Advances in the Understanding and Treatment of Nonalcoholic Fatty Liver Disease

The Coexistence of Nonalcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus

The incidence of nonalcoholic fatty liver disease (NAFLD) is growing worldwide. Epidemiological data suggest a strong relationship between NAFLD and T2DM. This is associated with common risk factors and pathogenesis, where obesity, insulin resistance and dyslipidemia play pivotal roles. Expanding knowledge on the coexistence of NAFLD and T2DM could not only protect against liver damage and glucotoxicity, but may also theoretically prevent the subsequent occurrence of other diseases, such as cancer and cardiovascular disorders, as well as influence morbidity and mortality rates. In everyday clinical practice, underestimation of this problem is still observed. NAFLD is not looked for in T2DM patients; on the contrary, diagnosis for glucose metabolism disturbances is usually not performed in patients with NAFLD. However, simple and cost-effective methods of detection of fatty liver in T2DM patients are still needed, especially in outpatient settings. The treatment of NAFLD, especially where it coexists with T2DM, consists mainly of lifestyle modification. It is also suggested that some drugs, including hypoglycemic agents, may be used to treat NAFLD. Therefore, the aim of this review is to detail current knowledge of NAFLD and T2DM comorbidity, its prevalence, common pathogenesis, diagnostic procedures, complications and treatment, with special attention to outpatient clinics.

Non-Alcoholic Fatty Liver Disease (NAFLD) in Patients with Psoriasis: A Review of the Hepatic Effects of Systemic Therapies

There is increasing interest in the association between psoriasis and non-alcoholic fatty liver disease (NAFLD), which is a prevalent liver disease characterized by excessive fat storage and inflammation that can progress to fibrosis and cancer. Patients with psoriasis have a two-fold higher risk to develop NAFLD and a higher risk to progress to more severe liver disease. Psoriasis and NAFLD share common risk factors such as smoking, alcohol consumption, and the presence of metabolic syndrome and its component disorders. In addition, both psoriasis and NAFLD hinge upon a systemic low-grade inflammation that can lead to a vicious cycle of progressive liver damage in NAFLD as well as worsening of the underlying psoriasis. Other important shared pathophysiological pathways include peripheral insulin resistance and oxidative stress. NAFLD should receive clinical awareness as important comorbidity in psoriasis. In this review, we assess the recent literature on the epidemiological and pathophysiological relationship of psoriasis and NAFLD, discuss the clinical implications of NAFLD in psoriasis patients, and summarize the hepatotoxic and hepatoprotective potential of systemic psoriasis therapies.

Efficacy of dietary intervention and physical activity in children and adolescents with nonalcoholic fatty liver disease associated with obesity: A scoping review

AIM

To identify and discuss the efficacy of dietary interventions, antioxidant supplementation, physical activity, and nutritional and psychologic counseling in the treatment of children and adolescents with non alcoholic fatty liver disease associated with obesity.

MATERIALS AND METHODS

A scoping review of studies on nutritional and educational interventions and physical activity in pediatric patients with non alcoholic fatty liver disease was conducted. A search for randomized clinical trials or quasi-experimental studies published up to December 2017 was carried out, utilizing seven databases (Medline, EBSCO, OVID, Science Direct, JSTOR, Wiley, and Biblioteca Digital UDG).

RESULTS

From a total of 751 articles, 729 were excluded due to the criteria of age, design, language, diagnostic method, and outcome variables. The analysis included 22 articles. The most frequently used intervention variables were diet and physical activity. The interventions had different durations, but most were carried out for one year. Some authors employed ascorbic acid, vitamin E, or omega-3 fatty acid supplementation. There were varying degrees of improvement in the variables analyzed in the majority of the studies, such as a decrease in ALT levels, a reduced frequency of steatosis determined through imaging studies, and a decrease in body mass index.

CONCLUSIONS

The dietary interventions, omega-3 fatty acid supplementation, physical activity, and nutritional and psychologic counseling were identified as efficacious measures in the treatment of non alcoholic fatty liver disease associated with obesity in children and adolescents, according to biochemical or imaging study indicators, within the time frame of the intervention.

Elevated serum α-fetoprotein levels in patients with chronic hepatitis C virus genotype 4: not the end of the story

BACKGROUND AND AIM

Elevated serum α-fetoprotein (AFP) is not uncommonly seen among patients with chronic hepatitis C. This study aimed to identify clinical characteristics, histological characteristics, and biochemical markers associated with increased serum AFP levels in hepatitis C virus genotype 4-infected patients with no evidence of hepatocellular carcinoma and to determine the effect of lifestyle modification on these parameters.

METHODS

The study included 447 chronic hepatitis C patients with no evidence of hepatocellular carcinoma and 100 healthy controls. They underwent liver biopsies, homeostasis model assessment-insulin resistance (HOMA-IR), measurement of serum insulin, leptin, adiponectin, tumor necrosis factor-α, and interleukin-6 levels by an enzyme-linked immunosorbent assay, and assessment of AFP levels. Eighty patients with HOMA-IR greater than 3 received prospective longitudinal lifestyle intervention.

