Ester Vanni

Università degli Studi di Torino, Torino, Piedmont, Italy

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Publications (44)216.42 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We recently demonstrated that the combination of liver stiffness measurement with NAFLD fibrosis score (NFS), two complementary, easy-to-perform, and widely available tools, is able to accurately diagnose or exclude the presence of severe liver fibrosis, in addition to reducing the number of needed diagnostic liver biopsies by about 50% - 60% [1]. We thank Dr. Sertoglu and colleagues for their comments, which prompted us to further clarify the results of our analyses. First, they pointed out that data from Sicilian and northern Italian patients should be assessed for normal distribution before comparing these patients in terms of demographic, laboratory, metabolic, and histologic variables. In response, we examined the data, and found that only some variables, such as ALT levels, did not have normal distributionThis article is protected by copyright. All rights reserved.
    Liver international: official journal of the International Association for the Study of the Liver 08/2014; · 3.87 Impact Factor
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    ABSTRACT: Background/AimsThe accuracy of nonivasive tools for the diagnosis of severe fibrosis in patients with nonalcoholic fatty liver disease(NAFLD) in clinical practice is still limited. We aimed at assessing the diagnostic performance of combined noninvasive tools in two independent cohorts of Italian NAFLD patients.Methods We analyzed data from 321 Italian patients(179 Sicilian-training cohort, and 142 Northern Italy-validation cohort) with an histological diagnosis of NAFLD. Severe fibrosis was defined as fibrosis≥F3 according to Kleiner classification. The APRI, AST/ALT, BARD, FIB-4, and NFS scores were calculated according to published algorithms. Liver stiffness measurement(LSM) was performed by FibroScan. Cut-off points of LSM, NFS and FIB-4 for rule-in or rule-out F3-F4 fibrosis were calculated by the reported formulas.ResultsIn the Sicilian cohort AUCs of LSM, NFS, FIB-4, LSM plus NFS, LSM plus FIB-4, and NFS plus FIB-4 were 0.857, 0.803, 0.790, 0.878, 0.888 and 0.807, respectively, while in the Northern Italy cohort the corresponding AUCs were 0.848, 0.730, 0.703, 0.844, 0.850, and 0.733 respectively. In the training cohort the combination of LSM plus NFS was the best performing strategy, providing false positive, false negative and uncertainty area rates of 0%,1.1% and 48%, respectively. Similar results were obtained in the validation cohort with false positive, false negative and uncertainty area rates of 0%,7.3% and 40.8%.Conclusions The combination of LSM with NFS, two complementary, easy to perform, and widely available tools, is able to accurately diagnose or exclude the presence of severe liver fibrosis, also reducing of about 50%-60% the number of needed diagnostic liver biopsies.This article is protected by copyright. All rights reserved.
    Liver international: official journal of the International Association for the Study of the Liver 05/2014; · 3.87 Impact Factor
  • Ester Vanni, Elisabetta Bugianesi
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    ABSTRACT: Obesity is an established risk factor for many types of cancers, particularly for hepatocellular carcinoma (HCC), owing to its carcinogenic potential and the association with nonalcoholic fatty liver disease (NAFLD). HCC may develop in cirrhotic and noncirrhotic livers with NAFLD, particularly in the presence of multiple metabolic risk factors such as obesity and diabetes. This issue is alarming because the population potentially at higher risk is greatly increasing. This review summarizes current evidence linking obesity and liver cancer, and discusses recent advances on the mechanisms underlying this relationship.
    Clinics in liver disease 02/2014; 18(1):191-203.
