Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0948265 (metabolic syndrome)
 24,271 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-alcoholic steatohepatitis (NASH) represents only a part of a wide spectrum of non-alcoholic fatty liver disease (NAFLD) and its prevalence is only 2 - 3% in the general population. Obesity, diabetes, hyperlipidemia and female sex are important risk factors for NASH. Two hit theory describes very well the pathogenesis of NASH wherein hepatic steatosis, the first hit is followed up by the second hit, one of which may be reactive oxygen species. Mitochondria is the main source of reactive oxygen species which may trigger steatohepatitis by lipid peroxidation, cytokine induction or induction of fas-ligand. Insulin resistance syndrome is the only metabolic syndrome that has been consistently associated with NASH. The diagnosis rests on the hallmark histological features and rigorous exclusion of significant alcohol consumption. Most patients are asymptomatic, have mild-to-moderate elevations of serum aminotransferase levels, clinical hepatomegaly and features of fatty liver on imaging. Liver biopsy is essential for positive diagnosis and prognostication of NASH. Histologically, fat deposition is typically macrovesicular and inflammation of steatohepatitis is predominantly lobular. Neutrophilic cells in lobular inflammatory infilterate are a distinguishing feature of steatohepatitis and differentiate it from other chronic hepatitis. The pattern of collagen deposition is perivenular & peri-sinusoidal spaces in zone 3. NASH is a progressive disease in more than one in four and has spontaneous regression in less than one in six. Therapy options include weight reduction in obese, good control in diabetics and exercise. Ursodeoxycholic acid has membrane stabilizing, cytoprotective and immunological effect and normalizes raised transaminases. Liver transplantation has been done in NASH but transplanted liver shows re-development in more than two thirds. Many more therapies are in the pipeline and show promise for the future.
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PMID:Non-alcoholic steatohepatitis. 1592 3

The prevalence of fatty liver is rising in association with the global increase in obesity and type 2 diabetes. In the past, simple steatosis was regarded as benign, but the presence of another liver disease may provide a synergistic combination of steatosis, cellular adaptation, and oxidative damage that aggravates liver injury. In this review, a major focus is on the role of steatosis as a co-factor in chronic hepatitis C (HCV), where the mechanisms promoting fibrosis and the effect of weight reduction in minimizing liver injury have been most widely studied. Steatosis, obesity, and associated metabolic factors may also modulate the response to alcohol- and drug-induced liver disease and may be risk factors for the development of hepatocellular cancer. The pathogenesis of injury in obesity-related fatty liver disease involves a number of pathways, which are currently under investigation. Enhanced oxidative stress, increased susceptibility to apoptosis, and a dysregulated response to cellular injury have been implicated, and other components of the metabolic syndrome such as hyperinsulinemia and hyperglycemia are likely to have a role. Fibrosis also may be increased as a by-product of altered hepatocyte regeneration and activation of bipotential hepatic progenitor cells. In conclusion, active management of obesity and a reduction in steatosis may improve liver injury and decrease the progression of fibrosis.
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PMID:Steatosis: co-factor in other liver diseases. 1596 20

Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepatic steatosis as well as the latter's role in the progression of fibrosis and treatment response. We assessed factors associated with hepatic steatosis in genotype 1 chronic hepatitis C and the impact of hepatic fat on fibrosis development and interferon responsiveness. Two hundred ninety-one non-diabetic patients with genotype 1 chronic hepatitis C were examined for the presence of steatosis and its correlation with clinical, virological, and biochemical data, including insulin resistance (IR), evaluated by the homeostasis model assessment (HOMA) score. Steatosis was graded as mild (1%-20% of hepatocytes involved), moderate (21%-40% of hepatocytes involved), and severe (>40% of hepatocytes involved). Steatosis was mild in 110 of 291 (37.8%) and moderate/severe in 55 of 291 (18.9%) subjects. By logistic regression, moderate/severe steatosis was independently associated with the female sex (odds ratio [OR] 2.74; 95% CI 1.40-5.35), high gamma-glutamyltransferase levels (OR 1.52; 95% CI 1.22-1.91), and HOMA-score (OR 1.076; 95% CI 1.001-1.26). By logistic regression, moderate/severe steatosis (OR 2.78; 95% CI 1.21-6.4), and platelet counts (OR 0.97; 95% CI 0.96-0.98) were independent predictors of advanced fibrosis. Patients with moderate/severe steatosis had an OR of 0.52 (95% CI 0.30-0.90) for sustained virological response compared with patients with mild/absent steatosis. In conclusion, in nondiabetic European patients with genotype 1 hepatitis C at low risk for the metabolic syndrome, the prevalence of steatosis was nearly 60%. IR is a risk factor for moderate/severe steatosis, especially in men. Moderate/severe steatosis has clinical relevance, being associated with advanced fibrosis and hyporesponsiveness to antiviral therapy.
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PMID:Insulin resistance is associated with steatosis in nondiabetic patients with genotype 1 chronic hepatitis C. 1679 69

