Fish Oil–Based Lipid Emulsions Prevent and Reverse Parenteral Nutrition–Associated Liver Disease: The Boston Experience

Parenteral nutrition–associated liver disease (PNALD) is the most prevalent and most severe complication of long‐term parenteral nutrition. Its underlying pathophysiology, however, largely remains to be elucidated. The currently approved parenteral lipid emulsions in the United States contain safflower or soybean oils, both rich in ω‐6 polyunsaturated fatty acids (PUFAs). Mounting evidence indicates that the ω‐6 PUFAs originating from plant oils in these lipid emulsions may play a role in the onset of liver injury. Fish oil–based lipid emulsions, in contrast, are primarily composed of ω‐3 PUFAs, thus providing a promising alternative. The authors review the literature on the role of lipid emulsions in the onset of PNALD and discuss prevention and treatment strategies using a fish oil–based lipid emulsion. They conclude that a fish oil–based emulsion is hepatoprotective in a murine model of PNALD, and it appears to be safe and efficacious for the treatment of this type of liver disease in children. A prospective randomized trial that is currently under way at the authors' institution will objectively determine the place of fish oil monotherapy in the prevention of PNALD.     

Supplemental Parenteral Vitamin E Into Conventional Soybean Lipid Emulsion Does Not Prevent Parenteral Nutrition–Associated Liver Disease in Full‐Term Neonatal Piglets

Background: Parenteral nutrition–associated liver disease (PNALD) continues to cause morbidity and mortality for neonates with intestinal failure. Lipid peroxidation is one potential etiological factor. This study was designed to test if supplementing vitamin E into conventional soy‐based lipid would reduce the risk of PNALD. Methods: Sixteen piglets, aged 2–5 days and weighing 1.8–2.5 kg, were randomized to parenteral nutrition (PN) with soy lipid (SO, n = 8) or the same lipid plus α‐tocopherol, the most bioactive form of vitamin E (SO+E, n = 8). After 17 days, bile flow, liver chemistry, gene expression associated with bile acid metabolism, and bile acid composition were assessed. C‐reactive protein (CRP) and oxidative stress markers, including plasma 8‐isoprostane, were measured. All results were compared with a sow‐reared control group (CON). Results: Comparing PN‐treated groups, SO vs SO+E mean bile flow (5.91 vs 5.54 µL/g liver; P = .83), serum bile acid concentration (39.2 vs 26.6 µmol/L; P = .12), and total bilirubin (35.2 vs 26.9 µmol/L; P = .56) were not different. Gene expression related to bile acid metabolism and bile composition was not different between PN groups. There was no difference in CRP (41.8 vs 36.8 µg/mL; P = .22) or in plasma 8‐isoprostane (27.9 vs 26.1 pg/mL; P = .77). Conclusions: In term neonatal piglets, supplemental vitamin E did not prevent cholestasis. Additional vitamin E was not associated with reduced inflammation or oxidative stress. The benefit of supplementing vitamin E into conventional lipid, vs adding fish oil, to prevent early onset of PNALD requires further clarification.     

Liver Disease,Systemic Inflammation,and Growth Using a Mixed Parenteral Lipid Emulsion,Containing Soybean Oil,Fish Oil,and Medium Chain Triglycerides,Compared With Soybean Oil in Parenteral Nutrition–Fed Neonatal Piglets

Background: The optimal parenteral lipid emulsion for neonates should reduce the risk of intestinal failure–associated liver disease and inflammation, while supporting growth and development. This could be best achieved by balanced content of ω‐6 and ω‐3 polyunsaturated fatty acids (PUFAs). Using a neonatal piglet model of parenteral nutrition (PN), we compared a 100% soy oil–based emulsion (ω‐6:ω‐3 PUFA: 7:1) with a mixed lipid emulsion comprising 30% soy oil, 30% medium‐chain triglycerides, 25% olive oil, and 15% fish oil (ω‐6:ω‐3 PUFA: approximately 2.5:1) with regard to liver disease, inflammation, and fatty acid content in plasma and brain. Method: Neonatal piglets, 3–6 days old, underwent jugular catheter insertion for isonitrogenous, isocaloric PN delivery over 14 days. The IL group (n = 8) was treated with Intralipid; the ML group (n = 10) was treated with the mixed lipid (SMOFlipid). Bile flow, liver chemistry, C‐reactive protein (CRP), and PUFA content in plasma phospholipids and brain were compared. Results: Compared with the IL group, ML‐treated piglets had increased bile flow (P = .008) and lower total bilirubin (P = .001) and CRP (P = .023) concentrations. The ω‐6 long‐chain PUFA content was lower in plasma and brain for the ML group. The key ω‐3 long‐chain PUFA for neonatal development, docosahexaenoic acid (DHA), was not different between groups. Conclusion: The mixed lipid, having less ω‐6 PUFA and more ω‐3 PUFA, was able to prevent liver disease and reduce systemic inflammation in PN‐fed neonatal piglets. However, this lipid did not increase plasma or brain DHA status, which would be desirable for neonatal developmental outcomes.     

