Non-alcoholic fatty liver disease, metabolic syndrome and patatin-like phospholipase domain-containing protein3 gene variants

BACKGROUND & AIMS

Non-alcoholic fatty liver disease was traditionally interpreted as a condition which may progress to liver-related complications. However, the increased mortality is primarily a result of cardiovascular diseases. It has been suggested that fatty liver can be considered as the hepatic consequence of the metabolic syndrome. The aim was to describe the different clinical presentations of non-alcoholic fatty liver disease on the basis of the patatin-like phospholipase domain-containing protein3 (PNPLA3) rs738409 gene variant.

METHODS

Fatty liver was defined by ultrasonographic Hamaguchi's criteria in 211 consecutive subjects with non-alcoholic fatty liver disease. The rs738409 polymorphism was determined by TaqMan assays. Metabolic syndrome was defined according to ATPIII modified criteria.

RESULTS

Prevalence of PNPLA3-148II, PNPLA3-148IM, and PNPLA3-148MM genotypes was 45.0%, 40.7%, and 14.3% respectively. Prevalence of metabolic syndrome progressively increased with the severity of liver steatosis (from 52.5% to 65.2%, and 82.3% respectively, p<0.01). The PNPLA3-148MM group had significantly lower mean serum triglycerides (p<0.001), Framingham cardiovascular risk score (p<0.01) and lower prevalence of metabolic syndrome (p<0.05) and its components. Age and HOMA-IR were positive independent predictors of metabolic syndrome, while a negative independent association was found between metabolic syndrome and the homozygotes PNPLA3 I148M variant.

CONCLUSIONS

We suggest a lower prevalence of MetS and reduced cardiovascular risk in NAFLD patients with PNPLA3MM genotype.

NOX2-generated oxidative stress is associated with severity of ultrasound liver steatosis in patients with non-alcoholic fatty liver disease

Background

Chronic oxidative stress is one of the key mechanisms responsible for disease progression in non-alcoholic fatty liver disease. However, so far, few studies reported increased circulating levels of oxidative stress markers in patients with non-alcoholic fatty liver and no study has been performed with newer markers of systemic oxidative stress. The aim was to assess the relationship between urinary 8-iso-prostaglandin F2α and serum soluble NOX2-derived peptide and the severity of liver steatosis in subjects with non-alcoholic fatty liver.

Methods

The study was performed in 264 consecutive patients referred for suspected metabolic disease. Steatosis was defined according to Hamaguchi ultrasonographic criteria. Oxidative stress was assessed by urinary 8-iso- prostaglandin F2α and serum soluble NOX2-derived peptide levels.

Results

Patients with non-alcoholic fatty liver had higher (p < 0.001) mean values of urinary 8-iso-PGF2α and of serum soluble NOX2-derived peptide, alanine aminotransferase, Cytokeratin-18 and homeostasis model of insulin resistance and lower values of serum adiponectin as compared to those without. Prevalence of metabolic syndrome and of its clinical features was significantly higher in patients with non-alcoholic fatty liver. Same findings were also observed after the exclusion of obese subjects, or subjects with diabetes or with metabolic syndrome and in those not taking statin medication. In addition, the levels of urinary 8-iso-PGF2α were independent predictors of non-alcoholic fatty liver and a strong association of urinary 8-iso-PGF2α and of serum soluble NOX2-derived peptide with the severity of steatosis at ultrasound was also observed.

Conclusions

We demonstrated increased markers of oxidative stress in subjects with non-alcoholic fatty liver. Urinary 8-iso-PGF2α and serum soluble NOX2-derived peptide levels were independent from obesity, diabetes and metabolic syndrome and increased with the severity of liver steatosis at ultrasound.

Adipose tissue fatty acid composition and colon cancer: a case-control study

PURPOSE

An increased dietary intake of fat, particularly polyunsaturated fatty acids (PUFAs), has been related to an increased risk of breast, prostate and colon cancers. Patients with and without colon cancer were tested for differences in their fatty stores composition.

