Statins in non-alcoholic fatty liver disease and chronically elevated liver enzymes: a histopathological follow-up study

Nonalcoholic Fatty liver disease: focus on lipoprotein and lipid deregulation

Obesity with associated comorbidities is currently a worldwide epidemic and among the most challenging health conditions in the 21st century. A major metabolic consequence of obesity is insulin resistance which underlies the pathogenesis of the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of obesity and metabolic syndrome. It comprises a disease spectrum ranging from simple steatosis (fatty liver), through nonalcoholic steatohepatitis (NASH) to fibrosis, and ultimately liver cirrhosis. Abnormality in lipid and lipoprotein metabolism accompanied by chronic inflammation is the central pathway for the development of metabolic syndrome-related diseases, such as atherosclerosis, cardiovascular disease (CVD), and NAFLD. This paper focuses on pathogenic aspect of lipid and lipoprotein metabolism in NAFLD and the relevant mouse models of this complex multifactorial disease.

Treatment of atherogenic liver based on the pathogenesis of nonalcoholic fatty liver disease: a novel approach to reduce cardiovascular risk?

Nonalcoholic fatty liver disease (NAFLD), which spans a spectrum of conditions ranging from simple steatosis to progressive nonalcoholic steatohepatitis (NASH), is the most common chronic liver disease and a relevant public health issue. The prevalence of NAFLD depends on adiposity, age, gender and ethnicity. The natural history of liver disease in those with NAFLD critically depends on liver histological changes. However, cardiovascular mortality is increased in NAFLD, particularly in middle-aged adults. Against such a background, this review consists of three sections. First, data on NAFLD as a novel mechanism of increased cardiovascular risk via hyperinsulinism, pro-thrombotic potential, and subclinical inflammation are summarized. Next, the role of atherogenic liver in the development of manifestations of oxidative stress and atherosclerosis is emphasized. Finally, whether and how treating NAFLD will mechanistically result in reduced cardiovascular risk through ameliorated metabolic syndrome is discussed.

Pitavastatin suppresses diethylnitrosamine-induced liver preneoplasms in male C57BL/KsJ-db/db obese mice

BACKGROUND

Obesity and related metabolic abnormalities, including inflammation and lipid accumulation in the liver, play a role in liver carcinogenesis. Adipocytokine imbalances, such as decreased serum adiponectin levels, are also involved in obesity-related liver tumorigenesis. In the present study, we examined the effects of pitavastatin - a drug used for the treatment of hyperlipidemia - on the development of diethylnitrosamine (DEN)-induced liver preneoplastic lesions in C57BL/KsJ-db/db (db/db) obese mice.

METHODS

Male db/db mice were administered tap water containing 40 ppm DEN for 2 weeks and were subsequently fed a diet containing 1 ppm or 10 ppm pitavastatin for 14 weeks.

RESULTS

At sacrifice, feeding with 10 ppm pitavastatin significantly inhibited the development of hepatic premalignant lesions, foci of cellular alteration, as compared to that in the untreated group by inducing apoptosis, but inhibiting cell proliferation. Pitavastatin improved liver steatosis and activated the AMPK-α protein in the liver. It also decreased free fatty acid and aminotransferases levels, while increasing adiponectin levels in the serum. The serum levels of tumor necrosis factor (TNF)-α and the expression of TNF-α and interleukin-6 mRNAs in the liver were decreased by pitavastatin treatment, suggesting attenuation of the chronic inflammation induced by excess fat deposition.

CONCLUSIONS

Pitavastatin is effective in inhibiting the early phase of obesity-related liver tumorigenesis and, therefore, may be useful in the chemoprevention of liver cancer in obese individuals.

Pitavastatin inhibits hepatic steatosis and fibrosis in non-alcoholic steatohepatitis model rats

AIM

  Non-alcoholic steatohepatitis (NASH) may progress to liver cirrhosis, and NASH patients with liver cirrhosis are at risk of developing hepatocellular carcinoma. Statins, 3-hydroxy-3-methyglutaryl-coenzyme A reductase inhibitors, are well known to reduce low-density lipoprotein cholesterol and reduce the incidence of coronary heart disease and other major vascular events by anti-inflammatory and antifibrotic effects, and antiproliferative properties in colorectal cancers have also been reported. Recently, statins have been reported to improve hepatic steatosis; however, the effect on fibrosis is controversial.

METHODS

  The effects of pitavastatin (one of the strongest statins) were examined using a choline-deficient L-amino acid-defined (CDAA) diet liver fibrosis model.

RESULTS

  Pitavastatin significantly attenuated increases in serum aspartate aminotransferase, alanine aminotransferase, hepatic steatosis, oxidative stress, pre-neoplastic lesions (glutathione S-transferase placental form-positive lesions), expression of cytokines, such as tumor necrosis factor-α and transforming growth factor-β1, and the expression of tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2 and type I procollagen genes followed by attenuating fibrosis of the liver of CDAA-fed rats.

CONCLUSION

  These results indicate that pitavastatin may inhibit steatosis, hepatic fibrosis and carcinogenesis in rat model of NASH.

