Diagnosis and therapy of nonalcoholic steatohepatitis

Significance of oral glucose tolerance tests in non-alcoholic fatty liver disease patients with a fasting plasma glucose level of <126 mg/dL and HbA1c level of ≤ 6.4% in Japan

OBJECTIVE

The aim of this study was to clarify the indications for oral glucose tolerance tests (OGTT) in non-alcoholic fatty liver disease (NAFLD) subjects with a HbA1c level of ≤6.4%, fasting plasma glucose (FPG) level of <126 mg/dL and no history of diabetes.

PATIENTS

A total of 569 NAFLD subjects underwent 75-g OGTT. The plasma glucose and insulin levels were analyzed periodically for three hours during the OGTT examinations. Impaired fasting glucose (IFG) was defined as a plasma glucose level of ≥100 mg/dL to <126 mg/dL. Diabetes was defined as a two-hour post-load plasma glucose level of ≥200 mg/dL. Elevated insulin resistance was defined as a homeostasis model assessment-insulin resistance (HOMA-IR) of ≥2.5. Insulin secretory insufficiency was defined as an insulinogenic index of <0.4.

RESULTS

The prevalence of diabetes on the OGTT was 7.7% (44/569) among the NAFLD patients with an HbA1c level of ≤6.4%, FPG level of <126 mg/dL and no history of diabetes. A multivariate analysis showed that diabetes occurred more frequently when the subjects had IFG [odds ratio (OR) 5.13; 95% confidential interval (CI) 3.01-8.76; p<0.001] and an HbA1c level of 5.7-6.4% (OR 5.45; 95% CI 3.33-8.93; p<0.001). Of the NAFLD subjects with both IFG and an HbA1c level of 5.7-6.4%, 22.8% (28/123) exhibited a pattern of diabetes on OGTT. Regarding insulin dynamics, among the NAFLD subjects with both IFG and an HbA1c level of 5.7-6.4%, 25.2% (31/123) had elevated IR alone, 25.2% (31/123) had insulin secretory deficiency alone and 27.6% (34/123) had both elevated insulin resistance and insulin secretory deficiency.

CONCLUSION

NAFLD subjects with IFG and an HbA1c level of 5.7-6.4% should undergo OGTT in order to determine whether they have diabetes and/or abnormal insulin dynamics.

Prevalence analysis of de novo hepatic steatosis following pylorus-preserving pancreaticoduodenectomy

BACKGROUND

Prevalence of hepatic steatosis following pylorus-preserving pancreaticoduodenectomy (PPPD) is high. This study intended to reveal the prevalence and patterns of de novo hepatic steatosis following PPPD.

METHODS

We investigated postoperative de novo hepatic steatosis following PPPD (n = 101) with a control group of bile duct resection (BDR) (n = 54).

RESULTS

At postoperative 1 year, hepatic steatosis occurred in 21 of 82 patients (25.6%) of PPPD group and in 2 of 47 patients (4.3%) of BDR group (p = 0.001). Thereafter, at 2 to 5 years, a high prevalence of hepatic steatosis persisted in the PPPD group, but no further occurrence developed in BDR group. Once steatosis developed, it persisted until the end of the study period or patient death. Five-year cumulative incidence of hepatic steatosis was 26.7% in the PPPD group and 3.7% in BDR group (p < 0.001). Univariate analyses showed that patient sex, age, body mass index, blood lipid profile, recurrence of tumor, and diabetes did not have significant influence on the development of hepatic steatosis following PPPD.

CONCLUSIONS

De novo hepatic steatosis may develop in a not negligible proportion of patients undergone PPPD. Multicenter studies with a high number of patients are needed to elucidate its pathogenesis and to find effective treatment for pancreaticoduodenectomy-associated hepatic steatosis.

Circulating extracellular vesicles with specific proteome and liver microRNAs are potential biomarkers for liver injury in experimental fatty liver disease

Background & Aim

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in both adult and children. Currently there are no reliable methods to determine disease severity, monitor disease progression, or efficacy of therapy, other than an invasive liver biopsy.

Design

Choline Deficient L-Amino Acid (CDAA) and high fat diets were used as physiologically relevant mouse models of NAFLD. Circulating extracellular vesicles were isolated, fully characterized by proteomics and molecular analyses and compared to control groups. Liver-related microRNAs were isolated from purified extracellular vesicles and liver specimens.

Results

We observed statistically significant differences in the level of extracellular vesicles (EVs) in liver and blood between two control groups and NAFLD animals. Time-course studies showed that EV levels increase early during disease development and reflect changes in liver histolopathology. EV levels correlated with hepatocyte cell death (r² = 0.64, p<0.05), fibrosis (r² = 0.66, p<0.05) and pathological angiogenesis (r² = 0.71, p<0.05). Extensive characterization of blood EVs identified both microparticles (MPs) and exosomes (EXO) present in blood of NAFLD animals. Proteomic analysis of blood EVs detected various differentially expressed proteins in NAFLD versus control animals. Moreover, unsupervised hierarchical clustering identified a signature that allowed for discrimination between NAFLD and controls. Finally, the liver appears to be an important source of circulating EVs in NAFLD animals as evidenced by the enrichment in blood with miR-122 and 192 - two microRNAs previously described in chronic liver diseases, coupled with a corresponding decrease in expression of these microRNAs in the liver.

Conclusions

These findings suggest a potential for using specific circulating EVs as sensitive and specific biomarkers for the noninvasive diagnosis and monitoring of NAFLD.

Complement alternative pathway activation in human nonalcoholic steatohepatitis

The innate immune system plays a major role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Recently we reported complement activation in human NASH. However, it remained unclear whether the alternative pathway of complement, which amplifies C3 activation and which is frequently associated with pathological complement activation leading to disease, was involved. Here, alternative pathway components were investigated in liver biopsies of obese subjects with healthy livers (n = 10) or with NASH (n = 12) using quantitative PCR, Western blotting, and immunofluorescence staining. Properdin accumulated in areas where neutrophils surrounded steatotic hepatocytes, and colocalized with the C3 activation product C3c. C3 activation status as expressed by the C3c/native C3 ratio was 2.6-fold higher (p<0.01) in subjects with NASH despite reduced native C3 concentrations (0.94±0.12 vs. 0.57±0.09; p<0.01). Hepatic properdin levels positively correlated with levels of C3c (r_s = 0.69; p<0.05) and C3c/C3 activation ratio (r_s = 0.59; p<0.05). C3c, C3 activation status (C3c/C3 ratio) and properdin levels increased with higher lobular inflammation scores as determined according to the Kleiner classification (C3c: p<0.01, C3c/C3 ratio: p<0.05, properdin: p<0.05). Hepatic mRNA expression of factor B and factor D did not differ between subjects with healthy livers and subjects with NASH (factor B: 1.00±0.19 vs. 0.71±0.07, p = 0.26; factor D: 1.00±0.21 vs. 0.66±0.14, p = 0.29;). Hepatic mRNA and protein levels of Decay Accelerating Factor tended to be increased in subjects with NASH (mRNA: 1.00±0.14 vs. 2.37±0.72; p = 0.22; protein: 0.51±0.11 vs. 1.97±0.67; p = 0.28). In contrast, factor H mRNA was downregulated in patients with NASH (1.00±0.09 vs. 0.71±0.06; p<0.05) and a similar trend was observed with hepatic protein levels (1.12±0.16 vs. 0.78±0.07; p = 0.08). Collectively, these data suggest a role for alternative pathway activation in driving hepatic inflammation in NASH. Therefore, alternative pathway factors may be considered attractive targets for treating NASH by inhibiting complement activation.

Effect of curcumin on hepatic heme oxygenase 1 expression in high fat diet fed rats: is there a triangular relationship?