METHODS

The fatty acid levels were determined by gas-liquid chromatography in adipose tissue samples, subcutaneous and visceral, obtained intra-operatively from 52 colon cancer and 50 nonneoplastic abdominal disease patients. Statistical analysis was performed using one-way ANOVA, SNK test and Dunnet test. Differences in the composition of saturated, monounsaturated and polyunsaturated fatty acids, in visceral and in subcutaneous samples of colon cancer and nonneoplastic patients, were assessed.

RESULTS

The sum of saturated and monounsaturated fatty acids, respectively, in visceral and in subcutaneous samples, was higher in neoplastic patients (p < 0.001). The sum of some n-6 polyunsaturated fatty acids (PUFAs), the dietary precursor linoleic acid (LA-18:2n-6), and their metabolites, gammalinolenic acid (GLA-18:3n-6) + dihomogammalinolenic acid (DGLA-20:3n-6) + arachidonic acid (AA-22:4n-6), was higher in subcutaneous fat of controls (p < 0.05). The samples from these patients had a fatty acid composition, both subcutaneous and visceral, with a higher content of alphalinolenic acid (ALA-18:3n-3) and stearidonic acid (SDA-18:4n-3) compared to neoplastic patients (p < 0.001). These had subcutaneous and visceral fat stores statistically higher in GLA, DGLA and AA (p < 0.001). Colon cancer patients had subcutaneous adipose stores higher in ALA and LA than visceral sites (p < 0.001).

CONCLUSIONS

Fatty acids may be involved in colon carcinogenesis and there is a depot-specific impact on this process by visceral fat.

Drugs improving insulin resistance for non‐alcoholic fatty liver disease and/or non‐alcoholic steatohepatitis

The review is withdrawn as it was outdated. A new team of authors, Goossens N, Isgro G, and Negro F, overtook the review title, and a new, revised protocol is published in this April issue of The Cochrane Library 2013.

Treatment of a patient with congenital analbuminemia with atorvastatin and albumin infusion

Congenital analbuminemia is a rare autosomic recessive inherited disorder characterized by low plasma albumin and hypercholesterolemia, which may increase cardiovascular risk. Patients are essentially asymptomatic, apart from ease of fatigue, minimal ankle oedema and hypotension. There is no accepted strategy for safely treating both hypercholesterolemia and analbuminemia in order to eventually decrease the atherosclerotic risk. We report a case of congenital analbuminemia (1.0 g/dL)

in a 38-year-old male with hypercholesterolemia (range: 406-475 mg/dL) and severe arterial dysfunction [no brachial artery flow-mediated dilation (FMD)]. Long-term, cholesterol-lowering treatment with atorvastatin was associated with the appearance of peripheral edema. Two-months of infusion with albumin improved FMD (7%) and reduced serum cholesterol (273 mg/dL), supporting the hypothesis of a compensatory role of hypercholesterolemia. Statin treatment, together with periodical albumin infusions, may contribute to the safe reduction of cardiovascular risk.

Reduced atherosclerotic burden in subjects with genetically determined low oxidative stress

OBJECTIVE

NADPH oxidase, one of the most important enzymes producing reactive oxidant species, is suggested to play a role in experimental atherosclerosis, but its role in human atherosclerosis is still unclear. We hypothesized that a reduced activity of NADPH oxidase might be linked to a reduced atherosclerotic burden.

METHODS AND RESULTS

Thirty-one women carriers of hereditary deficiency of NOX2, the catalytic subunit of NADPH oxidase, were matched for sex and age with 31 controls and 31 obese women. Flow-mediated dilation and intima-media thickness, 2 surrogate markers of atherosclerosis, serum activity of NOX2, urinary isoprostanes, serum levels of nitrite/nitrate, and platelet production of isoprostanes and nitrite/nitrate were determined. Compared with controls (5.7±3.0% and 0.60±0.11 mm), carriers of NOX2 deficiency had higher flow-mediated dilation (9.2±5.0%; P<0.001) and lower intima-media thickness (0.50±0.11 mm; P=0.002), whereas obese women had lower flow-mediated dilation (3.2±2.1%; P=0.007) and higher intima-media thickness (0.71±0.15 mm; P<0.001). Compared with controls, carriers of NOX2 deficiency had lower urinary isoprostanes (132.6±87.3 versus 82.3±46.0 pg/mg creatinine; P=0.007) and serum NOX2 activity (24.9±19.3 versus 12.8±11.9 pg/mL; P=0.004) and higher serum nitrite/nitrate (23.8±7.6 versus 30.5±6.3 µmol/L; P<0.001), whereas obese women had higher urinary isoprostanes (132.6±87.3 versus 182.2±84.6 pg/mg creatinine; P=0.008) and serum NOX2 activity (24.9±19.3 versus 36.1±18.6 pg/mL; P=0.008) and lower serum nitrite/nitrate (23.8±7.6 versus 12.6±4.2 µmol/L; P<0.001). Flow-mediated dilation correlated with intima-media thickness (r=-0.433; P<0.001), serum NOX2 activity (r=-325; P<0.001), and urinary isoprostanes (r=-0.314; P=0.002). Ex vivo study showed that, compared with controls, platelets from carriers of NOX2 deficiency had lower isoprostanes (P<0.001) and higher nitrite/nitrate (P<0.001), whereas platelets from obese women had higher isoprostanes (P<0.001) and lower nitrite/nitrate (P=0.013).