Effects of high-dose statin on the human hepatic expression of genes involved in carbohydrate and triglyceride metabolism

OBJECTIVES

Atorvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-limiting enzyme in cholesterol synthesis, lowers plasma cholesterol and triglyceride (TG) levels dose dependently. The aim of this study was to investigate the molecular mechanism(s) of this decrease in plasma TG levels in atorvastatin-treated subjects.

RESEARCH DESIGN AND METHODS

Lipoprotein separation and plasma analysis of lipids, glucose and insulin were performed in subjects randomly assigned to placebo (n = 9) or atorvastatin (80 mg per day) (n = 10) for 4 weeks. Liver TG mass was determined in pooled samples. Hepatic expression of several genes involved in carbohydrate and TG metabolism was determined.

RESULTS

  Atorvastatin lowered plasma levels of very low-density lipoprotein (VLDL) TG (∼50%, P < 0.05) and liver TG mass compared to placebo. Except for cholesterol changes, there were no other significant differences in plasma lipids, glucose or insulin. However, atorvastatin reduced mRNA expression of sterol regulatory element-binding protein 1c (SREBP1c) (>30%, P < 0.05), glucokinase (∼50%, P < 0.05) and angiopoietin-like protein 3 (ANGPTL3) (∼25%, P < 0.01), and induced mRNA expression of acetyl-coenzyme A carboxylase 1 (∼45%, P < 0.05) and glucose-6-phosphatase (∼90%, P < 0.05) compared to placebo.

CONCLUSIONS

Following treatment with atorvastatin, reduced ANGPTL3 mRNA expression may contribute to the reduced plasma levels of VLDL TG. The reduced liver TG mass induced by a high dosage of atorvastatin may be important for the treatment of patients with fatty liver.

Comparison of fibrate, ezetimibe, low- and high-dose statin therapy for the dyslipidemia of the metabolic syndrome in a mouse model

BACKGROUND AND AIM

The treatment-of-choice for the optimal management of the dyslipidemia of the metabolic syndrome (MetS) is not clearly defined. We compared the efficacy of 4 drug regimes for the management of this dyslipidemia in a mouse model.

MATERIALS AND METHODS

A total of 60 C57Bl6 mice comprised the study group. The first 10 received standard mouse food for the whole experiment (control group). The remaining 50 mice received atherogenic diet for 14 weeks until the development of the MetS. The mice were then divided into 5 groups: the 1st group continued receiving atherogenic diet, while the other 4 groups received atherogenic diet plus ezetimibe (10 mg/kg per day), fenofibrate (100 mg/kg per day), low-dose atorvastatin (10 mg/kg per day), or high-dose (40 mg/kg per day) atorvastatin, respectively, for another 8 weeks.

RESULTS

High-dose atorvastatin treatment achieved the best lipid profile compared with low-dose atorvastatin, ezetimibe, and fibrate therapy. The lipid profile of mice receiving atherogenic diet plus high-dose atorvastatin treatment was similar with mice on regular chow.

CONCLUSIONS

High-dose atorvastatin treatment resulted in optimization of the lipid profile in the presence of a high-fat atherogenic diet in a mouse model. Our results suggest that high-dose atorvastatin treatment may be the optimal treatment option for the dyslipidemia associated with MetS. Nevertheless, verification of these results in humans is required before any definite conclusions can be drawn.

Metformin and atorvastatin combination further protect the liver in type 2 diabetes with hyperlipidaemia

BACKGROUND

non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes are associated with dyslipidaemia, inflammation and oxidative stress. However, the pathophysiology of NAFLD in type 2 diabetes with hyperlipidaemia is not fully known, as well as the utility of the commonly prescribed anti-diabetic and lipid-lowering drugs in ameliorating liver injury markers.

METHODS

hepatic complications of type 2 diabetes with hyperlipidaemia and the effects of atorvastatin and metformin, isolated and in association, in systemic and hepatic inflammatory and oxidative stress markers were tested using genetic type 2 diabetic Goto-Kakizaki rats fed with a high-fat diet.

RESULTS

the high-fat diet aggravated the overall metabolic state and the hepatic markers of injury. All treatments decreased fasting glycaemia, insulin resistance and free fatty acid levels. Combined treatment further decreased C-reactive protein (CRP), adiponectin, liver tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), systemic and hepatic oxidative stress and portal inflammation.

CONCLUSIONS

our data provides evidence of a greater benefit with a combination of atorvastatin and metformin in improving liver injury in type 2 diabetes with hyperlipidaemia.

