Hyperinsulinemia and insulin resistance in non-alcoholic steatohepatitis

Lysosomal acid lipase regulates VLDL synthesis and insulin sensitivity in mice

AIMS/HYPOTHESIS

Lysosomal acid lipase (LAL) hydrolyses cholesteryl esters and triacylglycerols (TG) within lysosomes to mobilise NEFA and cholesterol. Since LAL-deficient (Lal (-/-) ) mice suffer from progressive loss of adipose tissue and severe accumulation of lipids in hepatic lysosomes, we hypothesised that LAL deficiency triggers alternative energy pathway(s).

METHODS

We studied metabolic adaptations in Lal (-/-) mice.

RESULTS

Despite loss of adipose tissue, Lal (-/-) mice show enhanced glucose clearance during insulin and glucose tolerance tests and have increased uptake of [(3)H]2-deoxy-D-glucose into skeletal muscle compared with wild-type mice. In agreement, fasted Lal (-/-) mice exhibit reduced glucose and glycogen levels in skeletal muscle. We observed 84% decreased plasma leptin levels and significantly reduced hepatic ATP, glucose, glycogen and glutamine concentrations in fed Lal (-/-) mice. Markedly reduced hepatic acyl-CoA concentrations decrease the expression of peroxisome proliferator-activated receptor α (PPARα) target genes. However, treatment of Lal (-/-) mice with the PPARα agonist fenofibrate further decreased plasma TG (and hepatic glucose and glycogen) concentrations in Lal (-/-) mice. Depletion of hepatic nuclear factor 4α and forkhead box protein a2 in fasted Lal (-/-) mice might be responsible for reduced expression of microsomal TG transfer protein, defective VLDL synthesis and drastically reduced plasma TG levels.

CONCLUSIONS/INTERPRETATION

Our findings indicate that neither activation nor inactivation of PPARα per se but rather the availability of hepatic acyl-CoA concentrations regulates VLDL synthesis and subsequent metabolic adaptations in Lal (-/-) mice. We conclude that decreased plasma VLDL production enhances glucose uptake into skeletal muscle to compensate for the lack of energy supply.

Increased apolipoprotein A5 expression in human and rat non-alcoholic fatty livers

Apolipoprotein A5 (apoA5) is a potent regulator of triglyceride (TG) metabolism and therefore may contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD), a disease characterised by excessive TG-rich lipid droplets in hepatocytes. To test this hypothesis, we examined the mRNA expression of apoA5 in paediatric NAFLD livers in comparison to healthy controls. According to microarray and quantitative real-time PCR, human NAFLD livers exhibited elevated apoA5 expression compared to healthy controls. The apoA5 expression levels were positively correlated with hepatic TG storage and a marker for lipid droplets (perilipin), but were not correlated with plasma TG levels. These observations were confirmed with a NAFLD rat model. Interestingly, apoA5 expression was not altered in cultured fat-laden HepG2 cells, demonstrating that fat storage does not induce apoA5 in NAFLD livers. Therefore, the correlation between apoA5 and intracellular fat storage is likely explained by the potent effect of apoA5 in promoting intracellular fat storage. Our NAFLD patients and rats had elevated insulin resistance, which may have a role in elevating apoA5 expression in NAFLD livers. Our data support the hypothesis that apoA5 promotes hepatic TG storage and therefore contributes to the pathogenesis of NAFLD, and may represent a potential target for therapeutic intervention.

Recurrence of non-alcoholic steatohepatitis and cryptogenic cirrhosis following orthotopic liver transplantation in the context of the metabolic syndrome

BACKGROUND

Non-alcoholic steatohepatitis (NASH) and cryptogenic cirrhosis (CC) are increasing indications for orthotopic liver transplantation (OLT). The aim of this study is to describe our outcomes and delineate predictors of recurrence of NASH and CC after OLT.

METHODS

This is a retrospective study from 1996 to 2008. Donor and recipient demographics, metabolic profile, insulin and steroid intake, immunosuppression regimen, operative factors, outcomes, and pathologies were reviewed. Fisher's exact test, Cox regression models, and Kaplan-Meier plots were used.

