Nonalcoholic fatty liver disease: a review of current understanding and future impact

Liver T1ρ MRI measurement in healthy human subjects at 3 T: a preliminary study with a two-dimensional fast-field echo sequence

OBJECTIVES

The aim of this study was to explore the technical feasibility of T(1)ρ MRI for the liver, and to determine the normal range of liver T(1)ρ in healthy subjects at clinical 3 T.

METHODS

There were 15 healthy volunteers. Three representative axial slices were selected to cut through the upper, middle and lower liver. A rotary echo spin-lock pulse was implemented in a two-dimensional fast-field echo sequence. Spin-lock frequency was 500 Hz, and the spin-lock times of 1, 10, 20, 30, 40 and 50 ms were used for T(1)ρ mapping. The images were acquired slice by slice during breath-holding. Regions of interest (ROIs; n=5) were manually placed on each slice of the liver parenchyma region, excluding artefacts and vessels. The mean value of these ROIs (n=15) was regarded as the liver T(1)ρ value for the subject. Six subjects were scanned once at fasting status; six subjects were scanned once 2 h post meal; three subjects were scanned twice at fasting status; and seven subjects were scanned twice 2 h post meal.

RESULTS

When two readers measured the same 10 data sets, the interreader reproducibility (ICC: intraclass correlation coefficient) was 0.955. With the 10 subjects scanned twice, the ICC for scan-rescan reproducibility was 0.764. There was no significant difference for the liver T(1)ρ value at the fasting status (43.08±1.41 ms) and post-meal status (42.97±2.38 ms, p=0.867). Pooling together all the 32 scans in this study, the normal liver T(1)ρ value ranged from 38.6 to 48.3 ms (mean 43.0 ms, median 42.6 ms).

CONCLUSION

It is feasible to obtain consistent liver T(1)ρ measurement for human subjects at 3 T.

A comparison of survival and pathologic features of non-alcoholic steatohepatitis and hepatitis C virus patients with hepatocellular carcinoma

AIM: To compare the clinical outcome and pathologic features of non-alcoholic steatohepatitis (NASH) patients with hepatocellular carcinoma (HCC) and hepatitic C virus (HCV) patients with HCC (another group in which HCC is commonly seen) undergoing liver transplantation.

METHODS: Patients transplanted for HCV and NASH at our institution from January 2000 to April 2011 were analyzed. All explanted liver histology and pre-transplant liver biopsies were examined by two specialist liver histopathologists. Patient demographics, disease free survival, explant liver characteristics and HCC features (tumour number, cumulative tumour size, vascular invasion and differentiation) were compared between HCV and NASH liver transplant recipients.

RESULTS: A total of 102 patients with NASH and 283 patients with HCV were transplanted. The incidence of HCC in NASH transplant recipients was 16.7% (17/102). The incidence of HCC in HCV transplant recipients was 22.6% (64/283). Patients with NASH-HCC were statistically older than HCV-HCC patients (P < 0.001). A significantly higher proportion of HCV-HCC patients had vascular invasion (23.4% vs 6.4%, P = 0.002) and poorly differentiated HCC (4.7% vs 0%, P < 0.001) compared to the NASH-HCC group. A trend of poorer recurrence free survival at 5 years was seen in HCV-HCC patients compared to NASH-HCC who underwent a Liver transplantation (P = 0.11).

CONCLUSION: Patients transplanted for NASH-HCC appear to have less aggressive tumour features compared to those with HCV-HCC, which likely in part accounts for their improved recurrence free survival.

The effectiveness of liraglutide in nonalcoholic fatty liver disease patients with type 2 diabetes mellitus compared to sitagliptin and pioglitazone

Background. Liraglutide leading to improve not only glycaemic control but also liver inflammation in non-alcoholic fatty liver disease (NAFLD) patients. Aims. The aim of this study is to elucidate the effectiveness of liraglutide in NAFLD patients with type 2 diabetes mellitus (T2DM) compared to sitagliptin and pioglitazone. Methods. We retrospectively enrolled 82 Japanese NAFLD patients with T2DM and divided into three groups (liraglutide: N = 26, sitagliptin; N = 36, pioglitazone; N = 20). We compared the baseline characteristics, changes of laboratory data and body weight. Results. At the end of follow-up, ALT, fast blood glucose, and HbA1c level significantly improved among the three groups. AST to platelet ratio significantly decreased in liraglutide group and pioglitazone group. The body weight significantly decreased in liraglutide group (81.8 kg to 78.0 kg, P < 0.01). On the other hands, the body weight significantly increased in pioglitazone group and did not change in sitagliptin group. Multivariate regression analysis indicated that administration of liraglutide as an independent factor of body weight reduction for more than 5% (OR 9.04; 95% CI 1.12–73.1, P = 0.04). Conclusions. Administration of liraglutide improved T2DM but also improvement of liver inflammation, alteration of liver fibrosis, and reduction of body weight.

Liver transplantation in adults: Choosing the appropriate timing

Liver transplantation is indicated in patients with acute liver failure, decompensated cirrhosis, hepatocellular carcinoma and rare liver-based genetic defects that trigger damage of other organs. Early referral to a transplant center is crucial in acute liver failure due to the high mortality with medical therapy and its unpredictable evolution. Referral to a transplant center should be considered when at least one complication of cirrhosis occurs during its natural history. However, because of the shortage of organ donors and the short-term mortality after liver transplantation on one hand and the possibility of managing the complications of cirrhosis with other treatments on the other, patients are carefully selected by the transplant center to ensure that transplantation is indicated and that there are no medical, surgical and psychological contraindications. Patients approved for transplantation are placed on the transplant waiting list and prioritized according to disease severity. Thus, the appropriate timing of transplantation depends on recipient disease severity and, although this is still a matter of debate, also on donor quality. These two variables are known to determine the “transplant benefit” (i.e., when the expected patient survival is better with, than without, transplantation) and should guide donor allocation.

Metabolic syndrome after liver transplantation: Preventable illness or common consequence?

The metabolic syndrome is common after liver transplant being present in approximately half of recipients. It has been associated with adverse outcomes such as progression of hepatitis C and major vascular events. As the United States population ages and the rate of obesity increases, prevention of the metabolic syndrome in the post-transplant population deserves special consideration. Currently, the metabolic syndrome after transplant appears at least two times more common than observed rates in the general population. Specific guidelines for patients after transplant does not exist, therefore prevention rests upon knowledge of risk factors and the presence of modifiable elements. The current article will focus on risk factors for the development of the metabolic syndrome after transplant, will highlight potentially modifiable factors and propose potential areas for intervention. As in the non-transplant population, behavioral choices might have a major role. Opportunities exist in this regard for health prevention studies incorporating lifestyle changes. Other factors such as the need for immunosuppression, and the changing characteristics of wait listed patients are not modifiable, but are important to know in order to identify persons at higher risk. Although immunosuppression after transplant is unavoidable, the contribution of different agents to the development of components of the metabolic syndrome is also discussed. Ultimately, an increased risk of the metabolic syndrome after transplant is likely unavoidable, however, there are many opportunities to reduce the prevalence.

Efficacy of Tumor Necrosis Factor and Interleukin-10 Analysis in the Follow-up of Nonalcoholic Fatty Liver Disease Progression

Tumor necrosis factor (TNF-α) is a cytokine involved in systemic inflammation during acute phase reactions. The current study was designed to investigate the levels of pro-inflammatory cytokine (TNF-α) along with the anti-inflammatory cytokine (IL-10) during progression of non-alcoholic fatty liver disease (NAFLD) from simple steatosis to non-alcoholic steatohepatitis (NASH) and fibrosis in diabetic patients, and correlate the levels of cytokines with the progression of NAFLD. Fifty-two diabetic patients compared to 18 healthy controls were participated in this study. Based on clinical diagnosis, patients were divided into three groups: simple steatosis, NASH and fibrosis. Serum liver function tests, fasting blood glucose, bilirubin, ALT, AST, TNF-α, IL-10 and lipid profile were measured. TNF-α levels were significantly higher in NAFLD patients compared to control subjects with a significant positive correlation with body mass index and fasting blood glucose (FBG) but with negative correlation with IL-10. Serum IL-10 levels were significantly lower in NAFLD patients compared with controls. A positive correlation between IL-10 and HDL-C with concomitant negative correlation between IL-10 and FBG and triacylglycerides was found. Cytokine analyses showed that there was a prominent imbalance between TNF-α and IL-10 in patients with NAFLD, and this imbalance increase by increasing the progression of NAFLD especially in obese diabetic patients. TNF-α and IL-10 could be used in diagnosis and follow-up of NAFLD stages in a way to avoid liver biopsies in greater proportion of patients.

