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Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since the discovery of the hepatitis C virus (HCV) in 1989, attention has been paid to the association of chronic HCV infection and the development of diabetes. The risk factors for diabetes include older age, HCV genotype 3, severe liver fibrosis, family history of diabetes, and liver/kidney transplantation. Emerging evidence in animals and humans has shown that HCV infection induces hepatic steatosis and increases tumor necrosis factor-alpha level, both resulting in the development of insulin resistance and subsequent type 2 diabetes. It is suggested that the presence of diabetes and hepatic steatosis may enhance fibrosis progression, hepatocellular carcinoma, and atherosclerosis. Interferon is reportedly associated with improved glucose tolerance. However, interferon might enhance underlying autoimmunity against beta cells, leading to overt type 1 diabetes that is genetically predisposed or give rise to hyperglycemia, resulting in the development of type 2 diabetes. In light of the national epidemic of type 2 diabetes, the link between HCV and diabetes would be a major public health problem. Further clinical researches are awaited in order to effectively detect, prevent, and treat HCV-associated type 2 diabetes, which would also slow the progression of hepatitis C itself.
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PMID:Hepatitis C infection and diabetes. 1650 40

The liver is one of the principal organs involved in glucose metabolism together with skeletal muscle and adipose tissue. A link between diabetes and chronic liver disease (CLD) was first observed in the early half of the last century, but to date several questions remain unsolved. Altered glucose tolerance has been well described in alcoholic CLD, non-alcoholic fatty liver disease, chronic hepatitis C and portal hypertension. Moreover, insulin resistance is assuming an ever-growing importance in CLD; chronic hepatitis C has recently been proposed as a metabolic disease and insulin sensitivity as a predictive factor for liver fibrosis.CLD is also complicated by acquired growth hormone (GH) resistance, characterized by low concentrations of insulin-like growth factor-1 (IGF-1) with respect to normal or elevated GH levels. GH resistance in CLD is determined by several factors, including malnutrition, impaired liver function and reduced expression of hepatic GH receptors. We recently described the possible role of tumour necrosis factor-alpha (TNF-alpha) in blunting the hepatic response to GH in patients with chronic hepatitis C. The role of GH in impaired glucose metabolism is well known, and recent evidence suggests a receptor and/or post-receptor modulation of insulin signalling. Moreover, as in other chronic inflammatory conditions, pro-inflammatory cytokines may directly modulate the signal cascade that follows insulin binding to its receptor in the course of CLD. In this review, the proposed links between impaired glucose tolerance and CLD are analysed, special emphasis being focussed on the most recent findings concerning the interplay of chronic inflammation, GH resistance and insulin resistance.
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PMID:Diabetes in chronic liver disease: from old concepts to new evidence. 1650 76

Steatosis is a common histological feature of chronic hepatitis C. Two distinct mechanisms seem to be involved in the pathogenesis of hepatic steatosis in chronic hepatitis C virus (HCV) infection. In HCV genotype 3-infected patients, steatosis is likely viral-induced, and represents a direct cytopathic effect of HCV, whereas in patients infected with other genotypes, host metabolic risk factors for insulin resistance such as obesity, type 2 diabetes and hyperlipidemia play a major role in intracellular lipids accumulation. Interestingly, the outcome of steatosis matches the virological response to treatment in HCV genotype 3-infected patients who have purely virus-induced steatosis but not in patients with metabolic causes of steatosis. Suspected molecular underlying mechanisms include interactions between the HCV core protein and intracellular lipid metabolism pathways as well as induction of insulin resistance. Steatosis is of clinical importance as it appears to be associated with more rapid liver fibrosis progression and impaired response to antiviral therapy. However, whether metabolic and host factors associated with steatosis, steatosis per se or both, may be responsible for this association remains to be clarified. This review is aimed at describing the current knowledge of steatosis, insulin resistance and fibrosis progression in chronic hepatitis C.
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PMID:Steatosis, insulin resistance and fibrosis progression in chronic hepatitis C. 1655 84

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.
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PMID:[Epidemiology and natural history of primary nonalcoholic fatty liver disease]. 1658 96