RESULTS

A total of 83 patients were included. Recurrence occurred in 20 patients. Thirty-four percent of the patients with metabolic syndrome (MS) had recurrence of NASH or CC compared with 13% of the patients without MS (p = 0.05). Recurrence also occurred in 32% of the patients with hypertension (HTN) vs. 12% in those without HTN (p = 0.05). Thirty-seven percent of those on insulin had recurrence vs. 6% of those not on insulin (p = 0.05). Five-yr survival probability for patients with MS, HTN, and insulin use was 52%, 61%, and 58%, respectively.

CONCLUSIONS

Higher recurrence of NASH and CC was associated with presence of MS, HTN and insulin use. Recurrence should be further evaluated in larger studies, with special emphasis on management of MS and prevention strategies.

Outcomes of liver transplantation in patients with cirrhosis due to nonalcoholic steatohepatitis versus patients with cirrhosis due to alcoholic liver disease

Nonalcoholic steatohepatitis (NASH) is becoming a common cause of liver cirrhosis requiring liver transplantation (LT). Cardiovascular complications related to metabolic syndrome and NASH recurrence in the transplanted liver may affect the outcome of LT in these patients. We compared the outcomes of LT for NASH cirrhosis and alcoholic cirrhosis (ETOH) in a large transplant center. A retrospective chart review was performed for all patients who underwent LT for cryptogenic cirrhosis with the NASH phenotype (the NASH group) or ETOH (the ETOH group) at the University of Miami from January 1997 to January 2007. There was no significant difference in survival between the NASH and ETOH groups, despite a trend toward lower survival in the former (P = 0.1699). Sepsis was the leading cause of posttransplant death in both groups, and it was followed by cardiovascular causes in the NASH group (26% versus 7% in the ETOH group, P = 0.21) and malignancies in the ETOH group (29% versus 0% in the NASH group, P = 0.024). Recurrent steatohepatitis (33% versus 0%, P < 0.0001) and acute rejection (41% versus 23%, P < 0.023) were significantly more frequent in the NASH group than in the ETOH group. There was no difference in graft failure between the groups (24% in the NASH group versus 18% in the ETOH group, P = 0.3973). In conclusion, despite a numerical trend favoring the ETOH group, there were no statistically significant differences in posttransplant survival and cardiovascular mortality between the NASH and ETOH groups. Acute rejection and recurrent steatohepatitis were significantly more frequent in the NASH group but did not lead to higher rates of retransplantation.

Non-alcoholic fatty liver disease: a brief review

The term 'non-alcoholic fatty liver disease' (NAFLD) includes cases with steatosis alone and those with non-alcoholic steatohepatitis (NASH). Usually there are no signs or symptoms, sometimes fatigue or pain, and apart from hepatomegaly the condition is revealed by abnormal liver biochemistry or by abdominal ultrasound. Most cases are associated with overweight or diabetes. Liver enzymes are usually elevated, especially GGT, ASAT and ALAT. Other conditions, including alcohol abuse and autoimmune hepatitis, have to be excluded. The diagnosis of steatosis can be made with ultrasound or CT scan. A liver biopsy is often needed to exclude other disease and to assess inflammation and fibrosis. Cirrhosis can develop. NAFLD is usually caused by two 'hits': the 'first hit' is peripheral insulin resistance, causing steatosis. The 'second hit' is caused by reactive oxygen species, inducing vicious cycles leading to inflammation. Weight loss, metformin or thiazolidinediones can improve NAFLD by increasing insulin sensitivity. Radical scavengers such as vitamin E, betaine and perhaps also urodeoxycholic acid may improve the hepatitis component. Further studies on treatment are needed.

