Epidemiology of nonalcoholic fatty liver

Pulmonary embolism risk in hospitalized patients with nonalcoholic fatty liver disease: A case-control study

Abundant research has associated nonalcoholic fatty liver disease (NAFLD) with atherosclerosis, but very few reports have evaluated the association between NAFLD and venous thromboembolism. We aimed to investigate the association between NAFLD and pulmonary embolism (PE) in hospitalized patients. In this retrospective case-control study, we included consecutive patients from 2 university-affiliated hospitals who were referred for CT pulmonary angiograms for a suspected PE. Patients with a history of excessive alcohol consumption, chronic liver diseases or cirrhosis were excluded. The imaging studies of the entire cohort were reviewed by 2 expert radiologists who confirmed the diagnosis of PE and examined the liver to detect and grade hepatic steatosis. Accordingly, patients were categorized into NAFLD patients and non-NAFLD controls. Patient demographics, medical history, hospitalization details as well as patients' outcomes were documented. Multivariate analysis was performed to identify predictors for developing PE and hazard ratios with corresponding 95% confidence intervals were estimated. A total of 377 patients (101 with NAFLD and 276 controls) were included. NAFLD patients had significantly higher BMI values (33.16 ± 6.78 vs 26.81 ± 5.6; P < .001) and prevalence of diabetes (41 (40%) vs 85 (30.8%); P = .03). The prevalence of PE was significantly higher in the NAFLD group (80 (79.2%) vs 147 (53.3%), P < .001). In a multivariate analysis, older age, recent surgery or trauma, active malignancy, smoking, and NAFLD (HR ratio = 4.339, P < .0001 and 95% CI = 2.196-8.572) were independently associated with PE development. Patients with NAFLD were associated with an increased risk of developing PE independent of other classical risk factors for PE.

Obesity-associated biochemical markers of inflammation and the role of grain phytochemicals

The incidence of obesity or excessive fat accumulation in the body is increasing worldwide and has become one of the major growing health problems. Obese condition is linked with an increased level of body lipids, oxidative stress, and expression of inflammatory markers. This leads to plasma and hepatic hyperlipidemia, activation of proinflammatory cytokines (TNF-α, IL-6, and IL-1β), and transcriptional factors, which in turn lead to a high risk of cardiovascular diseases, insulin resistance, diabetes, asthma, rheumatological problem, and liver failure. Grains are the major staple food crops grown for consumption in most of the developing countries. Cereals and millets, such as rice, wheat, maize, barley, finger millet, foxtail millet, proso millet, kodo millet in the whole form with bran, germ, and endosperm, are found to be rich in phytochemicals, such as phenolics acids, vitamin E, phytosterols, carotenoids, antioxidants, dietary fiber, which have a potential health benefit on various lifestyle disorders. In this article, we summarize the findings and investigations regarding the anti-inflammatory effect of various grain phytochemicals in in vitro and in vivo models and their potential health benefits. PRACTICAL APPLICATIONS: The occurrence of obesity is rising globally and is becoming a major health concern. Obesity will lead to multiple health problems due to oxidative and inflammatory stress in the body. Whole forms of cereals and millets consumptions have shown to reduce the risk of metabolic disorders and several chronic diseases. Potential bioactive components in various grains will act on the inhibition ofbiochemical markers connected with inflammation and adipogenesis.

Polyene Phosphatidylcholine Ameliorates High Fat Diet-Induced Non-alcoholic Fatty Liver Disease via Remodeling Metabolism and Inflammation

Recent years have witnessed a rise in the morbidity of non-alcoholic fatty liver disease (NAFLD), in line with the global outbreak of obesity. However, effective intervention strategy against NAFLD is still unavailable. The present study sought to investigate the effect and mechanism of polyene phosphatidylcholine (PPC), a classic hepatoprotective drug, on NAFLD induced by high fat diet (HFD). We found that PPC intervention reduced the mass of liver, subcutaneous, epididymal, and brown fats in HFD mice. Furthermore, PPC supplementation significantly mitigated liver steatosis and improved glucose tolerance and insulin sensitivity in HFD mice, which was accompanied by declined levels of hepatic triglyceride, serum triglyceride, low density lipoprotein, aspartate aminotransferase, and alanine aminotransferase. Using transcriptome analysis, there were 1,789 differentially expressed genes (| fold change | ≥ 2, P < 0.05) including 893 upregulated genes and 896 downregulated genes in the HFD group compared to LC group. A total of 1,114 upregulated genes and 1,337 downregulated genes in HFD + PPC group were identified in comparison to HFD group. With the help of Gene Ontology (GO) analysis, these differentially expressed genes between HFD+PPC and HFD group were discovered related to “lipid metabolic process (GO: 0006629),” “lipid modification (GO: 0030258),” and “lipid homeostasis (GO: 0055088)”. Though Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we found pathways associated with hepatic homeostasis of metabolism and inflammation. Notably, the pathway “Non-alcoholic fatty liver disease (mmu04932)” (P-value = 0.00698) was authenticated in the study, which may inspire the potential mechanism of PPC to ameliorate NAFLD. The study also found that lipolysis, fatty acid oxidation, and lipid export associated genes were upregulated, while the genes in uptake of lipids and cholesterol synthesis were downregulated in the liver of HFD mice after PPC supplementation. Interestingly, PPC attenuated the metabolic inflammation via inhibiting pro-inflammatory macrophage in the livers of mice fed by HFD. In summary, this study demonstrates that PPC can ameliorate HFD-induced liver steatosis via reprogramming metabolic and inflammatory processes, which inspire clues for further clarifying the intervention mechanism of PPC against NAFLD.

Ginsenoside Rg2 Ameliorates High-Fat Diet-Induced Metabolic Disease through SIRT1

Ginsenoside Rg2 has been previously reported to reduce glucose production and adipogenesis in adipose tissue. However, the effects of ginsenosides Rg2 on hepatic lipid metabolism remain vacant. In this study, we found that ginsenoside Rg2 treatment significantly attenuated oleic acid and palmitic acid (OA&PA)-induced intracellular lipid deposition and oxidative stress in mouse primary hepatocytes. C57BL/6J mice that are fed with a high-fat diet (HFD) and treated with ginsenosides Rg2 displayed decreased body weight, reversed hepatic steatosis, and improved glucose tolerance and insulin sensitivity. Ginsenoside Rg2 administration significantly ameliorated HFD-induced hepatic oxidative stress and apoptosis. Moreover, Ginsenoside Rg2 had a good affinity with Sirtuin1 (SIRT1) and regulated its expression in vivo and in vitro. Deficiency of SIRT1 eliminated the therapeutic effect of ginsenoside Rg2 on lipid accumulation and overproduction of reactive oxygen species (ROS) in OA&PA-induced mice primary hepatocytes. Ginsenoside Rg2 treatment failed to alter the lipid and glucose disorder in hepatic SIRT1 deficient mice feeding on HFD. SIRT1 deficiency dissolves the therapeutic effect of ginsenoside Rg2 on oxidative stress and hepatocyte apoptosis induced by HFD. In summary, ginsenoside Rg2 plays a therapeutic role in HFD-induced hepatosteatosis of mice by decreasing the lipogenesis process and improving antioxidant capacity in an SIRT1-dependent manner.

Osteoprotegerin Promotes Liver Steatosis by Targeting the ERK-PPAR-γ-CD36 Pathway

Previous cross-sectional studies have established that circulating osteoprotegerin (OPG) levels are associated with nonalcoholic fatty liver disease (NAFLD). However, the role of OPG in metabolic diseases, such as diabetes and NAFLD, is still unclear. In the current study, we demonstrated that hepatic OPG expression was downregulated in NAFLD individuals and in obese mice. OPG deficiency decreased lipid accumulation and expression of CD36 and peroxisome proliferator-activated receptor-γ (PPAR-γ) in the livers of OPG^-/- mice and cultured cells, respectively, whereas OPG overexpression elicited the opposite effects. The stimulatory role of OPG in lipid accumulation was blocked by CD36 inactivation in hepatocytes isolated from CD36^-/- mice. The overexpression of OPG led to a decrease in extracellular signal-regulated kinase (ERK) phosphorylation in the livers of OPG^-/- mice and in cultured cells, while OPG deficiency resulted in the opposite effect. The inhibition of PPAR-γ or the activation of ERK blocked the induction of CD36 expression by OPG in cultured cells. Mechanistically, OPG facilitated CD36 expression by acting on PPAR response element (PPRE) present on the CD36 promoter. Taken together, our study revealed that OPG signaling promotes liver steatosis through the ERK-PPAR-γ-CD36 pathway. The downregulation of OPG in NAFLD might be a compensatory response of the body to dampen excess hepatic fat accumulation in obesity.