RESULTS

In a multivariate analysis, platelet count less than 140×10/cm, a mean platelet volume of at least 9.5 fl, a neutrophil-lymphocyte ratio (NLR) of at least 2, an aspartate transaminase level of at least 55 IU/l, a γ-glutamyl transpeptidase level of at least 40 IU/l, an albumin level of up to 3.8 g/dl, HOMA-IR greater than 3, a leptin level of at least 10 pg/ml, an iron level of at least 165 μg/dl, a ferritin level of at level 175 ng/ml, and hepatic fibrosis F3-F4 were found to be independently associated with elevated AFP levels. The lifestyle intervention significantly improved BMI, platelet indices, NLR, γ-glutamyl transpeptidase, leptin, leptin/adiponectin ratio, tumor necrosis factor-α, interleukin-6, HOMA-IR, and AFP levels.

CONCLUSION

Elevated insulin resistance, leptin, serum iron, ferritin, mean platelet volume, NLR, and advanced fibrosis, as well as decreased platelet count and serum albumin, are independently associated with an elevated AFP level. Lifestyle modification can improve (reduce) insulin resistance, leptin, leptin/adiponectin ratio, platelet count and their indices, NLR, and AFP level.

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.

Hepatic free cholesterol accumulates in obese, diabetic mice and causes nonalcoholic steatohepatitis

BACKGROUND & AIMS

Type 2 diabetes and nonalcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to the pathogenesis of NASH.

METHODS

Alms1 mutant (foz/foz) and wild-type NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice.

RESULTS

Hepatic cholesterol accumulation was attributed to up-regulation of low-density lipoprotein receptor via activation of sterol regulatory element binding protein 2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and low-density lipoprotein receptor and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol levels exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis.

CONCLUSIONS

In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH.

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

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

Non-alcoholic fatty liver disease: is bariatric surgery the answer?

As the worldwide obesity epidemic continues to increase, the prevalence of non-alcoholic fatty liver disease (NAFLD) and specifically non-alcoholic steatohepatitis (NASH) will become increasingly prominent. NASH will surpass chronic hepatitis C infection as the primary indication for orthotopic liver transplantation in the near future. With the evolution of surgical techniques, bariatric surgery is currently recognized as the most effective method for achieving sustained weight loss and reversing numerous comorbidities in severely obese individuals. This review focuses on the potential risks and benefits of bariatric surgery in subjects with NAFLD and explores its role in the management of NASH in the obese patient.

Prevalence and predictors of hepatic steatosis in adults with newly diagnosed chronic liver disease due to hepatitis C

Obesity appears to be a risk factor for hepatic steatosis, which has been implicated in the development of hepatic fibrosis in patients with hepatitis C virus infection. We conducted the current study to examine whether obesity is associated with hepatic steatosis among patients with chronic hepatitis C identified from a population-based cohort. Study participants were persons with chronic hepatitis C who had had a liver biopsy, identified from a population-based study of persons with newly identified chronic liver disease conducted in gastroenterology practices. Data were collected through patient interviews, medical record abstraction, and review of previously performed liver biopsies. The outcome variable of interest was significant steatosis, defined as steatosis grade > or =2 determined from liver biopsy samples. Univariate and multivariate analyses were performed using logistic regression techniques. The analysis included 450 patients with chronic hepatitis C with available liver biopsy slides. Overall, only 15.8% of subjects had significant hepatic steatosis (grade > or =2), while 35.9% of obese subjects had significant steatosis. In multivariate analysis, significant fibrosis (defined as > or = grade 2) (odds ratio [OR], 3.43; 95% confidence interval [CI], 1.59-7.37), obesity (OR, 3.32; 95% CI, 1.84-5.98), genotype 3 (OR, 2.5; 95% CI, 1.09-5.75), and the presence of multiple metabolic comorbidities (OR, 1.91; 95% CI, 0.88-4.11) were independently associated with steatosis. In this unique United States cohort of patients with newly diagnosed chronic liver disease due to hepatitis C, obesity was independently associated with hepatic steatosis. The results of this study provide additional evidence that obesity worsens liver damage in patients with chronic hepatitis C, and suggest a role for weight loss as a treatment modality in these patients.

Epigallocatechin gallate attenuates experimental non-alcoholic steatohepatitis induced by high fat diet

BACKGROUND AND AIM

In the present study, we examined the preventive role of epigallocatechin gallate (EGCG) in an experimental non-alcoholic steatohepatitis model induced by a high fat diet.

METHODS

The study included 21 male Sprague-Dawley rats, which were equally divided into three groups. The first group was fed on a standard rat diet, the second group on a high fat diet (HFD), and the third group on a HFD + EGCG. The study concluded after 6 weeks. Histopathological examination was performed. Plasma and tissue MDA levels, glucose, insulin, alanine aminotransferase (ALT), aspartate aminotransferase, gamma glutamyltransferase, alkaline phosphatase, triglyceride, and cholesterol levels were studied. Insulin resistance was calculated by the homeostasis model of insulin resistance method.

