigated.

SUMMARY

Eicosapentaenoic and docosahexaenoic acids, but not alpha-linolenic acid, prevent sudden death and other cardiovascular catastrophies, and have therefore been recently incorporated into the pertinent guidelines of European and American cardiologic societies.