CONCLUSIONS

The study shows reduced atherosclerotic burden in carriers of NOX2 deficiency, suggesting that oxidative stress generated by this enzymatic pathway is implicated in human atherosclerosis.

Obesity and hypercholesterolemia are associated with NOX2 generated oxidative stress and arterial dysfunction

OBJECTIVE

To analyze the interplay among oxidative stress, NOX2, the catalytic core of nicotinamide-adenine dinucleotide phosphate oxidase, and endothelial dysfunction in children with obesity and/or hypercholesterolemia.

STUDY DESIGN

We performed a cross-sectional study comparing flow-mediated arterial dilation (FMD), oxidized low-density lipoprotein, and urinary excretion of isoprostanes (8-iso-PGF2α), as markers of oxidative stress, and NOX2 activity, as assessed by blood levels of soluble NOX2-dp (sNOX2-dp), in a population of 100 children, matched for age and sex, including 40 healthy subjects (HS), 20 children with hypercholesterolemia (HC), 20 obese children (OC), and 20 children with coexistence of hypercholesterolemia and obesity (HOC).

RESULTS

HOC had higher sNOX2-dp and oxidized low-density lipoprotein levels compared with HS, HC, and OC. HC, OC, and HOC had lower FMD values compared with HS. Urinary 8-iso-PGF2α excretion was higher in HOC compared with HS. FMD was inversely correlated with sNOX2-dp levels (r = -0.483; P < .001) and with the number of cardiovascular risk factors (r = -0.617; P < .001). Multiple linear regression analysis showed that the number of cardiovascular risk factors was the only independent predictive variable associated with FMD (β: -0.585; P < .001; R(2) = 35%) and sNOX2-dp (β: 0.587; P < .001; R(2) = 34%).

CONCLUSION

The study suggests that NOX2-generating oxidative stress may have a pathogenic role in the functional changes of the arterial wall occurring in HOC.

Liver vitamin D receptor, CYP2R1, and CYP27A1 expression: relationship with liver histology and vitamin D3 levels in patients with nonalcoholic steatohepatitis or hepatitis C virus

Evidence suggests an association between low serum 25-hydroxy-vitamin D(3) [25(OH)D(3) ] levels and the presence and prognosis of liver disease. Vitamin D receptor (VDR) has been widely detected in the liver, but its expression in the course of liver disease has never been investigated. We evaluated the hepatic expression of VDR along with that of vitamin D 25-hydroxylases in patients with nonalcoholic steatohepatitis (NASH) or chronic hepatitis C (CHC) and its relationship with hepatic histological features and serum 25(OH)D(3) levels. We evaluated 61 patients (25 NASH and 36 CHC) who had undergone liver biopsy for clinical purposes and 20 subjects without liver disease. Serum 25(OH)D(3) was measured via colorimetric assay. Expression of VDR, CYP2R1, and CYP27A1 was evaluated via immunohistochemistry in hepatocytes, cholangiocytes, and liver inflammatory cells. Parenchymal and inflammatory cells from liver biopsies of patients with NASH and CHC expressed VDR, CYP2R1, and CYP27A1. In NASH patients, VDR expression on cholangiocytes was inversely correlated with steatosis severity (P < 0.02), lobular inflammation (P < 0.01), and nonalcoholic fatty liver disease score (P < 0.03). Moreover, expression of CYP2R1 in hepatocytes correlated strongly with VDR positivity on liver inflammatory cells. In CHC subjects, fibrosis stage was associated with low hepatic CYP27A1 expression, whereas portal inflammation was significantly higher in patients with VDR-negative inflammatory cells (P < 0.009) and low VDR expression in hepatocytes (P < 0.03).