High fat diet (HFD) is associated with oxidative stress induced fatty liver. Curcumin, an extract of Curcuma longa, has been shown to possess potent antioxidant and hypolipidemic properties. In this study, we investigated the effect of curcumin treatment on hepatic heme oxygenase-1 (HO-1) expression along with pro-oxidant-antioxidant status and lipid accumulation in rats fed an HFD. Male Sprague-Dawley rats were distributed among 4 groups: Group 1, which was fed the control diet (10% of total calories from fat); Group 2, which was fed the HFD (60% of total calories from fat); and groups 3 and 4, which received the HFD supplemented with curcumin and the control diet supplemented with curcumin (1 g/kg diet; w/w), respectively, for 16 weeks. HFD caused increases in hepatic lipid levels, production of reactive oxygen species, and lipid peroxidation. Further, HO-1 expression was significantly decreased. Histopathological examination showed hepatic fat accumulation and slight fibrotic changes. Curcumin treatment reduced hepatic lipids and oxidative stress parameters, and HO-1 expression was significantly increased. These findings suggest that increased HO-1 expression, along with suppressed oxidative stress as well as reduced hepatic fat accumulation and fibrotic changes, contribute to the beneficial effects of curcumin in attenuating the pathogenesis of fatty liver induced metabolic diseases.

Serum immunoglobulin A concentration is a reliable biomarker for liver fibrosis in non-alcoholic fatty liver disease

AIM: To evaluate the diagnostic accuracy of serum Immunoglobulin A (IgA) for differentiating early stage nonalcoholic fatty liver disease (NAFLD) from nonalcoholic steatohepatitis (NASH).

METHODS: All cases had fatty liver change confirmed by ultrasound and aminotransferases of at least twice the normal level. Clinical and biochemical data, including serum IgA, were obtained from 50 histologically proven NAFLD cases and 54 healthy controls. Fasting whole blood samples were obtained from the study population. Immunoturbidimetric methods were used to measure the IgA levels. All NAFLD cases were hospitalized for liver biopsy. Liver specimens were examined for steatosis, steatohepatitis and fibrosis within hepatocytes. Patients were categorized into two groups: NASH and non-NASH. Variables were compared within cases (NASH vs non-NASH) and controls. Cut-off values of serum IgA were evaluated using analysis of receiver operating characteristic (ROC curves). Associations between the variables were tested using calculations of correlation coefficients. Statistical significances were assigned to P values < 0.05.

RESULTS: The extent of liver fibrosis correlated positively with IgA levels. Subjects with no fibrosis in their liver biopsies had a lower IgA level (301.5 ± 91.2 mg/dL) than subjects with any degree of fibrosis (388.8 ± 140.8 mg/dL), (P = 0.01). IgA levels were higher in NASH cases, and its value was significantly higher for higher degrees of fibrosis. Patients with perisinusoidal or pericellular fibrosis had significantly higher levels of IgA (403.5 ± 133.9 mg/dL, 418.2 ± 129.5 mg/dL) compared to those without it (301.8 ± 94.9 mg/dL, 297.7 ± 91.5 mg/dL), respectively. No significant correlation was found between steatosis grade and serum IgA levels. Based on ROC analysis, the best predictive IgA cutoff value for detecting liver fibrosis was 360 mg/dL (61% sensitivity, 81% specificity).

CONCLUSION: The serum IgA level is useful to evaluate the severity of liver fibrosis and can be used serially for evaluation and follow-up of NAFLD cases.

Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis

BACKGROUND

Concerns have been raised about the concurrent temporal trend between simple sugar intakes, especially of fructose or high-fructose corn syrup (HFCS), and rates of nonalcoholic fatty liver disease (NAFLD) in the United States.

OBJECTIVE

We examined the effect of different amounts and forms of dietary fructose on the incidence or prevalence of NAFLD and indexes of liver health in humans.

DESIGN

We conducted a systematic review of English-language, human studies of any design in children and adults with low to no alcohol intake and that reported at least one predetermined measure of liver health. The strength of the evidence was evaluated by considering risk of bias, consistency, directness, and precision.

RESULTS

Six observational studies and 21 intervention studies met the inclusion criteria. The overall strength of evidence for observational studies was rated insufficient because of high risk of biases and inconsistent study findings. Of 21 intervention studies, 19 studies were in adults without NAFLD (predominantly healthy, young men) and 1 study each in adults or children with NAFLD. We found a low level of evidence that a hypercaloric fructose diet (supplemented by pure fructose) increases liver fat and aspartate aminotransferase (AST) concentrations in healthy men compared with the consumption of a weight-maintenance diet. In addition, there was a low level of evidence that hypercaloric fructose and glucose diets have similar effects on liver fat and liver enzymes in healthy adults. There was insufficient evidence to draw a conclusion for effects of HFCS or sucrose on NAFLD.

CONCLUSIONS

On the basis of indirect comparisons across study findings, the apparent association between indexes of liver health (ie, liver fat, hepatic de novo lipogenesis, alanine aminotransferase, AST, and γ-glutamyl transpeptase) and fructose or sucrose intake appear to be confounded by excessive energy intake. Overall, the available evidence is not sufficiently robust to draw conclusions regarding effects of fructose, HFCS, or sucrose consumption on NAFLD.

Diet-induced obesity modulates epigenetic responses to ionizing radiation in mice

Both exposure to ionizing radiation and obesity have been associated with various pathologies including cancer. There is a crucial need in better understanding the interactions between ionizing radiation effects (especially at low doses) and other risk factors, such as obesity. In order to evaluate radiation responses in obese animals, C3H and C57BL/6J mice fed a control normal fat or a high fat (HF) diet were exposed to fractionated doses of X-rays (0.75 Gy ×4). Bone marrow micronucleus assays did not suggest a modulation of radiation-induced genotoxicity by HF diet. Using MSP, we observed that the promoters of p16 and Dapk genes were methylated in the livers of C57BL/6J mice fed a HF diet (irradiated and non-irradiated); Mgmt promoter was methylated in irradiated and/or HF diet-fed mice. In addition, methylation PCR arrays identified Ep300 and Socs1 (whose promoters exhibited higher methylation levels in non-irradiated HF diet-fed mice) as potential targets for further studies. We then compared microRNA regulations after radiation exposure in the livers of C57BL/6J mice fed a normal or an HF diet, using microRNA arrays. Interestingly, radiation-triggered microRNA regulations observed in normal mice were not observed in obese mice. miR-466e was upregulated in non-irradiated obese mice. In vitro free fatty acid (palmitic acid, oleic acid) administration sensitized AML12 mouse liver cells to ionizing radiation, but the inhibition of miR-466e counteracted this radio-sensitization, suggesting that the modulation of radiation responses by diet-induced obesity might involve miR-466e expression. All together, our results suggested the existence of dietary effects on radiation responses (especially epigenetic regulations) in mice, possibly in relationship with obesity-induced chronic oxidative stress.

CEUS and Fibroscan in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

AIM: To determine intra-hepatic blood flow and liver stiffness in patients with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) using contrast-enhanced ultrasound and fibroscan.

METHODS: This prospective study included 15 patients with NAFLD, 17 patients with NASH and 16 healthy controls. In each patient, real-time ultrasound was used to locate the portal vein (PV) and the right liver lobe, and 5 mL of SonoVue^® was then injected intravenous in a peripheral vein of the left arm over a 4-s span. Digital recording was performed for 3 min thereafter. The recording was subsequently retrieved to identify an area of interest in the PV area and in the right liver parenchyma (LP) to assess the blood flow by processing the data using dedicated software (Qontrast^®, Bracco, Italy). The following parameters were evaluated: percentage of maximal contrast activity (Peak%), time to peak (TTP, s), regional blood volume (RBV, cm³), regional blood flow (RBF, cm³/s) and mean transit time (MTT, s). At 24-48 h post-injection, liver stiffness was evaluated using Fibroscan and measured in kPa. The statistical evaluation was performed using Student’s t test.

RESULTS: In the PV, the Peak%, RBV and RBF were significantly reduced in the NAFLD and NASH patients compared with the controls (Peak%: NAFLD 26.3 ± 6.6, NASH 28.1 ± 7.3 vs controls 55.8 ± 9.9, P < 0.001; RBV: NAFLD 4202.3 ± 3519.7, NASH 3929.8 ± 1941.3 vs controls 7473 ± 3281, P < 0.01; RBF: NAFLD 32.5 ± 10.8, NASH 32.7 ± 12.1 vs controls 73.1 ± 13.9, P < 0.001). The TTP in the PV was longer in both patient groups but reached statistical significance only in the NASH patients compared with the controls (NASH 79.5 ± 37.8 vs controls 43.2 ± 30, P < 0.01). In the LP, the Peak%, RBV and RBF were significantly reduced in the NAFLD and NASH patients compared with the controls (Peak%: NAFLD 43.2 ± 7.3, NASH 41.7 ± 7.7 vs controls 56.6 ± 6.3, P < 0.001; RBV: NAFLD 4851.5 ± 2009, NASH 5069.4 ± 2292.5 vs controls 6922.9 ± 2461.5, P < 0.05; RBF: NAFLD 55.7 ± 10.1, NASH 54.5 ± 12.1 vs controls 75.9 ± 10.5, P < 0.001). The TTP was longer in both patient groups but did not reach statistical significance. The MTT in both the PV and LP in the NAFLD and NASH patients was not different from that in the controls. Liver stiffness was significantly increased relative to the controls only in the NASH patients (NASH: 6.4 ± 2.2 vs controls 4.6 ± 1.5, P < 0.05).