Differing Associations between Fatty Liver and Dyslipidemia According to the Degree of Hepatic Steatosis in Korea

Objective

Fatty liver is associated with insulin resistance-related diseases, such as dyslipidemia, obesity, and type 2 diabetes. The aim of this study was to evaluate the association of dyslipidemia with fatty liver and assess the differences in these associations according to the degree of hepatic steatosis.

Methods

A total of 2,462 subjects (1,679 men and 783 women) who underwent a comprehensive health check-up (including abdominal computed tomography) from January 2010 to December 2013 were enrolled at Samsung Changwon Hospital Healthcare Center. The liver attenuation index (LAI), defined as the difference between mean hepatic and splenic attenuation, was used to assess the degree of hepatic steatosis. An LAI below 5 Hounsfield units was defined as fatty liver.

Results

We found that 32.2% of the study subjects had fatty liver. Serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG), and fasting blood glucose concentrations and glycated hemoglobin (HbA1c percentage) were significant greater in the fatty liver group compared with the non-fatty liver group, while serum high-density lipoprotein cholesterol (HDL-C) was significantly lower in the fatty liver group. Subjects with fatty liver had 1.7-fold greater risk of dyslipidemia than those without fatty liver after adjusting for age, sex, body mass index (BMI), and HbA1c. When individuals with fatty liver were analyzed by tertiles of LAI values, LDL-C, TG, fasting glucose, BMI, and HbA1c concentrations increased while HDL-C decreased with decreasing LAI tertiles. Compared with LAI tertile 3, the risk for dyslipidemia significantly increased with adjusted odds ratios of 1.42, and 1.81 in tertiles 2 and 1, respectively.

Conclusion

Fatty liver was significantly associated with dyslipidemia and this association varied according to the degree of hepatic steatosis.

Age-Related Decrease in Skeletal Muscle Mass Is an Independent Risk Factor for Incident Nonalcoholic Fatty Liver Disease: A 10-Year Retrospective Cohort Study

Background/Aims

Sarcopenia has emerged as an important risk factor for nonalcoholic fatty liver disease (NAFLD). Although aging is the main cause of sarcopenia, the longitudinal association between age-related body composition changes and NAFLD development has not been fully investigated. Thus, we evaluated whether age-related increased fat mass or decreased muscle mass is an independent risk factor for incident NAFLD.

Methods

We conducted a retrospective cohort study involving 4,398 initially NAFLD-free subjects who underwent routine health examinations during 2004 to 2005 and returned for a follow-up during 2014 to 2015. Their body composition was measured by bioelectrical impedance analysis, and fatty liver was diagnosed by abdominal ultrasonography.

Results

At the 10-year follow-up, 591 out of 4,398 participants (13.4%) had developed NAFLD. In men and women, both increased fat mass and decreased appendicular skeletal muscle mass (ASM) with aging were significantly associated with incident NAFLD after adjustment. A subgroup analysis according to the baseline obesity status showed that increased fat mass was significantly associated with incident NAFLD in obese and nonobese subjects. However, decreased ASM was significantly associated with incident NAFLD in nonobese but not in obese subjects. According to ΔASM tertiles (decrease of ASM), the odds ratios for incident NAFLD in nonobese subjects were 1.38 (95% confidence interval [CI], 1.04 to 1.84) for the second tertile and 1.81 (95% CI, 1.34 to 2.45) for the third tertile after adjustment (p=0.001).

Conclusions

A progressive increase in fat mass and a loss of ASM with aging were significantly associated with incident NAFLD. This association was more prominent in nonobese subjects.

Hypoxia inducible factor-1 promotes liver fibrosis in nonalcoholic fatty liver disease by activating PTEN/p65 signaling pathway

Obesity is a major contributor to the development of steatohepatitis and fibrosis from nonalcoholic fatty liver disease (NAFLD). Hypoxia aggravates progression of NAFLD. In mice on high-fat diet (HFD), hepatic steatosis leads to liver tissue hypoxia, evidenced by accumulation of hypoxia inducible factor-1-alpha (HIF-1α), which is a central regulator of the global response to hypoxia. Hepatocyte cell signaling is an important factor in hepatic fibrogenesis. We here hypothesize that HIF-1α knockout in hepatocyte may protect against liver fibrosis. We first found that HFD led to 80% more hepatic collagen deposition than Hif1a^-/- hep mice, which was confirmed by a-SMA staining of liver tissue. Body weight and liver weight were similar between groups. We then found the increasing HIF1a expression and decreasing PTEN expression in the mice on HFD and in PA-treated HepG2 cells. Finally, we found that HIF1 mediated PTEN/nfkb-p65 pathway plays an important role in the development of NAFLD to liver fibrosis. Collectively, these results identify a novel HIF1a/PTEN/NF-κ Bp65 signaling pathway in NAFLD, which could be targeted for the therapy.

Factors influencing longitudinal changes of circulating liver enzyme concentrations in subjects randomized to placebo in four clinical trials

Liver enzyme concentrations are measured as safety end points in clinical trials to detect drug-related hepatotoxicity, but little is known about the epidemiology of these biomarkers in subjects without hepatic dysfunction who are enrolled in drug trials. We studied alanine and aspartate aminotransferase (ALT and AST) in subjects randomized to placebo who completed assessments over 36 mo in a cardiovascular outcome trial [the Stabilisation of Atherosclerotic Plaque by Initiation of Darapladib Therapy ("STABILITY") trial; n = 4,264; mean age: 64.2 yr] or over 12 mo in three trials that enrolled only subjects with type 2 diabetes (T2D) [the DIA trials; n = 308; mean age: 62.4 yr] to investigate time-dependent relationships and the factors that might affect ALT and AST, including body mass index (BMI), T2D, and renal function. Multivariate linear mixed models examined time-dependent relationships between liver enzyme concentrations as response variables and BMI, baseline T2D status, hemoglobin A_1c levels, and renal function, as explanatory variables. At baseline, ALT was higher in individuals who were men, <65 yr old, and obese and who had glomerular filtration rate (GFR) >60 ml·min^-1·1.73 m^-2. ALT was not significantly associated with T2D at baseline, although it was positively associated with HbA_1c. GFR had a greater impact on ALT than T2D. ALT concentrations decreased over time in subjects who lost weight but remained stable in individuals with increasing BMI. Weight change did not alter AST concentrations. We provide new insights on the influence of time, GFR, and HbA_1c on ALT and AST concentrations and confirm the effect of sex, age, T2D, BMI, and BMI change in subjects receiving placebo in clinical trials. NEW & NOTEWORTHY Clinical trials provide high-quality data on liver enzyme concentrations from subjects randomized to placebo that can be used to investigate the epidemiology of these biomarkers. The adjusted models show the influence of sex, age, time, renal function, type 2 diabetes, HbA_1c, and body mass index on alanine aminotransferase and aspartate aminotransferase concentrations and their relative importance. These factors need to be considered when assessing potential signals of hepatotoxicity in trials of new drugs and in clinical trials investigating subjects with nonalcoholic fatty liver disease.

IRGM Gene Variants Modify the Relationship Between Visceral Adipose Tissue and NAFLD in Patients With Crohn's Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized comorbidity in Crohn's disease (CD), but the mechanisms are poorly understood. Autophagy is a highly conserved process regulating innate immunity that contributes to CD susceptibility. Emerging data suggest that variants in the autophagy-governing IRGM gene may contribute to the accumulation of visceral adipose tissue (VAT) and hepatic fat. Our objective was to characterize the relationship between VAT, IRGM gene variants, and NAFLD risk in patients with CD.

METHODS

We included all CD patients in the Prospective Registry in Inflammatory Bowel Disease Study at Massachusetts General Hospital (PRISM) without history of alcohol abuse or liver disease. Hepatic fat was quantified by liver attenuation (LA) on computed tomography, with NAFLD defined by the validated liver:spleen (L:S) ratio. NAFLD severity was estimated by the FIB-4 Index and alanine aminotransferase (ALT). Using logistic regression modeling, we examined the relationship between VAT, autophagy gene variants, and NAFLD risk.