CONCLUSION

VDR is widely expressed in the liver and inflammatory cells of chronic liver disease patients and its expression is negatively associated with the severity of liver histology in both NASH and CHC patients. These data suggest that vitamin D/VDR system may play a role in the progression of metabolic and viral chronic liver damage. (HEPATOLOGY 2012;56:2180-2187).

Upstream therapy with statin and recurrence of atrial fibrillation after electrical cardioversion. Review of the literature and meta-analysis

Background

Atrial fibrillation (AF) is the most common sustained arrhythmia observed in clinical practice. Electrical cardioversion (EC) is commonly used to restore and maintain sinus rhythm but it is characterized by high rate of recurrences. Several trials analyzed the effects of statins to reduce the recurrences in AF with contradictory results.

Methods

We performed a meta-analysis of the interventional trials with statins in patients with persistent AF to evaluate recurrences after EC. Only randomized controlled trials were included in the analysis. Data sources included: Medline, ISI Web of Science, SCOPUS and Cochrane database (up to June 2012). Data extraction was performed by three authors. Study-specific odds ratios (ORs) were combined using fixed-effects model.

Results

Six studies with 515 patients were included in the analysis. Statins used in the selected trials were: atorvastatin (at dosages ranging from 10 to 80 mg/day), pravastatin (40 mg/day) and rosuvastatin (20 mg/day). AF recurrence after EC occurred in 108/258 (41.8%) of patients treated with statins and in 132/257 (51.3%) patients not on treatment with statins. Compared with control, recurrences were significantly reduced with statin treatment (O.R.: 0.662; 95% C.I., 0.45-0.96; p=0.03); statin treatment was associated with an absolute risk reduction of 0.095 and a number needed to treat of 11.

Conclusions

This review suggests that statin therapy was significantly associated with a decreased risk of recurrence in patients with persistent AF after EC.

Moderate weight loss decreases oxidative stress and increases antioxidant status in patients with metabolic syndrome

Background. Oxidative stress is enhanced in metabolic syndrome (MetS) and believed to contribute to accelerated atherosclerosis. Weight loss is associated with lowered oxidative stress. Methods. We performed a cross-sectional study in 92 consecutive patients with metabolic syndrome and 80 without. A dietary intervention with moderately low-calorie diet (600 calories/day negative energy balance) was carried out in 53 of metabolic syndrome patients. Oxidative stress, assessed by sNOX2-dp and urinary 8-iso-PGF2α, and antioxidant status, assessed by serum levels of vitamin E and adiponectin, were measured before and after 6 months. Results. Serum vitamin E/cholesterol ratio was significantly lower in metabolic syndrome compared to controls (P < 0.001) and decreased by increasing the number of metabolic syndrome components (P < 0.001). After six months, 23 and 30 patients showed >5% (group A) or <5% (group B) weight loss, respectively. Urinary 8-iso-PGF2α (−39.0%), serum sNOX2-dp (−22.2%), adiponectin (+125%), and vitamin E/cholesterol ratio (+129.8%) significantly changed only in A group. Changes in body weight and in serum adiponectin were independent predictors of vitamin E/cholesterol ratio variation. Conclusion. Our findings show that in metabolic syndrome moderate weight loss is associated with multiple health benefits including not only oxidative stress reduction but also enhancement of antioxidant status.

