Non-alcoholic fatty liver disease: an overview

Sex-influenced association of nonalcoholic fatty liver disease with coronary heart disease

OBJECTIVE

This study investigated whether nonalcoholic fatty liver disease (NAFLD) predicts prevalent coronary heart disease (CHD).

METHODS

Epidemiologic studies have used various definitions for NAFLD. Here, we considered both liver fat burden measured by CT (FL) and the non-specific measure of hepatic inflammation -alanine aminotransferase (ALT). The association of FL and ALT with CHD (self report of coronary bypass, myocardial infarction, or percutaneous transluminal coronary angioplasty) was investigated in 2756 European-American participants of the Family Heart Study.

RESULTS

FL (p = 0.0084) and ALT (≥40 U/L, p = 0.014) were each individually associated with prevalent CHD. However, when accounting for traditional metabolic risk factors in a multivariate model FL had no predictive value for CHD in either men or women; whereas ALT was a significant predictor of CHD in men, and the association strengthened among non-diabetic men. In non-diabetic women, neither FL nor ALT was associated with CHD.

CONCLUSIONS

ALT (≥40 U/L) was a predictor of prevalent CHD in men but not in women, while CT measured FL was not significant in either sex. The failure to account for traditional risk factors, heterogeneity by sex, and varying definitions of NAFLD may account for some of the conflicting evidence in the literature regarding the association between NAFLD and coronary disease.

The association of alanine aminotransferase within the normal and mildly elevated range with lipoproteins and apolipoproteins: the Insulin Resistance Atherosclerosis Study

AIMS/HYPOTHESIS

Markers of liver injury, such as alanine aminotransferase (ALT), have been associated with atherogenic lipoprotein changes. We examined the extent to which this association was explained by insulin resistance, adiposity, glucose tolerance and chronic inflammation.

METHODS

In this analysis we included 824 non-diabetic participants (age 40-69 years) in the Insulin Resistance Atherosclerosis Study. No participants reported excessive alcohol intake or treatment with lipid-lowering medications. Lipoproteins and apolipoproteins were measured by conventional methods and lipoprotein heterogeneity by nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

ALT had a positive relationship with triacylglycerols, LDL-to-HDL-cholesterol ratio and apolipoprotein B (ApoB) after adjusting for demographic variables (p < 0.001 for all three relationships). ALT was also associated with the following NMR lipoproteins: positively with large VLDL (p < 0.001), intermediate-density lipoprotein (IDL) (p < 0.001) and small LDL subclass particles (p < 0.001), and VLDL particle size (p < 0.001); and negatively with large LDL subclass particles (p < 0.05) and LDL (p < 0.001) and HDL particle sizes (p < 0.01). ALT remained associated with IDL and small LDL subclass particles and ApoB after adjusting for glucose tolerance, adiposity, directly measured insulin sensitivity and C-reactive protein.

CONCLUSIONS/INTERPRETATION

ALT is associated with a wide range of atherogenic lipoprotein changes, which are partially explained by insulin resistance, adiposity, glucose tolerance and chronic inflammation. Because of the significant variability in the relationship between ALT and liver fat, further studies are needed to assess the extent of the lipoprotein changes using a direct measure of liver fat.

Donor diabetes mellitus is an independent risk factor for graft loss in HCV positive but not HCV negative liver transplant recipients

BACKGROUND AND AIMS

Graft survival in HCV (hepatitis C virus) infected recipients is worse than those transplanted for other liver diseases. We studied whether several donor cardiovascular risk factors (including advanced age, smoking, hypertension, and diabetes mellitus) contribute to worse outcomes for HCV positive and HCV negative liver transplant recipients.

METHODS

We obtained data from the United Network for Organ Sharing on all adult liver transplants performed in the United States between January 1, 1998 and December 31, 2003. In total, 27,033 transplant cases were evaluated. Independent predictors of graft survival were determined using Cox proportional hazards regression analysis after controlling for factors previously found to be associated with differences in transplant outcomes.

RESULTS

Donor diabetes was a strong independent risk factor for graft failure [hazard ratio (HR) = 1.20, p = 0.006] only in HCV positive recipients. Neither donor smoking status nor hypertension predicted graft loss in either cohort. Consistent with previous studies, advanced donor age, donation after cardiac death, height, and African American donor all predicted graft loss amongst both cohorts.

CONCLUSION

Accounting for donor diabetes in relation to recipient HCV status in the selection of liver recipients may result in improved graft survival.

The alanine aminotransferase to triglycerides ratio as a marker to identify nonalcoholic fatty liver disease

OBJECTIVE

The aim of this study was to determine whether the alanine aminotransferase to triglycerides (ALT/TGL) ratio is useful to identify nonalcoholic fatty liver disease (NAFLD) in asymptomatic overweight and obese women.

METHODS

Asymptomatic overweight and obese women aged 20-65 years were enrolled in a cross-sectional study for evaluating their ALT/TGL ratio, which was considered as a diagnostic test for identifying NAFLD. Alcohol consumption of at least 20 g/week, smoking, positive markers of viral or autoimmune hepatitis, a previous diagnosis of acute or chronic liver disease, renal failure, glomerulopathies, neoplasia, cardiovascular disease, and intake of contraceptives or hepatotoxic drugs were the exclusion criteria. The sensitivity, specificity, and predictive values were calculated. The optimal ALT/TGL ratio to identify NAFLD was determined using a receiver operating characteristic scatter plot analysis.

RESULTS

A total of 412 asymptomatic women, average age of 45.1 ± 10.5 years, were enrolled, 199 (48.3%) without NAFLD and 213 (51.7%) with NAFLD. The best cut-off point of the ALT/TGL ratio to identify NAFLD was 7.0, which showed the highest sensitivity (84.0%) and specificity (91.0%). For this cut-off point, the positive and negative predictive values were 91.8 and 84.3%, respectively. The weighted κ test showed a good agreement between the ALT/TGL ratio and the hepatic ultrasound in the identification of NAFLD (κ = 0.758).

CONCLUSION

The results of this study indicate that the ALT/TGL ratio has a high sensitivity and specificity to identify NAFLD, suggesting that it could be a useful marker to recognize NAFLD in asymptomatic overweight and obese women.

Alanine aminotransferase/aspartate aminotransferase ratio is the best surrogate marker for insulin resistance in non-obese Japanese adults

Background

The aim of the present study was to examine how liver markers are associated with insulin resistance in Japanese community-dwelling adults.

Methods

This cross-sectional study included 587 men aged 58 ± 14 (mean ± standard deviation; range, 20–89) years and 755 women aged 60 ± 12 (range, 21–88) years. The study sample consisted of 998 (74.4%) non-obese [body mass index (BMI) <25.0 kg/m²] and 344 (25.6%) overweight (BMI ≥25 kg/m²) subjects. Insulin resistance was defined by homeostasis model assessment of insulin resistance (HOMA-IR) of at least 2.5, and HOMA-IR and potential confounders were compared between the groups. Areas under the curve (AUC) of the receiver operating characteristic curves (ROC) were used to compare the power of these serum markers.