Influence of Sleeve Gastrectomy on NASH and Type 2 Diabetes Mellitus

Background. Nonalcoholic fatty liver disease is present in up to 85% of adipose patients and may proceed to nonalcoholic steatohepatitis (NASH). With insulin resistance and obesity being the main risk factors for NASH, the effect of isolated sleeve gastrectomy (ISG) on these parameters was examined. Methods. 236 patients underwent ISG with intraoperative liver biopsy from December 2002 to September 2009. Besides demographic data, pre-operative weight/BMI, HbA1c, AST, ALT, triglycerides, HDL and LDL levels were determined. Results. A significant correlation of NASH with higher HbA1c, AST and ALT and lower levels for HDL was observed (P < .05, <.0001, <.0001, <.01, resp.). Overall BMI decreased from 45.0 ± 6.8 to 29.7 ± 6.5 and 31.6 ± 4.4 kg/m(2) at 1 and 3 years. An impaired weight loss was demonstrated for patients with NASH and patients with elevated HbA1c (plateau 28.08 kg/m(2) versus 29.79 kg/m(2) and 32.30 kg/m(2) versus 28.79 kg/m(2), resp.). Regarding NASH, a significant improvement of AST, ALT, triglyceride and HDL levels was shown (P < .0001 for all). A resolution of elevated HbA1c was observed in 21 of 23 patients. Summary. NASH patients showed a significant loss of body weight and amelioration of NASH status. ISG can be successfully performed in these patients and should be recommended for this subgroup.

Safety and efficacy of long-term statin treatment for cardiovascular events in patients with coronary heart disease and abnormal liver tests in the Greek Atorvastatin and Coronary Heart Disease Evaluation (GREACE) Study: a post-hoc analysis

BACKGROUND

Long-term statin treatment reduces the frequency of cardiovascular events, but safety and efficacy in patients with abnormal liver tests is unclear. We assessed whether statin therapy is safe and effective for these patients through post-hoc analysis of the Greek Atorvastatin and Coronary Heart Disease Evaluation (GREACE) study population.

METHODS

GREACE was a prospective, intention-to-treat study that randomly assigned by a computer-generated randomisation list 1600 patients with coronary heart disease (aged <75 years, with serum concentrations of LDL cholesterol >2·6 mmol/L and triglycerides <4·5 mmol/L) at the Hippokration University Hospital, Thessaloniki, Greece to receive statin or usual care, which could include statins. The primary outcome of our post-hoc analysis was risk reduction for first recurrent cardiovascular event in patients treated with a statin who had moderately abnormal liver tests (defined as serum alanine aminotransferase or aspartate aminotransferase concentrations of less than three times the upper limit of normal) compared with patients with abnormal liver tests who did not receive a statin. This risk reduction was compared with that for patients treated (or not) with statin and normal liver tests.

FINDINGS

Of 437 patients with moderately abnormal liver tests at baseline, which were possibly associated with non-alcoholic fatty liver disease, 227 who were treated with a statin (mainly atorvastatin 24 mg per day) had substantial improvement in liver tests (p<0·0001) whereas 210 not treated with a statin had further increases of liver enzyme concentrations. Cardiovascular events occurred in 22 (10%) of 227 patients with abnormal liver tests who received statin (3·2 events per 100 patient-years) and 63 (30%) of 210 patients with abnormal liver tests who did not receive statin (10·0 events per 100 patient-years; 68% relative risk reduction, p<0·0001). This cardiovascular disease benefit was greater (p=0·0074) than it was in patients with normal liver tests (90 [14%] events in 653 patients receiving a statin [4·6 per 100 patient-years] vs 117 [23%] in 510 patients not receiving a statin [7·6 per 100 patient-years]; 39% relative risk reduction, p<0·0001). Seven (<1%) of 880 participants who received a statin discontinued statin treatment because of liver-related adverse effects (transaminase concentrations more than three-times the upper limit of normal).

INTERPRETATION

Statin treatment is safe and can improve liver tests and reduce cardiovascular morbidity in patients with mild-to-moderately abnormal liver tests that are potentially attributable to non-alcoholic fatty liver disease.

FUNDING

None.

Novel treatment modalities for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the most common cause of chronic liver disease in the Western world. It can lead to cirrhosis and hepatocellular cancer, and is independently associated with an increased risk of death due to cardiovascular and liver diseases. Over the past 5 years, numerous advances in understanding its pathogenesis have been made, providing a rationale for translation of this information into clinical trials. Although the optimum therapy is still awaited, there is strong evidence to support the use of vitamin E in selected subjects. Many other potential therapeutic options are now available. In this paper, we review the status of both current and emerging therapeutic strategies for patients with NASH.

A meta-analysis of randomized trials for the treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) encompasses a histological spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). NAFLD carries a higher risk of cardio-metabolic and liver-related complications, the latter being confined to NASH and demanding specific treatment. We assessed the efficacy of proposed treatments for NAFLD/NASH by reviewing reports of randomized controlled trials (RCTs) on online databases and national and international meeting abstracts through January 2010. Primary outcome measure was histological improvement; secondary outcome was biochemical improvement; improvement in radiological steatosis was also evaluated. Two reviewers extracted articles using predefined quality indicators, independently and in duplicate. Main outcomes of randomized controlled trials (RCTs) were pooled using random-effects or fixed-effects models. Publication bias was assessed by funnel plots. Forty-nine RCTs (30 in NASH) were included: 23 RCTs (22 in NASH, 1 in NAFLD) had post-treatment histology. Most RCTs were small and did not exceed 1-year duration. Weight loss, thiazolidinediones (especially pioglitazone), and antioxidants were most extensively evaluated. Weight loss was safe and dose-dependently improved histological disease activity in NASH, but more than 50% of patients failed to achieve target weight loss. Thiazolidinediones improved steatosis and inflammation but yielded significant weight gain. RCTs with antioxidants yielded conflicting results and were heterogeneous with respect to type and dose of drug, duration, implementation of lifestyle intervention. Among the other agents, pentoxifylline, telmisartan and L-carnitine improved liver histology in at least 1 RCT in NASH; polyunsaturated fatty acid (PUFA) ameliorated biochemical and radiological markers of NAFLD. Other approaches yielded negative results.