RESULTS

Among 462 patients, 52% had NAFLD. Increasing VAT quartile was associated with reduced LA (mean change, -7.43; 95% confidence interval [CI], -10.05 to -4.81; Ptrend < 0.0001). In the fully adjusted model, patients in the highest VAT quartile had a 2.2-fold increased NAFLD risk (95% CI, 1.21 to 4.14; Ptrend = 0.032) and a 4.2-fold increased risk of ALT>upper limit of normal (ULN) (95% CI, 1.19 to 14.76; Ptrend = 0.017). The relationship between VAT and NAFLD was modified by IRGM variants rs4958847 and rs13361189 (Pinteraction = 0.005 and Pinteraction < 0.001, respectively).

CONCLUSIONS

In a large CD cohort, VAT was directly associated with prevalent NAFLD, and this relationship was augmented by functionally annotated IRGM variants associated with impaired autophagy.

JAZF1 ameliorates age and diet-associated hepatic steatosis through SREBP-1c -dependent mechanism

JAZF zinc finger 1 (JAZF1) is involved in glucose and lipid metabolisms. However, its role in aging- and nutrient-related hepatic steatosis is unclear. In the current study, we demonstrated that JAZF1 expression was markedly down-regulated in obesity-associated mice and nonalcoholic fatty liver disease (NAFLD) patients. During aging, JAZF1 expression was gradually down-regulated in both C57BL/6 J and JAZF1-Tg mice. In JAZF1-Tg mice, body fat content and hepatosteatosis were protected from HFD-induced steatosis, and accompanied by decreased lipogenesis gene expression. The inhibitory effects of hepatic steatosis in JAZF1-Tg mice, however, were disappeared during aging. In hepatocytes, over-expression of JAZF1 attenuated, while knockdown of JAZF1 enhanced the expression of lipogenesis genes. The over-expressing of JAZF1 in hepatocytes displayed the increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased sterol regulatory element-binding protein 1c (SREBP-1c) expression. The roles of JAZF1 were partially attenuated by Compound C. Mechanistically, JAZF1 suppressed SREBP-1c expression through the inhibition of transcriptional activity of liver X receptor response elements (LXREs) in the SREBP-1c promoter. Data illustrate that JAZF1 may have a crucial role in the regulation of age and nutrient-associated hepatosteatosis through an AMPK/SREBP-1c-dependent mechanism.

Patients with Nonalcoholic Fatty Liver Disease Have a Low Response Rate to Vitamin D Supplementation

Background: Hypovitaminosis D is associated with an increased severity of nonalcoholic fatty liver disease (NAFLD), but reports on the response to cholecalciferol (vitamin D₃) supplementation are conflicting.Objective: The objective of this study was to determine if standard vitamin D₃ supplementation is effective in NAFLD with hypovitaminosis D.Methods: Sixty-five well-characterized adults [age (mean ± SD): 51.6 ± 12.3 y] with biopsy-proven NAFLD were screened. Forty-two patients (the ratio of men to women was 13:29) had hypovitaminosis D (plasma 25-hydroxyvitamin D [25(OH)D] <30 ng/mL). An observational study was performed in NAFLD patients with hypovitaminosis D treated with 2000 IU cholecalciferol (vitamin D₃) daily for 6 mo per clinical practice. Plasma 25(OH)D, hepatic and metabolic panels, and metabolic syndrome components were assessed before and after cholecalciferol supplementation. Body composition was measured by using bioelectrical impedance analysis. The primary outcome measure was plasma 25(OH)D ≥30 ng/mL at the end of the study. Secondary outcomes included change in serum transaminases, fasting plasma glucose, and insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Chi-square, Student's t tests, correlation coefficient, and multivariate analysis were performed.Results: Twenty-six (61.9%) patients had nonalcoholic steatohepatitis (NASH), and 16 (38.1%) had hepatic steatosis. After 6 mo of cholecalciferol supplementation, plasma 25(OH)D ≥30 ng/mL was observed in 16 subjects (38.1%; responders) whereas the remaining 26 patients (61.9%) were nonresponders with plasma 25(OH)D <30 ng/mL. Significantly fewer (P < 0.01) patients with NASH were responders (4 of 26, 15.4%) than those with hepatic steatosis (12 of 16, 75%). Baseline fasting serum alanine aminotransferase, plasma glucose, and HOMA-IR were similar in the responders and nonresponders, but the NASH score on the liver biopsy was lower (16.5%) in the responders (P < 0.001). Nonresponders had a higher fat mass (10.5%) and lower fat-free mass (10.4%) than responders did. End-of-treatment alanine aminotransferase and HOMA-IR improved only in responders. The baseline HOMA-IR and histological NASH score were independent predictors of nonresponse to cholecalciferol supplementation.Conclusions: Daily supplementation with 2000 IU cholecalciferol for 6 mo did not correct hypovitaminosis D in the majority of patients with NASH. Further studies are needed to determine if higher doses are effective. This trial was registered at clinicaltrials.gov as 13-00153.

Dynamic mechanical analysis to assess viscoelasticity of liver tissue in a rat model of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in both developed and developing countries. A noninvasive method of detecting early stage NAFLD and distinguishing non-alcoholic steatohepatitis (NASH) from simple steatosis (SS) would be useful. The over-accumulation of fat in hepatocytes alters the physical microstructure and chemical contents of the liver tissue. This study included dynamic mechanical analysis (DMA) testing on liver samples from a rat model of NAFLD to determine whether the tissue shows any significant changes in viscoelasticity due to the histological changes. Liver steatosis was induced in 57 rats by gavage feeding of a high fat emulsion; 12 rats received a standard diet only and served as controls. Each rat provided 2 or 3 samples for DMA tests. The shear modulus and loss modulus were measured at 9 frequency points evenly-spaced in the range from 1Hz to 41Hz. The phase velocity of shear wave was calculated from the measured modulus. Multivariate T² test was used to assess the significance of intra-group difference. The results showed significant changes (p < 0.05) in storage modulus in livers with moderate to severe (S2 to S4) steatosis in comparison with livers without steatosis (S0), while the loss modulus demonstrated significant changes earlier in stage S1, indicating that fat accumulation affects the mechanical properties of liver, particularly viscosity. However, no significant differences were observed between the steatosis grades. These results also suggest that mild inflammation may affect the mechanical properties, which requires further verification. These findings provide new information about the mechanical properties of livers with NAFLD in low frequency range and suggest that it is possible to distinguish normal livers from livers with NAFLD.

Celastrol ameliorates liver metabolic damage caused by a high-fat diet through Sirt1

Objective

Celastrol was recently identified as a potential novel treatment for obesity. However, the effect of Celastrol on nonalcoholic fatty liver disease (NAFLD) remains elusive. The aim of this study is to evaluate the role of Celastrol in NAFLD.

Methods

Functional studies were performed using wild-type C57BL/6J (WT) mice and liver specific Sirt1-deficient (LKO) mice. The molecular mechanism was explored in primary mouse liver and primary hepatocytes.

Results

When WT mice receiving a high-fat diet (HFD) were treated with Celastrol, reductions in body weight, subcutaneous and visceral fat content, and liver lipid droplet formation were observed, along with reduced hepatic intracellular triglyceride and serum triglyceride, free fatty acid, and ALT concentrations. Furthermore, Celastrol decreased hepatic sterol regulatory element binding protein 1c (Srebp-1c) expression, enhanced the phosphorylation of hepatic AMP-activated protein kinase α (AMPKα), and increased the expression of hepatic serine–threonine liver kinase B1 (LKB1). Additionally, Celastrol treatment improved glucose tolerance and insulin sensitivity in WT mice fed the HFD. Celastrol administration also improved the anti-inflammatory and anti-oxidative status by inhibiting nuclear factor kappa B (NFκB) activity and the mRNA levels of proinflammatory cytokines and increasing mitochondrial DNA copy number and anti-oxidative stress genes expression in WT mice liver, in vivo and in vitro. Moreover, Celastrol induced hepatic Sirt1 expression in WT mice, in vivo and in vitro. These Celastrol-mediated protective effects in WT mice fed a HFD were abolished in LKO mice fed a HFD. It was more interesting that Celastrol aggravated HFD-induced liver damage in LKO mice fed a HFD by inhibiting the phosphorylation of AMPKα and boosting the translocation of NFκB into the nucleus, thereby resulting in the increase of Srebp-1c expression and the mRNA levels of liver proinflammatory cytokines.