Hepatic gene expression in histologically progressive nonalcoholic steatohepatitis

Although the molecular basis for the pathophysiology of nonalcoholic steatohepatitis (NASH) is poorly understood, insulin resistance and mitochondrial dysfunction are physiologic hallmarks of this condition. We sought evidence of a transcriptional or pretranscriptional basis for insulin resistance and mitochondrial dysfunction through measurement of hepatic gene expression (messenger RNA [mRNA]) using high-density synthetic oligonucleotide microarray analysis (Hu6800 GeneChip, Affymetrix, CA). Global hepatic gene expression was determined in snap-frozen liver biopsy specimens from 4 groups: (1) patients with cirrhotic-stage NASH (n = 6), (2) patients with cirrhosis caused by hepatitis C virus (HCV) (n = 6), (3) patients with cirrhosis secondary to primary biliary cirrhosis (PBC) (n = 6), and (4) healthy controls (n = 6). Genes were considered to be expressed differentially in NASH only if there was a greater than 2-fold difference in abundance of mRNA when compared with each of the control groups. Sixteen genes were uniquely differentially expressed (4 overexpressed and 12 underexpressed) in patients with cirrhotic-stage NASH. Genes that were significantly underexpressed included genes important for maintaining mitochondrial function (copper/zinc superoxide dismutase, aldehyde oxidase, and catalase). Glucose 6-phospatase, alcohol dehydrogenase, elongation factor-TU, methylglutaryl coenzyme A (CoA), acyl CoA synthetase, oxoacyl CoA thiolase, and ubiquitin also were underexpressed in NASH. Genes that were overexpressed in NASH included complement component C3 and hepatocyte-derived fibrinogen-related protein, potentially contributing to impaired insulin sensitivity. In conclusion, these studies provide evidence for a transcriptional or pretranscriptional basis for impaired mitochondrial function (attenuated capacity for the dismutation of reactive oxygen species) and diminished insulin sensitivity (increased acute phase reactants) in patients with histologically progressive NASH. Further studies are required to determine the mechanism and the physiologic significance of these findings.

Nonalcoholic steatohepatitis in children

Nonalcoholic steatohepatitis (NASH) is one entity in a spectrum of chronic liver disease related to obesity, hyperinsulinemia, insulin resistance, and liver cell injury from free fatty acid toxicity or other oxidant stress. The more inclusive term "nonalcoholic fatty liver disease" (NAFLD) is increasingly being used to encompass the entire spectrum, which includes simple hepatic steatosis without inflammation (which may not lead to progressive liver injury), NASH itself, and the resulting cirrhosis (which may be devoid of steatosis). Children get NAFLD, and the incidence of this pediatric liver disease is rising as childhood obesity becomes increasingly prevalent. Although much remains to be learned about pediatric NAFLD, it is already evident that children with NASH risk progressive liver damage, including cirrhosis. Liver biopsy is required for definitive diagnosis, and other causes of fatty liver in childhood must be excluded. Gradual weight loss through increased regular exercise and a low-fat, low-refined carbohydrate diet appears to be effective. Drug treatments are being developed. Pediatric NASH is a serious complication of childhood obesity.

Interim results of a pilot study demonstrating the early effects of the PPAR-gamma ligand rosiglitazone on insulin sensitivity, aminotransferases, hepatic steatosis and body weight in patients with non-alcoholic steatohepatitis

BACKGROUND/AIMS

Hyperinsulinemia may cause hepatic steatosis and non-alcoholic steatohepatitis (NASH). The aims of this pilot study were to examine the safety of using the insulin-sensitizing peroxisomal proliferator activated receptor (PPAR) gamma ligand rosiglitazone in patients with NASH and determine whether improved insulin sensitivity correlates with improved fatty liver.

METHODS

Thirty subjects with NASH and elevated alanine aminotransferase (ALT) levels received rosiglitazone, 4 mg twice daily for 48 weeks; the preliminary results presented here were obtained at 24 weeks. Insulin sensitivity was measured using fasting insulin and glucose levels and liver fat content was estimated by CT imaging.

RESULTS

By 24 weeks, rosiglitazone improved insulin sensitivity and reduced liver fat content. The mean ALT decreased from 86 to 37 U/l (P<0.01). Four subjects (13%) withdrew, one because of a rise in ALT from 59 to 277 U/l that coincided with concomitant prednisone use. Subjects experienced a mean weight gain of 3.5% and hemoglobin drop of 1.1 g/dl.

CONCLUSIONS

Treatment of NASH with rosiglitazone for 24 weeks improved insulin sensitivity, reduced liver fat content and improved biochemical evidence of hepatocellular injury. These preliminary data provide evidence that hyperinsulinemia may be a cause of NASH. Strategies to improve insulin sensitivity as a treatment of NASH deserve further investigation.