Results

In non-obese subjects, the best marker of insulin resistance was alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ratio of 0.70 (95% confidence interval (CI), 0.63-0.77). In overweight subjects, AUC values for the ALT/AST ratio and ALT were 0.66 (0.59-0.72) and 0.66 (0.59-0.72), respectively. Multiple linear regression analyses for HOMA-IR showed that ALT/AST ratios were independently and significantly associated with HOMA-IR as well as other confounding factors in both non-obese and overweight subjects. The optimal cut-off point to identifying insulin resistance for these markers yielded the following values: ALT/AST ratio of ≥0.82 in non-obese subjects and ≥1.02 in overweight subjects. In non-obese subjects, the positive likelihood ratio was greatest for ALT/AST ratio.

Conclusions

In non-obese Japanese adults, ALT/AST ratio may be the best reliable marker of insulin resistance.

Altered glucose homeostasis and hepatic function in obese mice deficient for both kinin receptor genes

The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM.

Cardiovascular disease and nonalcoholic fatty liver disease: does histologic severity matter?

GOALS

We aimed to investigate the prevalence of cardiovascular disease in patients with nonalcoholic steatohepatitis (NASH) versus non-NASH fatty liver.

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease, which is a leading cause of death in this patient population. NASH is a subset of NAFLD that carries a higher risk of progression to cirrhosis and its associated complications.

STUDY

We conducted a retrospective chart review of patients with biopsy-confirmed NAFLD, including NASH and non-NASH fatty liver, within the Gastroenterology and Hepatology clinic at Brooke Army Medical Center. Patients with secondary causes of chronic liver disease were excluded. The patients' records were reviewed for the presence of significant cardiovascular disease, which was defined as a history of stroke, unstable angina, myocardial infarction, congestive heart failure, or need for revascularization.

RESULTS

Nine hundred thirteen patients were identified and 377 patients met inclusion and exclusion criteria and were included in the final analysis. Of these, 219 patients had biopsies showing the presence of at least grade I NASH. The overall prevalence of cardiovascular disease was 6.63%. After controlling for age, sex, body mass index, and the presence of diabetes, there was no significant increase in the prevalence of cardiovascular disease in the NASH cohort over the non-NASH group.

CONCLUSIONS

Cardiovascular disease is common among patients with NAFLD. However, no increased risk of cardiovascular disease was found among those patients with NASH as compared with those with non-NASH fatty liver.

Identification of individuals with non-alcoholic fatty liver disease by the diagnostic criteria for the metabolic syndrome

AIM: To clarify the efficiency of the criterion of metabolic syndrome to detecting non-alcoholic fatty liver disease (NAFLD).

METHODS: Authors performed a cross-sectional study involving participants of a medical health checkup program including abdominal ultrasonography. This study involved 11 714 apparently healthy Japanese men and women, 18 to 83 years of age. NAFLD was defined by abdominal ultrasonography without an alcohol intake of more than 20 g/d, known liver disease, or current use of medication. The revised criteria of the National Cholesterol Education Program Adult Treatment Panel III were used to characterize the metabolic syndrome.

RESULTS: NAFLD was detected in 32.2% (95% CI: 31.0%-33.5%) of men (n = 1874 of 5811) and in 8.7% (95% CI: 8.0%-9.5%) of women (n = 514 of 5903). Among obese people, the prevalence of NAFLD was as high as 67.3% (95% CI: 64.8%-69.7%) in men and 45.8% (95% CI: 41.7%-50.0%) in women. Although NAFLD was thought of as being the liver phenotype of metabolic syndrome, the prevalence of the metabolic syndrome among subjects with NAFLD was low both in men and women. 66.8% of men and 70.4% of women with NAFLD were not diagnosed with the metabolic syndrome. 48.2% of men with NAFLD and 49.8% of women with NAFLD weren’t overweight [body mass index (BMI) ≥ 25 kg/m²]. In the same way, 68.6% of men with NAFLD and 37.9% of women with NAFLD weren’t satisfied with abdominal classification (≥ 90 cm for men and ≥ 80 cm for women). Next, authors defined it as positive at screening for NAFLD when participants satisfied at least one criterion of metabolic syndrome. The sensitivity of the definition “at least 1 criterion” was as good as 84.8% in men and 86.6% in women. Separating subjects by BMI, the sensitivity was higher in obese men and women than in non-obese men and women (92.3% vs 76.8% in men, 96.1% vs 77.0% in women, respectively).

CONCLUSION: Authors could determine NAFLD effectively in epidemiological study by modifying the usage of the criteria for metabolic syndrome.

The utility of Xenon-133 liver scan in the diagnosis and management of nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is an important and common condition affecting approximately 20% of the general population. Given the limitation of radiological investigations, diagnosis often requires a liver biopsy.

OBJECTIVE

To compare Xenon-133 (Xe-133) liver scanning with ultrasonography in the diagnosis of NAFLD.

METHODS

From January 2003 to February 2007, 258 consecutive patients with suspected NAFLD underwent Xe-133 liver scanning at Royal Victoria Hospital (Montreal, Quebec). Of these, 43 patients underwent ultrasonography and liver biopsy for the evaluation of NAFLD. Patients with other liver diseases and significant alcohol consumption were excluded. Two nuclear medicine physicians assessed liver Xe-133 uptake and measured the grade of steatosis using a standardized protocol. The degree of steatosis was determined from biopsy specimens assessed by two hepatopathologists.

RESULTS

NAFLD was identified by liver biopsy in 35 of 43 patients (81.4%). Xe-133 scan demonstrated 94.3% sensitivity (95% CI 81.4% to 98.4%) and 87.5% specificity (95% CI 52.9% to 99.4%) for the presence of NAFLD. The positive and negative predictive values for detection of steatosis by Xe-133 scan were 97.1% (95% CI 85.1% to 99.8%) and 77.8% (95% CI 45.3% to 93.7%), respectively. The positive and negative likelihood ratios were 7.54 (95% CI 1.20 to 47.26) and 0.07 (95% CI 0.02 to 0.26), respectively. Two patients with NAFLD (5.7%) who had a negative Xe-133 scan result had histologically mild steatosis (<10%). The grade of steatosis on liver biopsy was highly correlated with the results of the Xe-133 scan (r=0.87; P<0.001). The sensitivity and specificity of ultrasound in diagnosing steatosis were 62.9% and 75%, respectively.

CONCLUSION

Xe-133 liver scan proved to be a safe, reliable, noninvasive method for diagnosing and quantifying hepatic steatosis, and was superior to ultrasound.

Aging is a risk factor of nonalcoholic fatty liver disease in premenopausal women

AIM: To clarify the relationship between age, menopause, and nonalcoholic fatty liver disease (NAFLD) in women.

METHODS: We conducted a follow-up study on nonalcoholic fatty liver disease by using abdominal ultrasonography, and investigated the relationship of age and menopause with the development of NAFLD in women. We followed 1829 women and 2572 men (response rate, 86%) selected in 2001 to represent the non-institutionalized adult population of Gifu, Japan. Data collected included self-reported medical history, lifestyle factors, and menopausal status. The postmenopausal state was defined as beginning 1 year after the cessation of menses. We diagnosed NAFLD with the aid of abdominal ultrasonography by using diagnostic criteria described previously.