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    ABSTRACT: Series studies have associated increased serum levels of ferritin with liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We aimed to determine the accuracy with which measurements of serum ferritin determine the presence and severity of liver fibrosis, and whether combining noninvasive scoring systems with serum ferritin analysis increases the accuracy of diagnosis of advanced liver fibrosis. We performed a retrospective analysis of data from 1014 patients with liver biopsy-confirmed NAFLD. Three cut-points of serum ferritin level, adjusted for sex, were established based on receiver operating characteristics curve analysis: 1.0 (the upper limit of normal [ULN]), 1.5-fold ULN, and 2.0-fold ULN. Three multiple logistic regression models were created to determine the association of these cutoff values with liver fibrosis, adjusting for age, sex, race, diabetes, body mass index, and level of alanine aminotransferase. A greater proportion of patients with increased serum levels of ferritin had definitive NASH and more-advanced fibrosis than patients without increased levels. In all models, serum level of ferritin was significantly associated with the presence and severity of liver fibrosis. However, for all 3 cutoff values, area under the receiver operating characteristic curve values were low (less than 0.60) for the presence of fibrosis or any stage of liver fibrosis; ferritin level identified patients with fibrosis with 16%-41% sensitivity and 70%-92%specificity. The accuracy with which noninvasive scoring systems identified patients with advanced fibrosis did not change with inclusion of serum ferritin values. Although serum levels of ferritin correlate with more-severe liver fibrosis, based on adjusted multiple logistic regression analysis, serum ferritin levels alone have a low level of diagnostic accuracy for the presence or severity of liver fibrosis in patients with NAFLD.
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 12/2013; · 5.64 Impact Factor
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    ABSTRACT: To test the short-term clinical usefulness of venesection associated with lifestyle counselling as against counselling alone on insulin resistance and liver enzymes in subjects with non-alcoholic fatty liver disease (NAFLD), using a propensity score approach. We carried out a 6- to 8-month observational analysis of 198 NAFLD patients in three Italian referral centres (79 venesection and 119 counselling alone). Insulin resistance was measured by the homeostasis model assessment (HOMA) method. Logistic regression was used to identify factors associated with normal HOMA and normal alanine aminotransferase (ALT) at the end of observation. The results were adjusted for the propensity score to be enrolled in the venesection programme, based on clinical and laboratory data, including common HFE polymorphisms and liver biopsy (available in 161 cases). After adjustment for propensity and changes in BMI, venesection was significantly associated with normal HOMA [all cases: odds ratio (OR) 3.00; 95% confidence interval (CI) 1.51-5.97; cases with histology: OR 2.29; 95% CI 1.08-4.87] and ALT within normal limits (all cases: OR 2.56; 95% CI 1.29-5.10; cases with histology: OR 2.81; 95% CI 1.20-5.24). The results were confirmed in an analysis of 57 pairs matched for propensity, where venesection similarly increased the probability of normal HOMA (OR 3.27; 95% CI 1.16-7.84) and normal ALT (OR 5.60; 95% CI 2.09-15.00). Similar data were obtained in the subset of cases with normal basal ferritin (<350 ng/ml). Iron depletion by venesection favours the normalization of insulin resistance and raised liver enzymes in non-haemochromatosis patients with NAFLD.
    QJM: monthly journal of the Association of Physicians 02/2011; 104(2):141-9. · 2.36 Impact Factor
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    ABSTRACT: Increased visceral adiposity is considered the hallmark of the metabolic syndrome, whose hepatic manifestation is nonalcoholic fatty liver disease (NAFLD), although a subset of patients does not have visceral obesity. Our study aimed to compare metabolic alterations and liver damage in patients with NAFLD with and without visceral obesity. Four hundred and thirty one consecutive patients with liver biopsy-confirmed NAFLD were divided in three groups according to waist circumference, the simplest surrogate marker of visceral obesity. One hundred and thirty three patients (31%) had a waist circumference ≤94 (males) and ≤80 cm (females) (group A), 157 (36%) between 94 and 102, and 80 and 88 (B), and the remaining 141 (33%) had values higher than 102 and 88 cm (C). Significant trends for older age, higher prevalence of female gender, lower HDL, higher triglycerides, altered glucose metabolism, hypertension, and metabolic syndrome were observed with increasing visceral adiposity. In contrast, non-alcoholic steatohepatitis (NASH) detected in 55% and 72% of patients with normal and increased waist circumference, respectively, and the presence of fibrosis ≥2 were not associated with visceral adiposity. Alanine aminotransferase (ALT), ferritin, HOMA-IR >4, and severe steatosis were independently associated with NASH, whereas ferritin and impaired glucose tolerance were associated with fibrosis ≥2. Patients with normal waist circumference, despite milder metabolic alterations, may have NASH and are at risk of developing fibrosis, suggesting that once NAFLD is present, visceral obesity is not a major determinant of liver damage severity.