Non-alcoholic fatty liver disease (NAFLD) is now recognized as one of the most important causes of chronic liver disease in Western Countries, and is the hepatic manifestation of metabolic syndrome. The prevalence of NAFLD has increased with the global epidemic of obesity and type 2 diabetes mellitus. The pathophysiological hallmark of NAFLD is insulin resistance, associated with mediators of oxidative stress and inflammatory cytokines. Although simple steatosis by itself is generally benign, patients with histologically proven non-alcoholic steatohepatitis (NASH) can progress to cirrhosis. Hepatitis C (HCV) is another common cause of liver disease with some potential for progression to cirrhosis. Steatosis is present in almost 50% of patients infected by HCV. Hepatic steatosis in the setting of another liver disease (such as HCV) is associated liver disease progression. In particular, significant fibrosis is observed in patients with HCV whose liver biopsies show significant steatosis or superimposed NASH. This article reviews the host and viral factors potentially involved in the interaction between NAFLD and HCV. These factors include mediators of metabolic syndrome such as adipokines, inflammatory cytokines, factors associated with oxidative stress, lipid peroxidation products, as well as apoptosis and hepatic stellate cell activation with the resultant deposition of extracellular matrix. In addition to the mediators of metabolic syndrome (host factors), hepatic steatosis can be influenced by viral factors. The most important viral factor is HCV genotype 3, which has been independently associated with hepatic steatosis. Finally, superimposed NAFLD and visceral fat are associated with lower response rates to antiviral therapy in non-genotype 3 patients. Furthermore, viral clearance is associated with the resolution of hepatic steatosis in HCV genotype 3 but not other HCV genotypes. In these genotypes, hepatic steatosis and its impact on response to therapy are related to metabolic syndrome. Thus, the management of obesity and metabolic syndrome in patients with chronic hepatitis C may be important for reducing the risk of progression as well as improving the efficacy of antiviral therapy.
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PMID:Non-alcoholic fatty liver disease and hepatitis C infection. 1655 85

Obesity and the metabolic syndrome have hepatic manifestations, including steatosis and progression of fibrosis. In individuals with chronic hepatitis C, obesity is associated with inflammation, insulin resistance, steatosis, progression of fibrosis, and nonresponse to treatment with interferon or peginterferon alpha and ribavirin. Patients with both hepatitis C and obesity-related nonalcoholic fatty liver disease are at greater risk for more advanced liver disease. We review the mechanisms by which obesity may be associated with decreased efficacy of interferon-based therapies in individuals with chronic hepatitis C and the therapeutic strategies that may increase the effectiveness of these therapies in obese individuals.
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PMID:Impact of obesity on treatment of chronic hepatitis C. 1672 27

Nonalcoholic fatty liver disease (NAFLD) and the metabolic syndrome (MS) have been shown to play a role in disease progression and response to therapy in patients with chronic hepatitis C virus (HCV) infection. The primary objective of this study was to evaluate the impact of coexisting NAFLD and MS on the progression of fibrosis in patients with recurrent HCV treated with interferon (IFN)/ribavirin after orthotopic liver transplantation (OLT). From 1998 to 2004, a total of 418 patients underwent OLT in our center for HCV-related cirrhosis. Thirty-five patients with recurrent HCV on IFN/ribavirin treatment, who had at least 2 posttransplant liver biopsies at least 6 months apart, were included in the study. Patients who had MS at the time of their first posttransplant biopsy were identified. The first and last posttransplant biopsies were assessed for the presence and severity of NAFLD, grade of inflammation, and stage of fibrosis. The fibrosis progression rate (FPR) was calculated and expressed in fibrosis units per month (FU/mo). Among 35 patients, 34% were diagnosed with NAFLD in the first posttransplant biopsy. The mean FPR was 0.05+/-0.16 FU/mo in the presence of NAFLD compared to 0.07+/-0.10 FU/mo in its absence (P=.68) and 0.03+/-0.06 FU/mo in the presence of MS versus 0.10+/-0.15 FU/mo in its absence (P=.06). When FPR values were divided into two categories of <0.16 FU/mo or >or=0.16 FU/mo (below/above the 25% upper quartile) or <0.08 FU/mo or >or=0.08 FU/mo (below/above the 50% upper quartile), there was no correlation between FPR categories and the presence of NAFLD with or without MS, only MS, or the absence of both in the first liver transplant biopsy (P=.13). Coexisting NAFLD or MS had no significant effect on the progression of fibrosis after OLT in patients with treated hepatitis C after OLT.
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PMID:The impact of nonalcoholic fatty liver disease and the metabolic syndrome on progression of fibrosis in patients with recurrent HCV after liver transplantation. 1679 27