RESULTS: The prevalence of NAFLD in women increases with age, but does not alter with age in men. Furthermore, the prevalence of NAFLD in premenopausal women (6%) was lower than that in men (24%) and in postmenopausal women (15%). The associations of the postmenopausal state and hormone replacement therapy with NAFLD were statistically significant in a univariate logistic regression model. At the follow-up examination, 67 women (5%) were newly diagnosed with NAFLD. The incidence of NAFLD was 3.5% (28/802) in premenopausal women, 7.5% (4/53) in menopausal women, 6.1% (24/392) in postmenopausal women, and 5.3% (11/206) in women receiving hormone replacement therapy. The weight gain in premenopausal women was equal to that in postmenopausal women. Metabolic syndrome and weight gain were independent risk factors for NAFLD in pre- and postmenopausal women, but age was an independent risk factor in premenopausal women only.

CONCLUSION: Aging is a risk factor for NAFLD in premenopausal women, independent of weight gain or influence of metabolic syndrome.

Dietary restriction, caloric value and the accumulation of hepatic fat

BACKGROUND

Studies using laboratory animals under what are considered to be "standard" conditions normally offer unrestricted amounts of food to the animals, which can lead to metabolic disorders. Moreover, standard diets have different compositions.

AIM

Therefore, the aim of the present study was to assess the effects of two non-isocaloric diets (commercial Purina® and AIN-93M), which are considered standard diets, on the accumulation of fat in the liver of rats when offered ad libitum or in a restricted amount.

METHODS

Thus, 40 Wistar rats (90 days old) were separated into 4 groups according to the amount of food offered (ad libitum or dietary restriction) and the type of diet (commercial diet, 3,028.0 kcal/g or AIN-93M, 3,802.7 kcal/g): animals fed the commercial Purina® diet ad libitum (AP), animals fed restricted amounts of the commercial Purina® diet (RP), animals fed the AIN-93M diet ad libitum (AD), and animals fed restricted amounts of the AIN-93M diet (RD). Dietary restriction consisted of pair-feeding the RP and RD groups with 60% of the total food consumed by the corresponding ad libitum groups.

RESULTS

Because of its higher carbohydrate and calorie content, AIN-93M was found to accelerate weight gain, reduce glucose tolerance and peripheral insulin sensitivity, and increase the amount of fat in the liver when compared to the commercial diet. Conversely, a 40% dietary restriction assisted in weight loss without causing malnutrition, contributing to an improved glucose tolerance and higher levels of HDL cholesterol.

CONCLUSION

Therefore, differences in the amount of carbohydrates and calories provided by the diet can lead to important metabolic disorders, such as impaired tolerance and accumulation of hepatic fat, and dietary restriction improves serum and tissue lipid profiles in laboratory animals.

Nonalcoholic fatty liver disease markers are associated with insulin resistance in type 1 diabetes

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has been associated with the insulin resistance.

AIMS

To explore the relationship between markers of NAFLD, namely concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALK), γ-glutamyltransferase (GGT), ferritin and bilirubin and insulin resistance in type 1 diabetes.

METHODS

Our study included 353 patients with type 1 diabetes. Insulin sensitivity was measured with estimated glucose disposal rate calculated using the equation: eGDR = 24.31 - (12.22 × WHR) - (3.29 × HT) - (0.57 × HbA1c); WHR = waist to hip ratio, HT = hypertension. Correlations and multiple logistic regressions analysis were performed to identify the relationships between NAFLD associated markers and eGDR, individual components of insulin resistance and risk of insulin resistance.

RESULTS

AST, ALT, AST-to-ALT ratio, ALK and ferritin significantly correlated with insulin resistance measured by eGDR (r = -0.13, -0.14, 0.13, -0.18, and -0.24, respectively; all P < 0.05), and with individual components of insulin resistance, most notably WHR. In a multiple logistic regression model adjusted according to age, sex, duration of diabetes and BMI, increased levels of AST, ALT and ALK resulted in an increased risk for the development of insulin resistance in our subjects (OR = 1.03, 1.02, and 1.01, respectively; all P < 0.05).

CONCLUSIONS

These findings indicate that higher levels of ALT, AST and ALK are additional markers of insulin resistance in type 1 diabetes and suggest that those subjects must be considered as potentially affected not only by a hepatic but also by a multisystemic disease through altered insulin sensitivity.

Liver markers, prevalence of the metabolic syndrome abnormalities and effect of Roux-en-Y gastric bypass in morbidly obese subjects

OBJECTIVES

To evaluate the relations between liver markers (GGT, ALT and AST) and the metabolic syndrome (and its components) in morbidly obese subjects, and to determine the response of these metabolic factors and hepatic enzymes after weight loss induced by Roux-en-Y gastric bypass.

METHODS

This study was carried out at a university hospital, in Santo André (SP), Brazil. We evaluated 140 morbidly obese subjects aged from 18 to 60 years submitted to a Roux-en-Y gastric bypass, who were followed for a mean period of 8 months. Patients with a history of heavy drinking, type 1 diabetes, and/or liver disease were excluded.

RESULTS

Liver markers, most notably GGT, were strongly associated with metabolic abnormalities, mainly hyperglycemia. The prevalence of type 2 diabetes significantly increased with increasing levels of GGT (highest versus lowest quartile GGT: odds ratio 3.89 [95%CI: 1.07-14.17]). Liver markers significantly decreased 8 months after the Roux-en-Y gastric bypass and the reduction of GGT levels were associated with the reduction of glucose levels (Pearson r = 0.286; p = 0.001).

CONCLUSIONS

Elevated levels of liver markers, principally GGT, in morbidly obese subjects are associated with metabolic abnormalities. In addition to the well-known benefits of bariatric surgery, Roux-en-Y gastric bypass, reduced the levels of liver markers to the normal range.

Cryptogenic chronic hepatitis and its changing guise in adults

Cryptogenic chronic hepatitis is a disease that is unexplained by conventional clinical, laboratory and histological findings, and it can progress to cirrhosis, develop hepatocellular carcinoma, and require liver transplantation. The goals of this review are to describe the changing phenotype of cryptogenic chronic hepatitis in adults, develop a diagnostic algorithm appropriate to current practice, and suggest treatment options. The frequency of cryptogenic hepatitis is estimated at 5.4%. Cryptogenic cirrhosis is diagnosed in 5-30% of patients with cirrhosis, and it is present in 3-14% of adults awaiting liver transplantation. Nonalcoholic fatty liver disease has been implicated in 21-63% of patients, and autoimmune hepatitis is a likely diagnosis in 10-54% of individuals. Viral infections, hereditary liver diseases, celiac disease, and unsuspected alcohol or drug-induced liver injury are recognized infrequently in the current cryptogenic population. Manifestations of the metabolic syndrome heighten the suspicion of nonalcoholic fatty liver disease, and the absence of hepatic steatosis does not discount this possibility. The diagnostic scoring system of the International Autoimmune Hepatitis Group can support the diagnosis of autoimmune hepatitis in some patients. Certain genetic mutations may have disease-specificity, and they suggest that some patients may have an independent and uncharacterized disease. Corticosteroid therapy is effective in patients with autoimmune features, and life-style changes and specific therapies for manifestations of the metabolic syndrome are appropriate for all obese patients. The 1- and 5-year survivals after liver transplantation have ranged from 72-85% to 58-73%, respectively.

