Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic hemochromatosis (GH) is associated with two mutations of the HFE gene (Cys282Tyr and His63Asp). Heterozygosity for GH is associated with a mild increase in iron metabolism parameters, and increased iron stores are associated with abnormal glucose tolerance and decreased insulin sensitivity in the general population. We have previously shown that the frequency of the two HFE mutations is not increased in patients with type 2 diabetes. However, to assess whether the presence of HFE mutations modulates the clinical presentation of type 2 diabetes, we studied the clinical characteristics and iron metabolism indexes according to the presence of the two mutations in 266 patients with type 2 diabetes. The Cys282Tyr mutation and the His63Asp mutation were present in 9. 8% and 26% of the patients, respectively. Serum iron, transferrin saturation and ferritin concentrations were significantly increased in patients expressing either HFE mutations, compared to those without any mutation. There was no difference in the clinical characteristics in the two groups except that obesity was significantly less frequent in the patients with at least one mutation than in those without any mutation (27.6% vs 42.8%, p=0.02). This finding suggests that, in the absence of obesity, HFE mutations, through the insulin resistance associated with the increase in iron stores, may contribute to the onset of type 2 diabetes.
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PMID:Clinical characteristics of type 2 diabetes in patients with mutations of HFE. 1070 6

Insulin sensitivity (euglycemic clamp, insulin infusion rate: 40 mU. m(-2). min(-1)) was studied in 30 subjects with biopsy-proven nonalcoholic fatty liver disease (NAFLD), normal glucose tolerance, and a BMI <30 kg/m(2). Of those 30 subjects, 9 had pure fatty liver and 21 had evidence of steatohepatitis. In addition, 10 patients with type 2 diabetes under good metabolic control and 10 healthy subjects were studied. Most NAFLD patients had central fat accumulation, increased triglycerides and uric acid, and low HDL cholesterol, irrespective of BMI. Glucose disposal during the clamp was reduced by nearly 50% in NAFLD patients, as well as in patients with normal body weight, to an extent similar to that of the type 2 diabetic patients. Basal free fatty acids were increased, whereas insulin-mediated suppression of lipolysis was less effective (-69% in NAFLD vs. -84% in control subjects; P = 0.003). Postabsorptive hepatic glucose production (HGP), measured by [6,6-(2)H(2)]glucose, was normal. In response to insulin infusion, HGP decreased by only 63% of basal in NAFLD vs. 84% in control subjects (P = 0.002). Compared with type 2 diabetic patients, NAFLD patients were characterized by lower basal HGP, but with similarly reduced insulin-mediated suppression of HGP. There was laboratory evidence of iron overload in many NAFLD patients, but clinical, histological, and biochemical data (including insulin sensitivity) were not correlated with iron status. Four subjects were heterozygous for mutation His63Asp of the HFE gene of familiar hemochromatosis. We concluded that NAFLD, in the presence of normoglycemia and normal or moderately increased body weight, is characterized by clinical and laboratory data similar to those found in diabetes and obesity. NAFLD may be considered an additional feature of the metabolic syndrome, with specific hepatic insulin resistance.
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PMID:Nonalcoholic fatty liver disease: a feature of the metabolic syndrome. 1147 47