RESULTS

Steatosis, inflammation, ballooning degeneration, and necrosis increased significantly in the HFD group, compared to the control group (P < 0.01). Steatosis and inflammation decreased in the HFD + EGCG group, in comparison to the HFD group (P < 0.05, for each). There was a significant decline in ALT (P < 0.01), triglyceride (P < 0.01), insulin (P < 0.05), and glucose (P < 0.05) levels in the HFD + EGCG group, when compared to the HFD group. Plasma and liver MDA levels in the HFD + EGCG group were lower than those of the HFD group; the difference was significant (P < 0.01 for each). Glutathione levels in the HFD + EGCG group was significantly higher those in the HFD group. CYP 2E1 and alpha-smooth muscle actin expression decreased in the HFD + EGCG group, in comparison to the HFD group (P < 0.01, P < 0.05, respectively).

CONCLUSION

EGCG reduces the development of experimental non-alcoholic steatohepatitis induced by a high fat diet. It seems to exercise this effect through its effect on lipid metabolism and antioxidant characteristics.

Non-alcoholic fatty liver disease and its relationship with the nutritional status of vitamin A in individuals with class III obesity

BACKGROUND

The objective of the present study was to investigate vitamin A nutritional status in individuals with class III obesity through a biochemical indicator (retinol and beta-carotene serum levels), correlating these findings with non-alcoholic fatty liver disease (NAFLD) presence and its risk factors.

METHODS

The studied population was composed of 145 patients with morbid obesity [body mass index, BMI > or = 40 kg/m(2)) of both sexes. Retinol and beta-carotene serum levels were assessed by high performance liquid chromatography. The cutoff values used for serum retinol and beta-carotene inadequacy were <1.05 micromol/l and < or =40 microg/dl, respectively. Insulin resistance (IR) was assessed through homeostasis model assessment index (HOMA) method. Biochemical parameters of liver enzymes, lipid profile, and glycemia were analyzed. Anthropometric measurements were conducted. NAFLD diagnosis was performed through magnetic resonance.

RESULTS

NAFLD prevalence in the group was 71%. An inadequacy of 11.3 and 41.7% of retinol and beta-carotene serum levels, respectively, was found when NAFLD was present. A significant correlation of serum retinol with albumin liver and total bilirubin was found. As regards beta-carotene, a positive correlation for HDL-c variable and a negative correlation for the HOMA-IR, weight, and BMI variables were observed. There was a significant association between IR presence and retinol and beta-carotene inadequacy.

CONCLUSION

The high inadequacy of retinol and beta-carotene nutritional status in the sample, with a higher inadequacy in those with NAFLD, suggests an increase in the utilization of vitamin A in this group related to the fight against the oxidative stress to what they are exposed to. The significant association between retinol and beta-carotene with IR supports the hypothesis that vitamin A may have a protector effect on IR pathogenesis.

The effect of QuYuHuaTanTongLuo Decoction on the non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the most common cause of cryptogenic cirrhosis, is becoming more prevalent in China. However, there is as yet no clearly established therapy for reversing fatty liver. Our aim is to explore the effect of traditional Chinese herbs QuYuHuaTanTongLuo Decoction (QYHTTLD) on non-alcoholic steatohepatitis. Sixty-nine non-alcoholic steatohepatitis patients were randomly divided into two groups. One group of 35 patients were treated by QYHTTLD, another group of 34 patients were treated by Ursodeoxycholic acid (UDCA). The TNF-alpha, IL-8, MDA level, SOD activity and liver function, as well as B ultrasonic image were detected before and after being treated. The results showed: after 6 months treatment, MBI of the treatment group was obviously decreased (p<0.05). The levels of TC, TG and LDL-C were significantly decreased whereas the level of HDL-C increased (p<0.01, p<0.05, p<0.05, and p<0.05, respectively) in the treatment group, the levels of TC, TG, LDL-C and HDL-C had no significant difference in the control group (p>0.05). The levels of TNF-alpha, IL-8 and MDA were significantly decreased whereas SOD activity was significantly increased (p<0.01, p<0.05, p<0.01, and p<0.01, respectively) in the treatment group, the level of MDA was significantly decreased in the control group (p<0.05). B ultrasonic images were ameliorated in different degree (p<0.01 and p<0.01, respectively). Both QYHTTLD and UDCA had the effect in improving the scores of symptoms and signs of patients, however, the difference value of the scores in treatment group were significantly higher than that in control group after being treated for 6 months (p<0.05).

CONCLUSION

QYHTTLD is effective for treating non-alcoholic steatohepatitis, and its effect seems to relate with the ways of QYHTTL down-regulating inflammation cytokine IL-8 level and relieving lipid peroxidation of liver.

Resolution of nonalcoholic steatohepatits after gastric bypass surgery

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has been increasingly recognized as a common chronic liver condition. Previous studies have been variable regarding the histological outcomes after rapid weight loss. The aim of this study was to characterize the histopathologic changes in NASH following laparoscopic Roux-en-Y Gastric Bypass surgery (LRYGBP).

METHODS

We retrospectively analyzed paired needle liver biopsies taken during and following LRYGBP in 39 patients according to the recent NIH-based NAFLD criteria.