Soy protein retards the progression of non-alcoholic steatohepatitis via improvement of insulin resistance and steatosis

OBJECTIVE

Non-alcoholic steatohepatitis (NASH) is a common cause of liver disease, and it may progress to fibrosis or cirrhosis. The aim of this study was to investigate the effects of soy protein on hepatic steatosis and insulin resistance in NASH.

METHODS

Forty male Sprague-Dawley rats were fed a high-fat diet for 4 wk to induce NASH and then were allocated to one of four diets: a NASH-inducing diet, a standard diet, a NASH-inducing diet plus soy protein, and a standard diet plus soy protein.

RESULTS

After the 10-wk experimental period, the results showed that soy protein significantly lowered plasma cholesterol concentrations and body fat accumulation. Soy protein intake also decreased the hepatic lipid depots of triacylglycerols and cholesterol and decreased the concentrations of lipid peroxides. In an analysis of antioxidative status, rats fed the soy protein diet showed improved antioxidative potential due to increases in superoxide dismutase and catalase activities and a decrease in the protein expression of cytochrome P450 2E1.

CONCLUSION

Soy protein may improve the liver function in patients with NASH by lowering lipid levels in the blood and liver, increasing the antioxidative capacity, and improving insulin resistance.

Validation of the non-alcoholic fatty liver disease activity score

BACKGROUND

The non-alcoholic fatty liver disease (NAFLD) activity score (NAS) is a scoring system designed by the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network (CRN) to encompass the spectrum of NAFLD and evaluate histological changes. However, the NAS and the correlation between the NAS and a diagnosis of NASH have not been validated outside the NASH CRN.

AIM

To validate the NAS outside the NASH CRN.

METHODS

This study retrospectively examined liver biopsies from adults with NAFLD or steatohepatitis obtained from January 2003 to May 2010. Biopsy specimens were evaluated twice in a blinded manner by a single hepatopathologist, once to determine a diagnosis (steatohepatitis or steatosis/not-steatohepatitis), and a second time to determine the NAS.

RESULTS

A total of 386 liver biopsies were evaluated. Mean age of patients at time of biopsy was 49.9±10.2years. NASH was found in 51% of the patients. For NAS ≥5 as a diagnosis of steatohepatitis and NAS <5 for not-steatohepatitis, the sensitivity was 57%, specificity: 95%, negative predictive value (NPV): 68% and positive predictive value (PPV): 93%. Lowering the NAS to ≥4 as a diagnosis of steatohepatitis increased the sensitivity to 85% with a decrease in specificity to 81%; NPV: 84%, PPV: 82% and Cohen's kappa 0.658.

CONCLUSIONS

The NAFLD activity score is a valid scoring system encompassing the spectrum of NAFLD with an excellent level of agreement between the histological diagnosis and the NAFLD activity score. A NAFLD activity score ≥4 has optimal sensitivity and specificity for predicting steatohepatitis, and is the recommended value for admission into an interventional trial for NASH.

Evaluation of portal venous velocity with Doppler ultrasound in patients with nonalcoholic fatty liver disease

PURPOSE

We examined the relationship between portal venous velocity and hepatic-abdominal fat in patients with nonalcoholic fatty liver disease (NAFLD), using spectral Doppler ultrasonography (US) and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In this prospective study, 35 patients with NAFLD and 29 normal healthy adults (control group) underwent portal Doppler US. The severity of hepatic steatosis in patients with NAFLD was assessed by MRI through chemical shift imaging, using a modification of the Dixon method. Abdominal (intra-abdominal and subcutaneous) fat was measured by MRI.

RESULTS

The difference in portal venous velocity between the patients with NAFLD and the control group was significant (p < 0.0001). There was no correlation between the degree of abdominal or hepatic fat and portal venous velocity (p > 0.05). There were strong correlations between the hepatic fat fraction and subcutaneous adiposity (p < 0.0001), intraperitoneal fat accumulation (p = 0.017), and retroperitoneal fat accumulation (p < 0.0001).

CONCLUSION

Our findings suggest that patients with NAFLD have lower portal venous velocities than normal healthy subjects.

Statin-based treatment for cardiovascular risk and non-alcoholic fatty liver disease. Killing two birds with one stone?

Cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD) share common risk factors and may have a parallel course. Statin treatment alone or in combination with other drugs has a substantially beneficial effect on CVD morbidity and mortality. The question was if these regimens were harmful for the liver. Mounting data suggest that statin monotherapy or statin-based treatments are safe in patients with NAFLD and can improve liver tests and liver ultrasonographic evidence of NAFLD. Recent data suggest that statin-based therapies are beneficial to the liver and at the same time reduce CVD morbidity and mortality in patients with NAFLD more than in subjects without it. These findings suggest that with statins we are able to get two birds with one stone.

Impact of non-alcoholic fatty liver disease on microalbuminuria in patients with prediabetes and diabetes

BACKGROUND

It is unknown whether microalbuminuria is associated with non-alcoholic fatty liver disease (NAFLD) among patients with prediabetes and type 2 diabetes mellitus (DM). This study investigated the association of NAFLD with microalbuminuria among patients with prediabetes and diabetes.

METHODS

We evaluated 1361 subjects who had an abnormal oral glucose tolerance test (OGTT) on routine screening. All participants were divided into two groups, prediabetes and newly diagnosed type 2 DM, and the association of NAFLD with metabolic parameters on microalbuminuria was analysed.

RESULTS

The patients with NAFLD had higher prevalence rates of microalbuminuria (6.3% vs 19%; P = 0.001 in prediabetes, 4.5% vs 32.6%; P < 0.001 in diabetes) and also had a greater albumin-to-creatinine ratio (14.6 +/- 52.0 microg/mg Cr vs 27.7 +/- 63.9 microg/mg Cr; P = 0.051 in prediabetes, 11.4 +/- 21.4 microg/mg Cr vs 44.7 +/- 76.4 microg/mg Cr; P < 0.001 in diabetes) than those without NAFLD. The logistic regression analysis showed that NAFLD was associated with increased rates of microalbuminuria (odds ratio 3.66; 95%confidence interval (CI) 1.31-10.20, P = 0.013 in prediabetes, odds ratio 5.47;95% CI 1.01-29.61, P = 0.048 in diabetes), independently of age, sex, body mass index, waist circumference, liver enzymes, lipid profiles, HbA1c, insulin resistance as estimated by homeostasis model assessment, hypertension,smoking status and the metabolic syndrome.

CONCLUSIONS

The results of our study revealed a strong relationship between microalbuminuria and NAFLD in the patients with prediabetes and newly diagnosed diabetes. Further studies are required to confirm whether NAFLD is a predictor of the development of microalbuminuria in patients with prediabetes and diabetes.