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.     

Parenteral Fish Oil as Monotherapy Improves Lipid Profiles in Children With Parenteral Nutrition–Associated Liver Disease

Background: Parenteral nutrition (PN) is a life‐saving therapy but has been associated with dyslipidemia. Because fish oil has been shown to have positive effects on lipid profiles, the authors hypothesize that a parenteral fish oil lipid emulsion will improve lipid profiles in children who are PN dependent. Methods: The authors examined the lipid profiles of a unique cohort of 10 children who were exclusively administered a fish oil–based lipid emulsion while on PN for a median duration of 14 weeks. Longitudinal data analysis with a generalized estimating equations approach was used to determine the sterol and bilirubin levels based on duration of the fish oil–based lipid emulsion. Results: After 14 weeks of fish oil monotherapy, children had a 24% increase in high‐density lipoprotein. Compared to baseline, serum low‐density lipoprotein, very low‐density lipoprotein, total cholesterol, and triglyceride levels all significantly decreased by 22%, 41%, 17%, and 46%, respectively. Eight children had their bilirubin improved with a decreased direct bilirubin from 6.9 mg/dL (range, 4.4‐10.7) at baseline to 2.3 mg/dL (range, 1.3‐4.0) after 14 weeks, and a decrease in total bilirubin from 8.7 mg/dL (range, 5.5‐13.7) to 3.8 mg/dL (range, 2.2‐6.5). Conclusion: A fish oil–based lipid emulsion used as monotherapy in children who exclusively depended on PN for survival was associated with significant improvement in all major lipid panels as well as improvement of hyperbilirubinemia. Parenteral fish oil may be the preferred lipid source in children with dyslipidemia.     

Glucagon‐Like Peptide 2 Improves Cholestasis in Parenteral Nutrition–Associated Liver Disease

Background: Parenteral nutrition‐associated liver disease (PNALD) remains a significant cause of morbidity and mortality in neonates with intestinal failure. Although glucagon‐like peptide‐2 (GLP‐2) is being advanced as therapy, the effect of GLP‐2 treatment on PNALD is unknown. We aim to investigate the effect of exogenous GLP‐2 administration on hepatic function in a neonatal piglet model of PNALD. Methods: Neonatal piglets (aged 2–6 days) underwent jugular venous catheterization to receive isonitrogenous, isocaloric parenteral nutrition (PN). Piglets were allocated to 2 groups: group 1 (n = 8) received saline while group 2 (n = 7) received GLP‐2 (at 11 nmol/kg/d). After 17 days, piglets underwent terminal laparotomy, and bile flow was measured. Liver specimens were analyzed histologically and with immunoperoxidase staining. Age‐matched sow‐reared control piglets (group 3, n = 8) were used for comparison. Results: Both groups 1 and 2 receiving PN developed cholestasis relative to sow‐reared controls, as evidenced by a decrease in bile flow and increase in serum total bilirubin. However, group 2 had improved bile flow (1.35 vs 0.73 µL/g; P = .02) and diminished bilirubin (38.0 vs 78.5 µmol/L; P = .008) compared with group 1. Group 2 also had lower serum alanine aminotransferase levels, a marker of liver injury. Histologically, the liver specimens in group 1 had marked hepatocyte pigmentation, which was decreased in group 2 specimens. Conclusions: The exogenous administration of GLP‐2 is associated with the improvement of cholestasis and liver injury. This study introduces a novel role for GLP‐2 in improving PNALD in the setting of prolonged PN duration.     