RESULTS

The cohort included 33 females and 6 males (range 24-57 years). 23 patients (58.9%) had steatohepatitis, 12 with fatty liver (30.7%), and 4 were normal (10.2%). Follow-up needle liver biopsies were performed at a mean interval of 18 months (range 6-41 months). No significant differences in length or number of portal tracts between the paired biopsies were noted. The mean decrease in weight and BMI was 50.2 kg and 18.2 kg/m2, respectively. The initial prevalence of hepatic pathology: steatosis (89.7%), hepatocellular ballooning (58.9%), and centrilobular/perisinusoidal fibrosis (50%) improved significantly after LRYGBP: steatosis (2.9%), ballooning (0%), and centrilobular fibrosis (25%). Mitigation in the lobular inflammation score (2.23+/-0.63 vs 1.95+/-0.56, P=0.01) and stage of fibrosis (1.14+/-1.05 to 0.72+/-0.97, P=0.002) were also noted. However, no improvements were detected in portal tract inflammation and fibrosis.

CONCLUSIONS

Over a mean period of 18 months, histological improvements and resolution of NASH occurs after LRYGBP. Long-term studies are warranted to assess for potential changes in the portal regions or relapse of NASH that could result with weight regain or malnutrition.

Regenerative capacity differs between micro- and macrovesicular hepatic steatosis

INTRODUCTION

Independent of etiology, the hepatic microvesicular steatosis has a worse prognosis compared with macrovesicular steatosis. Proliferation compensates for apoptosis and reflects regenerative mechanisms following liver injury. It is unknown whether these two types of fatty liver have differences in regenerative capacity and apoptosis, which could have an impact on their prognosis.

METHODS

Two groups of pigs were studied for 72 days under a protein-deficient diet. One group received only protein-deficient diet (n=6), the other was treated in addition to the diet with 6g ethanol/kg/day by means of a percutaneous intragastric catheter (n=6). The rate of proliferating and apoptotic hepatocytes was determined, respectively, by proliferation cell nuclear antigen (PCNA) and ISEL/TUNEL staining for apoptosis in liver biopsies with similar steatosis grade in pigs with micro- or macrovesicular fatty liver.

RESULTS

The ethanol-treated group developed microvesicular steatosis, the other group developed macrovesicular steatosis. Proliferation index was significantly increased in macrovesicular in comparison with microvesicular steatosis (p<0.05). Apoptosis rate was similar in both groups.

CONCLUSIONS

Regeneration, but not apoptosis rate differs between micro- and macrovesicular steatosis. The reduced regenerative capacity in microvesicular steatosis may contribute to the worse prognosis of this subtype of fatty liver disease.

Importance of cytokines, oxidative stress and expression of BCL-2 in the pathogenesis of non-alcoholic steatohepatitis

OBJECTIVE

Non-alcoholic steatohepatitis (NASH) is a form of chronic hepatitis. The pathogenesis of NASH has been dealt with in only a few studies and so it has not been clearly identified yet. The purpose of this study was to investigate the roles of TNF-alpha, TGF-beta, IL-6, IL-8, malondialdehyde (MDA), nitric oxide (NO) and the expression of Bcl-2 and Bax in the pathogenesis of NASH.

MATERIAL AND METHODS

The study included 92 patients, 57 of whom were diagnosed with biopsy-proven NASH, 13 with biopsy-proven hepatosteatosis and 22 with ultrasonography-diagnosed hepatosteatosis. Serum levels of TNF-alpha, TGF-beta, IL-6 and IL-8 were measured using the ELISA method. The plasma levels of NO were studied using the Griess method. Expressions of Bcl-2 and Bax were examined in paraffin blocks of liver biopsy materials by means of immunohistochemical-staining. MDA levels were measured using the thiobarbituric acid method.

RESULTS

No significant difference was found in the levels of TNF-alpha, TGF-beta, IL-6 or NO between the three groups (p>0.05). No difference was found in expression of Bcl-2 and expression of Bax between the biopsy-proven NASH and biopsy-proven hepatosteatosis groups (p>0.05). In the NASH group, the levels of IL-8 and MDA were found to be higher than those in the hepatosteatosis groups (p<0.05).

CONCLUSIONS

The elevated levels of MDA may indicate the relationship between oxidative stress and NASH. Furthermore, IL-8 was found to be higher in the NASH group than in the hepatosteatosis group, demonstrating the importance of inflammation in the pathogenesis of NASH.

HIV-positive patients with nonalcoholic fatty liver disease have a lower body mass index and are more physically active than HIV-negative patients

OBJECTIVE

To determine whether the clinical and metabolic features associated with nonalcoholic fatty liver disease (NAFLD) are similar between HIV-positive and HIV-negative male subjects.

METHODS

Twenty-six HIV-positive and 25 HIV-negative subjects with liver biopsy-proven NAFLD were compared for liver histology (extent of steatosis, steatosis grading, and fibrosis staging), blood biochemistry (glucose, insulin, C-peptide, hemoglobin A1c, and lipid profile), insulin resistance (IR) using a homeostasis model assessment, anthropometry (body mass index [BMI], waist circumference, and arm muscle area), dietary intake, and physical activity.

RESULTS

The 2 groups were similar for age, liver histology, and IR. HIV-positive patients had a lower BMI (26.3 +/- 0.5 vs. 30.2 +/- 1.0 kg/m; P = 0.001) and lower percentage of fat mass (19.4 +/- 0.9 vs. 22.7 +/- 1.2; P = 0.026) when compared with HIV-negative patients. Although caloric intake was similar between groups, HIV-positive patients had a higher physical activity level (8.3 +/- 1.6 vs. 4.1 +/- 0.8 units of exercise per day; P = 0.029). Blood triglycerides were significantly higher (3.14 +/- 0.39 vs. 1.86 +/- 0.20 mmol/L; P = 0.006) in HIV-positive patients.