Dyslipidaemia of obesity, metabolic syndrome and type 2 diabetes mellitus: the case for residual risk reduction after statin treatment

Dyslipidaemia is frequently present in obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). The predominant features of dyslipidaemia in these disorders include increased flux of free fatty acids (FFA), raised triglyceride (TG) and low high density lipoprotein cholesterol (HDL-C) levels, a predominance of small, dense (atherogenic) low density lipoprotein cholesterol (LDL) particles and raised apolipoprotein (apo) B values Posprandial hyperlipidaemia may also be present. Insulin resistance (IR) appears to play an important role in the pathogenesis of dyslipidaemia in obesity, MetS and T2DM. The cornerstone of treatment of this IR-related dyslipidaemia is lifestyle changes and in diabetic patients, tight glycaemic control. In addition to these measures, recent clinical trials showed benefit with statin treatment. Nevertheless, a substantial percentage of patients treated with statins still experience vascular events. This residual vascular risk needs to be addressed. This review summarizes the effects of hypolipidaemic drug combinations (including statins with cholesterol ester protein inhibitors, niacin, fibrates or fish oil, as well as fibrate-ezetimibe combination) on the residual vascular risk in patients with obesity, MetS or T2DM.

Association of the leptin to high-molecular-weight adiponectin ratio with metabolic syndrome

Recent studies have reported that leptin and adiponectin are associated with metabolic syndrome. The leptin/adiponectin ratio has been suggested as an atherosclerotic index. The objective of this study was to compare the degree of association of metabolic syndrome with adiponectin levels, leptin levels, leptin/adiponectin ratio, and leptin/high-molecular-weight (HMW) adiponectin ratio. The study population included 3272 Koreans (men: 1915, women: 1357; age, 30-84 years), who had visited the Health Examination Center. Adipokines were divided into quartiles, and metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel-III (NCEP ATP III). A logistic regression model was fitted to establish the association between adipokines and metabolic syndrome. Adipokines, such as adiponectin, HMW adiponectin, and leptin, were found to be statistically related to metabolic syndrome. Compared to the lowest quartile, the leptin/HMW adiponectin ratio in the highest quartile was associated with a 5-fold increase in the probability of prevalent metabolic syndrome, which was independent of age, smoking status, exercise, low-density lipoprotein (LDL) cholesterol, and body mass index. There was a linear increase in the leptin/HMW adiponectin ratio as the number of metabolic syndrome components increased. The leptin/HMW adiponectin ratio had the highest odds ratio in women. In addition, compared to adiponectin or leptin alone, the AUC of the leptin/adiponectin ratio and leptin/HMW adiponectin ratio was higher for metabolic syndrome. We may suggest that the leptin/HMW adiponectin ratio is not superior to other adipokine markers, but is as effective as the leptin/total adiponectin ratio.

Weight control and prevention of metabolic syndrome by green tea

Green tea (Camellia sinensis, Theaceace) is the second most popular beverage in the world and has been extensively studied for its putative disease preventive effects. Green tea is characterized by the presence of a high concentrations of polyphenolic compounds known as catechins, with (-)-epigallocatechin-3-gallate (EGCG) being the most abundant and most well-studied. Metabolic syndrome (MetS) is a complex condition that is defined by the presence of elevated waist circumference, dysglycemia, elevated blood pressure, decrease serum high-density lipoprotein-associated cholesterol, and increased serum triglycerides. Studies in both in vitro and laboratory animal models have examined the preventive effects of green tea and EGCG against the symptoms of MetS. Overall, the results of these studies have been promising and demonstrate that green tea and EGCG have preventive effects in both genetic and dietary models of obesity, insulin resistance, hypertension, and hypercholesterolemia. Various mechanisms have been proposed based on these studies and include: modulation of dietary fat absorption and metabolism, increased glucose utilization, decreased de novo lipogenesis, enhanced vascular responsiveness, and antioxidative effects. In the present review, we discuss the current state of the science with regard to laboratory studies on green tea and MetS. We attempt to critically evaluate the available data and point out areas for future research. Although there is a considerable amount of data available, questions remain in terms of the primary mechanism(s) of action, the dose-response relationships involved, and the best way to translate the results to human intervention studies.

The inhibitory effect of genistein on hepatic steatosis is linked to visceral adipocyte metabolism in mice with diet-induced non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has been deeply associated with visceral adiposity, adipose tissue inflammation and a variety of adipocytokines. We reported previously that genistein inhibited NAFLD by enhancing fatty acid catabolism. However, this molecular approach focused on hepatic metabolism. Thus, we have attempted to determine whether this anti-steatotic effect of genistein is linked to visceral adipocyte metabolism. C57BL/6J mice were fed on normal-fat (NF) diet, high-fat (HF) diet and HF diet supplemented with genistein (1, 2 and 4 g/kg diet) for 12 weeks. Mice fed on the HF diet gained body weight, exhibited increased visceral fat mass and elevated levels of serum and liver lipids, and developed NAFLD, unlike what was observed in mice fed on the NF diet. However, genistein supplementation (2 and 4 g/kg diet) normalised these alternations. In the linear regression analysis, visceral fat (R 0·77) and TNFα (R 0·62) were strongly correlated with NAFLD among other NAFLD-related parameters. Genistein supplementation suppressed the hypertrophy of adipocytes via the up-regulation of genes involved in fatty acid β-oxidation, including PPARα, 5'-AMP-activated protein kinase and very long-chain acyl CoA dehydrogenase, as well as through the down-regulation of genes associated with adipogenesis or lipogenesis, including liver X receptor-α, sterol-regulatory element-binding protein-1c, PPARγ, retinoid X receptor-α and acetyl CoA carboxylase 2. Moreover, genistein supplementation augmented an anti-steatohepatitic adiponectin TNF and reduced a steatohepatitic TNFα. Collectively, these findings show that genistein may prevent NAFLD via the regulation of visceral adipocyte metabolism and adipocytokines.

Common reference intervals for aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) in serum: results from an IFCC multicenter study

BACKGROUND

Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) measurements are important for the assessment of liver damage. The aim of this study was to define the reference intervals (RIs) for these enzymes in adults, paying attention to standardization of the methods used and careful selection of the reference population.

METHODS

AST, ALT and GGT were measured with commercial analytical systems standardized to the IFCC-recommended reference measurement systems. Three centers (two in Italy and one in China) measured their own freshly collected samples; one of these centers also measured frozen samples from the Nordic Countries RI Project and from a Turkish center. RIs were generated using non-parametric techniques from the results of 765 individuals (411 females and 354 males, 18-85 years old) selected on the basis of the results of other laboratory tests and a specific questionnaire.

RESULTS

AST results from the four regions (Milan, Beijing, Bursa and Nordic Countries) were statistically different, but these differences were too small to be clinically relevant. Likewise, differences between the upper reference limits for genders was only 1.7 U/L (0.03 μkat/L), allowing a single RI of 11-34 U/L (0.18-0.57 μkat/L) to be defined. Interregional differences were not statistically significant for ALT, but partitioning was required due to significant gender differences. RIs for ALT were 8-41 U/L (0.13-0.68 μkat/L) for females and 9-59 U/L (0.15-0.99 μkat/L) for males, respectively. The upper reference limits for GGT from the Nordic Country population were higher than those from the other three regions and results from this group were excluded from final calculations. The GGT RIs were 6-40 U/L (0.11-0.66 μkat/L) for females and 12-68 U/L (0.20- 1.13 μkat/L) for males, respectively.

