Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-alcoholic steatohepatitis has been recognized as a significant cause of end-stage liver disease and hepatic decompensation. Despite the growing interest in this condition, the molecular mechanisms underlying the development of fibrosis in this setting are only partially understood. In this article, the cellular and molecular basis of fibrosis in chronic liver disease are briefly outlined. In addition, mechanisms specifically operating in the context of fatty liver and steatohepatitis are examined, including: insulin resistance, oxidative stress, and inflammation. Finally, recent developments indicating the possible contribution of cytokines derived from adipose tissue (adipokines) to liver fibrosis is discussed.
 ...
PMID:Review article: the pathogenesis of fibrosis in non-alcoholic steatohepatitis. 1622 72

The mechanisms responsible for the progression of nonalcoholic fatty liver disease (NAFLD) to more severe liver injury are still poorly understood. Data from animal models suggest that oxidative stress contributes to steatohepatitis and an increase of lipid peroxidation has been documented in human NAFLD. By measuring the titers of circulating antibodies against lipid peroxidation products as markers of oxidative stress we have observed that NAFLD patients have titers of these antibodies significantly higher than in controls. Moreover, the titers of lipid peroxidation-related antibodies are associated with a 3-fold increase in the risk of developing advanced fibrosis/cirrhosis. Although the mechanisms causing oxidative stress in NAFLD have not been elucidated, these results support the involvement of lipid peroxidation in the processes leading to liver fibrosis associated with NAFLD.
 ...
PMID:Review article: role of oxidative stress in the progression of non-alcoholic steatosis. 1622 78

There is increasing evidence that visceral adipose tissue is a causative risk factor for fatty liver and nonalcoholic steatohepatitis. Adipose tissue-derived secretory proteins are collectively named adipocytokines. Obesity and mainly visceral fat accumulation impair adipocyte function and adipocytokine secretion and the altered release of these proteins contributes to hypertension, impaired fibrinolysis and insulin resistance. This review summarizes recent findings on the role of the adipocytokines adiponectin, leptin and resistin in the context of hepatic insulin resistance, fatty liver and liver fibrosis. Elevated levels of resistin antagonize hepatic insulin action and raise plasma glucose levels. Leptin exerts insulin-sensitizing effects, but obesity has been linked to leptin resistance and low levels of circulating leptin receptor, indicating that high levels of leptin cannot mediate its beneficial effects. Adiponectin improves insulin sensitivity; however, low circulating adiponectin is found in the obese state. Adiponectin is an anti-inflammatory protein, whereas leptin augments inflammation and fibrogenesis. Disturbed adipocytokine secretion might, therefore, promote hepatic steatosis and the development of nonalcoholic steatohepatitis. The beneficial effects of the therapeutic approaches so far tested in the treatment of fatty liver disease and fibrosis might be due to the modulation of these adipocytokines.
 ...
PMID:Mechanisms of disease: adipocytokines and visceral adipose tissue--emerging role in nonalcoholic fatty liver disease. 1626 8

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.
 ...
PMID:Hepatitis C infection and diabetes. 1650 40

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

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.
 ...
PMID:Hepatitis C virus (HCV) infection and hepatic steatosis. 1661 43

Diabetes mellitus has been reported to have an increased prevalence and to be associated with more severe fibrosis in patients with chronic hepatitis C. We evaluated the prevalence of diabetes mellitus in patients with chronic hepatitis B or C as well as the possible association between presence of diabetes and extent of liver fibrosis. In total, 434 consecutive patients with histologically documented hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (n = 174) or chronic hepatitis C (n = 260) were studied. The relationships of diabetes and epidemiological, somatomorphic, laboratory and histological patient characteristics were evaluated. Liver histological lesions were blindly evaluated according to the Ishak's classification. Diabetes was present in 58 (13%) patients, without any difference between those with chronic hepatitis B (14%) or C (13%). Diabetes was observed significantly less frequently in patients with fibrosis score 0-2 (7.7%) than 3-4 (10.4%) than 5-6 (29.2%) (P < 0.001). The presence of diabetes was independently associated with higher gamma-glutamyl-transpeptidase (GGT) levels and more severe fibrosis or presence of cirrhosis (P < 0.001) as well as with presence of hepatic steatosis and increased serum triglycerides levels (P < 0.02). In the noncirrhotic patients, diabetes was significantly associated with older age and higher GGT levels, but not with the extent of fibrosis. In conclusion, diabetes mellitus is observed in more than 10% of patients with either HBeAg-negative chronic hepatitis B or chronic hepatitis C. The presence of diabetes is strongly associated with more severe liver fibrosis, but such an association may be related to the high prevalence of diabetes in patients with cirrhosis.
 ...
PMID:Diabetes mellitus in chronic hepatitis B and C: prevalence and potential association with the extent of liver fibrosis. 1663 60

