Gennaro Santorelli

Carotid Artery Intima-media Thickness in Nonalcoholic Fatty Liver Disease

PURPOSE To evaluate, in patients with nonalcoholic fatty liver disease with no or mild alterations of liver function tests, carotid artery intima-media thickness and the presence of plaques and to define determinants of vascular damage. METHODS A paired-sample case-control study: 125 patients with nonalcoholic fatty liver disease and 250 controls, without a prior diagnosis of diabetes, hypertension, and cardiovascular disease, matched for sex, age, and body mass index. B-mode ultrasound was used for evaluation of carotid intima-media thickness and presence of small plaques. RESULTS A significant difference in mean values of intima-media thickness (0.89+/-0.26 and 0.64+/-0.14 mm, P = .0001) and prevalence of plaques (26 [21%] and 15 [6%], P < .001) was observed in nonalcoholic fatty liver disease patients and controls. Variables significantly associated with intima-media thickness higher than 0.64 mm (median value in controls), in both patients and controls were: age (P = .0001), systolic blood pressure (P = .004), total and low-density lipoprotein cholesterol (P < or = .02 and P = .01, respectively), fasting glucose (P = .0001), and cardiovascular risk (P = .0001) and, only in controls, metabolic syndrome (P = .0001), HOMA-insulin resistance (P = .01), and body mass index (P = .0003). At multivariate logistic regression performed in the overall series of subjects, independent risk predictors of intima-media thickness higher than 0.64 mm were presence of steatosis (odds ratio [OR] = 6.9), age (OR 6.0), and systolic blood pressure (OR 2.3). CONCLUSION Patients with nonalcoholic fatty liver disease, even with no or mild alterations of liver tests, should be considered at high risk for cardiovascular complications.

Increased susceptibility to nonalcoholic fatty liver disease in heterozygotes for the mutation responsible for hereditary hemochromatosis.

BACKGROUND Insulin resistance is a key feature of nonalcoholic fatty liver disease. Patients with hereditary hemochromatosis, a disease characterized by progressive iron overload due, in most cases, to homozygosity for C282Y mutation in the HFE gene, have often decreased insulin sensitivity and release. AIMS To determine whether increased iron parameters/heterozygosity for the mutations of the HFE gene confer susceptibility to nonalcoholic fatty liver disease. PATIENTS One hundred and thirty-four consecutive Italian patients with clinical and ultrasonographic diagnosis of nonalcoholic fatty liver disease (82 with hyperferritinemia), half confirmed by liver biopsy. METHODS Insulin was determined by radioimmunoassay. HFE gene mutations were determined by polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS (1) Prevalence of C282Y HFE mutation was significantly higher in patients with nonalcoholic fatty liver disease compared to controls, the difference being more striking in patients with hyperferritinemia than in those without. (2) The presence of mild iron overload was associated with a lower insulin release. (3) Carriers of C282Y mutation developed nonalcoholic fatty liver disease despite lower body mass index and triglycerides. CONCLUSION The mild iron overload associated with heterozygosity for C282Y HFE mutation confers susceptibility to nonalcoholic fatty liver disease, causing relative insulin deficiency.

HFE Gene Mutations and Oxidative Stress Influence Serum Ferritin, Associated with Vascular Damage, in Hemodialysis Patients

Background/Aims: Hyperferritinemia has been associated with cardiovascular mortality in hemodialysis patients. The aim of this study was to evaluate whether serum ferritin was affected by iron and oxidative status and by genetic factors (HFE mutations and the Ala9Val MnSOD polymorphism), and to assess the association between ferritin and cardiovascular damage evaluated by ecocolor-Doppler. Methods: 63 hemodialysis patients were tested for HFE and MnSOD genotype by restriction analysis and oxidative status; vascular damage was assessed by measuring intima-media thickness, and by detecting plaques at carotid and femoral arteries. Results: Ferritin was correlated with transferrin saturation (p = 0.003), decreased iron-specific serum antioxidant activity (p = 0.01), age (p = 0.03), and C282Y and H63D HFE mutations (p = 0.05), but not with the MnSOD polymorphism. Ferritin was associated with advanced vascular damage, as evaluated by the presence of plaques, both at carotid (p = 0.03) and femoral arteries (p = 0.001), the other risk factors being age and low albumin. Low iron-specific antioxidant activity was associated with carotid plaques (p = 0.03). Conclusion: In hemodialysis patients, hyperferritinemia reflects a relative increase in iron availability and a decrease in iron-specific antioxidant activity, is favored by HFE mutations, and represents a risk factor for advanced cardiovascular damage.