Effectively assessing subtle hepatic metabolic functions by novel non-invasive tests might be of clinical utility in scoring NAFLD (non-alcoholic fatty liver disease) and in identifying altered metabolic pathways. The present study was conducted on 39 (20 lean and 19 obese) hypertransaminasemic patients with histologically proven NAFLD {ranging from simple steatosis to severe steatohepatitis [NASH (non-alcoholic steatohepatitis)] and fibrosis} and 28 (20 lean and eight overweight) healthy controls, who underwent stable isotope breath testing ([(13)C]methacetin and [(13)C]ketoisocaproate) for microsomal and mitochondrial liver function in relation to histology, serum hyaluronate, as a marker of liver fibrosis, and body size. Compared with healthy subjects and patients with simple steatosis, NASH patients had enhanced methacetin demethylation (P=0.001), but decreased (P=0.001) and delayed (P=0.006) ketoisocaproate decarboxylation, which was inversely related (P=0.001) to the degree of histological fibrosis (r=-0.701), serum hyaluronate (r=-0.644) and body size (r=-0.485). Ketoisocaproate decarboxylation was impaired further in obese patients with NASH, but not in patients with simple steatosis and in overweight controls. NASH and insulin resistance were independently associated with an abnormal ketoisocaproate breath test (P=0.001). The cut-off value of 9.6% cumulative expired (13)CO(2) for ketoisocaproate at 60 min was associated with the highest prediction (positive predictive value, 0.90; negative predictive value, 0.73) for NASH, yielding an overall sensitivity of 68% and specificity of 94%. In conclusion, both microsomal and mitochondrial functions are disturbed in NASH. Therefore stable isotope breath tests may usefully contribute to a better and non-invasive characterization of patients with NAFLD.
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PMID:Liver breath tests non-invasively predict higher stages of non-alcoholic steatohepatitis. 1660 25

There are two discrete forms of steatosis that may be found in patients infected with hepatitis C virus (HCV). Metabolic steatosis can coexist with HCV, regardless of genotype, in patients with risk factors such as obesity, hyperlipidemia, and insulin resistance. The second form of hepatic steatosis in HCV patients is a result of the direct cytopathic effect of genotype 3 viral infections. There have been proposed mechanisms for this process but it remains elusive. Both categories of steatosis tend to hasten the progression of liver fibrosis and therefore prompt recognition and management should be initiated in patients with HCV and steatosis. The authors review the current understanding of the relationship between hepatitis C infection and hepatic steatosis and discuss future research directions.
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PMID:Hepatitis C virus (HCV) infection and hepatic steatosis. 1661 43

Insulin resistance (IR) is a common condition in chronic hepatitis C. Recent studies have reported that IR is associated with liver fibrosis progression in these patients. However, there is no information available on this issue in human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients. For these reasons, we investigate the relationship between IR and liver fibrosis in patients with HIV and HCV infections. This was a cross-sectional study where patients from an Infectious Diseases Unit with HIV/HCV coinfection who underwent a liver biopsy, with available frozen sera samples at the time of biopsy and a known or estimated date of infection were included. IR was determined by the homeostasis model assessment (HOMA-IR) method. The relationship between histological findings and several variables, including HOMA-IR values, was examined. Seventy-nine patients fulfilled the inclusion criteria. Age at HCV infection >21 years was the only variable independently associated with advanced liver fibrosis (stages F3 and F4) [adjusted odds ratio (AOR) 4.15; 95% confidence interval (CI) 1.5-11.3]. The variables associated with a fibrosis progression rate above the median were age at HCV infection >21 years (AOR 6.41; 95% CI 2.16-27.96) and previous exposure to nevirapine (AOR 8.9; 95% CI 2.01-39.36). There was no association between HOMA-IR values and the presence of advanced fibrosis or a faster fibrosis progression. Thus IR is not associated with liver damage or fibrosis progression in HIV/HCV-coinfected individuals.
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PMID:Insulin resistance is not associated with liver fibrosis progression in HIV/hepatitis C virus-coinfected patients. 1679 38