Conclusions

Celastrol ameliorates NAFLD by decreasing lipid synthesis and improving the anti-oxidative and anti-inflammatory status. And Sirt1 has an important role in Celastrol-ameliorating liver metabolic damage caused by HFD.

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Celastrol alleviates high-fat diet-induced hepatic steatosis in wild type mice.

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Celastrol improves anti-inflammatory and antioxidant status in wild type mice.

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Celastrol induces the expression of hepatic Sirt1 in wild type mice.

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Celastrol promotes AMPKα phosphorylation in liver specific Sirt1-deficient mice.

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Celastrol increases the activity of NFκB in liver specific Sirt1-deficient mice.

Review: Non-alcoholic fatty liver disease: natural history, pathogenesis and treatment

Non-alcoholic fatty liver disease (NAFLD) is the term used to describe the alcohol-like liver injury that occurs in the absence of alcohol abuse. It embraces a range of histological abnormalities including simple steatosis or fatty liver, non-alcoholic steatohepatitis (NASH) and NAFLD induced cirrhosis. The predominant risk factor for NAFLD appears to be insulin resistance. Simple steatosis and NASH are generally asymptomatic and it is only the development of cirrhosis that has clinical consequence. At present, therapy in NAFLD concentrates on managing risk factors but in the future clinical trials may provide robust evidence for the use of insulin sensitising agents and other potential therapies.

Lipoprotein Profiles in Class III Obese Caucasian and African American Women with Nonalcoholic Fatty Liver Disease

Triglyceride content in the liver is regulated by the uptake, production and elimination of lipoproteins, and derangements in these processes contribute to nonalcoholic fatty liver disease (NAFLD). Previous studies show a direct relationship between intrahepatic fat and production of apolipoprotein B100 (apoB100) containing particles, VLDL and LDL, but little consensus exists regarding changes in lipoprotein production in the development of simple steatosis (SS) versus nonalcoholic steatohepatitis (NASH). Further, ethnic variations in lipoproteins among SS and NASH are unknown as is how such variations might contribute to the differential prevalence of disease among Caucasians versus African Americans. In this study, we assessed plasma lipoprotein profiles by nuclear magnetic resonance (NMR) spectroscopy in 70 non-diabetic class III obese females recruited from the surgical weight loss clinic. Of these, 51 females were stratified by biopsy-staged NAFLD severity (histologically normal, SS, or NASH). NASH females displayed increased circulating triglycerides and increased VLDL particle number and size relative to those with histologically normal livers, while total and large LDL concentration decreased in SS versus NASH and correlated with increased insulin resistance (via HOMA2-IR). When Caucasian women were examined alone (n = 41), VLDL and triglycerides increased between normal and SS, while total LDL and apoB100 decreased between SS and NASH along with increased insulin resistance. Compared to Caucasians with SS, African American women with SS displayed reduced triglycerides, VLDL, and small LDL and a more favorable small to large HDL ratio despite having increased BMI and HOMA2-IR. These findings suggest that ApoB100 and lipoprotein subclass particle number and size can delineate steatosis from NASH in obese Caucasian females, but should be interpreted with caution in other ethnicities as African Americans with SS display relatively improved lipoprotein profiles. This may reflect variation in the relationship between dyslipidemia and NAFLD progression across gender and ethnicity.

Extracts from Aralia elata (Miq) Seem alleviate hepatosteatosis via improving hepatic insulin sensitivity

Background

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease that is strongly associated with obesity and dysregulation of insulin in the liver. However, currently no pharmacological agents have been established for the treatment of NAFLD. In this regard, we sought to evaluate the anti-NAFLD effects of Aralia elata (Miq) Seem (AE) extract and its ability to inhibit hepatic lipid accumulation and modulate cellular signaling in a high fat diet (HFD)-induced obese mouse model.

Methods

A model of hepatic steatosis in the HepG2 cells was induced by oleic acid. Intracellular lipid droplets were detected by Oil-Red-O staining, and the expression of sterol regulatory element-binding protein 1(SREBP-1), Fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC) 1 and 2, Peroxisome proliferator activated receptor-α (PPARα), and carnitine palmitoyl transferase 1(CPT-1) was analyzed by real time reverse transcription–Polymerase chain reaction (qRT–PCR). And glucose consumption was measured with commercial kit. Furthermore, Male C57BL/6 J mice were fed with HFD to induce NAFLD. Groups of mice were given plant extracts orally at 100 and 300 mg/kg at daily for 4 weeks. After 3 weeks of AE extract treatment, we performed oral glucose tolerance test (OGTT). Liver tissue was procured for histological examination, Phosphoinositide 3-kinase (PI3K) and Protein kinase B (PKB/Akt) activity.

Results

In the present study, AE extract was shown to reduce hepatic lipid accumulation and significantly downregulate the level of lipogenic genes and upregulate the expression of lipolysis genes in HepG2 cells. And also, AE extract significantly increased the glucose consumption, indicating that AE extract improved insulin resistance. Subsequently, we confirmed the inhibitory activity of AE extract on NAFLD, in vivo. Treatment with AE extract significantly decreased body weight and the fasting glucose level, alleviated hyperinsulinism and hyperlipidemia, and reduced glucose levels, as determined by OGTT. Additionally, AE extract decreased PI3K and Akt activity.

Conclusions

Our results suggest that treatment with AE extract ameliorated NAFLD by inhibiting insulin resistance through activation of the Akt/GLUT4 pathway.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0871-5) contains supplementary material, which is available to authorized users.

Sirt1 mediates the effect of the heme oxygenase inducer, cobalt protoporphyrin, on ameliorating liver metabolic damage caused by a high-fat diet

BACKGROUND & AIMS

Heme oxygenase 1 (HO-1)-mediated increases in adiponectin, ameliorate the deleterious effects of obesity and metabolic syndrome; however, the effect of HO-1 on hepatic lipid metabolism remains elusive. The aim of this study is to evaluate the role of HO-1 in hepatic lipid metabolism.

METHODS

Functional studies were performed using C57BL/6J (WT) mice and Sirt1 liver specific mutant (Sirt1-deficient) mice. The molecular mechanism was explored in primary hepatocytes and mouse liver.

RESULTS

Chronic exposure to high-fat diet (HFD) induced hepatic steatosis in WT mice. Treatment of WT mice on HFD with cobalt protoporphyrin (CoPP), an inducer of HO-1 activity, decreased body weight and visceral fat content, reduced intracellular hepatic triglyceride and serum total cholesterol concentrations, and decreased liver lipid droplet formation. Compared with WT mice, the administration of CoPP to Sirt1-deficient mice on HFD increased visceral fat content, and slightly promoted liver lipid droplet formation. CoPP improved glucose tolerance and insulin sensitivity in WT mice on HFD, but compromised insulin sensitivity in Sirt1-deficient mice on HFD. Furthermore, CoPP-induced Sirt1 expression and decreased sterol regulatory element binding protein 1c (SREBP-1c) expression in WT mice on HFD. However, CoPP promoted SREBP-1c expression in Sirt1-deficient hepatocytes, which was reversed by a protein tyrosine phosphatase 1b inhibitor. Additionally, while the administration of CoPP to WT mice on HFD improved antioxidant and anti-inflammatory states, these CoPP-mediated effects were abolished in Sirt1-deficient mice.

CONCLUSIONS

Sirt1 mediates the effect of CoPP on ameliorating liver metabolic damage caused by HFD.

Solutions for low and high accuracy mass spectrometric data matching: a data-driven annotation strategy in nontargeted metabolomics

Ultra high pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) has become a widespread analytical technique in metabolomics investigations, however the benefit of high-performance chromatographic separation is often blunted due to insufficient mass spectrometric accuracy. A strategy that allows for the matching of UHPLC-MS data to highly accurate direct infusion electrospray ionization (DI-ESI) Fourier transform ion cyclotron resonance/mass spectrometry (FTICR/MS) data is developed in this manuscript. Mass difference network (MDiN) based annotation of FTICR/MS data and matching to unique UHPLC-MS peaks enables the consecutive annotation of the chromatographic data set. A direct comparison of experimental m/z values provided no basis for the matching of both platforms. The matching of annotation-based exact neutral masses finally enabled the integration of platform specific multivariate statistical evaluations, minimizing the danger to compare artifacts generated on either platform. The approach was developed on a non-alcoholic fatty liver disease (NAFLD) data set.