CONCLUSION: Blood flow derangement within the liver present not only in NASH but also in NAFLD suggests that a vascular flow alteration precedes liver fibrosis development.

The Effect of Chlorella vulgaris Supplementation on Liver En-zymes, Serum Glucose and Lipid Profile in Patients with Non-Alcoholic Fatty Liver Disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming a public health problem worldwide and using microalgae is a new approach on its treatment. The aim of this study was to investigate the effect of Chlorella vulgaris supplementation on liver enzymes, serum glucose and lipid profile in patients with NAFLD.

METHODS

This double-blind randomized placebo-controlled clinical trial was conducted on 60 NAFLD patients from specialized clinics of Tabriz University of Medical Sciences from December 2011 to July 2012. The subjects were randomly allocated into 2 groups: 1) "intervention" (n=30) received 400 mg/day vitamin E plus four 300 mg tablets of Chlorella vulgaris and, 2) "placebo" (n=30) received 400 mg/day vitamin E and four placebo tablets per day for 8 weeks. Weight, liver enzymes and metabolic factors were assessed in fasting serum and dietary data was collected at baseline and end of the study.

RESULTS

Weight, liver enzymes, fasting blood sugar (FBS) and lipid profile decreased significantly in both groups (P<0.05). The differences in weight, ALP and FBS between the two groups were statistically significant (P=0.01, P=0.04 and P=0.02, respectively).

CONCLUSION

C. vulgaris seems to improve FBS and lipid profile and therefore could be considered as an effective complementary treatment in NAFLD.

Metabolic syndrome and non-alcoholic fatty liver disease in liver surgery: The new scourges?

The aim of this topic highlight is to review relevant evidence regarding the influence of the metabolic syndrome (MS) and its associated liver manifestation, non-alcoholic fatty liver disease (NAFLD), on the development of liver cancer as well as their impact on the results of major liver surgery. MS and NAFLD, whose incidences are significantly increasing in Western countries, are leading to a changing profile of the patients undergoing liver surgery. A MEDLINE search was performed for relevant articles using the key words "metabolic syndrome", "liver resection", "liver transplantation", "non alcoholic fatty liver disease", "non-alcoholic steatohepatitis" and "liver cancer". On one hand, the MS favors the development of primary liver malignancies (hepatocellular carcinoma and cholangiocarcinoma) either through NAFLD liver parenchymal alterations (steatosis, steatohepatitis, fibrosis) or in the absence of significant underlying liver parenchyma changes. Also, the existence of NAFLD may have a specific impact on colorectal liver metastases recurrence. On the other hand, the postoperative period following partial liver resection and liver transplantation is at increased risk of both postoperative complications and mortality. These deleterious effects seem to be related to the existence of liver specific complications but also higher cardio-vascular sensitivity in a setting of MS/NAFLD. Finally, the long-term prognosis after curative surgery joins that of patients operated on with other types of underlying liver diseases. An increased rate of patients with MS/NAFLD referred to hepatobiliary units has to be expected. The higher operative risk observed in this subset of patients will require specific improvements in their perioperative management.

Controlled attenuation parameter (CAP) for the diagnosis of steatosis: a prospective study of 5323 examinations

BACKGROUND & AIMS

Controlled attenuation parameter (CAP) evaluated with transient elastography (FibroScan®) is a recent method for non-invasive assessment of steatosis. Its usefulness in clinical practice is unknown. We prospectively investigated the determinants of CAP failure and the relationships between CAP and clinical or biological parameters in a large cohort of consecutive patients.

METHODS

All CAP examinations performed in adult patients with suspected chronic liver disease were included. CAP failure was defined as zero valid shot. The following factors were analyzed for their influence on CAP value and the relationships between CAP and clinico-biological parameters: age, gender, body mass index, waist circumference, hypertension, diabetes, metabolic syndrome, alcohol use, liver stiffness measurement, indication, and different biological parameters.

RESULTS

CAP failure occurred in 7.7% of 5323 examinations. By multivariate analysis, factors independently associated with CAP measurement failure were female gender, BMI, and metabolic syndrome. By multivariate analysis, factors significantly associated with elevated CAP were BMI [25-30]kg/m(2), BMI >30kg/m(2), metabolic syndrome, alcohol >14 drink/week and liver stiffness >6kPa. CAP increased with the number of parameters of metabolic syndrome, BMI, waist circumference, the presence of diabetes or hypertension, and the cause of the disease. In the 440 patients with liver biopsy, for the diagnosis of steatosis >10%, steatosis >33%, and steatosis >66%, AUROCs of CAP were 0.79 (95% CI 0.74-0.84, p<0.001), 0.84 (95% CI 0.80-0.88, p<0.001), 0.84 (95% CI 0.80-0.88, p<0.001), respectively.

CONCLUSIONS

CAP provides an immediate assessment of steatosis simultaneously with liver stiffness measurement. The strong association of CAP with the metabolic syndrome and alcohol use could be of interest for the follow-up of NAFLD or alcoholic patients.

Resveratrol ameliorates hepatic metaflammation and inhibits NLRP3 inflammasome activation

OBJECTIVE

Resveratrol (RSV) regulates NAD bioavailability and sirtuin-related metabolism, which relates to aging, metabolic syndrome and non-alcoholic fatty liver disease. The purpose of this study was to investigate the effects of resveratrol on hepatic metaflammation in a rodent model of high-fat (HF) diet-induced obesity (DIO).

MATERIALS/METHODS

DIO was induced in a subset of mice given an HF diet (45% kcal fat). After 6weeks of HF diet feeding, RSV was delivered via an osmotic pump for 4weeks. The experimental groups were as follows: 1) lean control fed with a standard diet, 2) HF diet-induced obese control, and 3) HF_RSV (8mg/kg/day). After 4weeks of each treatment, blood and liver tissues were collected and the indices of glucose control, serum and liver triglyceride (TG), sirtuin pathway, inflammation, and NOD-like receptor family, pryin domain containing 3 (NLRP3) inflammasome were analyzed.

RESULTS

Body weight and food intake were not altered by administering resveratrol. Glucose control was impaired, and serum and liver TG levels were increased by the HF diet. Hepatic inflammation was aggravated in mice fed with the HF diet, as shown by the increased levels of the pro-inflammatory markers interleukin-1 (IL-1), IL-6 and tumor necrosis factor-alpha in the liver. However, resveratrol administration significantly improved glucose control, and serum and liver TG contents. Also, resveratrol treatment reduced the levels of the pro-inflammatory markers. These improvements were accompanied by alterations in sirtuin pathway and NLRP3 inflammasome activation.

CONCLUSION

These results demonstrate that resveratrol ameliorates hepatic metaflammation, accompanied by alterations in NLRP3 inflammasome.

Nonalcoholic fatty liver disease is a negative risk factor for prostate cancer recurrence

Nonalcoholic fatty liver disease (NAFLD) is closely related to the metabolic syndrome, which is associated with an increased risk of various malignancies. In this study, we investigated the association between NAFLD and prostate cancer biochemical recurrence (BCR) after radical prostatectomy. Consecutive prostate cancer patients who underwent radical prostatectomy were enrolled from two hospitals in Korea and randomly assigned to the training (n=147) or validation set (n=146). The presence of NAFLD, BMI, preoperative prostate-specific antigen, and histological findings including Gleason score (GSc) were analyzed in regard to their association with BCR. NAFLD was diagnosed based on ultrasonography or unenhanced computed tomography images. BCR-free survival rates were calculated using the Kaplan-Meier method. In the training set, 32 (21.8%) patients developed BCR during a median follow-up period of 51 (inter-quartile range, 35-65) months. In the multivariate analysis, the presence of NAFLD (hazard ratio (HR), 0.36; 95% CI, 0.14-0.97; P=0.04) was an independent negative predictive factor of BCR after adjustment for pathological GSc. Applied to the validation set, the presence of NAFLD maintained its prognostic value for longer time-to-BCR (HR, 0.17; 95% CI, 0.06-0.49; P=0.001). In the subgroup analysis of patients with NAFLD, NAFLD fibrosis score was a single independent negative predictor for BCR (HR, 0.54; 95% CI, 0.30-0.98; P=0.04). Our study demonstrated that NAFLD may play a protective role against BCR after radical prostatectomy for prostate cancer. Further study is warranted to elucidate the mechanism of protective effect in patients with NAFLD.