Complications associated with liver transplantation in the obese recipient

The prevalence of the metabolic syndrome with attendant morbid obesity continues to increase nationwide. A concomitant increase in non-alcoholic steatohepatitis (NASH) and associated end-stage liver disease requiring transplantation is expected to parallel this trend. Between January 1, 1997 and December 31, 2008, our center performed 813 solitary adult deceased-donor liver transplants. Patients were divided into groups based on the World Health Organization International Classification of obesity. Patients within each obesity class were compared to normal weight recipients. Preoperative demographics among all groups were similar. NASH was more common in higher BMI groups. Operative time, blood product usage, ICU length of stay, infectious complications, and biliary complications requiring intervention were all higher in obese recipients. Deep venous thrombosis occurred more commonly in patients with Class III obesity. Patients with Class II obesity had lower patient (HR 1.82, CI 1.09-3.01, p=0.02) and allograft survival (HR 1.62, CI 1.02-2.65, p=0.04). Obesity class did not reach statistical significance on multivariate analysis. Despite increased technical operative challenges and medical complexities associated with increasing recipient BMI, morbid obesity in and of itself should not be an absolute contraindication to liver transplantation as these patients have reasonable long-term outcomes.

The lipogenic transcription factor ChREBP dissociates hepatic steatosis from insulin resistance in mice and humans

Nonalcoholic fatty liver disease (NAFLD) is associated with all features of the metabolic syndrome. Although deposition of excess triglycerides within liver cells, a hallmark of NAFLD, is associated with a loss of insulin sensitivity, it is not clear which cellular abnormality arises first. We have explored this in mice overexpressing carbohydrate responsive element-binding protein (ChREBP). On a standard diet, mice overexpressing ChREBP remained insulin sensitive, despite increased expression of genes involved in lipogenesis/fatty acid esterification and resultant hepatic steatosis (simple fatty liver). Lipidomic analysis revealed that the steatosis was associated with increased accumulation of monounsaturated fatty acids (MUFAs). In primary cultures of mouse hepatocytes, ChREBP overexpression induced expression of stearoyl-CoA desaturase 1 (Scd1), the enzyme responsible for the conversion of saturated fatty acids (SFAs) into MUFAs. SFA impairment of insulin-responsive Akt phosphorylation was therefore rescued by the elevation of Scd1 levels upon ChREBP overexpression, whereas pharmacological or shRNA-mediated reduction of Scd1 activity decreased the beneficial effect of ChREBP on Akt phosphorylation. Importantly, ChREBP-overexpressing mice fed a high-fat diet showed normal insulin levels and improved insulin signaling and glucose tolerance compared with controls, despite having greater hepatic steatosis. Finally, ChREBP expression in liver biopsies from patients with nonalcoholic steatohepatitis was increased when steatosis was greater than 50% and decreased in the presence of severe insulin resistance. Together, these results demonstrate that increased ChREBP can dissociate hepatic steatosis from insulin resistance, with beneficial effects on both glucose and lipid metabolism.

MR T1ρ as an imaging biomarker for monitoring liver injury progression and regression: an experimental study in rats with carbon tetrachloride intoxication

OBJECTIVES

Recently it was shown that the magnetic resonance imaging (MRI) T1ρ value increased with the severity of liver fibrosis in rats with bile duct ligation. Using a rat carbon tetrachloride (CCl(4)) liver injury model, this study further investigated the merit of T1ρ relaxation for liver fibrosis evaluation.

METHODS

Male Sprague-Dawley rats received intraperitoneal injection of 2 ml/kg CCl(4) twice weekly for up to 6 weeks. Then CCl(4) was withdrawn and the animals were allowed to recover. Liver T1ρ MRI and conventional T2-weighted images were acquired. Animals underwent MRI at baseline and at 2 days, 2 weeks, 4 weeks and 6 weeks post CCl(4) injection, and they were also examined at 1 week and 4 weeks post CCl(4) withdrawal. Liver histology was also sampled at these time points.

RESULTS

Liver T1ρ values increased slightly, though significantly, on day 2, and then increased further and were highest at week 6 post CCl(4) insults. The relative liver signal intensity change on T2-weighted images followed a different time course compared with that of T1ρ. Liver T1ρ values decreased upon the withdrawal of the CCl(4) insult. Histology confirmed the animals had typical CCl(4) liver injury and fibrosis progression and regression processes.

CONCLUSIONS

MR T1ρ imaging can monitor CCl(4)-induced liver injury and fibrosis.

KEY POINTS

• MR T1ρ is a valuable imaging biomarker for liver injury/fibrosis. • Liver T1ρ was only mildly affected by oedema and acute inflammation. • Liver MR T1ρ decreased when liver fibrosis and injury regressed.

The negative impact of fatty liver on maximum standard uptake value of liver on FDG PET

PURPOSE

The purpose of the study is to evaluate the impact of fatty liver on maximum standard uptake value (SUVmax) of liver on 2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET).

MATERIALS AND METHODS

A total of 173 consecutive healthy subjects were retrospectively recruited for analysis. Subjects with acute renal disease, chronic renal disease, or malignancy were excluded. Demographic data were collected from chart records. All subjects performed whole-body FDG PET, sonography of liver, and glutamic pyruvic transaminase (GPT) level. The SUVmax of liver on FDG PET was calculated. The relationship between the severity of fatty liver and SUVmax of liver on FDG PET was analyzed.

RESULTS

There were significant differences in SUVmax of liver on FDG PET in four groups: no fatty liver, mild-degree, moderate-degree, and severe-degree fatty liver on sonography diagnosis (P=.041). After adjusting for possible covariates age, sex, body mass index, and GPT, there was a significantly negative correlation between the severity of fatty liver and SUVmax of liver on FDG PET (β=-.20, P<.001).

CONCLUSION

Based on the results of this study, the liver cannot be used as a comparator of extrahepatic foci of equivocal increased FDG activity in patients with fatty liver disease.

Growth hormone, dehydroepiandrosterone and adiponectin levels in non-alcoholic steatohepatitis: an endocrine signature for advanced fibrosis in obese patients

BACKGROUND AND AIMS

Liver-related clinical consequences of non-alcoholic fatty liver disease (NAFLD) are seen only in the minority of patients with advanced fibrosis. The aim of our study was to generate insight into a potential endocrine basis of steatohepatitis with advanced fibrosis in NAFLD.

METHODS

Biopsy and blood samples were prospectively collected from patients with medically complicated obesity. Patients were categorized, according to liver histology, into: (i) normal, (ii) simple steatosis (SS), (iii) non-alcoholic steatohepatitis (NASH) with fibrosis stage (FS) 0-1 and (iv) NASH with FS ≥ 2. A broad panel of potential biomarkers included DHEA-S, growth hormone (GH), homeostasis model assessment-insulin resistance (HOMA-IR), leptin, resistin, adiponectin and cytokeratin 18 (CK-18) fragments.

RESULTS

We studied 160 patients (mean BMI 46.8 ± 8.2 kg/m(2) ). Liver biopsies demonstrated normal histology in 10%, SS in 45%, NASH with FS 0-1 in 37.5% and NASH with FS ≥ 2 in 7.5%. C-reactive protein, IL-6, GH, CK-18, adiponectin, HOMA-IR and quantitative insulin sensitivity check index (QUICKI) were significantly associated with NASH in univariate analysis, but overall predictivity of these parameters was low (AUC ROC = 0.62-0.68). In contrast, all patients with NASH with FS ≥ 2 had insulin resistance, as measured by QUICKI, and GH levels <0.45 ng/ml and all but one patient with NASH FS 2-3 had low DHEA levels (<123 μg/dl).