Non-alcoholic fatty liver disease and cardiovascular disease: epidemiological, clinical and pathophysiological evidences

Non-alcoholic fatty liver disease is recognized as the most common and emerging chronic liver disease in western countries. The disease has been traditionally interpreted as a possibly progressing condition to liver fibrosis and cirrhosis. However, recently, a large number of publications have demonstrated that people with non-alcoholic fatty liver have an increased chance of developing cardiovascular diseases, which represent the major causes of death in this setting. This association is mainly explained by the atherogenic profile of the metabolic syndrome a condition frequently associated with fatty liver, which may represent its hepatic component. Some studies have also shown an association independent of traditional risk factors or of the clinical features of the metabolic syndrome. In this setting, cardiovascular disease seems to be the consequence of low-grade chronic inflammation and increased oxidative stress. Most studies did not differentiate cardiovascular risk between simple steatosis and non-alcoholic steatohepatitis, although the latter seems to be at higher cardiovascular risk. Few studies have investigated the direct correlation between hepatic inflammation and atherosclerosis. Genetic studies will probably improve the interpretation of the increased cardiovascular risk in patients with fatty liver and no metabolic syndrome.

Rosuvastatin reduces platelet recruitment by inhibiting NADPH oxidase activation

Rosuvastatin increased vascular endothelial NO and attenuated platelet activation after ischemia-reperfusion in mice; nevertheless, the influence of rosuvastatin on the activation of human platelets and the underlying mechanism has never been investigated. In an in vitro study platelets from 8 healthy donors were incubated with scalar concentrations of rosuvastatin (1-10 μM) before activation. Platelet recruitment (PR), that mimics the propagation of platelet aggregation and is dependent upon isoprostane formation, was investigated. PR was inhibited by rosuvastatin in concentration-dependent manner concomitantly with down-regulation of platelet release of the pro-thrombotic molecule CD40L. This effect was associated with lower production of platelet reactive oxygen species (ROS), isoprostane and activation of the glycoprotein IIb/IIIa and was counteracted by exogenous addition of isoprostanes. Conversely, rosuvastatin concentration-dependently increased platelet NO. Platelet isoprostane formation mainly depends from NADPH oxidase. Rosuvastatin concentration-dependently inhibited platelet sNOX2-dp release, a specific marker of NADPH oxidase activation, PKC phosphorylation and p47(phox) translocation from cytosol to membranes. In an ex vivo study 10 hypercolesterolemic patients were randomly allocated to diet or rosuvastatin (20 mg). We observed that as early as 2h after rosuvastatin PR, platelet isoprostanes formation, platelet CD40L and sNOX2-dp decreased while platelet NO increased; no changes were detected in diet-assigned patients. This study shows that in vitro rosuvastatin impairs platelet activation via inhibition of NOX2-derived oxidative stress. This effect, which is associated ex vivo with acute inhibition of platelet activation, suggests that rosuvastatin behaves as an antiplatelet drug.

Weight loss is associated with improved endothelial dysfunction via NOX2-generated oxidative stress down-regulation in patients with the metabolic syndrome

The aim of this study was to assess whether adherence to a restricted-calorie, Mediterranean-type diet improves endothelial dysfunction and markers of oxidative stress in patients with metabolic syndrome. A moderately low-calorie (600 calories/day negative energy balance), low-fat, high-carbohydrate diet (<30% energy from fat, <10% from saturated fat and 55% from carbohydrate) was prescribed to 53 outpatients with the metabolic syndrome. Participants were divided into two groups according to body weight loss > or < 5% after 6 months. Group A (n = 23) showed a remarkable decrease in body weight (-6.8%), body-mass-index (-4.6%), waist circumference (-4.8%), HOMA-IR (-27.2%), plasma glucose, glycosylated haemoglobin, total and LDL-cholesterol, blood pressure, serum NOX2 (the catalytic core of NADPH oxidase) (-22.2%) and urinary8-isoprostanes (-39.0%) and an increase of serum NOx (Nitrite/Nitrate) (+116.8%) and adiponectine (+125.5%) as compared with those in group B (n = 30). A statistically significant increase in brachial artery flow-mediated dilatation was observed in group A (+24.7%; p < 0.001), while no changes were present in group B. Variations of flow-mediated dilatation were statistically and negatively correlated with changes of serum NOX2 levels (p = 0.04), body-mass-index (p < 0.01), waist circumference (0.01), glycosylated haemoglobin (p < 0.01), LDL-cholesterol (p < 0.01) and triglycerides (p < 0.05) and positively correlated with changes of serum NOx (p < 0.001) and adiponectin (p = 0.01). The results show that moderate weight loss is able to improve endothelial dysfunction in patients with the metabolic syndrome. The coexistent decrease of NOX2 activation suggests a role for oxidative stress in eliciting artery dysfunction.