    Journal of Hepatology 11/2010; 54(6):1244-9. · 9.86 Impact Factor
  • Panminerva medica 09/2010; 52(3):265. · 0.98 Impact Factor
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    ABSTRACT: Inherited factors play a major role in the predisposition to nonalcoholic fatty liver disease (NAFLD), and the rs738409 C-->G polymorphism of PNPLA3/adiponutrin, encoding for the isoleucine-to-methionine substitution at residue 148 (I148M) protein variant, has recently been recognized as a major determinant of liver fat content. However, the effect of the rs738409 polymorphism on the severity of liver fibrosis in patients with NAFLD is still unknown. In this study, we considered 253 Italian patients, 179 healthy controls, and 71 family trios with an affected child with NAFLD. Analyses were replicated in 321 patients from the United Kingdom. The rs738409 polymorphism was determined by TaqMan assays. Liver histology was scored according to Kleiner et al. Hepatic expression of genes regulating liver damage was assessed by real-time polymerase chain reaction in 52 patients. The rs738409 GG genotype was more prevalent in patients than in controls (14% versus 3%, adjusted odds ratio [OR] = 3.29, 95% confidence interval [CI] = 1.8-6.9), and in the family study, the G allele was overtransmitted to affected children (P = 0.001). In Italian and United Kingdom patients, adiponutrin genotype influenced alanine aminotransferase levels and the severity of steatosis. Adiponutrin genotype was associated with the expression of genes involved in the steatosis-related liver damage, including the proapoptotic molecule Fas ligand. In the whole series combined, adiponutrin genotype was associated with steatosis grade >1 (OR = 1.35, 95% CI = 1.04-1.76), nonalcoholic steatohepatitis (OR = 1.5, 95% CI = 1.12-2.04), and fibrosis stage >1 (OR = 1.5, 95% CI = 1.09-2.12), independent of age, body mass index, and diabetes. Adiponutrin genotype demonstrated a dose effect with heterozygote risk intermediate between CC and GG homozygotes. Conclusion: In patients with NAFLD, adiponutrin rs738409 C-->G genotype, encoding for I148M, is associated with the severity of steatosis and fibrosis and the presence of nonalcoholic steatohepatitis.
    Hepatology 04/2010; 51(4):1209-17. · 12.00 Impact Factor
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    ABSTRACT: The metabolic syndrome encompasses metabolic and cardiovascular risk factors which predict diabetes and cardiovascular disease (CVD) better than any of its individual components. Nonalcoholic fatty liver disease (NAFLD) comprises a disease spectrum which includes variable degrees of simple steatosis (nonalcoholic fatty liver, NAFL), nonalcoholic steatohepatitis (NASH) and cirrhosis. NAFLD is the hepatic manifestation of the metabolic syndrome, with insulin resistance as the main pathogenetic mechanism. Recent data indicate that hyperinsulinemia is probably the consequence rather than cause of NAFLD and NAFLD can be considered an independent predictor of cardiovascular disease. Serum free fatty acids derived from lipolysis of visceral adipose tissue are the main source of hepatic triglycerides in NAFLD, although hepatic de novo lipogenesis and dietary fat supply contribute to the pathogenesis of NAFLD. Approximately 10-25% NAFLD patients develop NASH, the evolutive form of hepatic steatosis. Presumably in a genetically predisposed environment, this increased lipid overload overwhelms the oxidative capacity and reactive oxygen species are generated, leading to lipid peroxidation, cytokine induction, chemoattraction of inflammatory cells, hepatic stellate cell activation and finally fibrogenesis with extracellular matrix deposition. No currently available therapies for NAFLD and NASH exist. Recently nuclear receptors have emerged as key regulators of lipid and carbohydrate metabolism for which specific pharmacological ligands are available, making them attractive therapeutic targets for NAFLD and NASH.
    Digestive and Liver Disease 03/2010; 42(5):320-30. · 3.16 Impact Factor
  • Digestive and Liver Disease - DIG LIVER DIS. 01/2010; 42.