The presence of steatosis and inflammatory infiltrate in liver biopsies is essential for the diagnosis of non-alcoholic steatohepatitis (NASH). These findings are similar to those with alcoholic liver disease. However, in the NASH-situation alcohol doesn't play an important role. Risk factors for the development of NASH are obesity and diabetes. Most of the patients are clinically asymptomatic. This means, that a diagnosis of NASH is a diagnosis of exclusion: Viral induced, autoimmune, metabolic and toxic liver disease have to be excluded. The disease has a benign clinical course. The risk of cirrhosis is low. So far, there is no established treatment. Preliminary reports suggest a positive effect of weight-loss and ursodeoxycholic acid. Wilson's disease, a copper storage disorder, in which biliary copper excretion is reduced, is inherited as an autosomal recessive trait. Most patients with Wilson disease become symptomatic between the ages of 6 and 15. In about 90% of patients serum ceruloplasmin levels and serum copper concentrations are reduced. Copper excreation is increased. Histologic examination of liver biopsy specimens reveals fatty infiltration, Mallory bodies and ballooned glycogen nuclei, abnormalities which are also found in alcoholic liver disease. The definitive diagnostic parameter is the quantitative determination of liver copper content (> 250 micrograms/g dryweight). Untreated Wilson disease is always fatal. Lifelong treatment with anti-copper drugs are essential, D-penicillamine being the firstline therapy. Hereditary hemochromatosis (HH) is an iron overload disease inherited as an autosomal recessive trait. The frequency of the disease is high. The first symptoms usually can be found at the age of 20-50 years. Arthralgia develops in up to 50% of the patients. Many organs are involved, most often the liver. The organ is usually enlarged, transaminases are always moderately elevated. Laboratory findings disclose a marked elevation in serum ferritin and transferrin saturation. More than 80% of HH-patients are homozygous for the C282Y-mutation in the HFE-gene. The firstline treatment of HH is phlebotomy. Treatment is lifelong. When serum ferritin drops below 50 micrograms/l, the frequency of phlebotomy should be reduced (4-12 per year). If the patient already has cirrhosis, the risk of HCC is very high.
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PMID:[Rare, but important chronic liver diseases]. 1250 71

Nonalcoholic fatty liver disease (NAFLD) has emerged as a ubiquitous liver disorder with occasional serious overtones. Although diabetes and obesity were initially held culpable, insulin resistance (IR) is now considered the fundamental operative mechanism. IR is probably the "first step" in nonalcoholic steatohepatitis (NASH). Oxidative stress may be the elusive "second" of possibly multiple steps in the progression of steatosis to fibrosing steatohepatitis. Because hepatic iron promotes oxidative stress, it was mooted as a contributory cofactor in NASH. This proposal was strengthened by an association with hepatic fibrosis. Subsequent studies have shown neither a significant increase in hepatic iron nor an association between hepatic iron and any of the histologic determinants in NASH. Likewise, the increased prevalence of hemochromatosis gene (HFE) mutations in some studies appears to be largely irrelevant to the development of hepatic fibrosis. Excess hepatic iron may occur in insulin resistance-associated iron overload (IRHIO), characterized by hyperferritinemia with normal to mild increases in transferrin saturation. Although patients with IRHIO have a high prevalence of IR-related metabolic disorders, the relationship of IRHIO to NASH is unclear. A recent study showed improvement in insulin sensitivity with the use of venesection in patients with NAFLD, but this approach cannot be implemented without extensive review.
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PMID:Interaction of iron, insulin resistance, and nonalcoholic steatohepatitis. 1253 Sep 44

The mechanism(s) determining the progression from fatty liver to steatohepatitis is currently unknown. Our goal was to define the relative impact of iron overload, genetic mutations of HFE, and insulin resistance on the severity of liver fibrosis in a population of subjects with nonalcoholic fatty liver disease (NAFLD) who had low prevalence of obesity and no overt symptoms of diabetes. In a cohort of 263 prospectively enrolled patients with NAFLD, 7.4% of patients had signs of peripheral iron overload and 9% had signs of hepatic iron overload, but 21.1% had hyperferritinemia. The prevalence of C282Y and H63D HFE mutations was similar to the general population and mutations were not associated with iron overload. Although subjects were on average only moderately overweight, insulin sensitivity, measured both in the fasting state and in response to oral glucose, was lower. Univariate analysis demonstrated that the presence of severe fibrosis was independently associated with older age, female sex, overweight, aspartate/alanine aminotransferase ratio, serum ferritin level, fasting glucose and insulin levels, decreased insulin sensitivity, and with histologic features (degree of necroinflammation and steatosis). After adjustment for body mass index (BMI), age, sex, and degree of steatosis, ferritin levels (odds ratio [OR] = 1.77; 95% CI = 1.21- 2.58; P =.0032) and the oral glucose insulin sensitivity (OR = 0.53; CI = 0.33-0.87; P =.0113) were independent predictors of severe fibrosis. In conclusion, the current study indicates that insulin resistance is a major, independent risk factor for advanced fibrosis in patients with NAFLD. Increased ferritin levels are markers of severe histologic damage, but not of iron overload. Iron burden and HFE mutations do not contribute significantly to hepatic fibrosis in the majority of patients with NAFLD.
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PMID:Relative contribution of iron burden, HFE mutations, and insulin resistance to fibrosis in nonalcoholic fatty liver. 1518 21