CONCLUSION

Although NAFLD was similar between the 2 groups, HIV-positive patients had a lower BMI and were more physically active compared with HIV-negative patients. This may suggest that in HIV, NAFLD is associated with factors other than those related to body fatness, such as HIV infection and treatment.

Unchanged serum levels of advanced glycation endproducts in patients with liver disease

Advanced glycation end products (AGEs), e.g., carboxymethyllysine (CML) or imidazolone are involved in several age-related disorders. Concerning their accumulation, the importance of hepatic and renal function is controversially discussed. To test whether impairment of hepatic or renal function will affect their accumulation, both AGEs have been measured in various populations, such as 52 patients with liver disease [viral hepatitis C without (n = 19) and with (n = 10) fatty liver; nonalcoholic fatty liver (n = 13), nonalcoholic steatohepatitis (n = 10)]. Serum concentrations of both AGEs have been compared to those in 20 healthy controls and 24 patients with moderate renal impairment (creatinine clearance 23-55 ml/min). Concerning CML (95% C.I. 803-1200 ng/ml), no differences between the various groups could be observed. Likewise, serum levels of imidazolone (95% C.I. 1.3-5.6 units) were similar in all populations. In conclusion, moderate impairment in hepatic or in renal function did not affect serum levels of CML and imidazolone. Apparently, any increase observed in severe cirrhosis or renal failure seems to be rather a consequence than a cause of both disorders.

Musculoskeletal complaints and serum autoantibodies associated with chronic hepatitis C and nonalcoholic fatty liver disease

We sought to compare the musculoskeletal symptoms and immune markers found in chronic hepatitis C (HCV) and nonalcoholic fatty liver disease (NAFLD). Patients with HCV or NAFLD answered a questionnaire and donated serum for autoantibody testing. Univariate analysis between the HCV and NAFLD groups revealed joint pain in 67% of the HCV group and 65% of the NAFLD group. Those with joint pain reported inflammatory characteristics that were similar between the groups. The presence of a positive rheumatoid factor and cryoglobulins was higher in the HCV group, however both groups had a similar prevalence of a low positive antinuclear antibody (ANA). We conclude that the NAFLD group reported a higher amount of joint pain and inflammatory joint symptoms than anticipated. We were unable to determine a variable that predicted the presence of joint pain. Therefore, more investigation is needed to determine whether these findings are due to liver disease alone.

Soluble TNF-α receptor 2 produced by alternative splicing is paradoxically associated with markers of liver injury

Tumor necrosis factor-alpha and insulin resistance play central roles in the pathogenesis of abnormal hepatocellular function. We evaluate the relationship between a novel serum DS-TNFR2 (an alternatively spliced soluble TNF-alpha receptor 2) isoform and parameters of liver health. Serum ALT, AST and GGT, insulin resistance, adiponectin and DS-TNFR2 isoform concentrations were measured in 492 subjects from two different Caucasian Spanish populations. We found a significant negative association between serum ALT and DS-TNFR2 levels in both populations (r=-0.269; p=0.002 and r=-0.152; p=0.01, respectively). DS-TNFR2 levels also correlated negatively with serum AST (r=-0.142; p=0.042) and GGT (r=-0.206; p=0.003) in population 1 and with AST (r=-0.127; p=0.038) in population 2. In multiple regression analysis models, serum DS-TNFR2 was shown to be an independent modulator of serum ALT activity after adjusting for sex, age, BMI, HOMA and adiponectin in both populations. These results suggest potential anti-inflammatory properties of this TNF-alpha receptor 2 isoform at the hepatic level.

[Epidemiology and natural history of primary nonalcoholic fatty liver disease]

The clinical impact of nonalcoholic fatty liver disease depends on its prevalence and natural history. The prevalence in the adult population is estimated to be about 23% and is on the increase. Thus, it has become the most common cause of persistent elevated liver enzymes, chronic liver disease, and cryptogenic cirrhosis in developed countries. The increasing prevalence of nonalcoholic fatty liver disease, which is approaching epidemic proportions, is parallel to that of other disorders associated with insulin resistance, especially obesity and type 2 diabetes mellitus. This entity occurs in men and women equally and in all age groups. The natural history is poorly defined mainly due to the scarcity of histologic follow-up studies. Although steatosis alone has a more benign clinical course, steatohepatitis is a progressive fibrotic disease, in which cirrhosis and liver-related death occur in a similar way to other causes of chronic liver diseases. Progression seems to be mainly dependent on the severity of histological damage at diagnosis, but age older than 40 years, obesity, and type 2 diabetes have also been associated with an increased risk of liver fibrosis and progression to cirrhosis.

Non-alcoholic steatohepatitis: effect of Roux-en-Y gastric bypass surgery

OBJECTIVE

Non-alcoholic steatohepatitis (NASH) is an increasingly prevalent problem. Treatment options are still under investigation. The primary aim of the study was to determine whether weight loss, achieved through Roux-en-Y gastric bypass (RYGBP), improved histopathology in obese patients with biopsy proven NASH.