CONCLUSIONS

Low serum levels of GH and DHEA are very common in patients with NASH with more advanced fibrosis. Other biomarkers, including CK-18 fragment levels, have predictivity characteristics that would be of low clinical utility for distinguishing patients with normal histology or SS from those with NASH. These findings demonstrate an endocrine profile associated with advanced fibrosis.

Shear wave dispersion measures liver steatosis

Crawling waves, which are interfering shear wave patterns, can be generated in liver tissue over a range of frequencies. Some important biomechanical properties of the liver can be determined by imaging the crawling waves using Doppler techniques and analyzing the patterns. We report that the dispersion of shear wave velocity and attenuation, that is, the frequency dependence of these parameters, are strongly correlated with the degree of steatosis in a mouse liver model, ex vivo. The results demonstrate the possibility of assessing liver steatosis using noninvasive imaging methods that are compatible with color Doppler scanners and, furthermore, suggest that liver steatosis can be separated from fibrosis by assessing the dispersion or frequency dependence of shear wave propagations.

A multi-ethnic study of a PNPLA3 gene variant and its association with disease severity in non-alcoholic fatty liver disease

The adiponutrin (PNPLA3) rs738409 polymorphism has been found to be associated with susceptibility to non-alcoholic fatty liver disease (NAFLD) in various cohorts. We further investigated the association of this polymorphism with non-alcoholic steatohepatitis (NASH) severity and with histological features of NAFLD. A total of 144 biopsy-proven NAFLD patients and 198 controls were genotyped for PNPLA3 gene polymorphism (rs738409 C>G). The biopsy specimens were histologically graded by a qualified pathologist. We observed an association of G allele with susceptibility to NAFLD in the pooled subjects (OR 2.34, 95% CI 1.69–3.24, p < 0.0001), and following stratification, in each of the three ethnic subgroups, namely Chinese, Indian and Malay (OR 1.94, 95% CI 1.12–3.37, p = 0.018; OR 3.51, 95% CI 1.69–7.26, p = 0.001 and OR 2.05, 95% CI 1.25–3.35, p = 0.005, respectively). The G allele is associated with susceptibility to NASH (OR 2.64, 95% CI 1.85–3.75, p < 0.0001), with NASH severity (OR 1.85, 95% CI 1.05–3.26, p = 0.035) and with presence of fibrosis (OR 1.95, 95% CI 1.17–3.26, p = 0.013) but not with simple steatosis nor with other histological parameters. Although the serum triglyceride level is significantly higher in NAFLD patients compared to controls, the G allele is associated with decreased level of triglycerides (p = 0.029) in the NAFLD patients. Overall, the rs738409 G allele is associated with severity of NASH and occurence of fibrosis in patients with NAFLD.

Caffeine is protective in patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of metabolic syndrome, is the most common cause of primary liver disease. Although recent studies have found that coffee drinking is protective against end stage chronic liver disease, there are scarce caffeine intake data in NAFLD specifically.

AIM

To investigate the effects of dietary behaviour in NAFLD patients, using four continuous cycles of the National Health and Nutrition Examination Surveys (NHANES 2001-2008).

METHODS

Using data from four continuous cycles of NHANES, dietary intake questionnaires that list 62 nutrition components. Logistic regression was used to identify independent predictors of NAFLD among nutrition components after adjustment for potential clinical confounders. All analyses were run using sas 9.1 and SUDAAN 10.0 (SAS Institute Inc., Cary, NC, USA).

RESULTS

Of the 62 nutrient components used for the univariate analysis, 38% were significant (P-value <0.05) in NAFLD with caffeine consumption being higher in the control group (P-value <0.001). The multivariate analysis using demographics, clinical parameters and nutritional components found five factors independently associated with NAFLD [African American Race P-value <0.001); Male gender P-value <0.001); Obesity (BMI ≥ 30) P-value <0.001); Caffeine intake (mg) P-value <0.001) and total plain water consumption (g) P-value ≤ 0.02)].

CONCLUSIONS

Our analysis shows that caffeine intake is independently associated with a lower risk for NAFLD suggesting a potential protective effect. These data necessitate further research to elucidate the mechanism by which caffeine can protect against NAFLD.

Meta-analysis: natural history of non-alcoholic fatty liver disease (NAFLD) and diagnostic accuracy of non-invasive tests for liver disease severity

BACKGROUND. NAFLD ranges from simple steatosis (SS) to non-alcoholic steatohepatitis (NASH). The natural history of NAFLD and the optimal strategy to identify subjects with progressive liver disease are unclear. Objectives. To assess the evidence in: (1) natural history of NAFLD; and (2) non-invasive methods to differentiate NAFLD histological subtypes. DESIGN AND SETTING. Among 4185 articles published on MEDLINE, Cochrane Library, EMBASE, Pubmed, national and International meeting abstracts through July 2010, 40 articles assessing the natural history of NAFLD and 32 articles evaluating the diagnostic accuracy of non-invasive tests against liver biopsy (LB) were included. MEASUREMENTS. Two reviewers retrieved articles and evaluated study quality by appropriate scores. Main outcomes were pooled using random- or fixed-effects models. RESULTS. NAFLD has an increased overall mortality (OR: 1.57, 95% CI: 1.18-2.10), deriving from liver-related and cardiovascular disease, and a 2-fold risk of diabetes. Compared to SS, NASH has a higher liver-related (OR for NASH: 5.71, 2.31-14.13; OR for NASH with advanced fibrosis: 10.06, 4.35-23.25), but not cardiovascular mortality (OR: 0.91, 0.42-1.98). Three non-invasive methods received independent validation: pooled AUROC, sensitivity and specificity of cytokeratin-18 for NASH are 0.82 (0.78-0.88), 0.78 (0.64-0.92), 0.87 (0.77-0.98). For NASH with advanced fibrosis, pooled AUROC, sensitivity and specificity of NAFLD fibrosis score and Fibroscan are 0.85 (0.80-0.93), 0.90 (0.82-0.99), 0.97 (0.94-0.99) and 0.94 (0.90-0.99), 0.94 (0.88-0.99) and 0.95 (0.89-0.99). CONCLUSIONS. NAFLD warrants screening for cardio-metabolic risk and for progressive liver disease. The combination of three noninvasive tests with LB may optimally individuate patients with NASH, with or without advanced fibrosis.

Platelet count for predicting fibrosis in nonalcoholic fatty liver disease

BACKGROUND

The severity of liver fibrosis is known to be a good indicator for surveillance, and for determining the prognosis and optimal treatment of nonalcoholic fatty liver disease (NAFLD). However, it is virtually impossible to carry out liver biopsies in all NAFLD patients. The purpose of this study was to investigate the clinical usefulness of measuring the platelet count for predicting the severity of liver fibrosis in a large retrospective cohort of Japanese patients with NAFLD.

METHODS

A total of 1,048 patients with liver-biopsy-confirmed NAFLD seen between 2002 and 2008 were enrolled from nine hepatology centers in Japan. Laboratory evaluations were performed for all patients.

RESULTS

A linear decrease of the platelet count with increasing histological severity of hepatic fibrosis was revealed. The area under the receiver operating characteristic curve estimating the diagnostic performance of the platelet count for hepatic fibrosis Stage 3 was 0.774 (optimal cutoff value, 19.2 × 10(4)/μl; sensitivity, 62.7%; specificity, 76.3%), and that for Stage 4 was 0.918 (optimal cutoff value, 15.3 × 10(4)/μl; sensitivity, 80.5%; specificity, 88.8%).