There are limited data on nonalcoholic fatty liver disease (NAFLD) from India. The clinicopathological profile of Indian patients with NAFLD may be different from that of Western patients. One hundred NAFLD patients with increased liver enzymes were prospectively evaluated for clinical presentation, associated diseases, overweight/obesity, central obesity (n=54), presence of diabetes mellitus, lipid abnormalities, insulin resistance (n=39), metabolic syndrome (n=54), serum iron, serum ferritin, and transferrin saturation (n=60), and HFE gene mutations (n=30). Risk factors for the grade and stage of the disease on histology were studied in 38 biopsy-proven patients. Patients were treated with lifestyle modifications and ursodeoxycholic acid (UDCA). Seventeen nonresponder patients were treated with metformin. The majority of patients were males (n=70). Twenty percent of patients were overweight, 68% had obesity, and 78% had central obesity. Abnormal cholesterol, HDL, and triglycerides were present in 36%, 66%, and 53% of patients, respectively. Twelve percent of patients had diabetes mellitus and 16% patients had various associated diseases. All 22 (100%) patients studied by ITT and all but 1 (98%) studied by HOMA-IR were found to have reduced insulin sensitivity and 50% were found to have metabolic syndrome by the modified ATP III criteria. Two (3%) patients were found to have high serum iron, 4 (7%) patients had high ferritin, 5 (8%) patients had increased transferrin saturation, and 4 (13%) patients were found to be heterozygotes for H63D HFE gene mutation. Twenty patients of 38 (53%) had histological evidence of NASH (class 3=6, class 4=14). The other 18 (47%) qualified for class I (n=1) or class II (n=17) NAFLD. Four (10.5%) patients had bridging fibrosis and none had evidence of cirrhosis liver. Seventy-four (74%) patients achieved a biochemical response to lifestyle modification and UDCA. All 17 patients treated with metformin had a reduction in ALT level and 10 (59%) of them had normalization of their enzymes. We conclude that the clinicopathological profile of NAFLD in Indian patients is different from that in the West.
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PMID:The clinicopathological profile of Indian patients with nonalcoholic fatty liver disease (NAFLD) is different from that in the West. 1742 Sep 51

Nonalcoholic fatty liver disease (NAFLD) is an emerging clinical entity. There is limited data on NAFLD from India. The objective of this article was to review all the published literature on NAFLD from India. The epidemiological studies including prevalence ofNAFLD amongst special groups like in those with unexplained rise in transaminases, diabetes mellitus and cryptogenic cirrhosis, studies on pathogenesis including insulin resistance, iron abnormalities, and studies available for the treatment of such patients have been reviewed. In addition some of the differences between Indian patients and those from the West have been highlighted. Available literature show that majority of Indian patients with NAFLD have overweight or obesity as per Asian Pacific criteria even though they do not have the kind of morbid obesity as seen in patients from the West. Other differences between Indian patients and those from the West include less of metabolic syndrome including its components like diabetes mellitus and hypertension, less of iron abnormalities and HFE gene mutations and mild histological disease at presentation in Indian patients. More data is required to substantiate these findings and to prove if NAFLD patients in India are different at presentation.
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PMID:Nonalcoholic fatty liver disease in India--is it different? 1754 90

