Oxidative stress:New insights on the association of nonalcoholic fatty liver disease and atherosclerosis

Non-alcoholic fatty liver disease(NAFLD) represents the most common and emerging chronic liver disease worldwide. It includes a wide spectrum of liver diseasesranging from simple fatty liver to non-alcoholic steatohepatitis(NASH),which may progress to fibrosis and more severe liver complications such as cirrhosis,hepatocellular carcinoma and liver mortality. NAFLD is strongly associated with obesity,insulin resistance,hypertension,and dyslipidaemia,and is now regarded as the liver manifestation of the metabolic syndrome. The increased mortality of patients with NAFLD is primarily a result of cardiovascular disease and,to a lesser extent,to liver related diseases. Increased oxidative stress has been reported in both patients with NAFLD and patient with cardiovascular risk factors. Thus,oxidative stress represents a shared pathophysiological disorder between the two conditions. Several therapeutic strategies targeting oxidative stress reduction in patients with NAFLD have been proposed,with conflicting results. In particular,vitamin E supplementation has been suggested for the treatment of non-diabetic,non-cirrhotic adults with active NASH,although this recommendation is based only on the results of a single randomized controlled trial. Other antioxidant treatments suggested are resveratrol,silybin,L-carnitine and pentoxiphylline. No trial so far,has evaluated the cardiovascular effects of antioxidant treatment in patients with NAFLD. New,large-scale studies including as end-point also the assessment of the atherosclerosis markers are needed.

Modern approach to the clinical management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common and emerging form of chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to steatohepatitis, which may progress to cirrhosis, liver cancer, and liver mortality. Common metabolic diseases, which are well established cardiovascular risk factors, have been associated to NAFLD and cardiovascular disease is the single most important cause of morbidity and mortality in this patient population. The pathogenesis of NAFLD appears multifactorial and many mechanisms have been proposed as possible causes of fatty liver infiltration. Management of fatty liver has become a major challenge to healthcare systems as the consequence of the increasing rates of obesity worldwide. First-line management focuses on lifestyle modifications. Moderate weight reduction either by dietary restriction or by increased habitual physical activity is safe and highly recommended. Several therapeutic interventions have been proposed. These include insulin sensitizer agents, lipid lowering drugs, antioxidants such as vitamin E and supplementation of vitamin D3. However, therapeutic strategies have been largely empirical so far, and experimental trials have mostly been carried out in uncontrolled settings with small sample sizes. Metabolic conditions such as diabetes mellitus, obesity, hypertension and hyperlipidemia, should be strongly considered and a multidisciplinary approach should be personalized for individual patients. Treatment of co-morbidities should be regarded as of paramount importance in the management of these patients. The purpose of this review is to examine different approaches for the clinical management of non-alcoholic fatty liver disease.

Reduced lysosomal acid lipase activity: A new marker of liver disease severity across the clinical continuum of non-alcoholic fatty liver disease?

Lysosomal acid lipase(LAL)plays a key role in intracellular lipid metabolism.Reduced LAL activity promotes increased multi-organ lysosomal cholesterol ester storage,as observed in two recessive autosomal genetic diseases,Wolman disease and Cholesterol ester storage disease.Severe liver steatosis and accelerated liver fibrosis are common features in patients with genetic LAL deficiency.By contrast,few reliable data are available on the modulation of LAL activity in vivo and on the epigenetic and metabolic factors capable of regulating its activity in subjects without homozygous mutations of the Lipase A gene.In the last few years,a less severe and non-genetic reduction of LAL activity was reported in children and adults with non-alcoholic fatty liver disease(NAFLD),suggesting a possible role of LAL reduction in the pathogenesis and progression of the disease.Patients with NAFLD show a significant,progressive reduction of LAL activity from simple steatosis to non-alcoholic steatohepatitis and cryptogenic cirrhosis.Among cirrhosis of different etiologies,those with cryptogenic cirrhosis show the most significant reductions of LAL activity.These findings suggest that the modulation of LAL activity may become a possible new therapeutic target for patients with more advanced forms of NAFLD.Moreover,the measurement of LAL activity may represent a possible new marker of disease severity in this clinical setting.

Commentary on“Effect of green-Mediterranean diet on intrahepatic fat:the DIRECT PLUS randomised controlled trial”

Non-alcoholic fatty liver disease(NAFLD)represents the most prevalent liver disease worldwide with a high spread in Western countries.This high spread is due to the typical Western lifestyles.In fact,western diet,characterized by the high intake of red meat,processed meat,high-fat dairy products and high-sugar drinks and sedentary lifestyles are the principal factors promoting the growing prevalence of obesity and NAFLD together(1).