Review on the effect of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus (T2DM), dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors were widely used to treat T2DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor (GLP-1R) is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride (TG) content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and mRNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Chlorogenic acid/chromium supplement rescues diet-induced insulin resistance and obesity in mice

Abdominal obesity is a major risk factor for insulin resistance, type 2 diabetes and cardiovascular diseases. Dietary fat induces insulin resistance in humans and rodents. The current study investigates whether a Chlorogenic acid/Chromium III supplement rescues obesity and insulin resistance caused by high-fat feeding of male C57BL/6 J mice for 7 weeks. Administering an oral daily dose of this supplement in the last 3 weeks of feeding reversed diet-induced body weight gain and insulin resistance, assessed by hyperglycemia, glucose intolerance and insulin intolerance. Indirect calorimetry analysis revealed that this effect is mediated at least partly, by increasing energy expenditure and spontaneous locomoter activity. These findings underscore the important role that chlorogenic acid and chromium play in maintaining glucose metabolism and insulin response in mice fed a high-fat diet.

NASH resolution is associated with improvements in HDL and triglyceride levels but not improvement in LDL or non-HDL-C levels

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is associated with dyslipidemia and cardiovascular disease (CVD).

AIM

To determine the relationship between resolution of NASH and dyslipidemia.

METHODS

Individuals in the Pioglitazone vs. Vitamin E vs. Placebo for the Treatment of Nondiabetic Patients with Nonalcoholic Steatohepatitis (PIVENS) trial with paired liver biopsies and fasting lipid levels were included (N = 222). In the PIVENS trial individuals were randomised to pioglitazone 30 mg, vitamin E 800 IU or placebo for 96 weeks. Change in lipid levels at 96 weeks was compared between those with and without NASH resolution.

RESULTS

Dyslipidemia at baseline was frequent, with low high-density lipoprotein (HDL) (<40 mg/dL in men or <50 mg/dL in women) in 63%, hypertriglyceridaemia (≥150 mg/dL) in 46%, hypercholesterolaemia (≥200 mg/dL) in 47% and triglycerides (TG)/HDL >5.0 in 25%. Low-density lipoprotein (LD) ≥160 mg/dL was found in 16% and elevated non-HDL cholesterol (non-HDL-C) (≥130 mg/dL) in 73%. HDL increased with NASH resolution but decreased in those without resolution (2.9 mg/dL vs. -2.5 mg/dL, P < 0.001). NASH resolution was associated with significant decreases in TG and TG/HDL ratio compared to those without resolution (TG: -21.1 vs. -2.3 mg/dL, P = 0.03 and TG/HDL: -0.7 vs. 0.1, P = 0.003). Non-HDL-C, LDL and cholesterol decreased over 96 weeks in both groups, but there was no significant difference between groups. Treatment group did not impact lipids.

CONCLUSIONS

NASH resolution is associated with improvements in TG and HDL but not in other cardiovascular disease risk factors including LDL and non-HDL-C levels. Individuals with resolution of NASH may still be at increased risk of cardiovascular disease. ClinicalTrials.gov identifier: NCT00063622.

Data from a randomized and controlled trial of LCarnitine prescription for the treatment for Non- Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) consists of a range of complication. The disease describes clinical , para clinical and pathological conditions from simple steatosis in non-alcoholic steato hepatitis (NASH) to fibrosis, cirrhosis and hepato cellular carcinoma. Therefore, it is of interest to evaluate the grade of fatty liver and Liver Function Test in NAFLD patients. We collected samples and data from 80 patients referred to gastrointestinal clinic of Emam Reza hospital with sonography diagnosed NAFLD and were evaluated in two groups in a randomized clinical trial. The effects of L-Carnitine (500 mg) prescription twice a day on liver enzymes and echogenicity changes in case group was documented and compared with the control group. The mean age of the patients was 40.7±8 in the age range of 25 to 62 years old with 66 (82.5%) male and 14 (17.5%) female patients. Data show that fatty liver changes were not significantly different in the two groups (P=0.23). It is observed that the ALT was the only enzyme with significant changes (P=0.01) after a 24-week interval. It is also noted that the difference in fatty liver sonographic grading was also significant in the two groups (P=0.0001). Thus, proper therapeutic protocols can be adopted beside diet and weight loss to control the disease trend in consideration to the significant changes observed both in enzymatic levels and sonographic grading between the two groups of patients with NAFLD.

Animal models are reliably mimicking human diseases? A morphological study that compares animal with human NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a clinical-pathological syndrome that includes a wide spectrum of morphological alterations. In research, animal models are crucial in evaluating not only the pathogenesis of NAFLD and its progression, but also the therapeutic effects of various agents. Investigations on the ultrastructural features of NAFLD in humans are not copious, due to the difficulty to obtain human samples and to the long time of NAFLD to evolve. Translational comparative studies on the reliability of animal models in representing the histopathologic picture as seen in humans are missing. To overcome this lack of investigations, we compared the ultrastructural NAFLD features of an animal model versus human. Sprague-Dawley rats were fed with a high fat diet (HFD) for 1-4 weeks, while control rats were fed with a standard diet. Human specimens were collected from patients with diagnosed fatty liver disease, undergoing liver biopsies or surgery. Rat and human samples were examined by light microscopy and by transmission and high resolution scanning electron microscopy. The present work demonstrated that NAFLD in animal model and in human, share overlapping ultrastructural features. In conclusion, animal HFD represent an appropriate tool in studying the pathogenesis of NAFLD.

Non-alcoholic fatty liver disease, metabolic syndrome and patatin-like phospholipase domain-containing protein3 gene variants

BACKGROUND & AIMS

Non-alcoholic fatty liver disease was traditionally interpreted as a condition which may progress to liver-related complications. However, the increased mortality is primarily a result of cardiovascular diseases. It has been suggested that fatty liver can be considered as the hepatic consequence of the metabolic syndrome. The aim was to describe the different clinical presentations of non-alcoholic fatty liver disease on the basis of the patatin-like phospholipase domain-containing protein3 (PNPLA3) rs738409 gene variant.

METHODS

Fatty liver was defined by ultrasonographic Hamaguchi's criteria in 211 consecutive subjects with non-alcoholic fatty liver disease. The rs738409 polymorphism was determined by TaqMan assays. Metabolic syndrome was defined according to ATPIII modified criteria.

RESULTS

Prevalence of PNPLA3-148II, PNPLA3-148IM, and PNPLA3-148MM genotypes was 45.0%, 40.7%, and 14.3% respectively. Prevalence of metabolic syndrome progressively increased with the severity of liver steatosis (from 52.5% to 65.2%, and 82.3% respectively, p<0.01). The PNPLA3-148MM group had significantly lower mean serum triglycerides (p<0.001), Framingham cardiovascular risk score (p<0.01) and lower prevalence of metabolic syndrome (p<0.05) and its components. Age and HOMA-IR were positive independent predictors of metabolic syndrome, while a negative independent association was found between metabolic syndrome and the homozygotes PNPLA3 I148M variant.

CONCLUSIONS

We suggest a lower prevalence of MetS and reduced cardiovascular risk in NAFLD patients with PNPLA3MM genotype.

Alcoholic fatty liver disease elevates estimated coronary heart disease risk to levels comparable with those of nonalcoholic fatty liver disease in the Korean population: a cross-sectional study

Background/Aims

A close relationship has been established between nonalcoholic fatty liver disease (NAFLD) and an elevated risk of coronary heart disease (CHD), but little is known about the association between alcoholic fatty liver disease (AFLD) and CHD risk. The aim of this study was to determine whether AFLD is associated with elevated CHD risk.

Methods

We retrospectively enrolled 10,710 subjects out of 11,469 individuals who visited the Konkuk University Health Care Center for a routine health checkup in 2010. AFLD was diagnosed made when the usual amount of alcohol consumption exceeded 210 g/week in males and 140 g/week in females for the previous 2 years and when hepatic steatosis was detected by liver ultrasonography. The 10-year risk for CHD was estimated using the Framingham Risk Score.