CONCLUSION

Well-designed RCTs of adequate size and duration, with histological endpoints, are needed to assess long-term safety and efficacy of proposed treatments on patient-oriented clinical outcomes.

Risk factors for idiosyncratic drug-induced liver injury

Idiosyncratic drug-induced liver injury (DILI) is a rare disorder that is not related directly to dosage and little is known about individuals who are at increased risk. There are no suitable preclinical models for the study of idiosyncratic DILI and its pathogenesis is poorly understood. It is likely to arise from complex interactions among genetic, nongenetic host susceptibility, and environmental factors. Nongenetic risk factors include age, sex, and other diseases (eg, chronic liver disease or human immunodeficiency virus infection). Compound-specific risk factors include daily dose, metabolism characteristics, and propensity for drug interactions. Alcohol consumption has been proposed as a risk factor for DILI from medications, but there is insufficient evidence to support this. Many studies have explored genetic defects that might be involved in pathogenesis and focused on genes involved in drug metabolism and the immune response. Multicenter databases of patients with DILI (the United States Drug Induced Liver Injury Network, DILIGEN, and the Spanish DILI registry) are important tools for clinical and genetic research. A genome-wide association study of flucloxacillin hepatotoxicity has yielded groundbreaking results and many similar studies are underway. Nonetheless, DILI is challenging to investigate because of its rarity, the lack of experimental models, the number of medications that might cause it, and challenges to diagnosis.

The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.

Statins in the treatment of dyslipidemia in the presence of elevated liver aminotransferase levels: a therapeutic dilemma

The beneficial role of statins in primary and secondary prevention of coronary heart disease has resulted in their frequent use in clinical practice. However, safety concerns, especially regarding hepatotoxicity, have driven multiple trials, which have demonstrated the low incidence of statin-related hepatic adverse effects. The most commonly reported hepatic adverse effect is the phenomenon known as transaminitis, in which liver enzyme levels are elevated in the absence of proven hepatotoxicity. This class effect is usually asymptomatic, reversible, and dose-related. However, the increasing incidence of chronic liver diseases, including nonalcoholic fatty liver disease and hepatitis C, has created a new challenge when initiating statin treatment in patients with high cardiovascular risk. These diseases result in abnormally high liver biochemistry values, discouraging statin use by clinicians, fostering treatment discontinuation, and leaving a large number of at-risk patients untreated. A PubMed/MEDLINE search of the literature regarding statin safety (January 1, 1994-December 31, 2008) was performed, using the following search terms: statin safety, statin-related hepatotoxicity, and chronic liver disease and statin use, as well as the specific names of different statins and different liver diseases. Relevant clinical trials, review articles, panel discussions, and guideline recommendations were selected. This review supports the use of statin treatment in patients with high cardiovascular risk whose elevated aminotransferase levels have no clinical relevance or are attributable to known stable chronic liver conditions. For each patient, the decision should be based on an individual assessment of risks and benefits.

Treatment options for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of abnormal liver enzymes in the last few decades and is among the most common forms of chronic liver disease in the Western world and across the globe. With the growing epidemic of obesity and diabetes, NAFLD is estimated to affect about one-quarter of the US population. Although most patients with NAFLD have nonprogressive bland steatosis, a minority of patients develop the histological subtype of nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis, hepatocellular carcinoma, and liver-related death. This is especially true when NASH patients have type 2 diabetes. Treatment of NAFLD should therefore be directed towards patients with established NASH. Sustained weight loss seems to improve insulin resistance and associated NASH. In fact, weight loss with bariatric surgery leads to biochemical and histological improvement in morbidly obese patients with NASH. Several pharmacologic agents have been studied in an effort to improve insulin resistance and pro-inflammatory mediators potentially responsible for the development and progression of NASH. While some studies have shown initial promise, none has established long-term efficacy using randomized clinical trials. This paper briefly reviews the epidemiology, natural history, and pathophysiology of NAFLD and NASH and then focuses on the clinical trials of various therapeutic modalities for NAFLD. These include weight loss agents, bariatric surgery, insulin-sensitizing agents, lipid-lowering agents, antioxidants, probiotics, anti-tumor necrosis factor agents, cytoprotective and other novel agents.