OBJECTIVE Increased serum ferritin levels and iron stores may be involved in the development of abnormal glucose tolerance in women presenting with obesity and/or polycystic ovary syndrome (PCOS). We aimed to study the determinants of serum ferritin levels in premenopausal women among indexes of insulin resistance, adiposity, hyperandrogenism, and genotypes pertaining to inflammation, oxidative stress, and iron metabolism. RESEARCH DESIGN AND METHODS A total of 257 premenopausal women, classified depending on the presence or absence of PCOS, obesity, and/or abnormal glucose tolerance, underwent a complete metabolic evaluation, serum ferritin, haptoglobin, and C-reactive protein (CRP) measurements, and genotyping for proinflammatory and prooxidant variants and mutations in the HFE gene. RESULTS Serum ferritin concentrations were increased in women presenting with PCOS and/or abnormal glucose tolerance, independent of obesity. A stepwise multivariate linear regression analysis (R(2) = 0.18, P < 0.0001) retained menstrual dysfunction (beta = 0.14, P = 0.035), free testosterone (beta = 0.14, P = 0.052), insulin sensitivity index (beta = -0.12, P = 0.012), the His63Asp variant in HFE (beta = 0.16, P = 0.008), and abnormal glucose tolerance (beta = 0.15, P = 0.015) as significant predictors of the logarithm of ferritin levels, whereas CRP, haptoglobin, waist-to-hip ratio, or variants in the TNFalpha, TNFRSF1B, IL6, IL6ST, IL6Ralpha, PON1, and HFE Cys282Tyr mutation exerted no influence. CONCLUSIONS Androgen excess (partly because of hyperandrogenemia and partly because of menstrual dysfunction), insulin resistance, abnormal glucose tolerance, and the HFE His63Asp variant correlate with ferritin levels in premenopausal women.
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PMID:Body iron stores and glucose intolerance in premenopausal women: role of hyperandrogenism, insulin resistance, and genomic variants related to inflammation, oxidative stress, and iron metabolism. 1940 44

Although iron is an essential mineral for maintaining good health, excessive amounts are toxic. Nowadays, much interest is focused on the mechanisms and regulation of iron metabolism by down-regulation of the hormone hepcidin. The HAMP gene encodes for hepcidin appears to be exceptionally preserved. Disorders of iron metabolism could lead to iron overload, mainly causing the rare disease hereditary hemochromatosis, or on the other hand, iron deficiency and iron deficiency anaemia. Currently, these alterations constitute an important problem of public health. The genetic variation implicated in iron overload and iron deficiency anaemia, involves mutations in several genes such as HFE, TFR2,HAMP, HJV, Tf and TMPRSS6. Iron has the capacity to accept and donate electrons easily and can catalyze reactions of free radicals production. Therefore, iron overload causes lipid peroxidation and increases cardiovascular risk. Recently, a relationship between iron metabolism and insulin resistance and obesity has been described. In contrast, regarding a possible relationship between iron deficiency anaemia and cardiovascular disease, many aspects remain controversial. This review presents an overview of the most recent information concerning iron metabolism, iron bioavailability and iron overload/deficiency related diseases. The relation between iron and cardiovascular risk, in iron overload and in iron deficiency situations, is also examined. Finally, strategies to modify dietary iron bioavailability in order to prevent iron deficiency or alleviate iron overload are suggested.
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PMID:[Iron deficiency and overload. Implications in oxidative stress and cardiovascular health]. 2059 15

Nonalcoholic fatty liver disease (NAFLD) is emerging as an important cause of liver disease in India. Epidemiological studies suggest prevalence of NAFLD in around 9% to 32% of general population in India with higher prevalence in those with overweight or obesity and those with diabetes or prediabetes. Clinicopathological studies show that NAFLD is an important cause of unexplained rise in hepatic transaminases, cryptogenic cirrhosis and cryptogenic hepatocellular carcinoma in Indian patients. There is high prevalence of insulin resistance and nearly half of Indian patients with NAFLD have evidence of full-blown metabolic syndrome. Though oxidative stress is involved in the pathogenesis of NAFLD/nonalcoholic steatohepatitis, serum or liver iron and HFE gene mutations appear not to play a role in the pathogenesis of NAFLD in Indian patients. Imaging modalities are not useful in differentiating simple steatosis from NASH and liver biopsy may be useful in those with risk factors for significant liver disease. Pilot studies on treatment strategies have shown that weight reduction and exercise, ursodeoxycholic acid, metformin, vitamin E and pentoxyfylline are effective in normalizing transaminases and or in improving hepatic steatosis and inflammation in Indian patients with NAFLD. Randomized controlled treatment trials involving large number of patients with histological end point are required to assess the efficacy of different modalities. In conclusion, a lot has been done, yet more is required to understand various aspects of NAFLD in India.
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PMID:Nonalcoholic fatty liver disease in India - a lot done, yet more required! 2119 81


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