Results

Hepatic steatosis was diagnosed in 4,142 of the 10,710 individuals (38.7%); the remainder (i.e., n=6,568) became the control group. The 4,142 individuals with hepatic steatosis were divided into two groups: NAFLD (n=2,953) and AFLD (n=1,189). The risk of CHD was higher in AFLD (6.72±0.12) than in the control group (5.50±0.04, P<0.001), and comparable to that in NAFLD (7.32±0.07, P=0.02).

Conclusions

Individuals with AFLD have an elevated 10-year risk of CHD that is comparable to those with NAFLD. Therefore, AFLD should be considered a significant risk for future CHD, and preventive measures should be considered earlier.

Controlled attenuation parameter for evaluating liver steatosis in chronic viral hepatitis

AIM: To assess the performance of controlled attenuation parameter (CAP) in patients with chronic viral hepatitis.

METHODS: CAP is a new technique that measures the attenuation in the liver of an ultrasound beam, which is directly related to lipid accumulation. Consecutive patients undergoing liver biopsy for chronic viral hepatitis were studied using the M probe of FibroScan device (Echosens, Paris, France). The device estimates liver steatosis in decibel per meter (dB/m). An expert operator performed all measurements. Steatosis was graded according to Kleiner’s classification. Pearson or Spearman rank coefficient was used to test correlation between two study variables. Linear regression was used for multivariate model to assess the association between CAP and other variables. Receiver operating characteristic curve analysis was performed to calculate area under the curve (AUROC) for S0 vs S1-S3 and S0-S1 vs S2-S3.

RESULTS: 115 subjects (85 males and 30 females) were prospectively studied. The mean values of CAP were 227.1 ± 43.1 for S0; 254.6 ± 38.9 for S1; 297.8 ± 49.4 dB/m for S2-S3. In univariate analysis CAP showed a significant correlation with age, body mass index (BMI), degree of steatosis, and cholesterol. Multivariate regression analysis confirmed the correlation with the degree of steatosis [coefficient, 1.2 (0.60-1.83); P < 10^-5] and BMI [coefficient, 4.1 (0.5-7.8); P = 0.03] but not with all other variables. Optimal cutoff values for S ≥ 1 and S ≥ 2 were 219 dB/m [AUROC, 0.76 (0.67-0.84); sensitivity, 91.1% (78.8-97.5); specificity, 51.6% (38.7-64.2); positive predictive value, 56.9% (44.7-68.6); negative predictive value, 89.2% (74.3-97.0); positive likelihood ratio, 1.88 (1.4-2.5); negative likelihood ratio, 0.17 (0.07-0.5)] and 296 dB/m [AUROC, 0.82 (0.74-0.89); sensitivity, 60.0% (32.3-83.7); specificity, 91.5% (83.9-96.3); positive predictive value, 52.9% (27.8-77.0); negative predictive value, 93.5% (86.3-97.6); positive likelihood ratio, 7.05 (3.2-15.4); negative likelihood ratio, 0.44 (0.2-0.8)], respectively.

CONCLUSION: Controlled attenuation parameter could be a useful tool in the clinical management of patients with chronic viral hepatitis for detecting liver steatosis.

Ethanol extract of Cirsium japonicum attenuates hepatic lipid accumulation via AMPK activation in human HepG2 cells

One of the most common causes of chronic liver disease, nonalcoholic fatty liver disease (NAFLD), is strongly associated with obesity and dysregulated insulin action in the liver. However, there are no pharmacological agents currently established for the treatment of NAFLD. A flowering plant in the Asteraceae family, Cirsium japonicum (CJ), exhibits a variety of pharmacological and antioxidative properties that promote hepatoprotection. In the present study, CJ ethanol extract was shown to reduce hepatic triglyceride (TG) and cholesterol accumulation. CJ significantly increased AMP-activated protein kinase (AMPK) phosphorylation in HepG2 hepatocytes and downregulated the level of the target genes, acetyl-CoA carboxylase and fatty acid synthase. In addition, CJ upregulated the expression of carnitine palmitoyltransferase-1, which is involved in fatty acid oxidation. The results of the present study indicated that the positive effects of CJ extract on high-fat diet-induced hepatic TG accumulation were mediated via the AMPK signaling pathway, indicating a potential target for the preventative treatment of NAFLD.

Hepatic glucose intolerance precedes hepatic steatosis in the male aromatase knockout (ArKO) mouse

Estrogens are known to play a role in modulating metabolic processes within the body. The Aromatase knockout (ArKO) mice have been shown to harbor factors of Metabolic syndrome with central adiposity, hyperinsulinemia and male-specific hepatic steatosis. To determine the effects of estrogen ablation and subsequent replacement in males on whole body glucose metabolism, three- and six-month-old male ArKO mice were subjected to whole body glucose, insulin and pyruvate tolerance tests and analyzed for ensuing metabolic changes in liver, adipose tissue, and skeletal muscle. Estrogen-deficient male ArKO mice showed increased gonadal adiposity which was significantly reduced upon 17β-estradiol (E2) treatment. Concurrently, elevated ArKO serum leptin levels were significantly reduced upon E2 treatment and lowered serum adiponectin levels were restored to wild type levels. Three-month-old male ArKO mice were hyperglycemic, and both glucose and pyruvate intolerant. These phenotypes continued through to 6 months of age, highlighting a loss of glycemic control. ArKO livers displayed changes in gluconeogenic enzyme expression, and in insulin signaling pathways upon E2 treatment. Liver triglycerides were increased in the ArKO males only after 6 months of age, which could be reversed by E2 treatment. No differences were observed in insulin-stimulated ex vivo muscle glucose uptake nor changes in ArKO adipose tissue and muscle insulin signaling pathways. Therefore, we conclude that male ArKO mice develop hepatic glucose intolerance by the age of 3 months which precedes the sex-specific development of hepatic steatosis. This can be reversed upon the administration of exogenous E2.

Yin Yang 1 promotes hepatic steatosis through repression of farnesoid X receptor in obese mice

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is characterised by accumulation of excessive triglycerides in the liver. Obesity is usually associated with NAFLD through an unknown mechanism.

OBJECTIVE

To investigate the roles of Yin Yang 1 (YY1) in the progression of obesity-associated hepatosteatosis.

METHODS

Expression levels of hepatic YY1 were identified by microarray analysis in high-fat-diet (HFD)-induced obese mice. Liver triglyceride metabolism was analysed in mice with YY1 overexpression and suppression.

RESULTS

YY1 expression was markedly upregulated in HFD-induced obese mice and NAFLD patients. Overexpression of YY1 in healthy mice promoted hepatosteatosis under high-fat dietary conditions, whereas liver-specific ablation of YY1 using adenoviral shRNA ameliorated triglyceride accumulation in obese mice. At the molecular level, YY1 suppressed farnesoid X receptor (FXR) expression through binding to the YY1 responsive element at intron 1 of the FXR gene.

CONCLUSIONS

These findings indicate that YY1 plays a crucial role in obesity-associated hepatosteatosis, through repression of FXR expression.

Review of treatment options for nonalcoholic fatty liver disease

Although the future of NAFLD and NASH treatment has many promising agents, clinicians are currently faced with limited options with an emphasis on lifestyle modification. Figs. 1 and 2 summarize current practices for the diagnosis and treatment of NAFLD with the understanding that each patient's treatment must be customized to their comorbidities, exercise tolerance, and willingness to comply with therapy.

The efficacy and safety of traditional chinese medicine (jiang zhi granule) for nonalcoholic Fatty liver: a multicenter, randomized, placebo-controlled study

Objective. To evaluate the efficacy and safety of Jiang Zhi Granule (JZG), a Chinese herbal formula, in patients with nonalcoholic fatty liver (NAFL). Methods. A multicenter, randomized, double-blind, placebo-controlled, parallel clinical trial was conducted for 24 weeks in 224 patients with NAFL at 6 university-affiliated hospitals. Patients were randomized 1 : 1 to receive JZG and placebo, respectively. Primary outcome was the change of liver to spleen ratio (L/S ratio) over computed tomography (CT). Secondary outcomes included body mass index (BMI), serum triglyceride (TG), and total cholesterol (TC) levels. Results. Of all the 224 eligible patients, 221 patients were analyzed in the full analysis set (FAS), 205 in the per protocol set (PPS), and 3 patients were withdrawn prematurely. For FAS, JZG significantly increased L/S ratio from 0.74 ± 0.21 to 0.99 ± 0.24 compared to that from 0.79 ± 0.18 to 0.85 ± 0.27 in placebo group (P = 0.0011). For PPS, it showed an increase of 0.26 ± 0.23 of L/S ratio in the patients on JZG versus 0.07 ± 0.22 in those on placebo (P = 0.0003). Superiority of JZG over placebo was also observed with greater reduction in BMI (P < 0.05) in both FAS and PPS. No observable difference in decrease of serum TC and TG was recorded (P > 0.05). There were no serious adverse events (AEs) in the study process and safety indices were normal in both groups. Conclusions. The Chinese herbal formula JZG was found to be superior to placebo in increasing L/S ratio and reducing BMI in NAFL patients. It was also well tolerated in patients and might be a safe and effective medicine for NAFL.