CONCLUSIONS

The platelet count may be an ideal biomarker of the severity of fibrosis in NAFLD patients, because it is simple, easy to measure and handle, cost-effective, and accurate for predicting the severity of fibrosis. Furthermore, by using the platelet count cutoff value validated in our multiple large trials, efficient recruitment of NAFLD patients may be facilitated.

Fast food diet mouse: novel small animal model of NASH with ballooning, progressive fibrosis, and high physiological fidelity to the human condition

Although there are small animal platforms that recapitulate some of the histological features of nonalcoholic fatty liver disease, there are no small animal models of nonalcoholic steatohepatitis (NASH) with consistent hepatocellular ballooning and progressive fibrosis that also exhibit fidelity to the human condition physiologically. We examined the metabolic and histological effects of a diet on the basis of the composition of "fast food" (high saturated fats, cholesterol, and fructose). Mice (n = 8 in each group) were assigned to diets as follows: 1) standard chow (SC), i.e., 13% energy as fat [1% saturated fatty acids (SFA)], 2) high fat (HF), i.e., 60% energy as fat (1% SFA), and 3) fast food (FF), i.e., 40% energy as fat (12% SFA, 2% cholesterol). All three diets were supplemented with high fructose. All diets produced obesity. The HF and FF diets produced insulin resistance. Liver histology was normal in animals fed the SC diet. Steatohepatitis with pronounced ballooning and progressive fibrosis (stage 2) was observed in mice fed the FF diet. Although the HF diet produced obesity, insulin resistance, and some steatosis; inflammation was minimal, and there was no increase in fibrosis. The FF diet produced a gene expression signature of increased fibrosis, inflammation, and endoplasmic reticulum stress and lipoapoptosis. A diet based on high cholesterol, high saturated fat, and high fructose recapitulates features of the metabolic syndrome and NASH with progressive fibrosis. This represents a novel small animal model of fibrosing NASH with high fidelity to the human condition. These results highlight the contribution of dietary composition to the development of nonalcoholic fatty liver disease and NASH.

The steatohepatitic variant of hepatocellular carcinoma and its association with underlying steatohepatitis

Steatohepatitis and metabolic syndrome are increasingly recognized as important risk factors for development of hepatocellular carcinoma. We have recently described a histologic subtype of hepatocellular carcinoma termed steatohepatitic hepatocellular carcinoma, which shows features resembling steatohepatitis in the nonneoplastic liver. The present study is undertaken to assess the association between the steatohepatitic hepatocellular carcinoma variant and underlying steatohepatitis and features of metabolic syndrome. We examined all hepatocellular carcinomas diagnosed on resections and explant specimens over a 3.5-year period at our institution. Tumors were classified as either conventional hepatocellular carcinoma or steatohepatitic hepatocellular carcinoma variant based on their predominant histopathologic pattern. The underlying chronic liver disease in each case was determined. The steatohepatitic hepatocellular carcinoma variant represented 13.5% (16/118) of cases. All but one case of steatohepatitic hepatocellular carcinoma occurred in patients with underlying steatohepatitis. Steatohepatitic hepatocellular carcinoma was diagnosed in 35.7% of patients with either nonalcoholic steatohepatitis or alcoholic liver disease compared with 1.3% of patient with other chronic liver diseases (P < .0001). The steatohepatitic hepatocellular carcinoma group had a significantly higher number of metabolic syndrome risk factors (2.44 versus 1.48, P = .01) and a higher percentage of patients with at least 3 metabolic syndrome components (50% versus 22.5%, P = .02). Immunohistochemically, there were diffuse loss of cytoplasmic CK8/18 and increased numbers of activated hepatic stellate cells within steatohepatitic hepatocellular carcinoma, in a pattern identical to that seen in steatohepatitis in nonneoplastic liver. Hepatocellular carcinomas showing a "steatohepatitic" histologic phenotype are strongly associated with underlying steatohepatitis and metabolic syndrome. This association further supports a possible role of steatohepatitis in human hepatocarcinogenesis.

Association of genetic polymorphisms of glutathione-S-transferase genes (GSTT1, GSTM1, and GSTP1) and susceptibility to nonalcoholic fatty liver disease in Zahedan, Southeast Iran

Oxidative damage is thought to play a pivotal role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Glutathione-S-transferases (GSTs) are involved in cell protection against oxidative stress. We examined whether GSTM1, GSTT1, and GSTP1 polymorphisms are associated with NAFLD in a sample of the Iranian population. The current case-control study included 83 patients with NAFLD and 93 healthy subjects. The GSTM1 and GSTT1 polymorphisms were analyzed by multiplex polymerase chain reaction (PCR). The GSTP1 polymorphism was detected by tetra amplification refractory mutation system-PCR assay. The GSTM1-null genotype was significantly associated with the development of NAFLD (odds ratios [OR]=2.171, 95% confidence intervals [CI]=1.188-3.970, p=0.015). The GSTP1 Val allele was shown to be a risk factor for NAFLD (OR=1.739, 95% CI=1.089-2.777, p=0.024). The GSTT1 polymorphism was not significantly different between control and patient groups (p=0.221). This study showed that GSTM1 and GSTP1, but not GSTT1, genetic polymorphisms are associated with NAFLD in a sample of the Iranian population, and may be used to determine the risk of development of NAFLD.

Frequency and outcomes of liver transplantation for nonalcoholic steatohepatitis in the United States

BACKGROUND & AIMS

The relative frequency of nonalcoholic steatohepatitis (NASH) as an indication for liver transplantation and comparative outcomes following transplantation are poorly understood.

METHODS

We analyzed the Scientific Registry of Transplant Recipients for primary adult liver transplant recipients from 2001 to 2009.

RESULTS

From 2001 to 2009, 35,781 patients underwent a primary liver transplant, including 1959 for who NASH was the primary or secondary indication. The percentage of patients undergoing a liver transplant for NASH increased from 1.2% in 2001 to 9.7% in 2009. NASH is now the third most common indication for liver transplantation in the United States. No other indication for liver transplantation increased in frequency during the study period. Compared with other indications for liver transplantation, recipients with NASH are older (58.5±8.0 vs 53.0±8.9 years; P<.001), have a larger body mass index (>30 kg/m2) (63% vs 32%; P<.001), are more likely to be female (47% vs 29%; P<.001), and have a lower frequency of hepatocellular carcinoma (12% vs 19%; P<.001). Survival at 1 and 3 years after liver transplantation for NASH was 84% and 78%, respectively, compared with 87% and 78% for other indications (P=.67). Patient and graft survival for liver recipients with NASH were similar to values for other indications after adjusting for level of creatinine, sex, age, and body mass index.

CONCLUSIONS

NASH is the third most common indication for liver transplantation in the United States and is on a trajectory to become the most common. Outcomes for patients undergoing a liver transplant for NASH are similar to those for other indications.

Implications of worse renal dysfunction and medical comorbidities in patients with NASH undergoing liver transplant evaluation: impact on MELD and more

Increasing numbers of patients with non-alcoholic steatohepatitis (NASH) are referred for liver transplant (LT). Our objective was to characterize patients with NASH among referred LT candidates (from 1998 to 2008), and we compared demographics, etiology of liver disease, diabetes, hypertension, smoking, obesity, cardiac disease, cancer, laboratory data, model for end-stage liver disease (MELD), and outcomes between NASH and non-NASH patients. Patients with NASH (n = 71) were compared to other chronic liver disease (n = 472). Patients with NASH were older (58.7 vs. 52.5 yr, p < 0.0001), Asian (53.5% vs. 34.7%, p = 0.03) and women (50.7% vs. 32.1%, p = 0.003). Patients with NASH had more diabetes, hypertension, obesity, cardiac disease, and smoking history (p < 0.05). Patients with NASH were equally likely to have liver cancer, but more likely to have non-liver cancers (20.8% vs. 4.4%, p = 0.008). There was no difference in MELD, but patients with NASH had lower protime/international normalized ratio (1.14 vs. 1.27, p = 0.04) and higher creatinine (1.26 vs. 0.98 mg/dL, p = 0.0018). Patients with NASH were equally likely to undergo evaluation, listing, and transplantation compared to non-NASH patients. While all patients with chronic liver disease can have renal dysfunction because of hepatorenal syndrome, patients with NASH have more renal dysfunction, perhaps related to diabetes, hypertension, and cardiovascular disease. Transplant centers should consider this carefully in selection of candidates for LT.