Interaction of iron, insulin resistance, and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) has emerged as a ubiquitous liver disorder with occasional serious overtones. Although diabetes and obesity were initially held culpable, insulin resistance (IR) is now considered the fundamental operative mechanism. IR is probably the "first step" in nonalcoholic steatohepatitis (NASH). Oxidative stress may be the elusive "second" of possibly multiple steps in the progression of steatosis to fibrosing steatohepatitis. Because hepatic iron promotes oxidative stress, it was mooted as a contributory cofactor in NASH. This proposal was strengthened by an association with hepatic fibrosis. Subsequent studies have shown neither a significant increase in hepatic iron nor an association between hepatic iron and any of the histologic determinants in NASH. Likewise, the increased prevalence of hemochromatosis gene (HFE) mutations in some studies appears to be largely irrelevant to the development of hepatic fibrosis. Excess hepatic iron may occur in insulin resistance-associated iron overload (IRHIO), characterized by hyperferritinemia with normal to mild increases in transferrin saturation. Although patients with IRHIO have a high prevalence of IR-related metabolic disorders, the relationship of IRHIO to NASH is unclear. A recent study showed improvement in insulin sensitivity with the use of venesection in patients with NAFLD, but this approach cannot be implemented without extensive review.

Concurrence of histologic features of steatohepatitis with other forms of chronic liver disease

Steatohepatitis, of either alcoholic or nonalcoholic etiologies, is ultimately diagnosed by clinical-pathologic correlation and is characterized histologically by lesions that differ from the portal-based chronic inflammation and fibrosis of most other forms of chronic liver disease. With the increasing prevalence of steatohepatitis in our society, it is likely that some patients will have coexistent clinical and/or histopathologic findings of steatohepatitis concurrently with another form of liver disease. The aim of this study was to document clinical and histologic findings in biopsies in an academic referral center. Ninety-three non-allograft liver biopsies with lesions of both steatohepatitis and another liver disease were retrospectively identified in 85 patients. The finding of coexisting disease represented 5.5% of all hepatitis C biopsies and 4.0% of other forms of chronic liver disease in the 34 month time period. Clinical chart review of patients with concurrent disease showed the following: Group 1, patients with hepatitis C (n = 54); Group 2, patients with hepatitis C and prior or current history of more than 80 g/d alcohol consumption (n = 20); Group 3, patients with other forms of chronic liver disease (n = 11). Groups 1 and 3 had <10 g/d alcohol use. Obesity (body mass index >30) was noted in 75%, 60%, and 33% respectively, while 94%, 87% and 100% of patients were considered overweight (body mass index > or = 25). Diabetes was reported in 35%, 25%, and 9%. The concurrence of clinical and histologic features of steatohepatitis with another chronic liver disease may be a reflection of the frequency of steatohepatitis in the population at large.

Glucose intolerance and serum aminotransferase activities in Japanese men

BACKGROUND/AIMS

Elevated activities of serum aminotransferase are commonly observed in patients with diabetes mellitus. Few studies have addressed the relation between glucose intolerance and serum activities of aminotransferase in free-living populations.

METHODS

Using a 75 g oral glucose tolerance test, we examined the association of impaired fasting glycemia (IFG), impaired glucose tolerance (IGT), and type 2 diabetes mellitus with serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) among 4621 men aged 49-59 years of the Japan Self-Defense Forces. Statistical adjustment was made for body mass index, waist-hip ratio, and other possible confounding factors.

RESULTS

Proportions of an elevated ALT (>50 IU/l) in men with normal glucose tolerance, IFG, IGT, and newly diagnosed diabetes mellitus were 3.5%, 9.5%, 7.7%, and 18.0%, respectively. Adjusted odds ratios of an elevated ALT for IFG, IGT, and newly diagnosed diabetes mellitus were 2.2 (95% confidence interval 1.1-4.3), 1.7 (1.2-2.4), and 4.4 (3.0-6.6), respectively. IGT and diabetes mellitus were also significantly positively associated with elevated AST (>40 IU/l) and GGT (>50 IU/l).