Assessment of the relationship between non-alcoholic fatty liver disease and CAD using MSCT

Background

Some risk factors for atherosclerosis are followed by non-alcoholic fatty liver disease (NAFLD). We wanted to use Multislice computed tomography (MSCT) as technique for searching relationship between NAFLD and coronary artery disease (CAD).

Objective

The relationship between NAFLD and CAD was investigated using MSCT.

Methods

A total of 372 individuals with or without cardiac symptoms who had undergone MSCT angiography were included in the study. The patients were divided into two groups according to the presence of NAFLD. Coronary artery segments were visually evaluated via MSCT angiography. Based on the coronary artery stenosis degree, those with no or minimal plaques were considered normal, whereas those who had stenosis of less than 50% and at least one plaque were considered to have non-obstructive coronary artery disease (non-obsCAD). The patients who had at least one plaque and coronary artery stenosis of 50% or more were considered to have obstructive coronary artery disease (obsCAD). NAFLD was determined according to the MSCT protocol, using the liver density.

Results

According to the liver density, the number of patients with non-alcoholic fatty liver disease (group 1) was 204 (149 males, 54.8%) and with normal liver (group 2) was 168 (95 males, 45.2%). There were 50 (24.5%) non-obsCAD and 57 (27.9%) obsCAD cases in Group 1, and 39 (23.2%) non-obsCAD and 23 (13.7%) obsCAD cases in Group 2.

Conclusions

The present study using MSCT demonstrated that the frequency of coronary artery disease in patients with NAFDL was significantly higher than that of patients without NAFDL.

Association between resistin +299A/A genotype and nonalcoholic fatty liver disease in Chinese patients with type 2 diabetes mellitus

OBJECTIVE

To investigate the relationship between the resistin intronic +299G/A polymorphism and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

We selected 738 T2DM patients, including 395 with NAFLD and 343 without fatty liver disease, as well as 279 healthy control individuals, and analyzed their resistin +299G/A polymorphism genotype by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Plasma resistin levels in T2DM patients with NAFLD were at the highest (P<0.05). The frequency of AA genotype at the +299 site of the resistin gene in patients with concurrent T2DM combined with NAFLD was significantly different from that in the control (P<0.05). The AA genotype was found to be associated with a 1.80-fold increased risk for T2DM combined with NAFLD, 2.05-fold increased risk for obesity and 2.37-fold increased risk for obesity of abdominal type compared to the GG (P<0.05, respectively). The multivariate non-conditional logistic regression model analysis further shows that the AA genotype is a risk factor for the development of NAFLD in T2DM patients (OR, 2.32; 95% CI, 1.05-4.68; P<0.05).

CONCLUSION

The resistin +299AA genotype may be associated with increases in the risk of the NAFLD development in T2DM patients.

Liver enzymes, race, gender and diabetes risk: the Atherosclerosis Risk in Communities (ARIC) Study

AIMS

To examine the associations of the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase(AST), and gamma-glutamyl transferase (GGT) with diabetes risk and to determine whether associations differ by race and/or gender. We hypothesized that all liver enzymes would be associated with diabetes risk and that associations would differ by race and gender.

METHODS

Prospective cohort of 7495 white and 1842 black participants without diabetes in the Atherosclerosis Risk in Communities Study. Poisson and Cox models adjusted for demographic, socio-behavioural, and metabolic and health-related factors were used.

RESULTS

During a median of 12 years of follow-up, 2182 incident cases of diabetes occurred. Higher liver enzyme levels were independently associated with diabetes risk: adjusted hazard ratios (95% confidence intervals) were 1.68 (1.49-1.89), 1.16 (1.02-1.31) and 1.95 (1.70-2.24) comparing the highest with the lowest quartiles of ALT, AST, and GGT, respectively. Gamma-Glutamyl transferase was most strongly related to diabetes risk, even at levels considered within the normal range (≤ 60 U/l) in clinical practice. Adjusted incidence rates by quartiles of liver enzymes were similar by gender but higher in black versus white participants. Nonetheless, relative associations of ALT, AST, and GGT with diabetes were similar by race (P for interactions > 0.05).

CONCLUSIONS

Compared with ALT and AST, GGT was more strongly associated with diabetes risk. Our findings suggest that abnormalities in liver enzymes precede the diagnosis of diabetes by many years and that individuals with elevated liver enzymes, even within the normal range as defined in clinical practice, are at high risk for diabetes.

Probiotics as a novel treatment for non-alcoholic Fatty liver disease; a systematic review on the current evidences

CONTEXT

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, with 5-10% of liver having extra fat. Increase in its prevalence in all age groups is linked with obesity and Type II diabetes. The treatment of NAFLD remains controversial. A growing body of evidence suggests a relation between overgrowth of gut microbiota with NAFLD and non-alcoholic steatohepatitis (NASH). The objective of this review is to provide an overview on experimental and clinical studies assessing all positive and negative effects of probiotics.

EVIDENCE ACQUISITION

We made a critical appraisal on various types of documents published from 1999 to March 2012 in journals, electronic books, seminars, and symposium contexts including Medline, PubMed, and Cochrane Central Register of Controlled Trials databases. We used the key words: "non-alcoholic fatty liver disease, probiotics, non-alcoholic steatohepatitis, liver disease, and fatty liver".

RESULTS

Probiotics, as biological factors, control the gut microbiota and result in its progression. It is in this sense that they are suggestive of a new and a natural way of promoting liver function. Correspondingly, limited evidence suggests that probiotics could be considered as a new way of treatment for NAFLD.

CONCLUSIONS

Various experimental studies and clinical trials revealed promising effects of probiotics in improving NAFLD; however given the limited experience in this field, generalization of probiotics as treatment of NAFLD needs substantiation through more trials with a larger sample sizes and with longer-term follow up.

Pitavastatin ameliorated the progression of steatohepatitis in ovariectomized mice fed a high fat and high cholesterol diet

AIM

Many studies indicate an accelerated progression of non-alcoholic steatohepatitis (NASH) in postmenopausal women. Very recently, we reported that estrogen deficiency enhanced the progression of steatohepatitis in mice fed a high fat and high cholesterol (HFHC) diet. Hypercholesterolemia is often observed in postmenopausal women, and recent studies indicate it to be an important risk factor for the progression of NASH. Statins can slow NASH progression in the estrogen-deficient state but the precise mechanisms of their effects are still unclear.

METHODS

We investigated the effects of pitavastatin on steatohepatitis progression using ovariectomized (OVX) mice fed a HFHC diet or HFHC + pitava diet (containing 5 p.p.m. pitavastatin) for 6 weeks.

RESULTS

Serum alanine aminotransferase and cholesterol levels significantly decreased in mice fed the HFHC + pitava diet compared with mice fed the HFHC diet. Real-time reverse transcription polymerase chain reaction representing hepatic inflammatory gene expressions significantly decreased in mice fed the HFHC + pitava diet compared with the HFHC-fed mice. Pitavastatin treatment also decreased both hepatic macrophage infiltration and hepatocyte chemokine (C-C motif) ligand 2 expression and improved the liver fibrosis condition when compared with the mice fed the HFHC diet. In addition, the enhanced spleen monocyte chemokine (C-C motif) receptor 2 expression in ovariectomized mice fed the HFHC diet was also decreased by pitavastatin administration.

CONCLUSION

Our study demonstrated that the exacerbated steatohepatitis progression in OVX mice fed a HFHC diet could be attenuated by pitavastatin treatment at least through inhibition of hepatic macrophage infiltration. We concluded that statins should be useful for treating NASH in postmenopausal women.