Nonalcoholic fatty liver disease: pharmacologic and surgical options

The last decade has seen many studies examining the prevalence and natural history of NAFLD in the United States and it is clear that this disease is likely to be an important cause of liver-related morbidity in the future. Several pharmacologic therapies have shown some promise; currently, vitamin E and insulin-sensitizing agents such as pioglitazone can be considered in appropriate cases. Conservative measures to promote weight loss still have a role to play, but the obesity epidemic in the Western World has reached such proportions that bariatric surgery is proving to be an attractive option for patients with a BMI greater than 35 to 40 kg/m2. Well-designed prospective studies are required to ensure that all of these therapies are safe and effective in the long term. Newer agents will likely be investigated as the pathogenesis of NAFLD and fibrosis progression in NASH are further elucidated.

Obesity, Visceral Fat, and NAFLD: Querying the Role of Adipokines in the Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of clinicopathologic conditions ranging from steatosis alone to nonalcoholic steatohepatitis (NASH), with varying risks for progression to cirrhosis and hepatocellular carcinoma. There is mounting evidence that NAFLD not only complicates obesity, but also perpetuates its metabolic consequences. Critical event that leads to progressive liver injury in NAFLD is unknown. Obesity reflects a generalized proinflammatory state with its increased inflammatory markers like C reactive protein, IL-6, IL-8, IL-10, PAI-1, TNF-α, and hepatocyte growth factor. The elevated production of these adipokines is increasingly considered to be important in the development of diseases linked to obesity and the metabolic syndrome. Disordered cytokine production is likely to play a role in the pathogenesis of NAFLD. There is no effective treatment for NAFLD, though weight loss may halt disease progression and revert histological changes, the underlying mechanism remaining elusive. All stages of the disease pathway from prevention, early identification/diagnosis, and treatment require an understanding of the pathogenesis of liver injury in NAFLD.

Rutin inhibits oleic acid induced lipid accumulation via reducing lipogenesis and oxidative stress in hepatocarcinoma cells

Excessive lipid accumulation within liver has been proposed to cause obesity, hyperlipidemia, diabetes, and fatty liver disease. Rutin, a common dietary flavonoid that is consumed in fruits, vegetables, and plant-derived beverages, has various biological functions, including antioxidant, anti-inflammatory, and anticancer effects. However, a hypolipidemic effect of rutin on fatty liver disease has not been reported. In this study, we examined the effect of rutin on reducing lipid accumulation in hepatic cells. Hepatocytes were treated with oleic acid (OA) containing with or without rutin to observe the lipid accumulation by Nile red stain. The result showed rutin suppressed OA-induced lipid accumulation and increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activity in hepatocytes. The expression of critical molecule involved in lipid synthesis, sterol regulatory element binding proteins-1 (SREBP-1), was attenuated in rutin-treated cells. Moreover, long-term incubation of rutin inhibited the transcriptions of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR), glycerol-3-phosphate acyltransferase (GPAT), fatty acid synthase (FAS), and acetyl-coenzyme carboxylase (ACC). Besides, we also found out the antioxidative effect of rutin by increasing the expression of peroxisome proliferator-activated receptor (PPAR)-α and antioxidative enzymes. Taken together, our findings suggest rutin could attenuate lipid accumulation by decreasing lipogenesis and oxidative stress in hepatocyte.

Patients with NASH and cryptogenic cirrhosis are less likely than those with hepatitis C to receive liver transplants

BACKGROUND & AIMS

Many patients with cryptogenic cirrhosis (CC) have other conditions associated with nonalcoholic steatohepatitis (NASH) that put them at risk for complications that preclude orthotopic liver transplantation (OLT).

METHODS

We followed all patients with NASH and CC who were evaluated for OLT (n = 218) at Baylor Simmons Transplant Institute between March 2002 and May 2008. Data were compared with those from patients evaluated for OLT because of hepatitis C virus (HCV)-associated cirrhosis (n = 646).

RESULTS

Patients with NASH and CC were older, more likely to be female, had a higher body mass index, and a greater prevalence of diabetes and hypertension, compared with patients with HCV-associated cirrhosis, but the 2 groups had similar model for end-stage liver disease (MELD) scores. NASH and CC in patients with MELD scores ≤15 were less likely to progress; these patients were less likely to receive OLT and more likely to die or be taken off the wait list because they were too sick, compared with patients with HCV-associated cirrhosis. The median progression rate among patients with NASH and CC was 1.3 MELD points per year versus 3.2 MELD points per year for the HCV group (P = .003). Among patients with MELD scores >15, there were no differences among groups in percentage that received transplants or rate of MELD score progression. Hepatocellular carcinoma occurred in 2.7% of patients with NASH and CC per year, compared with 4.7% per year among those with HCV-associated cirrhosis.

CONCLUSIONS

Patients with NASH and CC and low MELD scores have slower disease progression than patients with HCV-associated cirrhosis and are less likely to receive OLT.

NAFLD and insulin resistance do not increase the risk of postoperative complications among patients undergoing bariatric surgery--a prospective analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and insulin resistance are common consequences of obesity and are highly prevalent among patients undergoing bariatric surgery. Insulin resistance and NAFLD have been reported to be associated with postoperative complications following major surgery.

METHODS

We prospectively evaluated complications in a cohort of 437 consecutive patients undergoing bariatric surgery. Detailed metabolic profile was obtained prior to surgery, and liver biopsies were taken routinely during surgery.

RESULTS

Mean age was 47.8 years (20-77), and mean body mass index (BMI) was 48.5 kg/m(2) (32-94). Common co-morbid conditions were metabolic syndrome (79%), obstructive sleep apnea (73%), and hypertension (60%). Seventy-seven percent underwent Roux-en-Y gastric bypass, 15% biliopancreatic diversion with duodenal switch, and 8% adjustable gastric banding. The operative approach was laparoscopic in 81% of patients. Liver histology was normal in 22% of patients. Seventy-eight percent of patients had NAFLD. Nonalcoholic steatohepatitis (NASH) was present in 18%. Advanced fibrosis (stage 3-4) was present in 5%. Complications were observed in 25% of the cohort, the most frequent being infection, occurring in 14%. The wound was the most frequent site of infection (9%). There were no cases of postoperative hepatic decompensation. Reoperation was necessary in 7%. In univariate analysis, the factors associated with complications were male gender (p = 0.009), type and approach of surgery (p = 0.023 and p = 0.0001, respectively), BMI (p = 0.000), serum creatinine (p = 0.023), and serum albumin (p = 0.0001). In multivariate analysis, the independent factors associated with complications in bariatric surgery were BMI (OR 1.039, 95% CI 1.010-1.068; p = 0.008), surgical approach (OR 2.696, 95% CI 1.547-4.698; p = 0.000), and serum albumin (OR 0.416, 95% CI 0.176-0.978; p = 0.044). NASH was not predictive of complications.

CONCLUSIONS

Bariatric surgery is a safe and efficient treatment for obesity. The occurrence of NAFLD or NASH without portal hypertension should not preclude the procedure.

[Experimental food-induced fatty liver and its adjuvant therapy with natural bioactive substances]

Changes of redox-homeostasis generate cytokines, and free radicals influence many intracellular signaling pathways in different liver diseases. Liophylised table beet and carrot powder (GPS Powder Kft. 1361/004/2003BFÁÉÉÁ) containing bioactive components such as betaine, betanins, betaxanthins, flavonoids, polyphenols, glutamine, beta carotene, vitamins and folic acid may induce changes in various cellular pathways.

AIM

The aim of this study was to determine the protecting effects of bioactive agents of the liophylised table beet and carrot powder on fatty liver in a "short term" experiment.