CONCLUSIONS

For AST and ALT, the implementation of common RIs appears to be possible, because no differences between regions were observed. However, a common RI for GGT that is applicable worldwide appears unlikely due to differences among populations.

Association between nonalcoholic fatty liver disease and coronary artery calcification

BACKGROUND

Both nonalcoholic fatty liver disease (NAFLD) and coronary artery disease (CAD) are closely related to many metabolic disorders. Multislice computed tomography (MSCT) is a reliable noninvasive method in demonstrating coronary plaque. However, the association between coronary artery calcium (CAC) score and NAFLD remains controversial.

AIMS

The aim of this study is to evaluate the association between CAC score and NAFLD.

METHODS

This retrospective study enrolled 295 consecutive asymptomatic subjects who had both coronary angiography by MSCT and hepatobiliary imaging during self-paid physical check-ups.

RESULTS

NAFLD was found in 41% of the enrolled 295 subjects; gall bladder stones were found in 10.8%, and CAC > 100 with moderate-high risk of CAD was found in 12.9% of subjects. Male gender (odds ratios (OR), 3.087; 95% confidence intervals (CI), 1.092-8.729), increased age (OR, 1.108; 95% CI, 1.067-1.151), diabetes mellitus (DM) (OR, 2.968; 95% CI, 1.129-7.803), and NAFLD (OR, 2.462; 95% CI, 1.065-5.691) were the independent factors that increased the risk of CAC > 100 in binary logistic regression. The prevalence of NAFLD also increased with the severity of CAC score (<or=100, 38.1%; 101-400, 58.3%; >400, 64.3%; P = 0.03).

CONCLUSIONS

Besides the traditional risk factors, such as male gender, increased age, and DM, NAFLD was also associated with moderate to high risk of CAD (CAC > 100).

Role of cysteine residues in thiol modification of acyl-CoA:diacylglycerol acyltransferase 2 from yeast

Acyl-CoA:diacylglycerol acyltransferase (EC 2.3.1.20, DGAT or DAGAT), which catalyzes the final step in triacylglycerol biosynthesis, has at least two discrete family members (DGAT1 and DGAT2) with different physiological roles. Here we report a systematic study of the local functional and structural role of seven cysteine residues present in DGAT2 from Saccharomyces cerevisiae (ScDGAT2, also known as Dga1p) using chemical modification in combination with site-directed mutagenesis. We demonstrate that although DGAT2 was susceptible to various thiol-modifying reagents, none of the cysteines were directly involved in the catalytic activity. Analysis of the accessibility of the sulfhydryl groups revealed that cysteines are also not involved in formation of intramolecular disulfide linkages. Inhibition of DGAT activity with thiol-specific reagents was localized to cysteine 314, which was found to be in the proximity of a highly conserved motif of DGAT2. Our work indicates that although this cysteine does not play a role in enzymatic catalysis, it may reside in a crucial position that is near a possible active site of DGAT2 or related to proper folding of the protein.

Liver transplantation of patients with cryptogenic cirrhosis: clinical characteristics and outcome

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD), autoimmune hepatitis (AIH) and unapparent alcohol abuse may be underlying causes of cryptogenic cirrhosis, but the frequencies of these underlying factors differ between studies. Also, previous studies have shown various outcomes after orthotopic liver transplantation (OLT) for cryptogenic cirrhosis. The aims of this study were (1) to evaluate the presence of NAFLD in patients with cryptogenic cirrhosis evaluated for OLT and (2) to compare the severity of liver disease and patient survival in OLT candidates with cryptogenic cirrhosis and those with cirrhosis of another known origin.

MATERIAL AND METHODS

Four-hundred and seventy adult patients with end-stage liver cirrhosis evaluated for OLT between 1990 and 2004 were included, of whom 39 had cryptogenic cirrhosis. Clinical, histological and laboratory data that had been prospectively collected were re-evaluated.

RESULTS

Seventeen (44%) of the cryptogenic patients had NAFLD in a previous liver biopsy and/or clinical features of the metabolic syndrome. Two patients had occult alcohol over-consumption and one patient had burnt-out AIH. Cryptogenic patients had significantly higher frequencies of diabetes, ascites, and hyponatraemia and weight loss. Patient survival was similar between cryptogenic patients and cirrhotics with a known aetiology.

CONCLUSIONS

Re-evaluation of patient data discovered probable underlying aetiologies in 51% of patients with cryptogenic cirrhosis evaluated for OLT, of which NAFLD was the most common (44%). Although cryptogenic patients had a more advanced liver disease when evaluated for OLT, patient survival was similar. Recent weight loss was significantly more common in cryptogenic patients, possibly being a sign of liver decompensation and signalling a need for OLT evaluation.

High-sensitivity C-reactive protein and liver enzymes in individuals with Metabolic Syndrome in Talca, Chile

Metabolic syndrome (MS) is a core set of disorders, including abdominal obesity, dyslipidemia, hypertension and hypertriglyceridemia that together predict the development of diabetes type 2 and cardiovascular disease. This study investigated the relationship between liver enzyme levels and high-sensitivity C-reactive protein (hs-CRP) in subjects with and without MS. Alanine-aminotransferase (ALAT), aspartate-aminotransferase (ASAT), γ-glutamyl transferase (GGT) and hs-CRP were measured in 510 subjects, aged 40 to 65 years old. Patients were selected from 1007 subjects from the Research Program for Cardiovascular Disease Risk Factors in Talca, Chile. Results showed that women with MS presented higher liver enzyme levels than those who did not have MS. This was not observed in male patients for the enzymes ALAT and ASAT. However, GGT and hs-PCR levels were higher in male and female patients with MS than in those without MS. In conclusion, it is important to search for the presence of MS when diagnosing fatty liver. Moreover, the presence of liver disease in patients with MS should be further investigated.

Markers of the hepatic component of the metabolic syndrome as predictors of mortality in renal transplant recipients

Cardiovascular disease (CVD) is a leading cause of mortality in renal transplant recipients (RTRs). Metabolic syndrome (MS) is highly prevalent in RTRs. Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic component of MS. We investigated associations of NAFLD markers with MS and mortality. RTRs were investigated between 2001 and 2003. NAFLD markers, alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (AP) were measured. Bone and nonbone fractions of AP were also determined. Death was recorded until August 2007. Six hundred and two RTRs were studied (age 52+/-12 years, 55% men). At baseline 388 RTRs had MS. Prevalence of MS was positively associated with liver enzymes. During follow-up for 5.3[4.5-5.7] years, 95 recipients died (49 cardiovascular). In univariate Cox regression analyses, GGT (HR=1.43[1.21-1.69], p<0.001) and AP (HR=1.34[1.11-1.63], p=0.003) were associated with mortality, whereas ALT was not. Similar associations were found for cardiovascular mortality. Adjustment for potential confounders, including MS, diabetes and traditional risk factors did not materially change these associations. Results for nonbone AP mirrored that for total AP. ALT, GGT and AP are associated with MS. Of these three enzymes, GGT and AP are associated with mortality, independent of MS. These findings suggest that GGT and AP are independently related to mortality in RTRs.

