The spectrum of nonalcoholic fatty liver disease (NAFLD) includes a nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). The specific types and amounts of lipids that accumulate in NAFLD are not fully defined. The free fatty acid (FFA), diacylglycerol (DAG), triacylglycerol (TAG), free cholesterol (FC), cholesterol ester, and phospholipid contents in normal livers were quantified and compared to those of NAFL and NASH, and the distribution of fatty acids within these classes was compared across these groups. Hepatic lipids were quantified by capillary gas chromatography. N onalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease in North America. 1 NAFLD is associated with insulin resistance and the metabolic syndrome. 2,3 The clinical-histologic spectrum of NAFLD extends from a nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). 4 Although NASH is distinguished from NAFL by the presence of cytologic ballooning and inflammation, both conditions are characterized by a fatty liver. 4,5 Thus, hepatic fat accumulation is the hallmark of NAFLD.The compositions of the lipids that accumulate in the livers of subjects with NAFLD are not well characterized. Most of the published literature has focused on triglyceride accumulation as the key defect in NAFLD. 6,7 However, it is not known whether there are substantial changes in other lipid classes, such as cholesterol and specific phospholipids (PLs). Although an increase in the n-6:n-3 fatty acid ratio in total lipids in NAFLD has been described recently, 8,9 the distribution of these fatty acids within specific lipid classes has not been extensively characterized. Given the important biological activities of many lipids, such information could provide potential insights into the pathophysiology of NAFLD and the metabolic syndrome.A lipidomic approach was taken to quantify the major lipid classes and the distribution of fatty acids within these classes in the liver. The specific aims of the study were to (1) quantify the absolute and relative amounts of free fatty acids (FFAs), diacylglycerol (DAG), triacylglycerol

Specific alterations in hepatic lipid composition characterize the spectrum of nonalcoholic fatty liver disease (NAFLD), which extends from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). However, the plasma lipidome of NAFLD and whether NASH has a distinct plasma lipidomic signature are unknown. A comprehensive analysis of plasma lipids and eicosanoid metabolites quantified by mass spectrometry was performed in NAFL (n = 25) and NASH (n = 50) subjects and compared with lean normal controls (n = 50). The key findings include significantly increased total plasma monounsaturated fatty acids driven by palmitoleic (16:1 n7) and oleic (18:1 n9) acids content (P < 0.01 for both acids in both NAFL and NASH). The levels of palmitoleic acid, oleic acid, and palmitoleic acid to palmitic acid (16:0) ratio were significantly increased in NAFLD across multiple lipid classes. Linoleic acid (8:2n6) was decreased (P < 0.05), with a concomitant increase in γ-linolenic (18:3n6) and dihomo γ-linolenic (20:3n6) acids in both NAFL and NASH (P < 0.001 for most lipid classes). The docosahexanoic acid (22:6 n3) to docosapentenoic acid (22:5n3) ratio was significantly decreased within phosphatidylcholine (PC), and phosphatidylethanolamine (PE) pools, which was most marked in NASH subjects (P < 0.01 for PC and P < 0.001 for PE). The total plasmalogen levels were significantly decreased in NASH compared with controls (P < 0.05). A stepwise increase in lipoxygenase (LOX) metabolites 5(S)-hydroxyeicosatetraenoic acid (5-HETE), 8-HETE, and 15-HETE characterized progression from normal to NAFL to NASH. The level of 11-HETE, a nonenzymatic oxidation product of arachidonic (20:4) acid, was significantly increased in NASH only. Conclusions: Although increased lipogenesis, desaturases, and LOX activities characterize NAFL and NASH, impaired peroxisomal polyunsaturated fatty acid (PUFA) metabolism and nonenzymatic oxidation is associated with progression to NASH.

Previous controlled trials are inconclusive regarding the efficacy of ursodeoxycholic acid (UDCA) for treating primary sclerosing cholangitis (PSC). One hundred fifty adult patients with PSC were enrolled in a long-term, randomized, double-blind controlled trial of highdose UDCA (28-30 mg/kg/day) versus placebo. Liver biopsy and cholangiography were performed before randomization and after 5 years. The primary outcome measures were development of cirrhosis, varices, cholangiocarcinoma, liver transplantation, or death. The study was terminated after 6 years due to futility. At enrollment, the UDCA (n ‫؍‬ 76) and placebo (n ‫؍‬ 74) groups were similar with respect to sex, age, duration of disease, serum aspartate aminotransferase and alkaline phosphatase levels, liver histology, and Mayo risk score. During therapy, aspartate aminotransferase and alkaline phosphatase levels decreased more in the UDCA group than the placebo group (P < 0.01), but improvements in liver tests were not associated with decreased endpoints. By the end of the study, 30 patients in the UDCA group (39%) versus 19 patients in the placebo group (26%) had reached one of the pre-established clinical endpoints. After adjustment for baseline stratification characteristics, the risk of a primary endpoint was 2.3 times greater for patients on UDCA than for those on placebo (P < 0.01) and 2.1 times greater for death, transplantation, or minimal listing criteria (P ‫؍‬ 0.038). Serious adverse events were more common in the UDCA group than the placebo group (63% versus 37% [P < 0.01]). Conclusion: Long-term, high-dose UDCA therapy is associated with improvement in serum liver tests in PSC but does not improve survival and was associated with higher rates of serious adverse events. (HEPATOLOGY 2009;50:808-814.)

The objective of this study was to prospectively define outcomes of cirrhosis due to nonalcoholic steatohepatitis (NASH) and compare them with those associated with hepatitis C virus (HCV) infection. We compared 152 patients with cirrhosis due to NASH with 150 matched patients with cirrhosis due to HCV. Over 10 years, 29/152 patients with cirrhosis due to NASH died compared with 44/150 patients with HCV (P < .04). This was mainly due to the lower mortality rate in patients with Child class A cirrhosis due to NASH versus HCV (3/74 vs. 15/75; P < .004). There were no significant across-group differences in mortality in patients with Child class B or C cirrhosis. Sepsis was the most common cause of death in both groups; patients with NASH had a higher cardiac mortality (8/152 vs. 1/150; P < .03). Patients with Child class A cirrhosis due to NASH also had a significantly lower risk of decompensation, defined by a 2-point increase in Child-Turcotte-Pugh score (P < .007). Cirrhosis due to NASH was associated with a lower rate of development of ascites (14/101 vs. 40/97 patients at risk; P < .006). NASH also had a significantly lower risk of development of hepatocellular carcinoma (10/149 vs. 25/147 patients at risk; P < .01). In conclusion, compensated cirrhosis due to NASH is associated with a lower mortality rate compared with that due to HCV. It is also associated with a lower rate of development of ascites, hyperbilirubinemia, and hepatocellular carcinoma. However, cardiovascular mortality is greater in patients with NASH. (HEPATOLOGY 2006;43:682-689.)

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