METHOD

Male Wistar rats were fed with chow with or without high fat (2% cholesterol, 0.5% cholic acid, 20% sunflower oil) and treated with 0.1 or 1 g/bwkg/day natural product for ten days parallel with the feedings. Cyclooxygenase-2, inducible nitric oxide synthase and tumor necrosis factor-α mRNA levels were determined using molecular biologic methods. Free radicals, H-donating activity, reducing power and free SH-group concentrations were determined by luminometry and spectrophotometry. Mobilized methyl groups were assayed by high pressure liquid chromatography method in liver homogenates.

RESULTS

It was found that the higher dose of the natural product better decreased the induced free radical reactions, cyclooxygenase-2, inducible nitric oxide synthase and tumor necrosis factor-α mRNA-levels both in normal and fatty liver tissues. Although treatments failed to exert significant changes in all global antioxidant parameters, mobilized methyl group concentrations were higher after treatments in fatty liver. Favorable tendencies were also noted in the redox-homeostasis of the fatty liver after treatment.

CONCLUSIONS

As expected, lyophylised table beet and carrot proved to be a "functional food" in rats with alimentary fat induced fatty liver. It cannot be ruled out that this beneficial effect may have clinical relevance.

Early detection of nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease by using MR elastography

PURPOSE

To investigate the diagnostic accuracy (area under the receiver operating characteristic curve [AUROC]) of magnetic resonance (MR) elastography for the early detection of nonalcoholic steatohepatitis (NASH) among patients with nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

An institutional review board-approved and HIPAA-compliant retrospective study was conducted in 58 NAFLD patients. Informed consent was waived by the review board. Hepatic stiffness, relative fat fraction, inflammation grade, and fibrosis stage were assessed from MR elastography, in-phase and out-of-phase gradient-echo imaging, and liver biopsy histopathologic review, respectively. Pairwise t testing, receiver operating characteristic analysis, and partial correlation analysis were performed.

RESULTS

The mean hepatic stiffness for patients with simple steatosis (2.51 kPa) was less (P = .028) than that for patients with inflammation but no fibrosis (3.24 kPa). The mean hepatic stiffness for patients with inflammation but no fibrosis was less (P = .030) than that for patients with hepatic fibrosis (4.16 kPa). Liver stiffness had high accuracy (AUROC = 0.93) for discriminating patients with NASH from those with simple steatosis, with a sensitivity of 94% and a specificity 73% by using a threshold of 2.74 kPa.

CONCLUSION

In patients with NAFLD, hepatic stiffness measurements with MR elastography can help identify individuals with steatohepatitis, even before the onset of fibrosis; NAFLD patients with inflammation but no fibrosis have greater liver stiffness than those with simple steatosis and lower mean stiffness than those with fibrosis.

Early detection of nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease by using MR elastography

PURPOSE

To investigate the diagnostic accuracy (area under the receiver operating characteristic curve [AUROC]) of magnetic resonance (MR) elastography for the early detection of nonalcoholic steatohepatitis (NASH) among patients with nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

An institutional review board-approved and HIPAA-compliant retrospective study was conducted in 58 NAFLD patients. Informed consent was waived by the review board. Hepatic stiffness, relative fat fraction, inflammation grade, and fibrosis stage were assessed from MR elastography, in-phase and out-of-phase gradient-echo imaging, and liver biopsy histopathologic review, respectively. Pairwise t testing, receiver operating characteristic analysis, and partial correlation analysis were performed.

RESULTS

The mean hepatic stiffness for patients with simple steatosis (2.51 kPa) was less (P = .028) than that for patients with inflammation but no fibrosis (3.24 kPa). The mean hepatic stiffness for patients with inflammation but no fibrosis was less (P = .030) than that for patients with hepatic fibrosis (4.16 kPa). Liver stiffness had high accuracy (AUROC = 0.93) for discriminating patients with NASH from those with simple steatosis, with a sensitivity of 94% and a specificity 73% by using a threshold of 2.74 kPa.

CONCLUSION

In patients with NAFLD, hepatic stiffness measurements with MR elastography can help identify individuals with steatohepatitis, even before the onset of fibrosis; NAFLD patients with inflammation but no fibrosis have greater liver stiffness than those with simple steatosis and lower mean stiffness than those with fibrosis.

Hepatic steatosis and hepatitis C: Still unhappy bedfellows?

Hepatic steatosis is commonly seen in patients with chronic hepatitis C virus (HCV) infection, and the prevalence is much higher prevalence than in the general population or in patients with chronic hepatitis B. Hepatic steatosis in patients with chronic hepatitis C can be due to alcohol consumption and host metabolic factors such as high body mass index (BMI), obesity, hyperlipidemia, metabolic syndrome and diabetes mellitus in which insulin resistance plays an important role. However, in genotype 3 HCV infection, hepatic steatosis can result from direct viral cytopathic effect. Demographic and clinical characteristics associated with hepatic steatosis in patients with chronic hepatitis C including older age, higher BMI, more genotype 3 infection, and higher mean serum levels of triglyceride, alanine aminotransferase and γ-glutamyl transpeptidase. The clinical relevance of hepatic steatosis in patients with chronic hepatitis C includes a close correlation with hepatic fibrosis, and a poor response to combination peginterferon and ribavirin treatment. In addition, hepatic steatosis has been reported to associate with increased frequency of hepatocellular carcinoma in patients with chronic HCV infection. Whether life style modification such as weight reduction or adding an insulin resistance reducing agent such as metformin or thiazolidinediones combined with current standard peginterferon plus ribavirin treatment will benefit to the chronic hepatitis C patients with hepatic steatosis deserves further evaluation.

Hepatic gene networks in morbidly obese patients with nonalcoholic fatty liver disease

BACKGROUND

Genetic factors alter the risk for nonalcoholic fatty liver disease (NAFLD). We sought to identify NAFLD-associated genes and elucidate gene networks and pathways involved in the pathogenesis of NAFLD.

METHODS

Quantitative global hepatic gene expression analysis was performed on 53 morbidly obese Caucasian subjects undergoing bariatric surgery (27 with NAFLD and 26 controls). After standardization of data, gene expression profiles were compared between patients with NAFLD and controls. The set of genes that significantly correlated with NAFLD was further analyzed by hierarchical clustering and ingenuity pathways analyses.

RESULTS

There were 25,643 quantitative transcripts, of which 108 were significantly associated with NAFLD (p < 0.001). Canonical pathway analysis in the NAFLD-associated gene clusters showed that the hepatic fibrosis signaling was the most significant pathway in the up-regulated NAFLD gene cluster containing three (COL1A1, IL10, IGFBP3) significantly altered genes, whereas the endoplasmic reticulum stress and protein ubiquitination pathways were the most significant pathways in the down-regulated NAFLD gene cluster, with the first pathway containing one (HSPA5) and the second containing two (HSPA5, USP25) significantly altered genes. The four primary gene networks associated with NAFLD were involved in cell death, immunological disease, cellular movement, and lipid metabolism with several significantly altered "hub" genes in these networks.

CONCLUSIONS

This study reveals the canonical pathways and gene networks associated with NAFLD in morbidly obese Caucasians. The application of gene network analysis highlights the transcriptional relationships among NAFLD-associated genes and allows identification of hub genes that may represent high-priority candidates for NAFLD.

Effects of interventions on intra- and interobserver agreement on interpretation of nonalcoholic fatty liver disease histology

Accurate and reproducible interpretation of nonalcoholic fatty liver disease (NAFLD) histology has significant clinical and research-related implications. We evaluated the impact of 2 interventions ([1] review of illustrative histologic images of NAFLD with the study pathologists; [2] use of a scoring sheet with written diagnostic criteria for different NAFLD phenotypes) on intra- and interobserver agreement on interpretation of NAFLD histology. Before and after the interventions, 2 pathologists twice read 65 liver biopsies done for evaluation of suspected NAFLD. The intra- and interobserver agreement was highest on assessment of steatosis and fibrosis. The interventions significantly improved the intraobserver agreement only on assessment of hepatocellular ballooning. The interobserver agreement was only fair on assessment of lobular inflammation, ballooning, and diagnostic classification and did not improve after the interventions. Methods to improve interobserver agreement on assessment of lobular inflammation and ballooning are needed and would likely increase pathologists' agreement on NAFLD diagnostic classification.