Detecting hepatic steatosis using ultrasound-induced thermal strain imaging: an ex vivo animal study

Hepatic steatosis or fatty liver disease occurs when lipids accumulate within the liver and can lead to steatohepatitis, cirrhosis, liver cancer and eventual liver failure requiring liver transplant. Conventional brightness mode (B-mode) ultrasound (US) is the most common noninvasive diagnostic imaging modality used to diagnose hepatic steatosis in clinics. However, it is mostly subjective or requires a reference organ such as the kidney or spleen with which to compare. This comparison can be problematic when the reference organ is diseased or absent. The current work presents an alternative approach to noninvasively detecting liver fat content using US-induced thermal strain imaging (US-TSI). This technique is based on the difference in the change in the speed of sound as a function of temperature between water- and lipid-based tissues. US-TSI was conducted using two system configurations including a mid-frequency scanner with a single linear array transducer (5-14 MHz) for both imaging and heating and a high-frequency (13-24 MHz) small animal imaging system combined with a separate custom-designed US heating transducer array. Fatty livers (n = 10) with high fat content (45.6 ± 11.7%) from an obese mouse model and control livers (n = 10) with low fat content (4.8 ± 2.9%) from wild-type mice were embedded in gelatin. Then, US imaging was performed before and after US induced heating. Heating time periods of ∼ 3 s and ∼ 9.2 s were used for the mid-frequency imaging and high-frequency imaging systems, respectively, to induce temperature changes of approximately 1.5 °C. The apparent echo shifts that were induced as a result of sound speed change were estimated using 2D phase-sensitive speckle tracking. Following US-TSI, histology was performed to stain lipids and measure percentage fat in the mouse livers. Thermal strain measurements in fatty livers (-0.065 ± 0.079%) were significantly (p < 0.05) higher than those measured in control livers (-0.124 ± 0.037%). Using histology as a gold standard to classify mouse livers, US-TSI had a sensitivity and specificity of 70% and 90%, respectively. The area under the receiver operating characteristic curve was 0.775. This ex vivo study demonstrates the feasibility of using US-TSI to detect fatty livers and warrants further investigation of US-TSI as a diagnostic tool for hepatic steatosis.

Prognostic factors for regression from impaired glucose tolerance to normal glucose regulation in Japanese patients with nonalcoholic fatty liver disease

OBJECTIVE

The aim of this retrospective cohort study was to assess the predictive factors for the regression from impaired glucose tolerance (IGT) to normal glucose regulation (NGR) in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

A total of 164 NAFLD patients who had IGT in the first 75-g oral glucose tolerance test (OGTT) and underwent a repeated OGTT five years later were enrolled. A multivariate logistic regression analysis was carried out to identify factors predicting the regression from IGT to NGR.

RESULTS

Out of the 164 patients, 29 regressed from IGT to NGR within five years after the first OGTT. The multivariate analysis by logistic regression showed that regression from IGT to NGR occurred when the patient was young (risk ratio for ten years: 0.38; 95% confidence interval [CI] 0.20-0.72; p=0.003), had a fasting plasma glucose (FPG) level of <100 mg/dL (risk ratio: 6.53; 95%CI 1.88-21.73; p=0.003), had a 2-hr post-load plasma glucose (PG) level of <160 mg/dL (risk ratio: 4.86; 95%CI 1.08-22.72; p=0.040), a body mass index (BMI) decrease of ≥1.5 (risk ratio: 5.20; 95% CI 1.41-19.24; p=0.014), physical activity of ≥2 Metabolic Equivalent of Task (MET) h/day (risk ratio: 5.57; 95%CI 1.68-18.44; p=0.005), and showed disappearance of the fatty liver by ultrasonography at five years (risk ratio: 9.92; 95%CI 2.87-34.34; p<0.001).

CONCLUSION

Our results suggest that six factors: young age, FPG <100 mg/dL, 2-hr post-load PG of <160 mg/dL, BMI decrease of ≥1.5, physical activity of ≥2 MET h/day, and the disappearance of fatty liver predict the regression from IGT to NGR in NAFLD patients.

Left atrial deformation parameters in patients with non-alcoholic fatty liver disease: a 2D speckle tracking imaging study

The presence of the metabolic syndrome is a strong predictor for the presence of NASH (non-alcoholic steatohepatitis) in patients with NAFLD (non-alcoholic fatty liver disease). In the present study, we assessed LA (left atrial) deformation parameters in patients with NAFLD using 2D-STE (speckle tracking echocardiography) and to investigate if any changes exist between subgroups of the NAFLD. A total of 55 NAFLD patients and 21 healthy controls were included in the study. The diagnosis of NAFLD was based on liver biopsy. After patients were categorized into groups according to histopathological analysis (simple steatosis, borderline NASH, definitive NASH), all patients underwent echocardiography with Doppler examination. In the 2D-STE analysis of the left atrium, LA-Res (peak LA strain during ventricular systole), LA-Pump (peak LA strain during atrial systole), LA-SR(S) (peak LA strain rate during ventricular systole), LA-SR(E) (peak LA strain rate during early diastole) and LA-SR(A) (peak LA strain rate during atrial systole) were obtained. LA-Res, LA-Pump and LA-SR(A) were lower in the NAFLD group than in the control group. LA-Res was found to be significantly lower in NAFLD subgroups compared with healthy subjects (43.9±14.2 in healthy controls compared with 31.4±8.3 with simple steatosis, 32.8±12.8 with borderline NASH and 33.8±9.0 with definitive NASH). LA-Pump was significantly lower in the NAFLD group (18.2±3.1 in healthy controls compared with 13.3±4.7 with borderline NASH and 14.4±4.7 with definitive NASH). There were significant differences in LA-SR(A) between healthy controls compared with simple steatosis and borderline NASH (-1.56±0.36 compared with 1.14±0.38 and 1.24±0.32 respectively). Correlation analysis showed significant correlation of LA-Res values with E (early diastolic peak velocity)/E(m) (early diastolic mitral annular velocity) ratio (r=-0.50, P≤0.001), with LAVI (LA volume index; r=-0.45, P≤0.001) and with V(p) (propagation velocity; r=0.39, P≤0.001). 2D-STE-based LA deformation parameters are impaired in patients with NAFLD with normal systolic function. Although LA-Res and pump function parameters might be useful in estimating LV (left ventricular) filling pressure in the NAFLD patient group, it could not be used for differentiating the subgroups.

Utility of magnetic resonance imaging versus histology for quantifying changes in liver fat in nonalcoholic fatty liver disease trials

The magnetic resonance imaging-estimated proton density fat fraction (MRI-PDFF) is a novel imaging-based biomarker that allows fat mapping of the entire liver, whereas the magnetic resonance spectroscopy-measured proton density fat fraction (MRS-PDFF) provides a biochemical measure of liver fat in small regions of interest. Cross-sectional studies have shown that MRI-PDFF correlates with MRS-PDFF. The aim of this study was to show the utility of MRI-PDFF in assessing quantitative changes in liver fat through a three-way comparison of MRI-PDFF and MRS-PDFF with the liver histology-determined steatosis grade at two time points in patients with nonalcoholic fatty liver disease (NAFLD). Fifty patients with biopsy-proven NAFLD who participated in a randomized trial underwent a paired evaluation with liver biopsy, MRI-PDFF, and MRS-PDFF at the baseline and 24 weeks. The mean age and body mass index were 47.8 ± 11.7 years and 30.7 ± 6.5 kg/m(2), respectively. MRI-PDFF showed a robust correlation with MRS-PDFF both at week 0 and at week 24 (r = 0.98, P < 0.0001 for both). Cross-sectionally, MRI-PDFF and MRS-PDFF increased with increases in the histology-determined steatosis grade both at week 0 and at week 24 (P < 0.05 for all). Longitudinally, patients who had a decrease (≥ 1%) or increase (≥ 1%) in MRI-PDFF (confirmed by MRS-PDFF) showed a parallel decrease or increase in their body weight and serum alanine aminotransferase and aspartate aminotransferase levels at week 24 (P < 0.05). This small increase or decrease in liver fat could not be quantified with histology.