METHODS

One hundred and forty-nine patients were identified from a surgical database as having RYGBP for obesity and concomitant intra-operative liver biopsies from October 2001 to September 2003. Thirty-five patients were found to have evidence of NASH at the time of surgery. Nineteen patients were contacted and underwent repeat percutaneous liver biopsies. Biopsies were evaluated and compared in blinded fashion by an experienced hepatopathologist. Fasting lipid panel, insulin and glucose, hemoglobin A1c (HgbA1c), and liver enzymes were obtained.

RESULTS

Significant differences were noted in the following variables pre- and post-bypass surgery: body mass index 46.8-28.8 kg/m2 (p < 0.001); body weight in kilograms 132.1-79.7 (p < 0.001); glucose 102.9-94.1 mg/dL (p = 0.015); Hgb A1c 5.79-5.15% (p = 0.026); high density lipoprotein 45.7-64.4 mg/dL (p < 0.001); low density lipoprotein 112-88.6 mg/dL (p = 0.003); triglycerides 132.1-97 mg/dL (p = 0.013). Significant improvements in steatosis, lobular inflammation, portal, and lobular fibrosis were noted. Histopathologic criteria for NASH were no longer found in 17/19 patients (89%).

CONCLUSIONS

Weight loss after gastric bypass surgery in obese patients with NASH results in significant improvement in glucose, HgbA1c. and lipid profiles. Furthermore, RYGBP results in significant improvement in the histological features of NASH with resolution of disease in a majority of these patients.

Demographic and clinicopathological characteristics of nonalcoholic fatty liver disease in the East-Southeastern Anatolia regions in Turkey

OBJECTIVE

To identify the demographic and clinicopathological characteristics of patients diagnosed with nonalcoholic fatty liver disease (NAFLD) and the risk factors for fibrosis based on histopathological findings in East-Southeastern Anatolia regions in Turkey.

SUBJECTS AND METHODS

The study included a total of 93 patients diagnosed with NAFLD from 5 different centers. Histopathological findings were evaluated by dividing them into four categories using Matteoni classifications. Cases with fibrosis were further evaluated using Brunt classifications.

RESULTS

The patients with a nonalcoholic fatty liver were in the 3rd and 4th decade age groups. The mean age was 38 years, 76% of the patients were male, 85% were overweight, 37% were obese, 18% had type 2 diabetes mellitus, and 80.6% had hyperlipidemia. A multiple regression analysis showed that age, type 2 diabetes mellitus, and aspartate aminotransferase (AST) levels were linked with the severity of the disease. Of the 93 patients, 55 (59.1%) had fibrosis, of which 10.8% were classified as severe. The severity of fibrosis was significantly higher in obese patients.

CONCLUSIONS

The risk factors for severity of NAFLD included advanced age, type 2 diabetes mellitus and serum AST level, while the risk factor for the severity of fibrosis was obesity.

Non-alcoholic hepatic steatosis and its relation to increased plasma biomarkers of inflammation and endothelial dysfunction in non-diabetic men. Role of visceral adipose tissue

AIMS

To compare plasma biomarkers of inflammation and endothelial dysfunction in individuals with and without non-alcoholic hepatic steatosis (HS), and to evaluate whether such differences were mediated by the adverse metabolic pattern, typically found in these subjects.

METHODS

HS (by ultrasound and computed tomography), visceral fat (by computed tomography), insulin resistance (by homeostasis model assessment-HOMA), plasma biomarkers of inflammation and endothelial dysfunction (hs-C reactive protein, fibrinogen, von Willebrand factor, plasminogen activator inhibitor-1 activity) were measured in 100 non-smoking, healthy, male volunteers.

RESULTS

Plasma hs-CRP, fibrinogen, v-WF and plasminogen activator inhibitor-1 (PAI-1) activity levels were markedly higher (P < 0.01 or less) in subjects with non-alcoholic HS (n = 35) than in those without HS (n = 65). The former also had significantly higher values for body mass index (BMI), visceral fat, diastolic blood pressure, HOMA insulin resistance score, plasma insulin (both fasting and after glucose load), triglycerides, liver enzymes, and lower high-density lipoprotein (HDL)-cholesterol concentration. While the marked differences in these pro-inflammatory biomarkers observed between the groups were little affected by adjustment for age, BMI, blood pressure values, HOMA insulin resistance score, plasma triglyceride and liver enzyme concentrations, they were completely abolished after controlling for visceral fat. Similarly, in multivariate regression analyses, increased visceral fat significantly predicted the pro-inflammatory biomarkers, independently of HS and other potential confounders.

CONCLUSIONS

These results indicate that, in non-smoking, non-diabetic men, the significant increase of plasma biomarkers of inflammation and endothelial dysfunction in the presence of non-alcoholic HS is largely mediated by abdominal visceral fat accumulation.

Serum alpha-fetoprotein levels in patients with advanced hepatitis C: results from the HALT-C Trial

BACKGROUND/AIMS

Alpha-fetoprotein (AFP) has been useful in the diagnosis of hepatocellular carcinoma (HCC) but lacks specificity. We assessed serum AFP among patients with chronic hepatitis C and advanced fibrosis to establish predictors of AFP elevations and changes with antiviral therapy.

METHODS

Serum AFP was measured at baseline and on therapy in patients in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C). AFP levels were correlated with patient demographic and clinical features.