Parenteral Soy Oil and Fish Oil Emulsions

Background: Parenteral nutrition (PN)–associated liver disease (PNALD) remains a significant cause of morbidity and mortality for neonates dependent on PN. Total fat emulsion dose and composition, particularly the large amount of ω‐6 long‐chain polyunsaturated fatty acids in plant oils, have been proposed as risk factors for PNALD. We hypothesized restriction of the dose of emulsion would prevent PNALD, regardless of the composition, but growth could be compromised. Methods: Using a neonatal piglet model, we compared conventional soy oil emulsion (Intralipid), dosed high (SO10, n = 8: 10 g/kg/d) and low (SO5, n = 6: 5 g/kg/d), with fish oil (Omegaven), dosed low (FO5, n = 8: 5 g/kg/d). Piglets were given isonitrogenous PN for 14 days. The normal range for all parameters was determined by measurement in equivalent aged sow‐reared piglets. Results: Bile flow was lower with high‐dose Intralipid, outside the normal range, while higher for the other groups (SO10, 5.4 µg/g; SO5, 8.6 µg/g; FO5, 13.4 µg/g; P = .010; normal range, 6.5–12.2 µg/g). Total body weight was low in all treatment groups (SO10, 4.4 kg; SO5, 4.5 kg; FO5, 5.0 kg; P = .038; normal range, 5.2–7.3 kg). Brain weight was not different between groups (SO10, 40.3 g; SO5, 36.0 g; FO5, 36.6 g; P = .122; normal range, 41.8–51.4 g). Corrected for body weight, brain weight was lowest in the fish oil group (SO10, 9.3 g/kg; SO5, 8.0 g/kg; FO5, 7.3 g/kg; P < .001; normal range, 5.9–9.0 g/kg). Conclusion: Low‐dose fat emulsions reduce the risk of developing PNALD. Further investigation of the risk to brain development in neonates exposed to dose restriction, particularly with fish oil, is required.     

Vitamin E in New‐Generation Lipid Emulsions Protects Against Parenteral Nutrition–Associated Liver Disease in Parenteral Nutrition–Fed Preterm Pigs

Introduction: Parenteral nutrition (PN) in preterm infants leads to PN‐associated liver disease (PNALD). PNALD has been linked to serum accumulation of phytosterols that are abundant in plant oil but absent in fish oil emulsions. Hypothesis: Whether modifying the phytosterol and vitamin E composition of soy and fish oil lipid emulsions affects development of PNALD in preterm pigs. Methods: We measured markers of PNALD in preterm pigs that received 14 days of PN that included 1 of the following: (1) Intralipid (IL, 100% soybean oil), (2) Intralipid + vitamin E (ILE, d‐α‐tocopherol), (3) Omegaven (OV, 100% fish oil), or (4) Omegaven + phytosterols (PS, β‐sitosterol, campesterol, and stigmasterol). Results: Serum levels of direct bilirubin, gamma glutamyl transferase, serum triglyceride, low‐density lipoprotein, and hepatic triglyceride content were significantly lower (P < .05) in the ILE, OV, and PS compared to IL. Hepatic cholesterol 7‐hydroxylase and organic solute transporter–α expression was lower (P < .05) and portal plasma FGF19 higher in the ILE, OV, and PS vs IL. Hepatic expression of mitochondrial carnitine palmitoyltransferase 1A and microsomal cytochrome P450 2E1 fatty acid oxidation genes was higher in ILE, OV, and PS vs IL. In vivo ¹³C‐CDCA clearance and expression of pregnane X receptor target genes, cytochrome P450 3A29 and multidrug resistance‐associated protein 2, were higher in ILE, OV, and PS vs IL. Conclusions: α‐tocopherol in Omegaven and added to Intralipid prevented serum and liver increases in biliary and lipidemic markers of PNALD in preterm piglets. The addition of phytosterols to Omegaven did not produce evidence of PNALD.     

Characterization of Fatty Acid Profiles in Infants With Intestinal Failure–Associated Liver Disease

Background

The purpose of this study was to characterize fatty acid profiles (FAPs) in parenteral nutrition (PN)‐dependent infants with intestinal failure–associated liver disease (IFALD) receiving soybean oil–based lipid emulsion (SO) doses of ～3 and ～1 g/kg/d.

Methods

Prospectively collected data were retrospectively reviewed. Serum FAPs of patients <1 year old who experienced development of IFALD while receiving standard PN with SO were examined before transitioning to a fish oil–based lipid emulsion for IFALD treatment. Time on SO, dose, gestational age, and weight‐ and length‐for‐age z scores were also reviewed.