CONCLUSION

In this longitudinal study, MRI-PDFF correlated well with MRS-PDFF and was more sensitive than the histology-determined steatosis grade in quantifying increases or decreases in the liver fat content. Therefore, it could be used to quantify changes in liver fat in future clinical trials.

Industrial, not fruit fructose intake is associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients

BACKGROUND & AIMS

Unhealthy food intake, specifically fructose, has been associated with metabolic alterations and with the severity of liver fibrosis in patients with non-alcoholic fatty liver disease. In a cohort of patients with genotype 1 chronic hepatitis C (G1 CHC), we tested the association of fructose intake with the severity of liver histology.

METHODS

Anthropometric and metabolic factors, including waist circumference (WC), waist-to-hip ratio (WHR), dorso-cervical lipohypertrophy and HOMA were assessed in 147 consecutive biopsy-proven G1 CHC patients. Food intake, namely industrial and fruit fructose, was investigated by a three-day structured interview and a computed database. All biopsies were scored by an experienced pathologist for staging and grading (Scheuer classification), and graded for steatosis, which was considered moderate-severe if ≥ 20%. Features of non-alcoholic steatohepatitis (NASH) in CHC were also assessed (Bedossa classification).

RESULTS

Mean daily intake of total, industrial and fruit fructose was 18.0±8.7g, 6.0±4.7g, and 11.9±7.2g, respectively. Intake of industrial, not fruit fructose, was independently associated with higher WHR (p=0.02) and hypercaloric diet (p<0.001). CHC patients with severe liver fibrosis (⩾F3) reported a significantly higher intake of total (20.8±10.2 vs. 17.2±8.1g/day; p=0.04) and industrial fructose (7.8±6.0 vs. 5.5±4.2; p=0.01), not fruit fructose (12.9±8.0 vs. 11.6±7.0; p=0.34). Multivariate logistic regression analysis showed that older age (OR 1.048, 95% CI 1.004-1.094, p=0.03), severe necroinflammatory activity (OR 3.325, 95% CI 1.347-8.209, p=0.009), moderate-severe steatosis (OR 2.421, 95% CI 1.017-6.415, p=0.04), and industrial fructose intake (OR 1.147, 95% CI 1.047-1.257, p=0.003) were independently linked to severe fibrosis. No association was found between fructose intake and liver necroinflammatory activity, steatosis, and the features of NASH.

CONCLUSIONS

The daily intake of industrial, not fruit fructose is a risk factor for metabolic alterations and the severity of liver fibrosis in patients with G1 CHC.

Diagnosis and management of non-alcoholic fatty liver disease and related metabolic disorders: consensus statement from the Study Group of Liver and Metabolism, Chinese Society of Endocrinology

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in Western countries, affecting 20%-33% of the general population. Large population-based surveys in China indicate a prevalence of approximately 15%-30%. Worldwide, including in China, the prevalence of NAFLD has increased rapidly in parallel with regional trends of obesity, type 2 diabetes and metabolic syndrome. In addition, NAFLD has contributed significantly to increased overall, as well as cardiovascular and liver-related, mortality in the general population. In view of rapid advances in research into NAFLD in recent years, this consensus statement provides a brief update on the progress in the field and suggests preferred approaches for the comprehensive management of NAFLD and its related metabolic diseases.

Efficacy and safety in sitagliptin therapy for diabetes complicated by non-alcoholic fatty liver disease

AIM

The aim of this case-control study was to assess the efficacy and safety of dipeptidyl peptidase-4 inhibitor (sitagliptin) for type 2 diabetes mellitus (T2DM) with non-alcoholic fatty liver disease (NAFLD).

METHODS

Twenty NAFLD patients with T2DM treated by sitagliptin were retrospectively enrolled as the sitagliptin group. These patients were given sitagliptin between January 2010 and July 2011. Another 20 NAFLD patients with T2DM treated only with diet and exercise for 48 weeks were selected as the control group. Serum levels of fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured before and 12, 24, 36 and 48 weeks after the initiation of treatment.

RESULTS

In the sitagliptin group, average HbA1c levels decreased approximately 0.7% at 48 weeks after the initiation of sitagliptin. Next, average FPG levels decreased approximately 15 mg/dL at 48 weeks after the initiation of sitagliptin. The serum levels of HbA1c and FPG in the sitagliptin group decreased with statistical significance compared to those in the control group (P < 0.05). All the patients could take sitagliptin of 50 mg/day without reduction necessitated by sitagliptin-related side-effects. There were no significant changes of average AST and ALT levels during follow up of 48 weeks in both sitagliptin and control groups.

CONCLUSION

Our results indicate sitagliptin is effective and safe for the treatment of T2DM complicated with NAFLD.

Serum gamma glutamyl transferase and alanine transaminase concentrations predict endothelial dysfunction in patients with non-alcoholic steatohepatitis

PURPOSE

Cardiovascular diseases are the leading cause of death in patients with non-alcoholic steatohepatitis (NASH). We aimed to investigate the presence of endothelial dysfunction and whether serum concentrations of liver enzymes may reflect the severity of such an endothelial dysfunction in patients with NASH.

METHODS

Fifty patients with NASH diagnosed by liver biopsies and 30 healthy controls were included. Blood samples after fasting were harvested for measurements of glucose, insulin, cholesterol, triglyceride, and liver enzymes. All patients underwent transthoracic echocardiography and brachial and carotid artery Doppler ultrasonography to evaluate flow-mediated dilatation (FMD) and carotid artery intima-media thickness (CIMT).

RESULTS

Patients with NASH had impaired FMD (4.9 ± 2.8% to 9.3 ± 4.4%, P < 0.001) and higher CIMT (0.79 ± 0.16 mm to 0.64 ± 0.11 mm, P < 0.001) when compared with healthy controls. Linear regression analyses revealed that serum concentrations of gamma glutamyl transferase (GGT) and alanine transaminase (ALT) were associated with FMD and CIMT.

CONCLUSIONS

Patients with NASH have impaired FMD and increased CIMT when compared with healthy controls. In patients with NASH, serum concentrations of GGT and ALT might have a predictive value for FMD and CIMT.

Lean NASH: distinctiveness and clinical implication

INTRODUCTION

Non-alcoholic fatty liver (NAFL) in the absence of overweight and/or obesity, defined by the anthropometric parameter, body mass index (BMI), has been designated as 'lean NASH.' While maintaining a close pathophysiological link with metabolic syndrome (MS) and insulin resistance (IR), the presence of subtle alterations in measures of total body and regional adiposity not exceeding the designed cut-offs, are hallmarks of 'lean NASH.'

MATERIAL AND METHODS

Available literature related to non-alcoholic steatohepatitis (NASH) in lean or non-obese individuals and its pathogenesis in general published in English language journals till the time of manuscript preparation were reviewed and critically analysed.

ANALYSIS

Being a closely related but variant phenotype of NASH, its features metabolically resemble the well-characterized entity 'metabolically obese normal weight (MONW)' individuals. Apart from total body adiposity, distribution of fat in different body compartments has assumed greater pathophysiologic relevance in characterizing 'lean NASH'. Detection of NASH in stringently defined non-obese individuals, by both BMI and waist circumference indices, indicates existence of a subset of NASH in which fat compartmentalization at ectopic sites is not picked up by the anthropometric yardsticks used. Volume [Quantity] and biological behavior of the visceral and deep subcutaneous adipose tissues contribute to this variant of NASH in non-obese subjects. Genetic predisposition to IR and MS along with the environmental influences like childhood nutritional status, dietary composition and gut microbiome possibly play pathogenetic role.

CONCLUSION

The most important concern is in the principles of nomenclature within syndromes where clinical dissimilarities exist despite biological similarities. Till a uniformly acceptable pathophysiological and/or etiology-based classification emerges, the term "lean NASH" would continue to provide us an opportunity to ponder over and refine this subset of fatty liver in non-obese people and potentially significant liver disease.