Platelet isoprostane overproduction in diabetic patients treated with aspirin

Aspirin modestly influences cardiovascular events in patients with type 2 diabetes mellitus (T2DM), but the reason is unclear. The aim of the study was to determine whether in T2DM patients aspirin enhances platelet isoprostanes, which are eicosanoids with proaggregating properties derived from arachidonic acid oxidation by platelet NOX2, the catalytic subunit of reduced NAD phosphate oxidase. A cross-sectional study was performed comparing T2DM patients, treated (n = 50) or not treated (n = 50) with 100 mg/day aspirin, with 100 nondiabetic patients, matched for age, sex, atherosclerosis risk factors, and aspirin treatment. A short-term (7 days) treatment with 100 mg/day aspirin also was performed in 36 aspirin-free diabetic and nondiabetic patients. Higher platelet recruitment, platelet isoprostane, and NOX2 activation was found in diabetic versus nondiabetic patients and in aspirin-treated diabetic patients versus nontreated patients (P < 0.001). Platelet thromboxane (Tx) A(2) (P < 0.001) was inhibited in all aspirin-treated patients. In the interventional study, aspirin similarly inhibited platelet TxA(2) in diabetic and nondiabetic patients (P < 0.001). Platelet recruitment, isoprostane levels, and NOX2 activation showed a parallel increase in diabetic patients (P < 0.001) and no changes in nondiabetic patients. These findings suggest that in aspirin-treated diabetic patients, oxidative stress-mediated platelet isoprostane overproduction is associated with enhanced platelet recruitment, an effect that mitigates aspirin-mediated TxA(2) inhibition.

Bleeding and thrombosis in cirrhotic patients: what really matters?

Bleeding complications, particularly in the gastro-intestinal tract, may complicate the clinical course of liver cirrhosis. Coexistence of abnormal global tests exploring the platelet and clotting systems generated the hypothesis that cirrhotic patients have "coagulopathy" predisposing to bleeding complications. Using more sophisticated laboratory methods this hypothesis has been partly confuted as cirrhotic patients actually disclose an ongoing prothrombotic state in the portal and systemic circulation that could predispose to thrombosis. Recent data of the literature support this hypothesis as portal vein thrombosis and peripheral thrombosis are frequent features of cirrhosis. We reviewed the literature data to assess the prevalence of bleeding and thrombotic complication in cirrhosis and the role of clotting activation in precipitating them. Whilst it appears scarcely relevant the interplay between the so called "coagulopathy" and bleeding, the interplay between clotting activation and thrombosis seems to be relevant but needs more accurate investigation in larger study populations.

NOX2 up-regulation is associated with artery dysfunction in patients with peripheral artery disease

OBJECTIVE

Oxidative stress seems to play a role in impairing flow-mediated dilation (FMD) in patients with peripheral artery disease (PAD) but the underlying mechanism is still undefined. We evaluated whether NOX2, the catalytic core of NADPH oxidase, the most important producer of reactive oxidant species (ROS), is implicated in impairing FMD.

METHODS

We measured FMD, urinary isoprostanes, a marker of oxidative stress, nitric oxide generation by serum levels of nitrite/nitrate (NOx), and serum levels of soluble NOX2-derived peptide (sNOX2-dp), a marker of NOX2 activation, in 50 PAD patients and 50 controls. Also, we performed an interventional cross-over study to assess if propionyl-L-carnitine (PLC) (6g/day), vs. placebo, was able to affect FMD via an oxidative stress-mediated mechanism.

RESULTS

Compared to controls, patients with PAD had enhanced sNOX2-dp and isoprostanes and reduced NOx and FMD. Multiple linear regression analysis showed that FMD was independently associated with sNOX2-dp. After PLC infusion FMD increased while sNOX2-dp and isoprostanes significantly decreased; no changes were observed after placebo. In vitro study by incubating platelets or white cells with PLC demonstrated a significant inhibition of p47(phox) translocation on cellular surface and ROS generated by NOX2 activation.