HFE Genotype Influences Erythropoiesis Support Requirement in Hemodialysis Patients: A Prospective Study

Background/Aims: HFE protein controls iron absorption and cycling, and HFE mutations influence iron status. The aim was to evaluate the effect of the HFE genotype on the need for iron and erythropoietin in Italian hemodialysis patients. Methods: Ninety-six prevalent patients were evaluated at the time of enrolment and prospectively followed for 3 years. Patients were given r-HuEPO and Fe3+-gluconate according to guidelines. The HFE genotype was determined by restriction analysis. Results: Three patients (3%) carried the C282Y mutation, 4 (4%) were homozygous and 18 (19%) heterozygous for the H63D mutation, and 71 (74%) were negative for both. At enrolment, subjects positive for HFE mutations had higher iron stores (ferritin 617 ± 663 vs. 423 ± 386 ng/ml, p = 0.05), were receiving less iron (82.5 ± 66 vs. 110 ± 154 mg/month, p = 0.05) and a lower r-HuEPO dosage (98 ± 83 vs. 142 ± 138 U/kg/week, p = 0.03). Consistently during the study period, patients positive for HFE mutations received a lower amount of r-HuEPO (94.5 ± 63 vs. 186 ± 344 U/kg/week, p = 0.01) and iron (97 ± 63 vs. 121 ± 68 mg/month, p = 0.07). Upon Cox regression analysis, after adjustment for confounding variables, the presence of HFE mutations was associated with a reduced risk of death (HR 0.6, 95% CI 0.34–1.03, p = 0.06). Conclusion:HFE mutations reduce the amount of r-HuEPO and iron necessary to support erythropoiesis in hemodialysis.

Iron overload, hfe gene mutations and insulin resistance in non alcoholic fatty liver disease (NAFLD)

Ca.ssade#, E. Ferrnnninr’, M. Rtzetto’. ‘Division of Gostrwnterolog~ *Department OJ Internal Medicine, University of Turin, “Metabolism Unit, CNR Institute, Piss. Background and aims: The increaxd lipid peroxidation demonstrated in NASH might be related either to higher circtdadng levels of prooxidants and/or to a peculiar vulnerability of plasma lipids to &dative stress. Insulin resistance, a common feature in NASH, has been associated with increased oxidative stress. The aims of our srUdy were to establish whether the susceptibility of LDL-cholesteml pa&es to oxidation is increased in NASH oatients and whether this could be related to insulin resistance. Methods: We studied 11 non-obese, non diabetic patients with NASH (BMI=26.6+1.6), and 5 matched contmls. The following parameters were evaluated: 1) plasma lipid profile 2) total body lipid oxidation by indirect calorimetry 2) plasma LDGcholesteml vulnerability to oxidation as assessed by the lenght of the lag-phase during copper-catalyzed LDL oxidative modifications; 3) insulin sensitivity by hyperinsuliiemic (I mu/Kg min) euglycetnic clamp. Results: The basal lag-phase was significantly shorter in NASH patients compared to contmls (49+11 vs. 68+10 min, respectively; p=O.Ol). Plasma lipid pmtile was comparable in the hvo groups, with the exception of slightly higher triglycerides concentration in NASH (117+49 in NASH and 7l+ll m&IL in controls; p=O.O5). A slight inverse correlation was found between plasma triglycerides (t= -0.43) and lae chase and F’FA concentrations It= -0.521 and lae ohase in NASH patienis’bm not in controls. Total liiid oxidation w&‘1.13+0.25 and l.O+O.Zl micmmolrkg min in NASH and controls, respectively (p=ns) and inversely correlated with the lag-phase in both groups (r= -0.58.and 0.46). Insulin sensitivitv was deftitelv reduced in NASH oatients con&red to contmls (giucose inlitsion t&e = 4.49+1.48 vs. 7.67+0.54 mgkg mitt; p<O.Ol). The lag-phase did not change afta the euglycemic hyperinsulinemic clamp in both groups @IS) and did noOt corre& with insulin sensitivity. Conelusions: The increased susceptibility of LDLcholesterol particles contributes to enhanced lipid peroxidation in patients with NASY independendy from lipid levels and lipid oxidation. Tbe LDL oxidabilitv is not al&&d bv insulin adminisbation and does not appear to be &ed to insulin resi&nce