Nonalcoholic fatty liver disease is associated with coronary artery disease in Koreans

AIM: To investigate whether nonalcoholic fatty liver disease (NAFLD) affects coronary artery disease (CAD) and identify candidate mediators.

METHODS: Patients who underwent coronary angiography were consecutively recruited. The patients were classified into four groups by coronary artery stenosis: A, insignificant; B, one-vessel disease; C, two-vessel disease; and D, three-vessel disease. Abdominal ultrasonography was performed to determine the presence of a fatty liver and categorize by grade: 0, no evidence; 1, mild; 2, moderate; and 3, severe. We measured not only known CAD risk factors, but also serum insulin, HOMA-index, adiponectin, interleukin-6, tumor necrosis factor-α and high-sensitivity C-reactive protein levels.

RESULTS: Of the 134 patients who met the inclusion criteria, 82 (61.2%) had ultrasonographically diagnosed NAFLD. Among the 46 patients with CAD, 37 (80.4%) had evidence of a fatty liver. The two groups (A vs B-D) were significantly different in terms of age, total cholesterol, triglycerides, low-density lipoprotein levels and fatty liver. Coronary artery stenosis was strongly associated with fatty liver in a grade-dependent manner (P = 0.025). In binary logistic regression, NAFLD was a significant independent predictor of CAD (P = 0.03, OR = 1.685; 95%CI: 1.051-2.702). Among the candidate mediators, the serum adiponectin level showed a trend toward lowering based on CAD progression (P = 0.071).

CONCLUSION: NAFLD is an independent risk factor for CAD in a grade-dependent manner. Moreover, adiponectin might be related to the pathogenesis of NAFLD.

Derangement of ghrelin secretion after long-term high-fat diet feeding in rats

AIM

Appetite control is an important goal for the management of non-alcoholic fatty liver disease, diabetes mellitus and obesity; however, little is known about how hormones concerning appetite regulation are affected by long-term consumption of a high-fat diet. We investigated the effect of high-fat diet on secretory regulation of ghrelin and leptin in rats.

METHODS

Rats were fed a control or a high-fat diet for 18 weeks and then killed. Before being killed, a glucose tolerance test was performed. Weight, total calorie intake and blood glucose levels were measured, and the plasma levels of total and active ghrelin, and leptin were analyzed by enzyme-linked immunosorbent assay.

RESULTS

Body and fat weight and total calorie intake were significantly higher in the high-fat diet group than in the control, although blood glucose levels did not differ. Plasma leptin was significantly higher in the high-fat diet group, and a significant positive correlation was observed between bodyweight and leptin levels in both groups. The levels of active and total ghrelin were not significantly changed by high-fat diet, and active ghrelin levels in the control group significantly correlated negatively with bodyweight, while its correlation was lost in the high-fat diet group. The glucose tolerance test showed that ghrelin levels were significantly higher than those of controls even 60 min after glucose loading.

CONCLUSION

These results indicate that secretion of ghrelin, but not leptin, are deranged by consumption of a high-fat diet, and active ghrelin levels lose their correlation with bodyweight and food intake.

Severity of non-alcoholic steatohepatitis is associated with substitution of adipose tissue in skeletal muscle

BACKGROUND AND AIMS

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is now focusing on its organ cross-talk with not only adipose tissue but also systemic skeletal muscle. Cross-sectional and longitudinal studies were conducted to determine the role of intramuscular adipose tissue content (IMAC) measured by computed tomography on the severity of NAFLD/non-alcoholic steatohepatitis (NASH).

METHODS

Two hundred eight Japanese patients with NAFLD/NASH diagnosed by liver biopsy were enrolled into a cross-sectional study. Twenty-one patients were enrolled in a longitudinal study and received a programmed diet and exercise intervention, in some cases the combination of pharmacotherapy. We measured IMAC in the multifidus muscle and biochemical parameters, and conducted liver histology to assess NAFLD/NASH status.

RESULTS

Histopathological stage in terms of simple steatosis and Brunt's classification was significantly correlated with IMAC (P < 0.01). Multivariate logistic regression analysis indicated that risk factors associated with the severity of NASH were IMAC and aging (IMAC: odds ratio = 2.444, P < 0.05; Age: odds ratio = 2.355, P < 0.05). The interventions improved histopathological changes in 11 patients with NASH as well as IMAC.

CONCLUSION

These results suggest that skeletal muscle fat accumulation may have been linked to the pathogenesis and severity of NASH.

Stepwise combination of simple noninvasive fibrosis scoring systems increases diagnostic accuracy in nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease ranging from simple fatty liver to steatohepatitis, fibrosis, and cirrhosis. We aimed to analyze the diagnostic performance and clinical utility of simple noninvasive tests alone or in combination for the detection of advanced fibrosis in patients with NAFLD.

DESIGN AND SUBJECTS

Data from 323 patients with biopsy-proven NAFLD/NASH who presented to the Clinic for Gastroenterology and Hepatology, University Hospital of Cologne between July 1998 and November 2009, were analyzed retrospectively. Sensitivity, specificity, positive predictive values, and negative predictive values were determined along with the area under receiver operating characteristic curves (AUROC) using published formulas for NAFLD, FIB-4, and BARD fibrosis scores.

RESULTS

The area under receiver operating characteristic curves were as follows: NAFLD fibrosis score 0.96 [95% confidence interval (CI), 0.92-0.99], FIB-4 0.95 (95% CI, 0.91-1.00), BARD 0.82 (95% CI, 0.71-0.92) with negative predictive values for advanced fibrosis of 96%, 98%, and 96%, respectively. When applying the NAFLD, FIB-4, or BARD scoring systems 25%, 15%, or 26% of cases with advanced fibrosis would have been missed. Combining FIB-4 and BARD in a stepwise fashion, patients would have been correctly classified without biopsy in 67% of cases without missing a single case of advanced fibrosis.

CONCLUSIONS

The FIB-4 and NAFLD fibrosis scores perform better than the BARD scoring system. Liver biopsy can securely be replaced only with a stepwise combination of simple noninvasive tests, otherwise the assessment of risk due to advanced fibrosis may be misleading in a clinically meaningful proportion of patients.

Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats

Background:

Various hepatoprotective herbal products from plants are available in Mexico, where up to 85% of patients with liver disease use some form of complementary and alternative medicine. However, only few studies have reported on the biological evaluation of these products.

Objective:

Using a model of carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats, we evaluated the effects of commercial herbal extracts used most commonly in the metropolitan area of Monterrey, Mexico.

Materials and Methods:

The commercial products were identified through surveys in public areas. The effect of these products given with or without CCl₄ in rats was evaluated by measuring the serum concentrations of aspartate amino transferase (AST) and alanine amino transferase (ALT), and histopathological analysis. Legalon^® was used as the standard drug.

Results:

The most commonly used herbal products were Hepatisan^® capsules, Boldo capsules, Hepavida^® capsules, Boldo infusion, and milk thistle herbal supplement (80% silymarin). None of the products tested was hepatotoxic according to transaminase and histological analyses. AST and ALT activities were significantly lower in the Hepavida+CCl₄-treated group as compared with the CCl₄-only group. AST and ALT activities in the silymarin, Hepatisan, and Boldo tea groups were similar to those in the CCl₄ group. The CCl₄ group displayed submassive confluent necrosis and mixed inflammatory infiltration. Both the Hepatisan+CCl₄ and Boldo tea+CCl₄ groups exhibited ballooning degeneration, inflammatory infiltration, and lytic necrosis. The silymarin+CCl₄ group exhibited microvesicular steatosis. The Hepavida+CCl₄- and Legalon+CCL₄-treated groups had lower percentages of necrotic cells as compared with the CCl₄-treated group; this treatment was hepatoprotective against necrosis.

Conclusion:

Only Hepavida had a hepatoprotective effect.

Emerging drugs for non-alcoholic steatohepatitis

INTRODUCTION

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing along with the worldwide epidemic of obesity and their strong association with metabolic syndrome. Currently existing pharmacological therapies include anti-oxidants, insulin-sensitizing agents, lipid-lowering drugs and cytoprotective agents, but there is a lack of consensus regarding the most effective and appropriate pharmacologic therapies for NASH. Clinical trials examining new therapeutic drugs for NASH that act via various mechanisms are being performed in several countries, and these drugs may strongly influence current NASH treatment.

AREAS COVERED

This article provides a review of recent data on the safety and efficacy of existing and emerging agents for the treatment of NASH.