Nonalcoholic fatty liver disease: a review and update

The spectrum of nonalcoholic fatty liver disease (NAFLD) ranges from asymptomatic steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Hepatic steatosis occurs when free fatty acids, released in the setting of insulin resistance and the metabolic syndrome, are taken up by the liver. Additional biochemical insults, including oxidative stress, upregulation of inflammatory mediators, and dysregulated apoptosis, can result in inflammation (producing NASH) and fibrosis. Noninvasive methods (e.g., abdominal ultrasonography) are safe ways to support a diagnosis of hepatic steatosis, but advanced liver histopathologic findings including NASH and fibrosis cannot be identified without pursuing liver biopsy. Recent advances in serologic and imaging methods aim to determine severity of inflammation and fibrosis noninvasively. Currently, therapeutic options for NAFLD are limited to medications that reduce risk factors, but the future holds promise for therapies that might slow the progression of this increasingly prevalent disorder.

Towards companion diagnostics for the management of statin therapy

BACKGROUND

Statins are the most commonly prescribed drugs in the world and are established first-line therapy for cardiovascular disease. Statin toxicity is related to dose, age, gender, ethnicity, body mass, renal and endocrine function and also to concomitant medications - particularly those that inhibit cytochrome P450 3A4.

OBJECTIVE/METHOD

This review describes the tests used before initiation of statin therapy, to establish their efficacy and to monitor their principal side effects. Lipids and apolipoproteins are used to measure efficacy and compliance, whereas transaminases and creatine kinase are used to measure toxicity. Guidelines agree in general, but differ in the details of measurement of baseline levels, action limits and management strategies for statin toxicity. Genetic factors are relevant to both the efficacy and the toxicity of statin therapy, with efficacy being associated with polymorphisms in lipid-related genes, whereas a function-related polymorphism in the organic anion transporting polypeptide 1B1 (OATP1B1; SLCO1B1) is associated with 60% of the cases of myopathy with high-dose simvastatin.

CONCLUSIONS

Although basic efficacy and safety panels for the initiation and monitoring of statin therapy are well established, controversy remains about the need for ancillary diagnostics in patients and to which patient groups these should be applied.

Treatment of nonalcoholic steatohepatitis with colestimide

AIM

To clarify the usefulness of colestimide in patients with nonalcoholic steatohepatitis (NASH) with hyperlipidemia.

METHODS

In an open-label randomized controlled trial, 17 NASH patients with hyperlipidemia received colestimide (3 g/day) for 24 weeks. There were 21 control patients. All patients received lifestyle modification therapy. Efficacy was assessed based on metabolic profile, insulin resistance, transaminases, serum hepatic fibrosis markers, adipokine levels, visceral fat on computed tomography (CT), and the fatty liver grade on CT. NASH patients with moderate to severe steatosis by histology were also evaluated separately.

RESULTS

Baseline clinical characteristics of the two groups were similar. Both groups experienced a significant decrease of BMI with no difference between them. However, visceral fat decreased significantly more in the colestimide group (P = 0.046). Aspartate aminotransferase (AST) showed a significantly greater decrease in the colestimide group compared with the control group (P = 0.042). In patients with moderate to severe histological steatosis, there were significant differences between the two groups regard to HbA(1c), transaminases, and hyaluronic acid (P = 0.018 for HbA(1c), P = 0.003 for AST, P = 0.042 for alanine aminotransferase, and P = 0.042 for hyaluronic acid). Steatosis significantly improved in patients in the colestimide group who had fatty liver on CT (P = 0.049). In the colestimide group, abdominal distension and/or constipation were seen, but mostly tolerable, no other clinical or laboratory adverse events associated with the use of this medicine were not observed.

CONCLUSIONS

Colestimide seems to increase the efficacy of lifestyle modification in NASH patients with hyperlipidemia. Its beneficial effects were more prominent in NASH patients with moderate to severe histological steatosis.

Is there an effective therapy available for non-alcoholic fatty liver disease?

Non-alcoholic fatty liver disease (NAFLD) is defined as fat accumulation in the liver, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Although it used to be considered a benign condition, nowadays it is known to be associated with liver injury and the development of end-stage liver disease. NAFLD is the hepatic manifestation of metabolic syndrome (MS) with an incidence rising in accordance with the increased prevalence of MS, the latter being considered the most common cause of liver enzyme elevation in Western countries. To date, no medications or surgical procedures have been approved for effective treatment of NAFLD, and all of the therapies tested so far must still be regarded as experimental. It is expected that, based on the large amount of data produced in the last few years and the ongoing large multicenter clinical trials, the effective treatment(s) for NASH will soon be defined. Meanwhile, lifestyle interventions and behavior therapy, the only treatments shown to be effective, must be introduced in daily clinical practice and, if possible, supported by public health programs.

Nonalcoholic fatty liver disease: a practical approach to evaluation and management

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common forms of chronic liver disease in the Western world. The rise in NAFLD is thought to be associated with the prevalence of metabolic syndrome. NASH is a subtype of NAFLD that may progress to cirrhosis and end stage liver disease. Although there are no approved treatment regimens for NAFLD or NASH, a number of different interventions are being tested. Meanwhile, most experts advocate that components of metabolic syndrome should be effectively treated.