Changes in hepatic gene expression upon oral administration of taurine-conjugated ursodeoxycholic acid in ob/ob mice

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent and associated with considerable morbidities. Unfortunately, there is no currently available drug established to treat NAFLD. It was recently reported that intraperitoneal administration of taurine-conjugated ursodeoxycholic acid (TUDCA) improved hepatic steatosis in ob/ob mice. We hereby examined the effect of oral TUDCA treatment on hepatic steatosis and associated changes in hepatic gene expression in ob/ob mice. We administered TUDCA to ob/ob mice at a dose of 500 mg/kg twice a day by gastric gavage for 3 weeks. Body weight, glucose homeostasis, endoplasmic reticulum (ER) stress, and hepatic gene expression were examined in comparison with control ob/ob mice and normal littermate C57BL/6J mice. Compared to the control ob/ob mice, TUDCA treated ob/ob mice revealed markedly reduced liver fat stained by oil red O (44.2±5.8% vs. 21.1±10.4%, P<0.05), whereas there was no difference in body weight, oral glucose tolerance, insulin sensitivity, and ER stress. Microarray analysis of hepatic gene expression demonstrated that oral TUDCA treatment mainly decreased the expression of genes involved in de novo lipogenesis among the components of lipid homeostasis. At pathway levels, oral TUDCA altered the genes regulating amino acid, carbohydrate, and drug metabolism in addition to lipid metabolism. In summary, oral TUDCA treatment decreased hepatic steatosis in ob/ob mice by cooperative regulation of multiple metabolic pathways, particularly by reducing the expression of genes known to regulate de novo lipogenesis.

Maternal obesity and infant outcomes

Obesity (Body mass index (BMI) above 30) is one of the major health issues of the 21st century. Over 1.1 billion of the world's population are now classified as obese. In the UK, women are more likely to be obese than men; over 50% of women of reproductive age are overweight or obese. Maternal obesity and the plethora of associated conditions, have a serious impact on the health and development of their offspring. In this review we describe the direct and indirect impact of maternal obesity on the health of the baby. Maternal obesity affects conception, duration and outcome of pregnancy. Offspring are at increased risk of both immediate and long term implications for health. We also briefly review potential mechanisms drawing on data from human and animal studies, and on the outcomes of clinical interventional studies.

Maternal high-fat intake predisposes nonalcoholic fatty liver disease in C57BL/6 offspring

OBJECTIVE

This work aimed to verify the hypothesis that maternal intake of high-fat diet in critical periods of pregnancy and/or suckling period predisposes nonalcoholic fatty liver disease in adult C57BL/6 mice offspring.

STUDY DESIGN

Male pups were divided into 5 groups: (1) SC, from standard chow-fed dams; (2) G, from high-fat chow (HF)-fed dams during the gestation (G) period; (3) L, from HF-fed dams during the lactation (L) period; (4) GL, from HF-fed dams during the gestation and lactation (GL) periods; and (5) GL/HF, from HF-fed dams during GL, maintaining an HF diet from postweaning to adulthood. We analyzed body mass, plasma blood, and liver structure.

RESULTS

The G offspring showed insulin resistance and lower glucose transporter-2 expression. Hepatic steatosis was present in the G, L, GL, and mainly in GL/HF offspring. Sterol regulatory element-binding protein-1c expression was higher in G, GL, and GL/HF offspring.

CONCLUSION

Programming by HF chow predisposes hepatic adverse remodeling in the liver of adult offspring.

Sonographic assessment of fatty liver infiltration using the measurement of para- and perirenal fat thickness

PURPOSE

Usefulness of abdominal ultrasonography for quantitative estimation of fatty liver by measurement of para- and perirenal sonographic fat thickness (UFT) was investigated.

METHODS

Study subjects were 286 patients hospitalized for the treatment of diabetes. These subjects underwent blood chemistry studies, abdominal ultrasonography, and CT. On sonography, the thickness of combined para- and perirenal fat was measured between the kidney and the inner aspect of the abdominal musculature. Measurements on both sides were averaged as the UFT. Fatty liver infiltration was graded on a scale of grade 0 to 3: 0, none; 1, mild; 2, moderate; and 3, severe. With abdominal CT, the ratio of CT attenuation value of the liver to that of the spleen (L/S ratio) was measured.

RESULTS

A positive correlation was found between UFT and FL grade or between UFT and L/S ratio (p < 0.0001). Positive correlations were also found between UFT and glutamic pyruvic transaminase (p < 0.05), or cholinesterase (p < 0.0001).

CONCLUSION

Measurement of UFT is a useful method for the quantification of fatty liver as well as for the quantification of visceral fat.

Practical management of the increasing burden of non-alcoholic fatty liver disease

Obesity-induced liver disease (non-alcoholic fatty liver disease (NAFLD)) describes a spectrum from steatosis through steatohepatitis to cirrhosis. Its prevalence is rising in tandem with societal rates of obesity which through consequent insulin resistance and fat deposition in hepatocytes lead to hepatocyte death and attempts at repair, which if persistent, lead to activation of liver fibrogenic cells. NAFLD, which may also progress to primary liver cancer, is now the most common cause of chronic liver disease in affluent countries. There is currently no single accurate diagnostic test besides a liver biopsy. The decision to consider a liver biopsy will be informed by the presence of insulin resistance determined by comparatively easy-to-measure factors together with other putative markers of progression such as hypertension. If a liver biopsy is performed, patients with steatosis with no evidence of inflammation may be less aggressively managed while those with steatohepatitis, since they have a faster trajectory to cirrhosis, should be managed more robustly. Besides lifestyle changes and increased aerobic exercise other strategies include considering referral to centres with ongoing clinical trials. Emerging treatments include α1 adrenoceptors antagonists, angiotensin receptor blockers, glitazones and vitamin E.

Insulin- and leptin-regulated fatty acid uptake plays a key causal role in hepatic steatosis in mice with intact leptin signaling but not in ob/ob or db/db mice

Hepatic steatosis results from several processes. To assess their relative roles, hepatocellular long-chain fatty acid (LCFA) uptake was assayed in hepatocytes from C57BL/6J control mice, mice with steatosis from a high-fat diet (HFD) or 10%, 14%, or 18% ethanol (EtOH) in drinking water [functioning leptin-signaling groups (FLSGs)], and ob/ob and db/db mice. V(max) for uptake was increased vs. controls (P < 0.001) and correlated significantly with liver weight and triglycerides (TGs) in all FLSG mice but was minimally or not increased in ob/ob and db/db mice, in which liver weights and TGs greatly exceeded projections from regressions in FLSG animals. Coefficients of determination (R(2)) for these FLSG regressions suggest that increased LCFA uptake accounts for ∼80% of the increase in hepatic TGs within these groups, but increased lipogenic gene expression data suggest that enhanced LCFA synthesis is the major contributor in ob/ob and db/db. Got2, Cd36, Slc27a2, and Slc27a5 gene expression ratios were significantly upregulated in the EtOH groups, correlating with sterol regulatory element binding protein 1c (SREBP1c) and V(max), but only Cd36 expression was increased in HFD, ob/ob, and db/db mice. Comparison of V(max) with serum insulin and leptin suggests that both hormones contribute to upregulation of uptake in the FLSG animals. Thus, increased LCFA uptake, reflecting SREBP1c-mediated upregulation of four distinct transporters, is the dominant cause of steatosis in EtOH-fed mice. In ob/ob and db/db mice, increased LCFA synthesis appears more important. In FLSG animals, insulin upregulates hepatocellular LCFA uptake. Leptin appears to upregulate LCFA uptake or to be essential for full expression of upregulation by insulin.