EXPERT OPINION

Ideally, treatment for NASH should not only improve liver disease, but also reduce the risks of adverse cardiovascular outcomes and the development of diabetes and cancers. However, this goal is likely to be too high in the context of clinical trials designed to obtain approval for the treatment of liver disease. The only way to achieve the goal is to accumulate the results of these relatively short-term clinical trials.

Gastrointestinal complications of diabetes mellitus

Diabetes mellitus affects virtually every organ system in the body and the degree of organ involvement depends on the duration and severity of the disease, and other co-morbidities. Gastrointestinal (GI) involvement can present with esophageal dysmotility, gastro-esophageal reflux disease (GERD), gastroparesis, enteropathy, non alcoholic fatty liver disease (NAFLD) and glycogenic hepatopathy. Severity of GERD is inversely related to glycemic control and management is with prokinetics and proton pump inhibitors. Diabetic gastroparesis manifests as early satiety, bloating, vomiting, abdominal pain and erratic glycemic control. Gastric emptying scintigraphy is considered the gold standard test for diagnosis. Management includes dietary modifications, maintaining euglycemia, prokinetics, endoscopic and surgical treatments. Diabetic enteropathy is also common and management involves glycemic control and symptomatic measures. NAFLD is considered a hepatic manifestation of metabolic syndrome and treatment is mainly lifestyle measures, with diabetes and dyslipidemia management when coexistent. Glycogenic hepatopathy is a manifestation of poorly controlled type 1 diabetes and is managed by prompt insulin treatment. Though GI complications of diabetes are relatively common, awareness about its manifestations and treatment options are low among physicians. Optimal management of GI complications is important for appropriate metabolic control of diabetes and improvement in quality of life of the patient. This review is an update on the GI complications of diabetes, their pathophysiology, diagnostic evaluation and management.

CCR2 and CD44 promote inflammatory cell recruitment during fatty liver formation in a lithogenic diet fed mouse model

Non-alcoholic fatty liver disease (NAFLD) is a common disease with a spectrum of presentations. The current study utilized a lithogenic diet model of NAFLD. The diet was fed to mice that are either resistant (AKR) or susceptible (BALB/c and C57BL/6) to hepatitis followed by molecular and flow cytometric analysis. Following this, a similar approach was taken in congenic mice with specific mutations in immunological genes. The initial study identified a significant and profound increase in multiple ligands for the chemokine receptor CCR2 and an increase in CD44 expression in susceptible C57BL/6 (B6) but not resistant AKR mice. Ccr2^−/− mice were completely protected from hepatitis and Cd44^−/− mice were partially protected. Despite protection from inflammation, both strains displayed similar histological steatosis scores and significant increases in serum liver enzymes. CD45⁺CD44⁺ cells bound to hyaluronic acid (HA) in diet fed B6 mice but not Cd44^−/− or Ccr2^−/− mice. Ccr2^−/− mice displayed a diminished HA binding phenotype most notably in monocytes, and CD8⁺ T-cells. In conclusion, this study demonstrates that absence of CCR2 completely and CD44 partially reduces hepatic leukocyte recruitment. These data also provide evidence that there are multiple redundant CCR2 ligands produced during hepatic lipid accumulation and describes the induction of a strong HA binding phenotype in response to LD feeding in some subsets of leukocytes from susceptible strains.

Deletion of Nrf2 leads to rapid progression of steatohepatitis in mice fed atherogenic plus high-fat diet

BACKGROUND

The transcription factor nuclear factor-E2-related factor-2 (Nrf2) inhibits lipid accumulation and oxidative stress in the liver by interfering with lipogenic pathways and inducing antioxidative stress genes.

METHODS

The involvement of Nrf2 in defense against the development of steatohepatitis was studied in an experimental model induced by an atherogenic plus high-fat (Ath + HF) diet. Wild-type (WT) and Nrf2-null mice were fed the diet. Their specimens were analyzed for pathology as well as for the expression levels of genes involved in fatty acid metabolism and those involved via the Nrf2 transcriptional pathway.

RESULTS

In Nrf2-null mice fed the diet, steatohepatitis developed rapidly, leading to precirrhosis. The Ath + HF diet increased hepatic triglyceride levels and changed fatty acid composition in both mouse groups. However, oleic acid (C18:1 n-9) predominated in the livers of Nrf2-null mice. Correlating well with the pathology, the mRNA levels of the factors involved in fatty acid metabolism (Lxr, Srebp-1a, 1c, Acc-1, Fas, Scd-1, and Fatty acid transporting peptides 1, 3, 4), the inflammatory cytokine genes (Tnf-α and IL-1β), and the fibrogenesis-related genes (Tgf-β1 and α-Sma) were significantly increased in the livers of Nrf2-null mice fed the diet, compared with the levels of these factors in matched WT mice. Oxidative stress was significantly increased in the livers of Nrf2-null mice fed the diet. This change was closely associated with the decreased levels of antioxidative stress genes.

CONCLUSIONS

Nrf2 deletion leads to the rapid onset and progression of steatohepatitis induced by an Ath + HF diet, through both up-regulation of co-regulators of fatty acid metabolism and down-regulation of oxidative metabolism regulators in the liver.

NIKEI: a new inexpensive and non-invasive scoring system to exclude advanced fibrosis in patients with NAFLD

Aims

To develop, validate and compare a non-invasive fibrosis scoring system for non-alcoholic fatty liver disease (NAFLD) derived from routinely obtained clinical and biochemical parameters.

Methods

267 consecutive patients with biopsy proven fatty liver or non-alcoholic steatohepatitis were randomly assigned to the estimation (2/3) or validation (1/3) group to develop a model for the prediction of advanced fibrosis. Univariate statistics were performed to compare patients with and without advanced fibrosis, and following a multivariate logistic regression analysis a new scoring system was constructed. This non-invasive Koeln-Essen-index (NIKEI) was validated and compared to the FIB-4 index by calculating the area under the receiver operating characteristic curve (AUC). We evaluated a stepwise combination of both scoring systems for the precise prediction of advanced fibrosis. To set in contrast, we additionally tested the diagnostic accuracy of the AST/ALT ratio, BARD score and the NAFLD fibrosis score in our cohort.

Results

Age, AST, AST/ALT ratio, and total bilirubin were identified as significant predictors of advanced fibrosis and used to construct the NIKEI with an AUC of 0.968 [0.937; 0.998] compared to 0.929 [0.869; 0.989] for the FIB-4 index. The absence of advanced fibrosis could be confirmed with excellent accuracy (99–100%). The positive predictive value of the FIB-4 index was higher (100% vs. 60%), however, the false negative rate was also high (33%). With a stepwise combination of both indices 82%–84% of biopsies would have been avoidable without a single misclassification. The AUROC for AST/ALT ratio, the NAFLD fibrosis score, and the BARD score were 0.81 (95% CI, 0.72–0.90), 0.96 (95% CI 0.92–0.99), and 0.67 (95% CI 0.55–0.78), respectively.

Conclusion

The NIKEI can reliably exclude advanced fibrosis in subjects with NAFLD. In combination with the FIB-4 index misclassification with inadequate clinical management can be avoided while the need for liver biopsies can be reduced.

Gly482Ser mutation impairs the effects of peroxisome proliferator-activated receptor γ coactivator-1α on decreasing fat deposition and stimulating phosphoenolpyruvate carboxykinase expression in hepatocytes

Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a transcriptional coactivator of nuclear receptor peroxisome proliferator-activated receptor γ that critically regulates glucose and fat metabolism. Although clinical evidence suggests that Gly482Ser polymorphism of PGC-1α is associated with an increased incidence of nonalcoholic fatty liver disease, a direct role for Gly482Ser mutation in altering PGC-1α actions on hepatocyte fat deposition remains to be explored. We hypothesized that Gly482Ser mutation impairs the abilities of PGC-1α in ameliorating overnutrition-induced hepatocyte fat deposition and in stimulating hepatocyte expression of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C; encoded by a key PGC-1α target gene). In the present study, treatment of cultured hepatocytes with palmitate induced fat deposition, serving as a cell model of hepatic steatosis. Upon overexpression of wild-type PGC-1α, H4IIE cells exhibited a significant decrease in palmitate-induced hepatocyte fat deposition compared with control cells and/or cells upon overexpression of mutant PGC-1α (Gly482Ser). Overexpression of wild-type PGC-1α, but not mutant PGC-1α, also caused a significant increase in hepatocyte expression of carnitine palmitoyl transferase 1a, a rate-determining enzyme that transfers long-chain fatty acids into mitochondria for oxidation. In addition, overexpression of mutant PGC-1α did not stimulate PEPCK-C expression as overexpression of wild-type PGC-1α did, likely due to a decrease in the ability of mutant PGC-1α in increasing PEPCK promoter transcription activity. Together, these results suggest that Gly482Ser mutation impairs the abilities of PGC-1α in decreasing fat deposition and in stimulating PEPCK-C expression in cultured hepatocytes.