Mouse KLF11 regulates hepatic lipid metabolism

BACKGROUND & AIMS

Missense mutations in human Krüppel-like factor 11 (KLF11) lead to the development of diabetes, as a result of impaired insulin synthesis in the pancreas. However, the role of KLF11 in peripheral tissues is largely unknown. The aim of this study is to evaluate the role of KLF11 in the regulation of hepatic lipid homeostasis using different mouse models.

METHODS

Adenoviruses expressing KLF11 (Ad-KLF11) or KLF11-specific shRNA (Ad-shKLF11) were injected into db/db diabetic, high-fat diet-induced obese (DIO), or normal C57BL/6J mice. Histological analysis of the fatty liver phenotype and biochemical analysis of hepatic and serum TG levels in these mice were performed. The molecular mechanism by which KLF11 regulates lipid metabolism in primary hepatocytes and mouse livers was explored.

RESULTS

The expression of the transcription factor KLF11 gene is dysregulated in the livers of db/db and DIO mice. Adenovirus-mediated overexpression of KLF11 in the livers of db/db and DIO mice activates the PPARα signaling pathway, subsequently markedly improving the fatty liver phenotype. Conversely, knockdown of KLF11, by adenovirus (Ad-shKLF11) in livers of wild type C57BL/6J and db/m mice, increases hepatic triglyceride (TG) levels, owing to decreased fatty acid oxidation. Finally, the treatment of diabetic mice with Ad-shPPARα abolishes KLF11 stimulatory effects on the expression of genes involved in fatty acid oxidation and inhibitory effects on hepatic TG content. In contrast, PPARα rescue restores the increased hepatic TG levels in Ad-shKLF11-infected db/m mice to normal levels.

CONCLUSIONS

KLF11 is an important regulator of hepatic lipid metabolism.

Does PPARγ2 gene Pro12Ala polymorphism affect nonalcoholic fatty liver disease risk? Evidence from a meta-analysis

Genetic factors can substantially contribute to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). A missense Pro12Ala substitution in the PPARγ2 gene (rs1801282) has been studied in relation with NAFLD risk in different ethnic groups, but findings have been inconclusive. The aim of this was to evaluate the association between rs1801282 and NAFLD through meta-analysis of all relevant published evidence. A systematic search to find eligible studies was performed in Medline, HuGE Navigator, and SCOPUS databases. The strength of association was evaluated using odds ratios with 95% confidence intervals obtained from a random effect approach and under additive, dominant, co-dominant, recessive, and allelic contrast models. Seven studies comprising 1474 cases and 2259 controls met the eligibility criteria and included in the meta-analysis. Combined results did not indicate any predisposing or protective effect for rs1801282 under any of the assessed modes of inheritance. The rate of heterogeneity was generally high due to the inter-study variations in terms of age, gender, and ethnicity. Evidence from the current meta-analysis indicated that rs1801282 variants are not associated with NAFLD risk. Future large-scale studies are required to substantiate the present findings.

Impact of weight-loss surgery and diabetes status on serum ALT levels

BACKGROUND

Alanine aminotransferase (ALT) is used to detect non-alcoholic fatty liver disease and has been associated with increased risk of metabolic syndrome and type II diabetes mellitus (T2DM). Bariatric procedures result in significant weight loss and a rapid resolution of T2DM. We aimed to study the impact of bariatric interventions on ALT levels in patients with or without T2DM and compare this effect between different types of weight-loss procedures.

METHODS

We reviewed 756 patients undergoing bariatric surgery. Demographics, co-morbidities, baseline and post-operative ALT and HbA1C levels, weight-loss data, and diabetes status were recorded. ALT levels were compared between different procedures and between diabetic and non-diabetic patients. Chi-square test, ANOVA, and t test were used to evaluate outcomes.

RESULTS

Males and diabetics had significantly higher ALT at baseline. Both Roux-en-Y gastric bypass surgery (RYGB) and laparoscopic adjustable gastric banding (LAGB) resulted in significant reduction in ALT levels beginning at the third post-operative month (20 and 17 %, respectively, compared to baseline, p < 0.001). ALT remained at the new low level up to year 3 after surgery. The degree of reduction was similar for both procedures and was independent of the degree of weight loss. In diabetics, ALT reduction was associated with improvement in disease; but in T2DM patients who remained on insulin, ALT remained elevated.

CONCLUSIONS

RYGB and LAGB decrease ALT levels to the same degree and independent of weight loss. Our data confirm higher ALT in diabetics and demonstrate a rapid normalization after bariatric surgery with a simultaneous decrease in HbA1C. These results suggest that ALT may be used as a marker of metabolic improvement after bariatric surgery.

The effects of chronic AMPK activation on hepatic triglyceride accumulation and glycerol 3-phosphate acyltransferase activity with high fat feeding

BACKGROUND

High fat feeding increases hepatic fat accumulation and is associated with hepatic insulin resistance. AMP Activated Protein Kinase (AMPK) is thought to inhibit lipid synthesis by the acute inhibition of glycerol-3-phosphate acyltransferase (GPAT) activity and transcriptional regulation via sterol regulatory element binding protein-1c (SREBP-1c).

METHODS

The purpose of this study was to determine if chronic activation of AMPK prevented an increase in GPAT1 activity in rats fed a high fat diet. Rats were fed a control (C), or a high fat (HF) diet (60% fat) for 6 weeks and injected with saline or a daily aminoimidazole carboxamide ribnucleotide (AICAR) dose of 0.5 mg/g body weight.

RESULTS

Chronic AMPK activation by AICAR injections resulted in a significant reduction in hepatic triglyceride accumulation in both the C and HF fed animals (C, 5.5±0.7; C+AICAR, 2.7 ±0.3; HF, 21.8±3.3; and HF+AICAR, 8.0±1.8 mg/g liver). HF feeding caused an increase in total GPAT and GPAT1 activity, which was not affected by chronic AMPK activation (GPAT1 activity vs. C, C+AICAR, 92±19%; HF, 186±43%; HF+AICAR, 234±62%). Markers of oxidative capacity, including citrate synthase activity and cytochrome c abundance, were not affected by chronic AICAR treatment. Interestingly, HF feeding caused a significant increase in long chain acyl-CoA dehydrogenase or LCAD (up 66% from C), a marker of fatty acid oxidation capacity.

CONCLUSIONS

These results suggest that chronic AMPK activation limits hepatic triglyceride accumulation independent of a reduction in total GPAT1 activity.

Reduced heme oxygenase-1 expression in steatotic livers infected with hepatitis C virus

Hepatic nonalcoholic fatty liver disease (NAFLD) is known to exacerbate liver injury due to chronic hepatitis C infection. Heme oxygenase-1 (HO-1) is an important protective antioxidative defense enzyme that is known to be induced in response to NAFLD and other liver injuries. The aim of this study was to evaluate HO-1 expression in HCV infected human livers with concomitant NAFLD.

METHODS

We compared levels of HO-1 in NAFLD liver biopsies from patients with or without chronic HCV infection using immunohistochemistry, immunoblots and real time RT-PCR. We also evaluated frozen sections of liver with dihydroethidium (DHE) or dichlorofluorescein (DCF) fluorescence staining to evaluate O(2)(-) and peroxide production respectively.

RESULTS

HO-1 expression was only increased in NAFLD livers without HCV infection, while HCV infected livers showed reduced HO-1 levels, regardless whether NAFLD was present. In uninfected livers with NAFLD, HO-1 expression was primarily localized in hepatocytes containing fat and areas of injury around the central vein. However, both NAFLD with and without concomitant HCV infection showed high levels of O(2)(-) or peroxide production compared to normal human liver control samples.

CONCLUSIONS

These findings support the hypothesis that NAFLD is an important process for hepatocyte oxidative stress and injury in liver diseases. They also suggest that HCV can repress HO-1 induction in vivo even when other inducers of HO-1 are present.

Psychological and psychiatric aspects of treatment of obesity and nonalcoholic fatty liver disease

Chronic illnesses incur a tremendous cost to American lives in dollars and quality of life. Outcomes in these illnesses are often affected by psychological, behavioral, and pharmacologic issues related to mental illness and psychological symptoms. This article focuses on psychological and psychiatric issues related to the treatment of obesity and nonalcoholic fatty liver disease (NAFLD), including available weight-loss interventions, the complex relationship between psychiatric disorders and obesity, and special considerations regarding use of psychiatric drugs in patients with or at risk for NAFLD and obesity. Recommendations for collaborative care of individuals with comorbid NAFLD and psychological disorders/symptoms are discussed.