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    ABSTRACT: Mutations in the hemochromatosis gene (HFE) (C282Y and H63D) lead to parenchymal iron accumulation, hemochromatosis, and liver damage. We investigated whether these factors also contribute to the progression of fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We studied clinical, histologic (liver biopsy samples for hepatocellular iron accumulation), serologic (iron and enzyme levels), and genetic (HFE genotype) data from 587 patients from Italy with NAFLD and 184 control subjects. Iron accumulation predominantly in hepatocyes was associated with a 1.7-fold higher risk of a fibrosis stage greater than 1 (95% confidence interval [CI]: 1.2-2.3), compared with the absence of siderosis (after adjustment for age, body mass index, glucose tolerance status, and alanine aminotransferase level). Nonparenchymal/mixed siderosis was not associated with moderate/severe fibrosis (odds ratio, 0.72; 95% CI: 0.50-1.01). Hepatocellular siderosis was more prevalent in patients with HFE mutations than in those without; approximately one third of patients with HFE mutations had parenchymal iron accumulation (range, 29.8%-35.7%, depending on HFE genotype). Predominantly hepatocellular iron accumulation occurred in 52.7% of cases of patients with HFE mutations. There was no significant association between either the presence of HFE mutations or specific HFE genotypes and the severity of liver fibrosis. Iron deposition predominantly in hepatocyes is associated with more severe liver damage in patients with NAFLD. However, HFE mutations cannot be used to identify patients with hepatocellular iron accumulation.
    Gastroenterology 11/2009; 138(3):905-12. · 12.82 Impact Factor
  • Ester Vanni, Elisabetta Bugianesi
    Hepatology 07/2009; 49(6):1790-2. · 12.00 Impact Factor
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    ABSTRACT: Chronic hepatitis C (CHC) has been associated with type 2 diabetes and insulin resistance, but the extent of impairment in insulin action, the target pathways involved, and the role of the virus per se have not been defined. In this study, we performed a euglycemic hyperinsulinemic clamp (1 mU x minute(-1) x kg(-1)) coupled with infusion of tracers ([6,6-(2)H(2)]glucose, [(2)H(5)]glycerol) and indirect calorimetry in 14 patients with biopsy-proven CHC, who were selected not to have any features of the metabolic syndrome, and in seven healthy controls. We also measured liver expression of inflammatory cytokines/mediators and tested their association with the metabolic parameters. Compared to controls, in patients with CHC: (1) total glucose disposal (TGD) during the clamp was 25% lower (P = 0.003) due to impaired glucose oxidation (P = 0.0002), (2) basal endogenous glucose production (EGP) was 20% higher (P = 0.011) and its suppression during the clamp was markedly reduced (P = 0.007), and (3) glycerol appearance was not different in the basal state or during the clamp, but lipid oxidation was less suppressed by insulin (P = 0.004). Lipid oxidation was higher in patients with CHC who had more steatosis and was directly related to EGP, TGD, and glucose oxidation. The decreased insulin-stimulated suppression of EGP was associated with increased hepatic suppressor of cytokine signaling 3 (SOCS3; P < 0.05) and interleukin-18 (P < 0.05) expression. Conclusion: Hepatitis C infection per se is associated with peripheral and hepatic insulin resistance. Substrate competition by increased lipid oxidation and possibly enhanced hepatic expression of inflammatory cytokines/mediators could be involved in the defective glucose regulation.
    Hepatology 05/2009; 50(3):697-706. · 12.00 Impact Factor
  • Journal of Hepatology - J HEPATOL. 01/2009; 50.
  • Digestive and Liver Disease - DIG LIVER DIS. 01/2009; 41(3).