Results

Among the 49 patients analyzed, there were no differences in demographics or anthropometrics between patients who received standard SO (SO‐S) (n = 14, range of dosage 2.06–3.31 g/kg/d) and reduced SO (SO‐R) (n = 35, range of dosage 0.90–1.34 g/kg/d). Patients received SO for a median of 53 days (interquartile range 39, 73) before FAP measurement. Patients who received SO‐R had significantly higher Mead acid and lower α‐linolenic, eicosapentaenoic, linoleic, stearic, total ω‐3, and total ω‐6 fatty acid levels than patients who received SO‐S (P < .01). Triene:tetraene ratios were higher in patients who received SO‐R (P = .0009), and no patients experienced biochemical essential fatty acid deficiency (EFAD).

Conclusion

PN‐dependent infants with IFALD receiving SO‐R have different FAPs than patients receiving SO‐S. No patients in either group had biochemical EFAD.     

Effect of an Olive Oil–Based Lipid Emulsion Compared With a Soybean Oil–Based Lipid Emulsion on Liver Chemistry and Bile Acid Composition in Preterm Infants Receiving Parenteral Nutrition

Background: The pathogenesis of parenteral nutrition (PN)–associated liver dysfunction is multifactorial. Lipid emulsions may be one of the putative mechanisms. Our aim was to comparatively assess the effect of parenteral olive oil– and soybean oil–based lipid emulsions on liver chemistry and bile acid composition in preterm infants. Methods: We performed a double‐blind, randomized clinical study in which 103 preterm infants were randomly assigned to PN using either soybean oil–based lipid emulsion (SO; n = 51) or olive oil (OO)–based lipid emulsion (OO; n = 52). The primary end point was liver chemistry. The secondary end point was the plasma bile acid composition. Results: One hundred infants completed this study. In the SO group, the serum direct bilirubin was significantly higher after PN for 7 days compared with the OO group. Bile acids increased over time in both treatment groups. However, specific differences in the change in bile acid composition over time were noted between groups. Conclusions: Differences in direct bilirubin and bile acid composition were observed over time between the 2 groups. Considering the long‐term use of lipid emulsions in higher risk babies, these findings might be useful for understanding the pathogenesis of PN‐associated liver dysfunction.     

Long‐Term Fish Oil Lipid Emulsion Use in Children With Intestinal Failure–Associated Liver Disease

Background: Fish oil lipid emulsion (FOLE) and multidisciplinary care for infants with intestinal failure (IF) have been associated with reduced morbidity and mortality due to IF‐associated liver disease (IFALD). With increased survival, a greater proportion of infants with IF are now able to remain on parenteral nutrition (PN) in the long term. The purpose of this study was to examine outcomes in children with IFALD who have required long‐term PN and FOLE therapy due to chronic IF. Materials and Methods: A review of prospectively collected data was performed for children with IFALD who required at least 3 years of PN and FOLE therapy due to chronic IF. Outcomes examined include the incidence of death, transplantation, and essential fatty acid deficiency (EFAD), as well as growth parameters and the biochemical markers of liver disease. Results: Of 215 patients with IFALD treated from 2004–2015, 30 required PN and FOLE therapy for at least 3 years (median, 4.6 years). To date, no patients have died, required transplantation, or developed EFAD. Biochemical markers of liver disease normalized within the first year of therapy with no recurrent elevations in the long term. Weight‐for age and length‐for‐age z scores improved and PN dependence decreased in the first year of therapy, with a stable rate of growth in the long term. Conclusions: Children with IFALD who required long‐term PN and FOLE for chronic IF had no mortality, need for transplantation, EFAD, or recurrence of liver disease in the long term, allowing for continued intestinal rehabilitation.     

Reversal of Intestinal Failure–Associated Liver Disease by Switching From a Combination Lipid Emulsion Containing Fish Oil to Fish Oil Monotherapy

Intestinal failure–associated liver disease (IFALD) is a serious complication of parenteral nutrition (PN). Studies have shown that the amount and content of intravenous lipid emulsions (LEs) used is closely related to the development of IFALD. We report 2 cases of IFALD reversed by switching from a combination lipid emulsion containing fish oil to fish oil monotherapy (Omegaven; Fresenius Kabi Austria Gmbh, Graz, Austria). Patients initially received PN containing SMOFlipid 20% (SMOF; Fresenius Kabi Austria Gmbh, Graz, Austria), 2.0–3.0 g/kg/d, over 24 hours. When IFALD developed, LE was switched from SMOF to Omegaven starting at 1.0 g/kg/d over 12 hours. Case 1 was an 11‐month‐old girl with a diagnosis of extensive Hirschsprung disease up to the proximal jejunum. She developed direct bilirubinemia at 3 months, and the patient's LE was switched to Omegaven. A decrease in direct bilirubin was observed after 60 days on Omegaven, and IFALD was completely resolved after 90 days. Case 2 was a 1‐month‐old boy with a history of gastroschisis diagnosed with megacystis microcolon intestinal hypoperistalsis syndrome. He could not tolerate any oral feeds and was kept on full PN. He had elevated direct bilirubin and developed IFALD since 5 weeks. Omegaven treatment was initiated at 5 months. Direct bilirubin rose to 8 mg/dL during the first month on Omegaven. Then a gradual decrease in direct bilirubin was observed, and after 5 months on Omegaven, IFALD was completely resolved. In conclusion, 2 infants with advanced IFALD showed reversal of cholestasis by switching from SMOF to Omegaven monotherapy.     