Noninvasive diagnosis of pediatric nonalcoholic fatty liver disease

Because nonalcoholic steatohepatitis can progress towards cirrhosis even in children, early detection of hepatic fibrosis and accurate diagnosis of nonalcoholic fatty liver disease (NAFLD) are important. Although liver biopsy is regarded as the gold standard of diagnosis, its clinical application is somewhat limited in children due to its invasiveness. Noninvasive diagnostic methods, including imaging studies, biomarkers of inflammation, oxidative stress, hepatic apoptosis, hepatic fibrosis, and noninvasive hepatic fibrosis scores have recently been developed for diagnosing the spectrum of NAFLD, particularly the severity of hepatic fibrosis. Although data and validation are still lacking for these noninvasive modalities in the pediatric population, these methods may be applicable for pediatric NAFLD. Therefore, noninvasive imaging studies, biomarkers, and hepatic fibrosis scoring systems may be useful in the detection of hepatic steatosis and the prediction of hepatic fibrosis, even in children with NAFLD.

Curcumin prevents liver fat accumulation and serum fetuin-A increase in rats fed a high-fat diet

Fetuin-A is synthesized in the liver and is secreted into the bloodstream. Clinical studies suggest involvement of fetuin-A in metabolic disorders such as visceral obesity, insulin resistance, diabetes, and fatty liver. Curcumin is extracted from the rhizome Curcuma longa and has been shown to possess potent antioxidant, anticarcinogenic, anti-inflammatory, and hypoglycemic properties. In this study, we investigated the effect of curcumin treatment on serum fetuin-A levels as well as hepatic lipids and prooxidant-antioxidant status in rats fed a high-fat diet (HFD). Male Sprague-Dawley rats were divided into six groups. Group 1 was fed control diet (10 % of total calories from fat). Groups 2 and 3 were given curcumin (100 and 400 mg/kg bw/day, respectively ) by gavage for 8 weeks and were fed control diet. Group 4 was fed with HFD (60 % of total calories from fat). Groups 5 and 6 received HFD together with the two doses of curcumin, respectively. Curcumin treatment appeared to be effective in reducing liver triglycerides and serum fetuin-A levels. These findings suggest that the reduction of fetuin-A may contribute to the beneficial effects of curcumin in the pathogenesis of obesity.

A novel inhibitor of stearoyl-CoA desaturase-1 attenuates hepatic lipid accumulation, liver injury and inflammation in model of nonalcoholic steatohepatitis

Stearoyl-CoA desaturase-1 (SCD-1) catalyzes the biosynthesis of monounsaturated fatty acids, and their abnormality is possibly responsible for obesity, insulin resistance, hepatic steatosis and nonalcoholic steatohepatitis (NASH). A novel SCD-1 inhibitor, N-(2-hydroxy-2-phenylethyl)-6-[4-(2-methylbenzoyl)piperidin-1-yl]pyridazine-3-carboxamide, has been obtained. The compound inhibited liver SCD-1 activity and increased liver triglyceride accumulation in mice fed with non-fat, high-sucrose diets. In order to evaluate the effects of the SCD-1 inhibitor on NASH development, rats were fed with lipogenic methionine and choline-deficient (MCD) diets for 8 weeks. The SCD-1 inhibitor was administered once-daily at a dose of 30 or 100 mg/kg/d by oral gavage. Administration of a high dose of the SCD-1 inhibitor decreased triglyceride accumulation in the liver of NASH rats by 80%. Administration of a high dose of the SCD-1 inhibitor attenuated the increase of aspartate aminotransferase (AST) and alanine transaminase (ALT) by 86% and 78%, respectively. Hepatic steatosis, hepatocellular degeneration and inflammatory cell infiltration were histologically observed in the liver of NASH rats, and administration of the SCD-1 inhibitor ameliorated these crucial observations in NASH. In summary, an SCD-1 inhibitor ameliorated hepatic triglyceride accumulation, liver injury, hepatocellular degeneration and inflammation in experimental NASH models. These results suggest that SCD-1 maybe a promising target for the treatment of NASH.

Nonalcoholic fatty liver disease and the metabolic syndrome: clinical implications and treatment

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to rise along with the global obesity epidemic. As NAFLD is the most common cause of chronic liver disease in the United States, it has become a major health concern. It affects all ethnicities, with the highest prevalence among the Hispanic population. Individuals with nonalcoholic steatohepatitis (NASH), the more serious form of NAFLD, are at increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Since NAFLD is intricately associated with the metabolic syndrome and insulin resistance, increased risk of cardiovascular disease and mortality become a real concern. It has recently been shown that current nutrition trends, such as increased consumption of high-fructose corn syrup and certain types of fats, may have an important role in the increased NAFLD prevalence. As there are no ideal treatment options available for NAFLD, a multifaceted treatment approach should be tailored to each individual patient.

Markers in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide, encompasses a spectrum of abnormal liver histology ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Population studies show that NAFLD is strongly associated with insulin resistance, obesity, type 2 diabetes mellitus, and lipid abnormalities. In the context of hepatic steatosis, factors that promote cell injury, inflammation, and fibrosis include oxidative stress, early mitochondrial dysfunction, endoplasmic reticulum stress, iron accumulation, apoptosis, adipocytokines, and stellate cell activation. The exact NASH prevalence is unknown because of the absence of simple noninvasive diagnostic tests. Although liver biopsy is the "gold standard" for the diagnosis of NASH, other tests are needed to facilitate the diagnosis and greatly reduce the requirement for invasive liver biopsy. In addition, the development of new fibrosis markers in NASH is needed to facilitate the assessment of its progression and the effectiveness of new therapies. The aim of this chapter, which is overview of biomarkers in NASH, is to establish a systematic approach to laboratory findings of the disease.

Antioxidant therapy in nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) affects up to 3% of the North American population. It occurs as a manifestation of the insulin-resistant state and oxidative stress is thought to be a key component of its pathophysiology. Exercise and diet, which are the mainstay of therapy, are difficult to achieve and maintain with a disappointing long-term compliance record. There is growing literature on the potential for antioxidant therapy. The recent literature strongly suggests that vitamin E supplementation and other putative free radical scavengers and/or antioxidants are beneficial in improving biochemical and histological parameters in NASH.

Nonalcoholic fatty liver disease: current and potential therapies

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver injury worldwide. It covers a wide spectrum of hepatic disorders ranging from simple steatosis, through steatohepatitis (steatosis with inflammation), to cirrhosis. The molecular and cellular mechanisms underlying hepatic injury in NAFLD are not clear. Several evidences suggest that multiple mechanisms including insulin resistance, oxidative stress, inflammation, and genetic factors interact to initiate the development of NAFLD. Despite that there is currently no approved drug therapy for NAFLD, many approaches appear to be beneficial. Insulin sensitizers, antioxidants and antiinflammatory agents showed promising effects. This review highlights the current as well as the potential therapies of NAFLD.

Higher hepatic gene expression and serum levels of matrix metalloproteinase-2 are associated with steatohepatitis in non-alcoholic fatty liver diseases

We investigated the gene expression of tissue inhibitor metalloproteinases (TIMPs) and matrix metalloproteinases (MMPs) and serum levels of TIMPs, MMPs, and hyaluronic acid that are associated with liver fibrosis in 64 patients with nonalcoholic fatty liver diseases (NAFLD). Whereas, no differences were found between patients with and without nonalcoholic steatohepatitis (NASH) in serum levels of hyaluronic acid when excluding NASH patients with advanced fibrosis, the quantity of MMP2 mRNA in liver tissue and serum MMP2 levels were significantly higher in patients with NASH than those without, even focusing on patients with less advanced fibrosis, indicating the initiation of liver fibrosis.