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    ABSTRACT: It is uncertain whether patients with nonalcoholic fatty liver disease (NAFLD) and normal alanine aminotransferase (ALT) have a milder disease and should undergo liver biopsy. We reviewed the histological data of 458 Italian patients with NAFLD in whom liver biopsy was indicated by altered liver enzymes (395 cases, 86%), or persistently elevated ferritin or long-lasting severe steatosis (63 cases). Factors associated with nonalcoholic steatohepatitis (NASH) and fibrosis >/= 2 were identified by multivariate analysis. Patients with normal ALT were significantly older, had lower body mass index, fasting triglycerides, insulin resistance according to homeostasis model assessment (HOMA-IR), ALT, and gamma-glutamyltransferase, but a higher prevalence of hypertension. NASH was diagnosed in 59% and 74% of the patients with normal and increased ALT, respectively (P = 0.01). In the overall series of patients, NASH was independently predicted by ALT (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.04-1.19 per 10-IU/mL increase) and diabetes (OR, 1.5; 95% CI, 1.1-2.0). The same variables were selected in patients with increased ALT, whereas in those with normal ALT, HOMA-IR and ALT were independent predictors. Severe fibrosis was independently predicted by serum ferritin (OR, 1.04; 95% CI, 1.001-1.08 per 50-ng/mL increase), ALT (OR, 1.07; 95% CI, 1.02-1.14), and diabetes (OR, 1.8; 95% CI, 1.4-2.3) in the overall series, serum ferritin and diabetes in those with increased ALT, and only HOMA-IR (OR, 1.97; 95% CI, 1.2-3.7) in patients with normal ALT. CONCLUSION: Normal ALT is not a valuable criterion to exclude patients from liver biopsy. Alterations in glucose metabolism and insulin resistance in subjects with normal ALT should also be considered in the selection of NAFLD cases for histological assessment of disease severity and progression.
    Hepatology 09/2008; 48(3):792-8. · 12.00 Impact Factor
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    Diabetes care 11/2007; 30(10):2638-40. · 7.74 Impact Factor
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    ABSTRACT: The risk of chronic liver disease and liver-related mortality is increased in patients with type 2 diabetes mellitus. Several cohort studies have suggested a metabolic pathway from nonalcoholic fatty liver, nonalcoholic steatohepatitis, cryptogenic cirrhosis, and eventually hepatocellular carcinoma. Although cardiovascular risk remains the major cause for excess mortality in type 2 diabetes mellitus, the risk of progressive liver disease should no longer be underscored.
    Current Diabetes Reports 07/2007; 7(3):175-80. · 3.17 Impact Factor
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    ABSTRACT: Hyperferritinemia is frequently observed in nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome characterized by hepatic insulin resistance and considered high cardiovascular risk. Iron depletion by phlebotomy has been reported to decrease insulin resistance in NAFLD in small, uncontrolled studies. Aims of this study were to define the relationship between ferritin and iron stores in patients with NAFLD, the effect of iron depletion on insulin resistance, and whether basal ferritin levels influence treatment outcome. Subjects were included if ferritin and/or ALT were persistently elevated after 4 months of standard therapy. Sixty-four phlebotomized subjects were matched 1:1 for age, sex, ferritin, obesity, and ALT levels with patients who underwent lifestyle modifications only. Insulin resistance was evaluated by insulin levels, determined by RIA and the HOMA-R index, at baseline and after 8 months. Baseline ferritin levels were associated with body iron stores (P<0.0001). Iron depletion produced a significantly larger decrease in insulin resistance (P=0.0016 for insulin, P=0.0042 for HOMA-R) compared with nutritional counseling alone, independent of changes in BMI, baseline HOMA-R, and the presence of the metabolic syndrome. Iron depletion was more effective in reducing HOMA-R in patients in the top two tertiles of ferritin concentrations (P<0.05 vs controls), and in carriers of the mutations in the HFE gene of hereditary hemochromatosis (P<0.05 vs noncarriers). Given that phlebotomy reduces insulin resistance, which is associated with liver tissue damage, future studies should evaluate the effect of iron depletion on liver histology and cardiovascular end points.
    The American Journal of Gastroenterology 06/2007; 102(6):1251-8. · 7.55 Impact Factor
  • Digestive and Liver Disease - DIG LIVER DIS. 01/2007; 39(3).

Publication Stats

3k Citations
216.42 Total Impact Points

Institutions

  • 2002–2014
    • Università degli Studi di Torino
      • Department of Medical Science
      Torino, Piedmont, Italy
  • 2007–2009
    • University of Milan
      • Department of Internal Medicine
      Milano, Lombardy, Italy
    • Ospedale Pediatrico Bambino Gesù
      Roma, Latium, Italy
  • 2003
    • University of Bologna
      • Institute of Genetic Medicine
      Bolonia, Emilia-Romagna, Italy