Providing the Best Parenteral Nutrition before and after Surgery for NEC: Macro and Micronutrients Intakes

Necrotizing enterocolitis (NEC) is the main gastrointestinal emergency of preterm infants for whom bowel rest and parenteral nutrition (PN) is essential. Despite the improvements in neonatal care, the incidence of NEC remains high (11% in preterm newborns with a birth weight <1500 g) and up to 20–50% of cases still require surgery. In this narrative review, we report how to optimize PN in severe NEC requiring surgery. PN should begin as soon as possible in the acute phase: close fluid monitoring is advocated to maintain volemia, however fluid overload and electrolytes abnormalities should be prevented. Macronutrients intake (protein, glucose, and lipids) should be adequately guaranteed and is essential in each phase of the disease. Composite lipid emulsion should be the first choice to reduce the risk of parenteral nutrition associated liver disease (PNALD). Vitamin and trace elements deficiency or overload are frequent in long-term PN, therefore careful monitoring should be planned starting from the recovery phase to adjust their parenteral intake. Neonatologists must be aware of the role of nutrition especially in patients requiring long-term PN to sustain growth, limiting possible adverse effects and long-term deficiencies.     

The role of parenteral lipids in the development of advanced intestinal failure-associated liver disease in infants: a multiple-variable analysis

Background: Given the recent interest in the role of ω‐6 lipids in the development of intestinal failure–associated liver disease (IFALD), the authors sought to examine the role of parenteral lipids in the development of a serum conjugated bilirubin >100 µmol/L (5.9 mg/dL; CB100) in infants. Method: Between 2003 and 2004, data were collected prospectively on infants undergoing an abdominal surgical procedure. Univariate logistic regression models for the prediction of CB100 by 1 year postoperatively were developed. Predictors significant at the 0.2 level on univariate analysis were entered into a backward stepwise multiple variable logistic regression. Results: Of 152 infants who received parenteral nutrition (PN) postoperatively, 22 developed CB100. Predictors that met criteria for consideration in the multiple‐variable model were age, weight, small bowel length, presence of a stoma, proportion of enteral feeds postoperatively, septic episodes, days of maximal PN amino acid (>2.5 g/kg/d), days of maximal lipid (>2.5 g/kg/d), and PN duration. The final model included septic episodes (odds ratio, 3.23; 95% confidence interval, 1.8–5.9) and days of lipid >2.5 g/kg/d (1.04; 1.003–1.06). At 60 days of maximal lipid, the odds of advanced IFALD were increased 10‐fold. Conclusions: This model suggests a key role of parenteral lipids and septic events in the development of CB100 from IFALD. These data may provide targets, such as careful line care, reduction in maximal lipid dose, or alternate lipids such as ω‐3 fatty acids, to prevent CB100, an identified marker of subsequent liver failure from IFALD.     

Intravenous Lipid Emulsions in Parenteral Nutrition

Fat is an important macronutrient in the human diet. For patients with intestinal failure who are unable to absorb nutrients via the enteral route, intravenous lipid emulsions play a critical role in providing an energy-dense source of calories and supplying the essential fatty acids that cannot be endogenously synthesized. Over the last 50 y, lipid emulsions have been an important component of parenteral nutrition (PN), and over the last 10–15 y many new lipid emulsions have been manufactured with the goal of improving safety and efficacy profiles and achieving physiologically optimal formulations. The purpose of this review is to provide a background on the components of lipid emulsions, their role in PN, and to discuss the lipid emulsions available for intravenous use. Finally, the role of parenteral fat emulsions in the pathogenesis and management of PN-associated liver disease in PN-dependent pediatric patients is reviewed.     