RESULTS

Baseline AFP was > or = 20 ng/mL in 191 of 1145 patients (16.6%). Mean AFP values were significantly higher in patients with cirrhosis than in those with bridging fibrosis (22.5 vs. 11.4 ng/mL, P < 0.0001). Factors independently associated with raised serum AFP in patients with cirrhosis were female gender, black race, decreased platelet count, increased serum AST/ALT ratio, serum ferritin, and Mallory bodies in liver biopsies. Serum AFP levels decreased significantly during therapy with pegylated interferon alpha-2a and ribavirin. HCC was identified in six subjects, only three of whom had AFP > 20 ng/mL.

CONCLUSIONS

Among patients with advanced chronic hepatitis C, serum AFP values are frequently elevated, even in the absence of HCC. Factors associated with raised AFP include severity of liver disease, female gender and black race. Serum AFP levels decline during antiviral therapy.

[Pathogenesis of primary nonalcoholic fatty liver disease]

The challenges of growing prevalence and evident trend to progressive damage of primary nonalcoholic fatty liver disease confront a poorly understood pathogenesis. It appears to develop in two steps. First, a high adipocyte protein production in the context of a silent inflammatory background causes insulin resistance in adipose tissue. It leads both to lipolysis, with increase of the circulating and hepatic uptake of free fatty acids, and hyperinsulinemia. Within hepatocytes, the subsequent lipogenesis, together with a decreased secretion of lipoproteins, induces an accumulation of excessive hepatic triglycerides (steatosis), impliying some oxidative damage, but it remain balanced by uncoupling protein upregulation and antioxidant systems activation. Second, a more forceful fat catabolism by beta and omega oxidation results in respiratory chain hyperactivity with overproduction of free radicals and reactive oxygen species that exceed the antioxidant capacity. These agents lead to hepatocellular injury and necrosis, inflammatory infiltration and fibrosis (steatohepatitis) through induction of Fas ligand and cytokines (tumor necrosis factor alpha, transforming growth factor beta, interleukin-8), and lipid peroxidation and by-products (malondialdehyde and 4-hydroxynonenal). Other mechanisms (hepatic iron, Kupffer cells dysfunction or endotoxemia) play uncertain roles.

Hepatic and cardiovascular consequences of familial hypobetalipoproteinemia

OBJECTIVE

Individuals with familial hypobetalipoproteinemia (FHBL) have been reported to be prone to fatty liver disease (FLD). Conversely, the profound reduction of low-density lipoprotein (LDL) cholesterol in this disorder might decrease cardiovascular risk. In the present study, we assessed hepatic steatosis as well as noninvasive surrogate markers for cardiovascular disease (CVD) in subjects with FHBL and in matched controls.

METHODS AND RESULTS

Hepatic steatosis was assessed by abdominal ultrasonography. Carotid intima-media thickness (IMT) and distal common carotid arterial wall stiffness as surrogate markers for CVD risk were measured using high-resolution B-mode ultrasonography. Whereas transaminase levels were only modestly elevated, both prevalence (54% versus 29%; P=0.01) and severity of steatosis were significantly higher in FHBL individuals compared with controls. Despite similar IMT measurements, arterial stiffness was significantly lower in FHBL (P=0.04) compared with controls. Additionally, the increase in arterial stiffness as seen in the presence of traditional risk factors was attenuated, suggesting that very low levels of apoB-containing lipoproteins can negate the adverse effects of other risk factors on the vasculature.

CONCLUSIONS

FHBL is characterized by an increased prevalence and severity of fatty liver disease. The observed decreased level of arterial wall stiffness, most pronounced in the presence of nonlipid risk factors, is indicative of cardiovascular protection in these subjects.

Tratamiento médico de la hepatopatía grasa no alcohólica primaria

The need for an effective and safe medical treatment of nonalcoholic fatty liver disease is urgent due to its high prevalence and progressive character. At the moment, therapeutic strategies are largely empirical and based on the control of associated clinical conditions (especially obesity, type 2 diabetes mellitus, and hypertriglyceridemia) and the use of some specific drugs (insulin sensitizing agents, cytoprotectives, antioxidants, and anticytokines) as an attempt to counteract known elements of the pathogenesis. None of these specifics measures have been found to display enough evidence to recommend their clinical use. It is indispensable to join efforts in coordinated networks to define, as soon as possible, the best treatment and the best time to start it.

Hyperhomocysteinemia induces hepatic cholesterol biosynthesis and lipid accumulation via activation of transcription factors