Molecular mechanisms involved in NAFLD progression

Non-alcoholic fatty liver disease (NAFLD) is an emerging metabolic-related disorder characterized by fatty infiltration of the liver in the absence of alcohol consumption. NAFLD ranges from simple steatosis to non-alcoholic steatohepatitis (NASH), which might progress to end-stage liver disease. This progression is related to the insulin resistance, which is strongly linked to the metabolic syndrome consisting of central obesity, diabetes mellitus, and hypertension. Earlier, the increased concentration of intracellular fatty acids within hepatocytes leads to steatosis. Subsequently, multifactorial complex interactions between nutritional factors, lifestyle, and genetic determinants promote necrosis, inflammation, fibrosis, and hepatocellular damage. Up to now, many studies have revealed the mechanism associated with insulin resistance, whereas the mechanisms related to the molecular components have been incompletely characterized. This review aims to assess the potential molecular mediators initiating and supporting the progression of NASH to establish precocious diagnosis and to plan more specific treatment for this disease.

Current treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in Western World and frequently associated with insulin resistance and overweight and occurs often with type 2 diabetes. Interestingly, NAFLD is not only regarded as a hepatic component of the metabolic syndrome but also as an independent risk factor and a marker for increase in cardiovascular disease (CVD). Significantly, NAFLD is associated with an increased risk of all-cause mortality and predicts future CVD events independent of age, sex, LDL-cholesterol and features of metabolic syndrome. Although there was initial concern about drug toxicity with NAFLD, increasing evidence suggests that commonly used drugs such as metformin and statins do not cause harm and the thiazolidinediones (TZDs) may even confer a therapeutic benefit in NAFLD. Interestingly, medical and surgical treatments of obesity show potential benefit in treating NAFLD. In this review, we have focused on the safety and therapeutic impact of TZDs, statins, metformins and obesity medications in NAFLD. The potential benefit of bariatric surgery and the role of weight loss per se in treating NAFLD are also discussed.

Current status of therapy in nonalcoholic Fatty liver disease

The obesity epidemic has now spread worldwide. With increase in weight, there is an increase in dysregulated energy metabolism ultimately leading to dysfunction of multiple organ systems recognized as the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease worldwide, and is thought to be the hepatic manifestation of metabolic syndrome. It is a nondiscriminating disease affecting both children and adults and no socioeconomic class is spared. There is a well-defined increase in both liver-related and all-cause mortality. Current projections foresee a continued worsening in prevalence, especially with the increased rate of childhood obesity. Prevention would be the ultimate goal, but with continued trends in obesity, therapeutic options are needed to manage this chronic liver disease and prevent its complications of cirrhosis and even hepatocellular carcinoma. Therapies will need to be affordable, tolerable, and safe to be useful on such a large scale. This article will discuss some of the basic understanding of NAFLD, as well as review the currently tested therapies, some novel therapies, and potential future therapeutic options.

Role of nonalcoholic fatty liver disease in the development of insulin resistance and diabetes

Nonalcoholic fatty liver disease (NAFLD) is a common disease that is usually accompanied by insulin resistance (IR). Whether or how NAFLD and IR are temporally and mechanistically related is controversial. Recent studies focus on their epidemiology, the importance of dietary fat, the role of adipocytokines and the sterol regulatory element-binding protein-1c. NAFLD and IR may progress to severe diseases, such as cirrhosis, diabetes or both, and understanding the pathogenesis of the precursor conditions has preventive and therapeutic implications. This review focuses on the possible relationships between NAFLD and IR and the treatment options available.

Molecular mechanisms and therapeutic targets in steatosis and steatohepatitis

Steatosis of the liver may arise from a variety of conditions, but the molecular basis for lipid droplet formation is poorly understood. Although a certain amount of lipid storage may even be hepatoprotective, prolonged lipid storage can result in an activation of inflammatory reactions and loss of metabolic competency. Apart from drug-induced steatosis, certain metabolic disorders associated with obesity, insulin resistance, and hyperlipidemia give also rise to nonalcoholic fatty liver diseases (NAFLD). It is noteworthy that advanced stages of nonalcoholic hepatic steatosis and steatohepatitis (NASH) result ultimately in fibrosis and cirrhosis. In this regard, the lipid droplets (LDs) have been discovered to be metabolically highly active structures that play major roles in lipid transport, sorting, and signaling cascades. In particular, LDs maintain a dynamic communication with the endoplasmic reticulum (ER) and the plasma membrane via sphingolipid-enriched domains of the plasma membrane-the lipid rafts. These microdomains frequently harbor receptor tyrosine kinases and other signaling molecules and connect extracellular events with intracellular signaling cascades. Here, we review recent knowledge on the molecular mechanisms of drug and metabolically induced hepatic steatosis and its progression to steatohepatitis (NASH). The contribution of cytokines and other signaling molecules, as well as activity of nuclear receptors, lipids, transcription factors, and endocrine mediators toward cellular dysfunction and progression of steatotic liver disease to NASH is specifically addressed, as is the cross-talk of different cell types in the pathogenesis of NAFLD. Furthermore, we provide an overview of recent therapeutic approaches in NASH therapy and discuss new as well as putative targets for pharmacological interventions.