Expert Beliefs Regarding Novel Lipid‐Based Approaches to Pediatric Intestinal Failure–Associated Liver Disease

Objective: To determine expert beliefs regarding the probability of intestinal failure–associated liver disease (IFALD) with novel lipid‐based approaches (lipid minimization/ω‐3 lipids) in managing IFALD to facilitate Bayesian analyses of clinical trials of these therapies. Study Design: Structured interviews were conducted using a validated approach to belief elicitation with 60 intestinal failure (IF) experts from across North America. Participants were asked to estimate, in an average population of infants referred for management of IF with early IFALD, the probability of advanced IFALD at 3 months following referral in each of 3 scenarios: (1) conventional lipid, (2) ω‐3 lipids, and (3) lipid minimization. Probability distributions of the risk of advanced IFALD with each strategy were developed. Distributions of the elicited treatment effect for the novel approaches, relative to conventional lipid, were calculated. Results: Median duration of experience of participants managing patients with IF was 8.5 (range, 2–35) years. The median probability of advanced IFALD using conventional lipid was 32.5%; ω‐3 lipids, 17.5%; and lipid minimization, 13%. The median of the elicited treatment effects relative to conventional lipid was a relative risk of 0.53 for the ω‐3 lipid and 0.45 for lipid minimization. Conclusions: There was consistent expert opinion that the novel lipid‐based approaches are superior to conventional therapy, with similar estimates of treatment efficacy for the 2 approaches. The distributions of the elicited treatment effects can be used as prior distributions in Bayesian analyses of clinical trials of these novel strategies.     

Elevated Alkaline Phosphatase in Infants With Parenteral Nutrition–Associated Liver Disease Reflects Bone Rather Than Liver Disease

Background: Elevated serum alkaline phosphatase (ALP) in infants with intestinal failure (IF) can be due to parenteral nutrition–associated liver disease (PNALD) or metabolic bone disease (MBD). The purpose of the study was to determine the utility of serum ALP in the diagnostic criteria for PNALD by measuring tissue‐specific levels in infants with IF and PNALD. Methods: A retrospective review of patient data for 15 infants diagnosed with PNALD between December 2012 and August 2013 was performed. PNALD was defined as the presence of 2 consecutive direct bilirubin (DB) levels >2 mg/dL. Fractionated serum alkaline phosphatase was measured in each patient, while the DB was >2 mg/dL. Parathyroid hormone (PTH), vitamin D₃, calcium, and phosphate levels were recorded where available. Results: In 15 infants with PNALD, elevation in total ALP was due to marked elevations in bone‐specific ALP. The median liver‐specific ALP remained within the normal range. PTH, vitamin D₃, calcium, and phosphate levels were within normal limits. Conclusion: While elevated ALP can reflect biliary stasis, the ALP elevation observed in infants with IF and PNALD is predominantly of bone rather than hepatic origin. An elevated unfractionated ALP in infants with PNALD should therefore raise suspicion of underlying bone disease, rather than being attributed to liver disease alone.     

Effects on Varying Intravenous Lipid Emulsions on the Small Bowel Epithelium in a Mouse Model of Parenteral Nutrition

Background: Injectable fat emulsions (FEs) are a clinically dependable source of essential fatty acids (FA). ω‐6 FA is associated with an inflammatory response. Medium‐chain triglycerides (MCT, ω‐3 FA), fish oil, and olive oil are reported to decrease the inflammatory response. However, the effect of these lipids on the gastrointestinal tract has not been well studied. To address this, we used a mouse model of parenteral nutrition (PN) and hypothesized that a decrease in intestinal inflammation would be seen when either fish oil and MCT or olive oil were added. Methods: Three FEs were studied in adult C57BL/6 mice via intravenous cannulation: standard soybean‐based FE (SBFE), 80% olive oil ‐supplemented FE (OOFE), or a combination of a soybean oil, MCT, olive oil, and fish oil emulsion (SMOF). PN was given for 7 days, small bowel mucosa‐derived cytokines, animal survival rate, epithelial cell (EC) proliferation and apoptosis rates, intestinal barrier function and mucosal FA composition were analyzed. Results: Compared to the SBFE and SMOF groups, the best survival, highest EC proliferation and lowest EC apoptosis rates were observed in the OOFE group; and associated with the lowest levels of tumor necrosis factor‐α, interleukin‐6, and interleukin‐1β expression. Jejunal FA content showed higher levels of eicosapentaenoic and docosapentaenoic acid in the SMOF group and the highest arachidonic acid in the OOFE group. Conclusion: The study showed that PN containing OOFE had beneficial effects to small bowel health and animal survival. Further investigation may help to enhance bowel integrity in patients restricted to PN.