CONCLUSIONS

Glucose intolerance is associated with elevated serum aminotransferase independent of obesity, but even a mildly elevated ALT is relatively uncommon in free-living men with glucose intolerance.

Steatohepatitis in children

Steatohepatitis in children occurs in the childhood version of non-alcoholic fatty liver disease (NAFLD), as a result of hepatotoxicity and with certain genetic/metabolic diseases. Until recently, NAFLD was considered to be rare in children. It is now recognized as an important childhood liver disease, especially because childhood obesity is much more common. Children with NAFLD may present as young as 4 years old; males tend to predominate; fibrosis is often found on liver biopsy and cirrhosis has been reported. Treatment for childhood NAFLD currently consists of weight reduction plus regular aerobic exercise; vitamin E may be an effective adjunctive therapy. Drug hepatotoxicity and genetic/metabolic diseases that can cause fatty liver, such as Wilson's disease and cystic fibrosis, must be excluded since treatment is radically different. Other causes of chronic hepatitis, such as chronic viral hepatitis, must also be excluded. Multisystemic inherited diseases with hyperinsulinaemia plus insulin resistance may have NAFLD as hepatic involvement and should be identified.

Fasting insulin and uric acid levels but not indices of iron metabolism are independent predictors of non-alcoholic fatty liver disease. A case-control study

BACKGROUND

Non-alcoholic fatty liver disease is a common reason for hepatological consultation and may herald severe hepatic and extra-hepatic disease. The aetiopathogenesis of this condition is an area of increasing interest.

AIM

To evaluate anthropometric and biochemical factors associated to non-alcoholic fatty liver disease in a case-control study. Methods. Demographic and biochemical data of 60 consecutive patients with bright liver absent-to-low alcohol consumption, no evidence of viral, genetic and autoimmune diseases, were compared to those of 60 age- and gender-matched historical controls without fatty liver by univariate and multiple logistic regression analysis.

RESULTS

Patients were more often hypertriglyceridaemic, obese and diabetic than controls (p<.01). Mean values of alanine transaminase, gammaglutamyltranspeptidase, triglycerides, uric acid, fasting and log insulin, transferrin percent saturation and ferritin were significantly higher in the patients, while transferrin and quantitative insulin sensitivity check index, a quantitative insulin sensitivity index, were lower. No iron storage was found in those who underwent liver biopsy At univariate analysis the relative risk for non-alcoholic fatty liver disease significantly increased (p<0. 05) with increasing body mass index, fasting insulin, alanine transaminase, uric acid, triglycerides and gammaglutamyltranspeptidase; it decreased with increasing transferrin and quantitative insulin sensitivity check index. Multiple logistic regression analysis disclosed only fasting insulin and uric acid to be independent predictors of non-alcoholic fatty liver disease (p<0.05).

CONCLUSIONS

Fasting insulin and serum uric acid levels indicating insulin resistance, but not indices of iron overload, are independent predictors of non-alcoholic fatty liver disease.

Non-alcoholic steatohepatitis: clinical significance and pathogenesis

Non-alcoholic steatohepatitis (NASH) is a form of liver disease resembling alcoholic liver disease in a patient who does not consume significant amounts of alcohol. Since its first description in 1980 it has been recognized with increasing frequency. The natural course is relatively benign, but liver cirrhosis. together with all its sequelae, may develop; sometimes liver transplantation is indicated. NASH should probably be regarded as a two-stage acquired metabolic disorder consisting of the development of the insulin resistance syndrome in a patient with pre-existing metabolic abnormalities. The insulin resistance syndrome may well be the most important metabolic abnormality giving rise to hepatic steatosis. The preexisting metabolic abnormalities can be diverse, and may well be multifactorial and/or polymorphogenetic. A steatotic liver may be more susceptible to the deleterious effects of the pre-existing metabolic abnormalities. Pre-existing metabolic abnormalities of particular interest are increased hepatic iron storage and derangements of lipoprotein metabolism. While awaiting the complete resolution of the pathogenesis, current treatment is largely conservative. Every patient should be encouraged to lose weight and to avoid alcohol and other hepatotoxins. In addition, diabetes, lipid abnormalities and increased iron stores should be looked for.