The newly developed elastometer, FibroScan((R)), was utilized to evaluate liver fibrosis in hepatitis C virus (HCV)- and human immunodeficiency virus (HIV)-coinfected 33 hemophiliacs and HIV-uninfected 24 patients with chronic hepatitis C. Chronicity in the liver was categorized into 4 stages by abdominal ultrasound (AUS): 1 (normal or fatty liver); 2 (chronic liver disease, mild); 3 (moderate); and 4 (severe). Stiffness of the liver was significantly increased as AUS stages advanced: 5.4+/-2.2 (N=3) versus 7.5+/-2.7 (N=9), in stage 1; 4.9+/-1.7 (N=2) versus 9.9+/-6.0 (N=10), in stage 2, 13.5+/-4.7 (N=5) versus 12.9+/-5.9 (N=6), in stage 3, and 22.0+/-9.5 (N=14) versus 28.1+/-21.3 (N=8), in stage 4, in non-HIV group and in HIV group, respectively (P=0.004 and 0.007). Stiffness was correlated with AUS stages (r=0.740, P<0.001), platelet counts (PLT; r=-0.642, P=0.001) and 7S domain of type IV collagen (IV-coll; r=0.480, P=0.024) in non-HIV group, while in HIV group, with IV-coll (r=0.801, P<0.001), AUS stages (r=-0.603, P<0.001), procollagen type III peptides (P-III-P; r=0.621, P=0.001), PLT (r=-0.480, P=0.005), and hyaluronic acid (r=0.433, P=0.027). FibroScan((R)) is absolutely noninvasive and can be the alternative to liver biopsy, especially in patients with bleeding tendency.
 ...
PMID:Usefulness of elastometry in evaluating the extents of liver fibrosis in hemophiliacs coinfected with hepatitis C virus and human immunodeficiency virus. 1671 34

Hepatic steatosis has been associated with fibrosis, but it is unknown whether the latter is independent of the etiology of fat infiltration. We analyzed the relationship between clinical characteristics, insulin resistance (HOMA-R) and histological parameters in 132 patients with "viral" steatosis caused by genotype 3 chronic hepatitis C (CHC-3) and 132 patients with "metabolic" steatosis caused by nonalcoholic fatty liver disease (NAFLD), matched by age, BMI, and degree of liver fat accumulation. Tests of liver function were comparable in the two study populations. The prevalence of features of insulin resistance was higher in NAFLD, as was HOMA-R (P = .008). Logistic regression analysis confirmed that steatosis was associated with a high viral load and low serum cholesterol in CHC-3, and with high aminotransferase, glucose, ferritin and hypertriglyceridemia in NAFLD. At univariate analysis, advanced fibrosis was associated with steatosis in NAFLD, but not in CHC-3. Other parameters related to fibrosis severity were HOMA-R and a low platelet count in CHC-3, and high aminotransferases, HOMA-R, ferritin and low HDL-cholesterol in NAFLD. On multivariate analysis, only low platelet count (OR = 0.78; 95% CI, 0.67-0.92) and HOMA-R (OR = 2.98; 1.13-7.89) were independent predictors of advanced fibrosis in CHC-3. In NAFLD, severe fibrosis was predicted by fat grading (OR = 3.03; 1.41-6.53), ferritin (OR = 1.13; 1.03-1.25) and HOMA-R (OR = 1.16; 1.02-1.31). In conclusion, insulin resistance is an independent predictor of advanced fibrosis in both NAFLD and CHC-3, but the extent of steatosis contributes to advanced disease only in NAFLD. Virus-induced hepatic steatosis as seen in CHC-3 does not contribute significantly to liver fibrosis.
 ...
PMID:Fibrosis in genotype 3 chronic hepatitis C and nonalcoholic fatty liver disease: Role of insulin resistance and hepatic steatosis. 1713 73


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>