Metabolically healthy but obese individuals: relationship with hepatic enzymes

The purpose of this study was to investigate the level of plasma hepatic enzymes in obese women displaying the metabolically healthy but obese (MHO) phenotype. We studied 104 obese, sedentary, postmenopausal women. Subjects were classified as MHO or at risk based on insulin sensitivity as assessed with the oral glucose tolerance test-derived Matsuda index. Subjects were divided into quartiles according to insulin sensitivity values. Subjects in the upper quartile were categorized as MHO, whereas subjects in the lower 3 quartiles represented at-risk subjects. Outcome measures were hepatic enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], alkaline phosphatase, and gamma-glutamyltransferase [GGT]], high-density lipoprotein cholesterol, triglycerides, triglycerides to high-density lipoprotein cholesterol ratio, apolipoprotein B, fatty liver index, body composition (dual-energy x-ray absorptiometry), and visceral adipose tissue (computed tomography). The MHO individuals had significantly lower concentrations of ALT, AST, and GGT as well as a lower fatty liver index compared with at-risk subjects (P < .05). In addition, lean body mass index and visceral adipose tissue were significantly lower in MHO individuals (P < .05). Moreover, stepwise regression analysis showed that ALT explained 17.9% of the variation in insulin sensitivity in our cohort, which accounted for the greatest source of unique variance. Results of the present study indicate that postmenopausal women displaying the MHO phenotype present favorable levels of ALT, AST, and GGT. Lower concentrations of hepatic enzymes, in particular, lower circulating ALT levels, in MHO individuals may reflect lower hepatic insulin resistance and lower liver fat content; and this could be involved, at least in part, in the protective profile of MHO individuals.

Rats fed fructose-enriched diets have characteristics of nonalcoholic hepatic steatosis

Nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease are increasing in adults and are likely to be increasing in children. Both conditions are hepatic manifestations of metabolic syndrome. Experimental animals fed fructose-enriched diets are widely recognized as good models for metabolic syndrome. However, few reports have described the hepatic pathology of these experimental animals. In this study, 5-wk-old Wistar specific pathogen-free rats, which are a normal strain, were fed experimental diets for 5 wk. We then evaluated the degree of steatohepatitis. The 5 diet groups were as follows: cornstarch (70% wt:wt) [control (C)], high-fructose (70%) (HFr), high-sucrose (70%) (HS), high-fat (15%) (HF), and high-fat (15%) high-fructose (50%) (HFHFr) diets. The macrovesicular steatosis grade, liver:body weight ratio, and hepatic triglyceride concentration were significantly higher in the HFr group than in the other 4 groups. However, the HFr group had a significantly lower ratio of epididymal white fat:body weight than the other 4 groups and had a lower final body weight than the HF and HFHFr groups. The HF group had a greater final body weight than the C, HFr, and HS groups, but no macrovesicular steatosis was observed. The HFr group had a significantly higher grade of lobular inflammation than the other 4 groups. The distribution of lobular inflammation was predominant over portal inflammation, which is consistent with human NASH. In conclusion, rats fed fructose-enriched diets are a better model for NASH than rats fed fat-enriched diets.

Expression of adiponectin and its receptor 2 during the development of nonalcoholic steatohepatitis

AIM: To investigate the expression of adiponectin and adiponectin receptor 2 (AdipoR2) in the liver during the development of nonalcoholic steatohepatitis (NASH) resulting from a methionine-choline deficient (MCD) diet.

METHODS: Rats were fed either MCD or CS diets and sacrificed at weeks 3, 5, 8 and 12, respectively, to take liver samples. Liver slices were stained to assess the effects of these diets. After total RNA was extracted from frozen liver tissue, RT-PCR was performed to determine the mRNA expression of adiponectin and AdipoR2 genes. The expression levels of adiponectin and AdipoR2 genes relative to β-actin were then determined.

RESULTS: In rats fed the CS diet, the expression of adiponectin and AdipoR2 genes showed no significant changes with the prolongation of feeding duration (all P > 0.05). In rats fed the MCD diet, the expression of adiponectin and AdipoR2 genes gradually declined at weeks 3, 5 and 8, with a very significant difference (1.004 ± 0.08 vs 1.25 ± 0.09, 0.83 ± 0.06 vs 1.26 ± 0.07, 0.68 ± 0.10 vs 1.24 ± 0.08; 1.00 ± 0.06 vs 1.24 ± 0.07, 0.84 ± 0.0.7 vs 1.22 ± 0.09, 0.75 ± 0.09 vs 1.19 ± 0.05, all P < 0.05). At week 12, liver fibrosis was observed, and the expression of both AdipoR2 and adiponectin genes significantly declined (P = 0.073).

CONCLUSION: The expression of adiponectin and AdipoR2 genes in the liver declines during the development of NASH, suggesting that they may be involved in the pathogenesis of NASH. Further study on adiponectin and AdipoR2 genes will deepen our understanding of the pathogenesis of NASH and may provide new treatments for this disease.

Non-alcoholic fatty liver disease (NAFLD), insulin resistance and lipid profile in antiepileptic drug treatment

PURPOSE

Patients undergoing long-term treatment with valproic acid (VPA) are prone to develop different features of the metabolic syndrome (MS). The aim of the present study was to evaluate the occurrence of non-alcoholic fatty liver disease (NAFLD), insulin resistance (IR) and a pro-atherogenic lipid profile in patients undergoing VPA, carbamazepine (CBZ) and lamotrigine (LTG) monotherapy compared to healthy controls.

METHODS

Abdominal ultrasound as well as measurement of serum fasting insulin and glucose, serum lipids and liver function parameters were performed in VPA (n=23), CBZ (n=22) and LTG (n=23) treated non-diabetic and non-obese epileptic patients compared to healthy controls (n=16).

RESULTS

Ultrasound measurement demonstrated characteristics of fatty liver disease in 60.9% of VPA, in 22.7% of CBZ, in 8.7% of LTG treated patients and in 12.5% of the healthy controls, with highest level of steatosis seen in VPA treated patients. In addition, patients on VPA monotherapy showed a higher body-mass index (BMI) when compared to LTG treated patients and controls (p<or=0.049). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and gamma-glutamyltransferase (gammaGT) were greatest in the CBZ group (p<or=0.043). Interestingly, serum fasting glucose, serum fasting insulin as well as the HOMA-IR did not differ significantly between groups.

CONCLUSION

In conclusion, VPA (and moderately CBZ) therapy is related to increased risk for ultrasonographic signs of fatty liver disease, emphasizing the importance of regular ultrasound measurements as well as monitoring of serum lipids and BMI during enzyme-modulating AED treatment.

Prevalence of non-alcoholic fatty liver disease in urban south Indians in relation to different grades of glucose intolerance and metabolic syndrome

AIM

To estimate prevalence of non-alcoholic fatty liver disease (NAFLD) and its association with glucose intolerance (type 2 diabetes (DM), prediabetes) and metabolic syndrome (MS) in urban south Indians.