Nonalcoholic fatty liver disease (NAFLD), a common cause of chronic liver disease in adults, is incompletely characterized in children. We conducted a prospective study to better characterize the clinical presentation of NAFLD in children and to determine the effect of lifestyle advice in the management of pediatric NAFLD. From June 2001 to April 2003, 84 children (age 3-18.8 yr) who had elevated aminotransferases and the diagnosis of NAFLD confirmed via liver biopsy underwent a 2-hour oral glucose tolerance test and a 12-month program of lifestyle advice consisting of diet and physical exercise. Thirty-four (40.5%) patients were obese (body mass index [BMI] >97th percentile), and 43 (51.2%) were overweight (BMI 85th-97th percentile). Ten (12%) had abnormal glucose tolerance; 10 (12%) had elevated triglycerides, cholesterol, or both; and all had normal blood pressure. Most children (67/84, 80%) were insulin-resistant, including the 7 children with normal BMI (<85th percentile). Increased liver fibrosis was present in 49 (58.1%) patients and was independently associated with obesity (OR 2.7, 95% CI 1.2-6.2) and age (1-year increase; OR 1.2, 95% CI 1.04-1.5). A 12-month program with diet and physical exercise resulted in a significant decrease in BMI, and levels of fasting glucose, insulin, lipids, and liver enzymes, as well as liver echogenicity on ultrasonography. In conclusion, children with NAFLD are almost always insulin-resistant regardless of BMI. Obesity and older age are independently associated with increased liver fibrosis. A simple lifestyle advice program significantly improves insulin resistance, and the liver disease in pediatric NAFLD.
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PMID:NAFLD in children: a prospective clinical-pathological study and effect of lifestyle advice. 1687 74

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of elevated liver enzymes in patients of developed countries. We determined the long-term clinical and histological courses of such patients. In a cohort study, 129 consecutively enrolled patients diagnosed with biopsy-proven NAFLD were reevaluated. Survival and causes of death were compared with a matched reference population. Living NAFLD patients were offered repeat liver biopsy and clinical and biochemical investigation. Mean follow-up (SD) was 13.7 (1.3) years. Mortality was not increased in patients with steatosis. Survival of patients with nonalcoholic steatohepatitis (NASH) was reduced (P = .01). These subjects more often died from cardiovascular (P = .04) and liver-related (P = .04) causes. Seven patients (5.4%) developed end-stage liver disease, including 3 patients with hepatocellular carcinoma. The absence of periportal fibrosis at baseline had a negative predictive value of 100% in predicting liver-related complications. At follow-up, 69 of 88 patients had diabetes or impaired glucose tolerance. Progression of liver fibrosis occurred in 41%. These subjects more often had a weight gain exceeding 5 kg (P = .02), they were more insulin resistant (P = .04), and they exhibited more pronounced hepatic fatty infiltration (P = .03) at follow-up. In conclusion, NAFLD with elevated liver enzymes is associated with a clinically significant risk of developing end-stage liver disease. Survival is lower in patients with NASH. Most NAFLD patients will develop diabetes or impaired glucose tolerance in the long term. Progression of liver fibrosis is associated with more pronounced insulin resistance and significant weight gain.
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PMID:Long-term follow-up of patients with NAFLD and elevated liver enzymes. 1700 14

Plasminogen activator inhibitor 1 (PAI-1) is an important mediator of atherosclerosis and liver fibrosis in insulin resistance. Circulating levels of PAI-1 are elevated in obese individuals, and PAI-1 messenger RNA is significantly higher in the livers of obese type 2 diabetic individuals than in nonobese type 2 diabetic individuals. To address the mechanism underlying the up-regulation of hepatic PAI-1 in obesity, we tested the effects of tumor necrosis factor alpha (TNF-alpha), an important link between obesity and insulin resistance, on PAI-1 production in the nonmalignant human hepatocyte cell line, THLE-5b. Incubation of THLE-5b cells with TNF-alpha stimulated PAI-1 production via protein kinase C-, mitogen-activated protein kinase-, protein tyrosine kinase-, and nuclear factor-kappaB-dependent pathways. A thiazolidinedione, pioglitazone, reduced TNF-alpha-induced PAI-1 production by 32%, via protein kinase C- and nuclear factor-kappaB-dependent pathways. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor cerivastatin inhibited TNF-alpha-induced PAI-1 production by 59%, which was reversed by coincubation with mevalonic acid. In conclusion, obesity and TNF-alpha up-regulation of PAI-1 expression in human hepatocytes may contribute to the impairment of the fibrinolytic system, leading to the development of atherosclerosis and liver fibrosis in insulin-resistant individuals. A thiazolidinedione and a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor may thus be candidate drugs to inhibit obesity-associated hepatic PAI-1 production.
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PMID:Tumor necrosis factor-alpha-induced production of plasminogen activator inhibitor 1 and its regulation by pioglitazone and cerivastatin in a nonmalignant human hepatocyte cell line. 1704 48


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