Fatty acid metabolism in the liver, measured by positron emission tomography, is increased in obese individuals

BACKGROUND & AIMS

Hepatic lipotoxicity results from and contributes to obesity-related disorders. It is a challenge to study human metabolism of fatty acids (FAs) in the liver. We combined (11)C-palmitate imaging by positron emission tomography (PET) with compartmental modeling to determine rates of hepatic FA uptake, oxidation, and storage, as well as triglyceride release in pigs and human beings.

METHODS

Anesthetized pigs underwent (11)C-palmitate PET imaging during fasting (n = 3) or euglycemic hyperinsulinemia (n = 3). Metabolic products of FAs were measured in arterial, portal, and hepatic venous blood. The imaging methodology then was tested in 15 human subjects (8 obese subjects); plasma (11)C-palmitate kinetic analyses were used to quantify systemic and visceral lipolysis.

RESULTS

In pigs, PET-derived and corresponding measured FA fluxes (FA uptake, esterification, and triglyceride FA release) did not differ and were correlated with each other. In human beings, obese subjects had increased hepatic FA oxidation compared with controls (mean +/- standard error of the mean, 0.16 +/- 0.01 vs 0.08 +/- 0.01 micromol/min/mL; P = .0007); FA uptake and esterification rates did not differ between obese subjects and controls. Liver FA oxidation correlated with plasma insulin levels (r = 0.61, P = .016), adipose tissue (r = 0.58, P = .024), and systemic insulin resistance (r = 0.62, P = .015). Hepatic FA esterification correlated with the systemic release of FA into plasma (r = 0.71, P = .003).

CONCLUSIONS

PET imaging can be used to measure FA metabolism in the liver. By using this technology, we found that obese individuals have increased hepatic oxidation of FA, in the context of adipose tissue insulin resistance, and increased FA flux from visceral fat. FA flux from visceral fat is proportional with the mass of the corresponding depot.

Crucial role of impaired Kupffer cell phagocytosis on the decreased Sonazoid-enhanced echogenicity in a liver of a nonalchoholic steatohepatitis rat model

AIMS

To evaluate the dynamics of Kupffer cell (KC) phagocytosis by performing both in vivo and in vitro studies using Sonazoid (GE Healthcare, Oslo) in a rat nonalcoholic steatohepatitis (NASH) model.

METHODS

Contrast enhanced ultrasonography (CEUS) was performed on a rat NASH model induced by a methionine choline deficient diet (MCDD) and control rats, and Sonazoid was used to measure the signal intensity in the liver parenchyma. The uptake of Sonazoid by the KCs was observed by intravital microscopy. Their phagocytic capability was evaluated in vitro using isolated and cultured KCs. The uptake of fluorescein isothiocyanate (FITC)-labeled latex beads was observed and quantitatively analyzed by flow cytometry.

RESULTS

In the MCDD group, liver parenchymal enhancement was reduced 20 min after the Sonazoid injection. Microscopic observation of the isolated and cultured KCs revealed that the number of phagocytosed Sonazoid microbubbles was significantly decreased. Confocal laser scanning microscopic (CLSM) observation showed a decrease in the uptake of the latex beads. A decreased phagocytic capacity in the MCDD group was suggested by the quantitative analysis using flow cytometry, as well as by intravital microscopy.

CONCLUSIONS

CEUS with Sonazoid is a powerful evaluation tool to diagnose NASH from an early stage of the disease.

Measurement of spleen volume is useful for distinguishing between simple steatosis and early-stage non-alcoholic steatohepatitis

AIM

Although non-alcoholic fatty liver disease (NAFLD) is now a common cause of chronic liver disease, discriminating between simple steatosis and non-alcoholic steatohepatitis (NASH), especially early-stage NASH, remains difficult. We investigated the clinical usefulness of measuring the spleen volume as a marker of early-stage NASH.

METHODS

We evaluated computed tomography (CT) images obtained in 84 patients with histologically diagnosed NAFLD (22 with simple steatosis, 62 with NASH with mild fibrosis [stages 1-2]). We defined the data obtained by the following formula as a spleen-body index (SBI): SBI = maximal CT axial section area of the spleen (cm(2))/body surface area (BSA) (cm(2)) x 10(4). We compared the SBI between patients with simple steatosis and those with NASH with mild fibrosis.

RESULTS

The mean SBI of the simple steatosis group was 15.8 +/- 3.9, while that of the NASH with mild fibrosis group was 18.7 +/- 5.7. This difference between the two groups was significant (P = 0.0314). A multiple logistic regression analysis showed that the SBI was significantly correlated with the discrimination of simple steatosis and NASH with mild fibrosis. The area under the receiver-operator curve was 0.661 for distinguishing between simple steatosis and NASH with mild fibrosis (P = 0.026, 95% confidence interval = 0.532-0.789).

CONCLUSION

Spleen enlargement may be a distinct feature of NASH, especially early-stage NASH. SBI might be a non-invasive and simple method of differentiating NASH and simple steatosis.

Metabolic syndrome and liver transplantation: a review and guide to management

Metabolic syndrome is common among liver transplant recipients before and after transplantation. The components of metabolic syndrome are often exacerbated in the post-transplant period by transplant specific factors, such as immunosuppression, and are strong predictors of patient morbidity and mortality. Many aspects of the metabolic syndrome are modifiable. Early recognition, prevention and treatment of post-transplant hypertension, obesity, dyslipidemia and diabetes may impact long-term post-transplant survival. Further study into the prevention and management of these issues in the transplant patient are needed.

Nonalcoholic fatty liver disease: US-based acoustic radiation force impulse elastography

PURPOSE

To investigate the clinical usefulness of ultrasonography-based acoustic radiation force impulse (ARFI) elastography (ie, ARFI sonoelastography) in patients with a diagnosis of nonalcoholic fatty liver disease (NAFLD) and compare ARFI sonoelastography results with transient sonoelastography and serum fibrosis marker test results.

MATERIALS AND METHODS

Written informed consent was obtained from all subjects, and the local ethics committee approved the study. Fifty-four patients with a liver biopsy-confirmed diagnosis of NAFLD (mean age, 50.6 years +/- 13.7) were examined. All patients with NAFLD and healthy volunteers underwent ARFI sonoelastography, transient sonoelastography, and serum liver fibrosis marker testing (hyaluronic acids, type IV collagen 7 S domain). Ten healthy volunteers underwent ARFI sonoelastography. ARFI sonoelastography results were compared with liver biopsy findings, the reference standard. ARFI sonoelastography findings were compared with liver biopsy, transient sonoelastography, and serum fibrosis marker test results. Student t testing was used for univariate comparisons; Kruskal-Wallis testing, for assessments involving more than two independent groups; and areas under the receiver operating characteristic curve (A(z)), to assess the sensitivity and specificity of ARFI sonoelastography for detection of stage 3 and stage 4 fibrosis.

RESULTS

Median velocities in the patients with NAFLD were 1.040 m/sec for those with stage 0 fibrosis, 1.120 m/sec for those with stage 1, 1.130 m/sec for those with stage 2, 1.780 m/sec for those with stage 3, and 2.180 m/sec for those with stage 4. The A(z) for the diagnosis of hepatic fibrosis stages 3 or higher was 0.973 (optimal cutoff value, 1.77 m/sec; sensitivity, 100%; specificity, 91%), while that for the diagnosis of stage 4 fibrosis was 0.976 (optimal cutoff value, 1.90 m/sec; sensitivity, 100%; specificity, 96%). Significant correlations between median velocity measured by using ARFI sonoelastography and the following parameters were observed: liver stiffness measured with transient sonoelastography (r = 0.75, P < .0001), serum level of hyaluronic acid(r = 0.459, P = .0009), and serum level of type IV collagen 7 S domain (r = 0.445, P = .0015).

CONCLUSION

There is a significant positive correlation between median velocity measured by using ARFI sonoelastography and severity of liver fibrosis in patients with NAFLD. The results of ARFI sonoelastography were similar to those of transient sonoelastography.