CONCLUSION

This study suggests that in PAD patients ROS generated by NOX2 contribute to reduce FMD and that the administration of an antioxidant is able to improve arterial dilatation via NOX2 inhibition.

NADPH oxidase-mediated platelet isoprostane over-production in cirrhotic patients: implication for platelet activation

BACKGROUND

In patients with cirrhosis conflicting findings, inherent to platelet function and its clinical implication, are still matters of discussion. Cirrhosis is characterized by enhanced production of isoprostanes, index of oxidative stress in vivo, that is known to stem from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2)-generating oxidative stress and elicit platelet activation.

AIM

To analyse the relationship between oxidative stress and platelet activation in cirrhosis.

METHODS

A cross-sectional study including 51 cirrhotic patients and sex- and age-matched control patients has been designed. Soluble NOX2-derived peptide (sNOX2-dp), a direct marker of NADPH oxidase activation, isoprostanes urinary excretion, platelet isoprostanes and two markers of in vivo platelet activation, i.e. soluble CD40 Ligand (sCD40L) and soluble P-selectin (sPs), were measured.

RESULTS

Compared with controls, cirrhotic patients had higher levels of sPs (P = 0.034), sCD40L (P < 0.0001), sNOX2-dp (P = 0.0016), urinary excretion of isoprostanes (P < 0.0001) and arachidonic acid-induced platelet isoprostane formation (P < 0.0001). A significant correlation between sNOX2-dp and platelet (R(s) = 0.39, P = 0.0051) and urinary (R(s) = 0.67, P < 0.0001) isoprostanes was detected; also, sNOX2-dp and isoprostanes significantly correlated with sPs and sCD40L. A stepwise regression analysis revealed that sNOX2-dp was independently related to sCD40L plasma levels.

CONCLUSIONS

This study provides evidence that in cirrhosis, platelet isoprostanes are over-produced and could be implicated in platelet activation.

Strong association between non alcoholic fatty liver disease (NAFLD) and low 25(OH) vitamin D levels in an adult population with normal serum liver enzymes

BACKGROUND

Hypovitaminosis D has been recently recognized as a worldwide epidemic. Since vitamin D exerts significant metabolic activities, comprising free fatty acids (FFA) flux regulation from the periphery to the liver, its deficiency may promote fat deposition into the hepatocytes. Aim of our study was to test the hypothesis of a direct association between hypovitaminosis D and the presence of NAFLD in subjects with various degree of insulin-resistance and related metabolic disorders.

METHODS

We studied 262 consecutive subjects referred to the Diabetes and Metabolic Diseases clinics for metabolic evaluation. NAFLD (non-alcoholic fatty liver disease) was diagnosed by upper abdomen ultrasonography, metabolic syndrome was identified according to the Third Report of National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATPIII) modified criteria. Insulin-resistance was evaluated by means of HOMA-IR. Fatty-Liver-Index, a recently identified correlate of NAFLD, was also estimated. Serum 25(OH)vitamin D was measured by colorimetric method.

RESULTS

Patients with NAFLD (n=162,61.8%) had reduced serum 25(OH) vitamin D levels compared to subjects without NAFLD (14.8±9.2 vs 20.5±9.7 ng/ml, p<0.001, OR 0.95, IC 95% 0.92-0.98). The relationship between NAFLD and reduced 25(OH)vitamin D levels was independent from age, sex, triglycerides, high density lipoproteins (HDL) and glycaemia (p<0.005) and Fatty Liver Index inversely correlated with low 25(OH) vitamin D regardless sex, age and HOMA-IR (p<0.007).

CONCLUSIONS

Low 25(OH)vitamin D levels are associated with the presence of NAFLD independently from metabolic syndrome, diabetes and insulin-resistance profile.

Obstructive sleep apnoea syndrome and the metabolic syndrome in an internal medicine setting

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) is widely accepted as a cardiovascular risk factor. Lately it has been considered in turn as both a component and one of the causes of the metabolic syndrome (MS).

METHODS

We studied 281 heavy snorers of both sexes consecutively attending a metabolic clinic. Aim was to evaluate the association of OSAS and MS in a large series of patients within an internal medicine setting. Patients underwent a clinical and biochemical work up and performed unattended polysomnography.