Review article: diagnosis and treatment of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent condition affecting adults and children, leading to significant morbidity. It is often associated with the metabolic syndrome, although multiple pathogenetic mechanisms have been suggested. In the coming decades, it promises to be the leading cause of liver disease in industrial countries.

AIM

To provide a comprehensive, updated review of diagnosis and management of NAFLD and to appraise the evolution of new modalities in these areas.

METHODS

An Ovid MEDLINE search was performed to identify pertinent original research and review articles. Selected references in these articles were also evaluated.

RESULTS

The diagnosis of hepatic steatosis and steatohepatitis or non-alcoholic steatohepatitis (NASH) is not yet possible without liver biopsy. This is impractical given the large numbers affected by the condition. Current therapy has focused on improving insulin resistance and mediators of inflammation, factors probably associated with disease progression.

CONCLUSIONS

There are no proven non-invasive diagnostic modalities to distinguish NAFLD and NASH, but new biomarker panels are approximating the liver biopsy in accuracy. Therapeutic targets of drug development are in early stages, but a multifaceted approach will probably yield several treatment options in the years to come.

Non-alcoholic fatty liver disease: an overview of prevalence, diagnosis, pathogenesis and treatment considerations

The global increase in the prevalence of obesity has heralded a rise in associated liver injury namely NAFLD (non-alcoholic fatty liver disease). It is estimated that 20–30% of adult populations in developed countries have NAFLD and, although high quality data is currently lacking, the condition is clearly increasing in children also. NAFLD should be suspected in those with commonly available simple clinical signs and biochemistry consistent with insulin resistance. A small number of individuals with NAFLD, often considered a relatively benign condition, will progress to more severe stages of liver disease including NASH (non-alcoholic steatohepatitis) with or without fibrosis, cirrhosis and occasionally hepatocellular carcinoma. NAFLD is also commonly associated with an increased risk of developing Type 2 diabetes and treatable features of insulin resistance such as dyslipidaemia and dysglycaemia. Histological examination of liver tissue remains the only proven method to distinguish between simple steatosis and NASH, a condition far more likely to progress to cirrhosis. Identification of an imaging technique or non-invasive marker to achieve this distinction is therefore much sought after and would allow larger clinical trials and better clinical assessment. Case series and pilot studies of lifestyle advice, insulin sensitizers and other medications have shown improvements in liver histology and serum liver enzymes but robust randomized controlled studies are needed. Furthermore, the cost/benefit ratio of any new therapies, and any potential harms, must be evaluated carefully before being clinically advocated.

Statins in liver disease: a molehill, an iceberg, or neither?

A growing number of chronic liver disease patients, especially those with metabolic syndrome-associated nonalcoholic fatty liver disease or hepatitis C virus-associated dysmetabolic syndrome, will take statins to prevent cardiovascular disease. As a result, clinicians will weigh complex issues raised by the interaction of statins with liver metabolism in these disorders. In this article, we critically review data concerning statins and liver pathophysiology with an emphasis on nonalcoholic fatty liver disease and hepatitis C virus, while also touching on other chronic liver diseases. Basic research interests include statins' mechanism of action and their effects on cholesterol-related cell signaling pathways and angiogenesis. From the clinical standpoint, many chronic liver diseases increase cardiovascular risk and would undeniably benefit from sustained statin use. The false alarms and security accompanying aminotransferase monitoring, however, are disturbing in light of the scarcity of data on statins' long-term effects on liver histology. Although some actions of statins might eventually prove to be particularly useful in nonalcoholic steatohepatitis, hepatitis C virus, or hepatocellular carcinoma, others may prove harmful. The lack of definitive data makes a fully informed decision impossible. Research using histological endpoints is urgently needed to determine the indications and contraindications of this extraordinary class of agents in patients with chronic liver disease.

Atorvastatin does not improve liver biochemistries or Mayo Risk Score in primary biliary cirrhosis

Statin treatment reduces hypercholesterolemia and may be anti-inflammatory. Case reports noted decreased alkaline phosphatase and histological improvement following statin treatment in primary biliary cirrhosis. The objective of this study was to assess the long-term effects of statin treatment in primary biliary cirrhosis. A retrospective analysis compared clinical and biochemical data from 15 hypercholesterolemic individuals with primary biliary cirrhosis who were treated long-term with atorvastatin with an age and gender matched, primary biliary cirrhosis control group. A significant decrease in total cholesterol and low-density lipoprotein (LDL)-cholesterol (p < or = 0.002) was observed throughout atorvastatin treatment (median time 2.5 years). LDL-cholesterol levels in the control group were not significantly changed after 2 years (p > 0.050). No significant changes were noted in alanine aminotransferase (ALT), alkaline phosphatase, total bilirubin and Mayo Risk Score in either group (p > 0.05). Long-term atorvastatin treatment reduced LDL-cholesterol in primary biliary cirrhosis, but there was no evidence of any anti-inflammatory effect.