Evolving pathophysiologic concepts in nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is increasingly recognized as a relatively prevalent disorder (ie, occurring in 3% of adults) that may progress to cirrhosis in 15% to 40% of those who are afflicted. NASH is a subset of a broader diagnostic category, nonalcoholic fatty liver disease, a term applied to a condition involving the presence of excess fat in the liver with or without inflammation and cellular injury. A diagnosis of NASH is established by the presence of morphologic changes on liver biopsy similar to those seen in alcoholic hepatitis, including hepatocellular fat accumulation, evidence of lobular inflammation and cell injury, and in some cases, progressive fibrosis. Obesity and type 2 diabetes, two conditions associated with insulin resistance, are major risk factors for the development of NASH. Accumulating evidence suggests that the hyperinsulinemia associated with insulin resistance may be important in the pathogenesis of NASH. Clinical trials will now determine whether treatment of insulin resistance is an effective therapy for NASH.

NASH and insulin resistance: Insulin hypersecretion and specific association with the insulin resistance syndrome

Nonalcoholic steatohepatitis (NASH) is often linked with disorders that are clearly associated with insulin resistance (IR): obesity, type 2 diabetes mellitus, and hypertriglyceridemia. We tested the hypotheses that (1) IR is an essential requirement for the development of NASH and (2) a high association between IR and liver disease is relatively specific for NASH. We measured body mass index (BMI), waist/hip ratio, and fasting serum lipid, insulin, C-peptide, and glucose levels in 66 patients with NASH (21 with advanced fibrosis and 45 with mild fibrosis). IR was determined by the homeostasis model assessment (HOMA). We also determined the strength of the association of NASH with insulin resistance syndrome (IRS) as defined by World Health Organization criteria. To assess whether the finding of IR was relatively specific to NASH rather than simply to obesity or liver disease, we compared the results of a subset of 36 patients with less-severe NASH with 36 age- and sex-matched patients with chronic hepatitis C virus (HCV) of comparable fibrotic severity. IR was confirmed in 65 patients (98%) with NASH, and 55 (87%) fulfilled minimum criteria for IRS. IR was found in lean as well as in overweight and obese patients. The IR values and the prevalence of IRS (75% vs. 8.3%) were significantly higher in those with NASH than in comparable cases of HCV. Hyperinsulinemia was attributable to increased insulin secretion rather than decreased hepatic extraction. In conclusion, most patients with NASH have IRS, and there is a near-universal association between NASH and IR irrespective of obesity. IR is present in mild as well as advanced cases of NASH but is unusual in chronic HCV of similar fibrotic severity.

Recurrent and de novo non-alcoholic steatohepatitis following orthotopic liver transplantation

BACKGROUND

Non-alcoholic steatohepatitis was coined in 1980 to describe pathological and clinical features of non-alcoholic disease associated with pathological features, commonly seen in alcoholic-liver disease itself. It is now a well-recognised cause of end-stage liver disease and a rare cause of orthotopic liver transplantation. A small number of cases with recurrent non-alcoholic steatohepatitis following liver transplantation have been reported, however de novo non-alcoholic steatohepatitis in the liver allograft is not well recognised.

AIMS/RESULTS

We report four cases of non-alcoholic steatohepatitis following orthotopic liver transplantation describing the factors related with the pathology. The recurrence of fatty infiltration occurred within 21 months and transition from mild steatosis to non-alcoholic steatohepatitis and early fibrosis was observed within 60 months post transplant in all four patients. All four cases had association with one or multiples risk factors (obesity, type 2 diabetes and/or hyperlipidemia).

CONCLUSIONS

Management of this risk factors may play a therapeutic role in the prevention of recurrent and de novo non-alcoholic steatohepatitis following orthotopic liver transplantation.

Nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a condition characterized by hepatomegaly, elevated serum aminotransferase levels, and a histologic picture similar to alcoholic hepatitis in the absence of alcohol abuse. Most patients with NASH are obese women, and many have diabetes mellitus, hypercholesterolemia, or hypertriglyceridemia. NASH has also been associated with a number of metabolic conditions, surgical procedures, and drug treatments. Most patients are asymptomatic. The most common sign of NASH is hepatomegaly. Stigmata of chronic liver disease are rare. Laboratory abnormalities include a 2-4-fold elevation of serum aminotransferase levels; other liver function test results are usually normal. Histologically, there is moderate to severe macrovesicular steatosis and lobular hepatitis with necrosis or ballooning degeneration and/or fibrosis. The pathogenesis of NASH is poorly understood, but lipid peroxidation and oxidative stress are the leading culprits. The natural history of NASH is unknown, but NASH seems to be a stable disease in most patients. Treatment of NASH is unproven, but weight reduction is recommended in obese patients. Small pilot studies of several drugs have shown promise, but large randomized clinical trials are awaited. Orthotopic liver transplantation is the treatment of choice for end-stage liver disease secondary to NASH.

Development of nonalcoholic fatty liver disease after orthotopic liver transplantation for cryptogenic cirrhosis

Many subjects with cryptogenic cirrhosis have underlying nonalcoholic steatohepatitis (NASH). The natural history of NASH-related cryptogenic cirrhosis after orthotopic liver transplantation (OLT) is not well defined. A primarily retrospective study of patients with the clinical histological phenotype of NASH-related cirrhosis undergoing OLT was performed. Data were compared with 2 sets of age- and weight-matched controls with (1) primary biliary cirrhosis or primary sclerosing cholangitis or (2) alcoholic liver disease. After OLT, all patients were managed by a standard immunosuppressive protocol. Liver biopsies were performed at 6 and 12 months after OLT and at 1- to 2-year intervals thereafter, as well as when liver enzyme levels were elevated enough to warrant diagnostic biopsy. Twenty-seven subjects with cryptogenic cirrhosis and a clinical histological phenotype of NASH and 3 patients with a long-standing diagnosis of NASH before OLT were included. The 30-day perioperative mortality was 1 in 30 patients. During a median follow-up of 3.5 +/- 2.7 years, 2 additional patients died of sepsis. There was a time-dependent increase in the risk for allograft steatosis that approached 100% by 5 years compared with only an approximately 25% incidence of steatosis in the control groups (P <.009, log-rank test). On multivariate analysis, only the cumulative steroid dose correlated with time to development of allograft steatosis. Three patients developed histological progression from hepatic steatosis to steatohepatitis. Of these, 1 patient developed progressive fibrosis. Four patients experienced at least 1 episode of acute cellular rejection; however, no patient developed chronic rejection or graft failure. In conclusion, nonalcoholic fatty liver disease occurs frequently after OLT in patients with the phenotype of NASH-related cirrhosis. Despite the frequent histological recurrence of disease, clinical outcomes are similar to those of other groups of patients undergoing OLT.

Nonalcoholic steatohepatitis. Mayo Clin Proc. 2000;75:733-739. [PMID: 10907390 DOI: 10.1016/s0025-6196(11)64621-1]

Nonalcoholic steatohepatitis (NASH) is a liver disease that, until recently, has been underrecognized as a common cause of elevated liver enzymes. This distinct clinical entity is characterized by liver biopsy findings similar to those seen in alcoholic hepatitis but in the absence of alcohol consumption sufficient to cause such changes. Patients with NASH are often middle-aged and obese, with coexisting diabetes or hyperlipidemia, but NASH also occurs in younger lean, otherwise healthy individuals and even in children. Although NASH is generally a benign disorder, it may be progressive, leading to cirrhosis and complications of portal hypertension. Liver biopsy remains the gold standard for diagnosis. Therapy for NASH remains poorly defined, although weight reduction and ursodeoxycholic acid may have a beneficial effect.

Nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a liver disease that, until recently, has been underrecognized as a common cause of elevated liver enzymes. This distinct clinical entity is characterized by liver biopsy findings similar to those seen in alcoholic hepatitis but in the absence of alcohol consumption sufficient to cause such changes. Patients with NASH are often middle-aged and obese, with coexisting diabetes or hyperlipidemia, but NASH also occurs in younger lean, otherwise healthy individuals and even in children. Although NASH is generally a benign disorder, it may be progressive, leading to cirrhosis and complications of portal hypertension. Liver biopsy remains the gold standard for diagnosis. Therapy for NASH remains poorly defined, although weight reduction and ursodeoxycholic acid may have a beneficial effect.