RESULTS

Of 226 non-diabetic snorers, 48 had primary snoring; 54 mild, 51 moderate, and 73 severe OSAS. A positive association was found between OSAS severity, central obesity indices and the mean metabolic score (p=0.016). Prevalence of hypertension increased with OSA severity (p=0.010). Polysomnographic indices were correlated with the metabolic score, insulin levels and central obesity indices. At regression analysis, male sex (t=3.92; p=0.000) and waist circumference (t=3.93; p=0.000) were independently associated with AHI (apnoea/hypopnoea index), while ODI (oxygen desaturation index) and waist circumference were the independent predictors (t=2.16; p=0.033 and t=3.74; p=0.000 respectively) of the metabolic score. Prevalence of OSA was 83% in 55 patients with diabetes and 34% had severe OSA. Almost all diabetics with OSA had MS. The metabolic score was higher in diabetic OSA as compared to non-diabetic OSAS (p=0.000).

CONCLUSIONS

Our findings show a high prevalence of OSAS among patients referred to a metabolic outpatient clinic because of suspected metabolic disorders and heavy snoring and suggest a strong bidirectional association between OSAS and MS.

[Secondary cardiovascular prevention after acute coronary syndrome in clinical practice]

Secondary prevention after acute coronary syndromes should be aimed at reducing the risk of further adverse cardiovascular events, thereby improving quality of life, and lengthening survival. Despite compelling evidence from large randomized controlled trials, secondary prevention is not fully implemented in most cases after hospitalization for acute coronary syndrome. The Lazio Region (Italy) has about 5.3 million inhabitants (9% of the entire Italian population). Every year about 11 000 patients are admitted for acute coronary syndrome in hospitals of the Lazio Region. Most of these patients receive state-of-the art acute medical and interventional care during hospitalization. However, observational data suggest that after discharge acute coronary syndrome patients are neither properly followed nor receive all evidence-based treatments. This consensus document has been developed by 11 Scientific Societies of Cardiovascular and Internal Medicine in order develop a sustainable and effective clinical approach for secondary cardiovascular prevention after acute coronary syndrome in the local scenario of the Lazio Region. An evidence-based simplified decalogue for secondary cardiovascular prevention is proposed as the cornerstone of clinical intervention, taking into account regional laws and relative shortage of resources. The following appropriate interventions should be consistently applied: smoking cessation, blood pressure control (blood pressure < 130/80 mmHg), optimal lipid management (LDL cholesterol < 80 mmHg), weight and diabetes management, promotion of physical activity and rehabilitation, correct use of antiplatelet agents, beta-blockers, renin-angiotensin-aldosterone system blockers.

Clinical trial: low plasma cholesterol and oxidative stress predict rapid virological response to standard therapy with peginterferon and ribavirin in HCV patients

BACKGROUND

Rapid virological response (RVR) is the best predictor of sustained response to standard HCV treatment.

AIM

To evaluate predictive factors of RVR.

METHODS

Sixty-five patients (mean age 52.6 +/- 13.8; 37 genotype-1, and 28 genotypes-2/3) were consecutively treated with pegIFN-alpha 2a or 2b once weekly plus daily ribavirin based on body weight for 24 or 48 weeks, according to genotype. RVR was defined as undetectable HCV-RNA at week 4.

RESULTS

Twenty-seven percent of patients achieved RVR in genotypes 1 and 60.7% in genotypes 2/3 (P < 0.01). Rapid responders had higher mean serum baseline total and LDL-cholesterol levels (P < 0.01). RVR was 20.0% in the bottom tertile of total cholesterol and 63.6% in the top tertile (P < 0.01). HCV-RNA levels at week 4 were positively correlated with baseline serum insulin (P < 0.01), HOMA-IR (P < 0.01), body mass index (P < 0.05) and number of components of metabolic syndrome (P < 0.01) and negatively correlated with cholesterol levels (P < 0.05). At multivariate analysis, age, LDL-cholesterol, HCV genotype and serum 8-iso-PGF 2 alpha, a marker of oxidative stress, were independent predictors of RVR.

CONCLUSIONS

Our prospective study supports a role of low serum total and LDL-cholesterol and of oxidative stress as positive independent predictive factors of poor RVR in HCV patients.