Hyperhomocysteinemia is an independent risk factor for cardiovascular disorders. Elevated plasma homocysteine (Hcy) concentration is associated with other cardiovascular risk factors. We previously reported that Hcy stimulated cholesterol biosynthesis in HepG2 cells. In the present study, we investigated the underlying mechanisms of Hcy-induced hepatic cholesterol biosynthesis in an animal model. Hyperhomocysteinemia was induced in Sprague-Dawley rats by feeding a high-methionine diet for 4 wk. The mRNA expression and the enzyme activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase were significantly increased in livers of hyperhomocysteinemic rats. There were marked hepatic lipid accumulation and an elevation of plasma cholesterol concentration in hyperhomocysteinemic rats. Three transcription factors, namely, sterol regulatory element-binding protein-2 (SREBP-2), cAMP response element-binding protein (CREB), and nuclear factor Y (NF-Y) were activated in livers of hyperhomocysteinemic rats. Upon Hcy treatment of hepatocytes, there was a significant increase in HMG-CoA reductase mRNA expression in these cells. The activation of SREBP-2, CREB, and NF-Y preceded the increase in HMG-CoA reductase expression in Hcy-treated cells. Pretreatment of hepatocytes with inhibitors for transcription factors not only blocked the activation of SREBP-2, CREB, and NF-Y but also attenuated Hcy-induced HMG-CoA reductase mRNA expression. These results suggested that hyperhomocysteinemia-induced activation of SREBP-2, CREB, and NF-Y was responsible for increased cholesterol biosynthesis by transcriptionally regulating HMG-CoA reductase expression in the liver leading to hepatic lipid accumulation and subsequently hypercholesterolemia. In conclusion, the stimulatory effect of Hcy on hepatic cholesterol biosynthesis may represent an important mechanism for hepatic lipid accumulation and cardiovascular disorder associated with hyperhomocysteinemia.

Effect of Sinai San decoction on the development of non-alcoholic steatohepatitis in rats

AIM: To explore the effect of Sinai san decoction on the development of non-alcoholic steatohepatitis induced by CCL₄ combined with a fat-rich diet in rats.

METHODS: Twenty-seven Sprague-Dawley rats were divided into three groups randomly: control group (n = 9), model group (n = 9) and treatment group (n = 9). The rats of model group and treatment group were given small dosage of CCL₄ combined with a fat-rich diet, and those of control group were given normal diet. After four weeks of fat-rich diet feeding, the rats of treatment group were given Sinai san decoction. The serum levels of aminotransferase and lipid were measured, and the pathology of livers was observed by HE staining after the rats were sacrificed at eight weeks.

RESULTS: The rats’ livers presented the pathology of steatosis and inflammation with higher serum levels of ALT and AST in the model group. In the treatment group the serum ALT and AST levels decreased significantly and were close to the control group. The hepatic inflammation scores also decreased markedly, but were still higher than those of control group. And the degree of hepatocyte steatosis was similar to that of model group.

CONCLUSION: Sinai san decoction may ameliorate the hepatic inflammation of rats with steatohepatitis induced by small dosage of CCL₄ combined with a fat-rich diet, but does not prevent the development of hepatocyte steatosis.

Comparison of the natural history of alcoholic and nonalcoholic fatty liver disease

Fatty liver disease represents a common clinical entity. It is classically divided into alcoholic fatty liver disease (AFLD) and nonalcoholic fatty liver disease (NAFLD). Whereas AFLD occurs in as many as 10 million Americans, NAFLD represents the most common chronic liver disease and is the most common cause of liver enzyme abnormalities in the United States. Both diseases encompass the clinical spectrum of steatosis, steatohepatitis, and cirrhosis. Although they are histologically indistinct, AFLD and NAFLD follow different clinical courses. This article compares the natural history of these diseases.

Reduced hepatic extraction of palmitate in steatosis correlated to lower level of liver fatty acid binding protein

Nonalcoholic fatty liver disease is the most common of all liver diseases. The hepatic disposition [(3)H]palmitate and its low-molecular-weight metabolites in perfused normal and steatotic rat liver were studied using the multiple indicator dilution technique and a physiologically based slow diffusion/bound pharmacokinetic model. The steatotic rat model was established by administration of 17 alpha-ethynylestradiol to female Wistar rats. Serum biochemistry markers and histology of treated and normal animals were assessed and indicated the presence of steatosis in the treatment group. The steatotic group showed a significantly higher alanine aminotransferase-to-aspartate aminotransferase ratio, lower levels of liver fatty acid binding protein and cytochrome P-450, as well as microvesicular steatosis with an enlargement of sinusoidal space. Hepatic extraction for unchanged [(3)H]palmitate and production of low-molecular-weight metabolites were found to be significantly decreased in steatotic animals. Pharmacokinetic analysis suggested that the reduced extraction and sequestration for palmitate and its metabolites was mainly attributed to a reduction in liver fatty acid binding protein in steatosis.

Hepatitis C and steatosis

Steatosis is a common finding in patients with chronic hepatitis C (CHC) due to a combination of the direct steatogenic effect of hepatitis C virus (HCV) and the prevalence of metabolic risk factors in the HCV population. Steatosis is now established as a risk factor for disease progression in CHC and significantly impacts therapeutic response. Research efforts should continue to focus on defining the complex viral and host interactions involved in the pathogenesis of HCV-related steatosis so that future therapeutic strategies may be accurately and appropriately targeted.

Pharmacologic management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is an emerging epidemic in Western societies, and therapeutic modalities to treat this condition are needed desperately. Most early treatment studies tended to focus on improvement in the serum aminotransferases. Presently, treatment of NAFLD is aimed at improving the underlying steatosis, necroinflammatory activity, and fibrosis because elevations of the aminotransferases may not accurately reflect these important histologic endpoints. Unfortunately, well-defined treatment options are few,which is largely due to limited experience reported in small, prospective pilot trials. This article focuses on the various therapeutic agents that have been evaluated in the treatment of NAFLD and their efficacy as well as their limitations.