Leptin and adiponectin, the main metabolic products of adipose tissue, have been implicated in a wide spectrum of human diseases. Given the frequent presence of hepatic steatosis in several chronic liver diseases, there is currently increasing interest in the role of these adipokines in the development of hepatic steatosis and also in necroinflammation and fibrosis, mostly in patients with nonalcoholic fatty liver disease or chronic hepatitis C. According to experimental data, reduced adiponectin levels and increased leptin levels associated with leptin resistance, which are usually observed in obese patients with or without metabolic syndrome, may result in fat accumulation in the liver and in the enhancement of liver inflammation and mostly fibrogenesis. Increased leptin and decreased adiponectin serum levels have been detected initially in patients with nonalcoholic steatohepatitis and more recently in patients with chronic hepatitis C compared to healthy controls in most but not all studies, while the data on the associations between these adipokine levels and the severity of hepatic steatosis or fibrosis are still rather conflicting. However, several potential confounding parameters were not evaluated in all studies. Therefore, the associations between adipokines and liver histological lesions and their effects on liver cells should be evaluated further in prospective, carefully designed studies, including larger cohorts of patients with detailed assessment of metabolic and other potential confounding factors.
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PMID:The evolving role of leptin and adiponectin in chronic liver diseases. 1695 81

Insulin resistance is the major feature of the metabolic syndrome and depends on insulin secretion and insulin sensitivity. In chronic hepatitis C, insulin resistance and type 2 diabetes mellitus are more often seen than in healthy controls or chronic hepatitis B patients. Hepatitis C virus (HCV) infection promotes insulin resistance, mainly by increased TNF production together with enhancement of suppressor of cytokine (SOC-3); both events block PI3K and Akt phosphorylation. Two types of insulin resistance could be found in chronic hepatitis C patients: "viral" and "metabolic" insulin resistance. Insulin resistance in chronic hepatitis C is relevant because it promotes steatosis and fibrosis. The mechanisms by which insulin resistance promotes fibrosis progression include: (1) steatosis, (2) hyperleptinemia, (3) increased TNF production, (4) impaired expression of PPARgamma receptors. Lastly, insulin resistance has been found as a common denominator in patients difficult-to-treat like cirrhotics, overweight, HIV coinfected and Afro-American. Insulin resistance together with fibrosis and genotype has been found to be independently associated with impaired response rate to peginterferon plus ribavirin. Indeed, in genotype 1, the sustained response rate was twice (60%) in patients with HOMA < or = 2 than patients with HOMA > 2. In experiments carried out on Huh-7 cells transfected by full length HCVRNA, interferon alpha blocks HCV replication. However, when insulin (at doses of 128 microU/mL, similar that seen in the hyperinsulinemic state) was added to interferon, the ability to block HCV replication disappeared, and the PKR synthesis was abolished. In summary, hepatitis C promotes insulin resistance and insulin resistance induces interferon resistance, steatosis and fibrosis progression.
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PMID:Insulin resistance and hepatitis C. 1713 67

Both diabetes and chronic hepatitis C virus (HCV) infection are common conditions that often coexist in the same subject. Studies seem to confirm the presence of an association between them. Mechanisms leading to HCV-induced insulin resistance and glucose intolerance are beginning to be elucidated. Insulin resistance in the setting of chronic HCV infection could be related etiologically to viral factors but is also often seen with concomitant nonalcoholic fatty liver disease, the hepatic manifestation of the metabolic syndrome. Insulin resistance decreases the likelihood of response to interferon-based therapies and may be an independent risk factor for the progression of HCV-related liver disease.
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PMID:Mechanisms of glucose intolerance in patients with chronic hepatitis C: implications for treatment. 1732 47

Liver steatosis is frequent in patients with chronic hepatitis C. Two main types are described: (1) "viral steatosis" induced by the virus, especially genotype 3, which probably inhibits the "Microsomal Triglyceride Transfer Protein", thus decreasing "Very Low Density Lipoprotein" secretion and leading to triglyceride accumulation within hepatocytes; (2) "metabolic steatosis" which is a feature of the metabolic syndrome and insulin resistance, a systemic disorder associated with a high risk of cardiovascular disease and diabetes mellitus. Insulin resistance induces intrahepatic triglyceride accumulation due to excess free fatty acid flux from increased adipose tissue lipolysis as well as increased intrahepatic lipogenesis through activation of the "Sterol Response Element Binding Protein". Hepatitis C Virus itself can also be responsible for insulin resistance, possibly through impairment of the insulin signalling pathway because of increased"Tumor Necrosis Factor Alpha" levels and/or upregulated "Cytokine Signalling Suppressor" expression. Insulin resistance and steatosis, appear to be associated with fibrosis progression and impairment of sustained response to antiviral treatment.
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PMID:[Steatosis during chronic hepatitis C: the role of insulin resistance and viral factors]. 1792 61


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