Diagnosis and therapy of nonalcoholic steatohepatitis

The increasing prevalence of obesity, insulin resistance, and the metabolic syndrome has significant implications for the future of chronic liver disease. The resultant increase in the number of patients with nonalcoholic fatty liver disease (NAFLD) is expected to translate into increased numbers of patients with end-stage liver disease (cirrhosis), liver failure, and hepatocellular carcinoma. It is particularly important to identify the patients who are at greatest risk of these aforementioned complications of chronic liver disease, those nonalcoholic fatty liver disease patients with nonalcoholic steatohepatitis. Currently liver biopsy is the gold standard for diagnosis, but less invasive, highly accurate, and affordable screening tools are required. These tools may include radiologic or laboratory studies to identify patients noninvasively who may benefit from therapeutic interventions. Clinical scoring systems that may be used in general practice as initial screening tools also may prove useful. Most therapeutic modalities available or under development target the major pathways thought essential in the pathogenesis of nonalcoholic steatohepatitis and often are directed at reducing body mass index and improving insulin resistance via pharmacologic, surgical, dietary, or exercise regimens. Other potential therapeutic agents directed at cytoprotection or reduction of fibrosis are under investigation. This article focuses on diagnosis and therapy available and under development for this chronic liver disease.

Emerging drugs for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a condition of emerging relevance that includes different forms of chronic liver damage, from a simple fatty infiltration (steatosis) of hepatocytes to steatohepatitis (NASH) with fibrosis. This last form may evolve to cirrhosis and hepatocellular carcinoma.

OBJECTIVE

To discuss therapeutic management of NAFLD. Theoretically, only patients with non-alcoholic steatohepatitis (NASH) need to be treated, as only NASH may evolve to cirrhosis. Differentiation between steatosis and NASH currently requires a liver biopsy.

METHODS

We discuss different therapeutic approaches proposed in literature for patients with NAFLD.

RESULTS

The treatment of associated conditions leads to an improvement of NAFLD and NASH. No specific drug is actually present to treat liver steatosis or NASH.

CONCLUSIONS

The treatment of NAFLD depends on the individual characteristics of each patient. Diet and physical exercise may be considered a basal universal approach. Future research will discover possible specific liver drugs.

Elevated liver enzymes in Turner syndrome during a 5-year follow-up study

OBJECTIVES

To study the prevalence and incidence of elevated liver enzymes and their relationship with body weight, metabolic factors and other diseases in Turner syndrome (TS).

DESIGN

Five-year follow-up.

PATIENTS

Women with TS (n = 218, mean age 33 +/- 13, range 16-71 years) from outpatient clinics at university hospitals in Sweden.

MEASUREMENTS

Fasting blood samples for aspartate (AST) and alanine aminotransferase (ALT), bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GT), viral hepatitis serology and hepatic auto-antibodies, vitamin B12, blood glucose, lipids and hormones.

RESULTS

Seventy-nine subjects (36%) had one or more liver enzyme levels higher than the reference level, the most prevalent being GT. Karyotype 45,X was present in 51% of all TS women and in 48% of those with elevated liver enzymes. Body weight, body mass index (BMI), total cholesterol, triglycerides, and apolipoproteins A and B at start were higher in TS women with elevated liver enzymes than in TS women with normal levels. At 5 years, AST, ALT and GT were increased and another 23% of patients had developed elevated liver enzymes, that is, 59% in total (36% + 23%), while in 6%, the elevated liver enzymes had been normalized and all 6% also had lowered cholesterol levels. Multivariate analysis showed that GT was correlated with total cholesterol; P = 0.0032 at start and P = 0.0005 at 5 years, independently of other factors. Liver biopsy in six TS women showed one cholangitis, one hepatitis C, two steatosis and two normal biopsies. Withdrawal of oestrogen substitution did not influence the liver enzymes.

CONCLUSIONS

Pathological liver enzymes were common in TS women, with a prevalence of 36% at 33 years of age, an annual incidence over 5 years of 3.4%. There was no relation to karyotype, alcohol, viral hepatitis, E(2) or autoimmunity, but a connection with total serum cholesterol.

Liver biopsy in a district general hospital: Changes over two decades

AIM: To study liver biopsy practice over two decades in a district general hospital in the United Kingdom.

METHODS: We identified all patients who had at least one liver biopsy between 1986 and 2006 from the databases of the radiology and gastroenterology departments. Subjects with incomplete clinical data were excluded from the study.

RESULTS: A total of 103 liver biopsies were performed. Clinical data was available for 88 patients, with 95 biopsies. Between 1986 and 1996, 18 (95%) out of the 19 liver biopsies performed were blind and 6 (33%) were for primary biliary cirrhosis. Between 1996 and 2006, 14 (18%) out of 76 biopsies were blind; and the indications were abnormal liver tests (33%), hepatitis C (12%) and targeted-biopsies (11%). Liver biopsies were unhelpful in 5 (5%) subjects. Pain was the most common complication of liver biopsy (5%). No biopsy-related mortality was reported. There was a trend towards more technical failures and complications with the blind biopsy technique.

CONCLUSION: Liver biopsies performed in small district hospitals are safe and useful for diagnostic and staging purposes. Abnormal liver tests, non-alcoholic fatty liver disease and targeted biopsies are increasingly common indications. Ultrasound-guided liver biopsies are now the preferred method and are associated with fewer complications.