METHODS

This study was carried out in 541 subjects (response rate 92%) of the original sample of 26,001 subjects in the Chennai Urban Rural Epidemiology Study maintaining the representativeness. Anthropometry and lipid estimations were done in all and oral glucose tolerance test in all, except self-reported diabetic subjects. NAFLD was diagnosed by ultrasonography and MS by modified Adult Treatment Panel III (ATP III) criteria. DM, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were defined using WHO consulting group criteria.

RESULTS

Overall prevalence of NAFLD was 32% (173/541 subjects) (men: 35.1%, women: 29.1%, p=0.140). Prevalence of most cardio-metabolic risk factors was significantly higher in NAFLD subjects. Prevalence of NAFLD (54.5%) was higher in subjects with DM compared to those with prediabetes (IGT or IFG) (33%), isolated IGT (32.4%), isolated IFG (27.3%) and normal glucose tolerance (NGT) (22.5%) (DM vs. prediabetes: p<0.05, DM vs. NGT: p<0.001, prediabetes vs. NGT: p<0.05). Even after adjusting for age, gender and waist circumference, NAFLD was associated with diabetes (OR: 2.9, 95% C.I.: 1.9-4.6, p<0.001) and MS (OR: 2.0, 95% C.I.: 1.3-3.1, p<0.001).

CONCLUSION

NAFLD is present in a third of urban Asian Indians and its prevalence increases with increasing severity of glucose intolerance and in MS. This is the first population-based prevalence of NAFLD from south Asia which faces the brunt of the diabetes epidemic.

Evaluation of diffuse liver steatosis by ultrasound, computed tomography, and magnetic resonance imaging: which modality is best?

PURPOSE

To compare ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) determination of diffuse liver steatosis.

MATERIALS AND METHODS

Quantification of liver steatosis on ultrasound, CT, and MRI was correlated with histopathology in 67 patients.

RESULTS

Opposed-phase MRI demonstrated the highest correlation with steatosis (0.68 and 0.69, P<.01; intraclass correlation coefficient, 0.93). Spearman's correlation (and intraclass correlation) coefficients were lowest for ultrasound [0.54, 0.33 (0.40)] and enhanced CT [0.33, 0.39 (0.97)].

CONCLUSION

Opposed-phase MRI demonstrated best overall performance for determining steatosis.

The Risk Factors for Ultrasound-diagnosed Non-alcoholic Fatty Liver Disease Among Adolescents

Introduction: Non-alcoholic fatty liver disease (NAFLD) is garnering increasing interest and acceptance as one of the most important causes of chronic liver disease. The aim of this study was to investigate the risk factors for NAFLD among selected adolescent students in Hualien City, Taiwan. Materials and Methods: A stratified random sampling scheme was carried out among 1724 adolescent students aged 12 or 13 years old in Hualien City. In total, 220 students (normal: overweight: obese = 97:48:75) agreed to join the study. They underwent physical examination, laboratory tests and ultrasonography examination of the liver. Diagnosis of NAFLD in this study was based on sonographic evidence of a fatty liver and testing negative for serum HBsAg and anti- HCV antibody. Results: Of the 220 participants, 4 were excluded because they tested positive for HBsAg or anti-HCV antibody. NAFLD was detected in 86 (39.8%) out of the 216 subjects. The rate of NAFLD in the adolescents increased progressively from 16.0% in the normal group to 50.5% in the overweight group, and 63.5% among the obese subjects. Compared to their normal counterparts, adolescents with NAFLD had a significantly higher weight, body mass index (BMI), waist circumference, levels of alanine aminotransferase (ALT), triglyceride and non- high-density-lipoprotein (non-HDL) cholesterol. However, among the participants with NAFLD, only 20 (23.3%) showed ALT abnormality but there was an increasing trend of ALT abnormality as the severity of fatty liver increased. In addition, the higher ALT, Homeostasis model assessment- insulin resistance (HOMA-IR), cholesterol, triglyceride, and non-HDL levels and lower HDL-C as the severity of fatty liver increased. In a stepwise logistic regression analysis, the most significant factor associated with the presence of NAFLD was weight category. When compared with their normal counterparts, overweight and obese adolescents had a 4.14 and 5.98 times the risk of having NAFLD, respectively. Elevated ALT was the second most important factor as adolescents with elevated ALT were more likely to have NAFLD (odds ratio = 3.32, 95% CI: 1.16 to 9.50). Non-HDL cholesterol level was the third most important factor associated with NAFLD with a 3.81-fold increase in risk incurred for every l n (1 mg/dL) increment. Conclusions: Obesity, ALT abnormality and elevated non-HDL-cholesterol are risk factors for NAFLD in adolescents. However, only 23.3% of the adolescents with NAFLD showed an abnormality for ALT. Therefore, ALT alone is not a sufficient indicator; and it is recommended that ultrasonog- raphy of the liver should be part of the routine health examination of obese adolescents. Key words: Adolescents, Non-alcoholic fatty liver disease, Obese, Risk factors

Epidemiology and natural history of non-alcoholic fatty liver disease (NAFLD)

The authors summarize and update the most recent knowledge in the field of prevalence, natural history and incidence of Non Alcoholic Fatty Liver Disease (NAFLD) and Non Alcoholic Steatohepatitis (NASH). These novel diseases, firstly recognized at the beginning of the second millennium, arose suddenly to the attention of the clinicians, because they are the hepatic expression of the "so-called" metabolic syndrome. Due to the epidemic burden of obesity, diabetes, and metabolic diseases, NAFLD and NASH will become soon probably the most common hepatic disease worldwide, and they surely will keep busy our future young hepatologists.

Comparison of alanine aminotransferase, white blood cell count, and uric acid in their association with metabolic syndrome: a study of Korean adults

The aim of this study is to investigate the respective associations of alanine aminotransferase (ALT), white blood cell (WBC) count, and uric acid with metabolic syndrome and compare the magnitude in their association with metabolic syndrome, using modified Adult Treatment Panel III (ATP III) and its components. We studies 5,020 Korean adults (20-70 years of age; 2,501 men and 2,519 women) who visited Center for Health Promotion in Pusan National University Hospital for routine health examinations. Metabolic parameters and biochemical markers including ALT, WBC count, and uric acid were obtained. Alcohol intake, smoking status, and the presence of fatty liver were also evaluated. The prevalence of metabolic syndrome was 17.3%. In the partial correlation coefficients adjusted for age, alcohol consumption, smoking status, and presence of fatty liver, ALT was correlated significantly with all components of metabolic syndrome among three markers in men and women respectively. Moreover, ALT showed the highest correlation with HOMA-IR (r=0.311, P<0.001 in men and r=0.285, P<0.001 in women) in both genders. With the increase in the number of metabolic syndrome components, the mean values of all three markers were also significantly increased. In addition, the adjusted mean values of each marker were all significantly increased in metabolic syndrome. In ALT, the adjusted mean values were significantly increased in subjects with all metabolic component disorders. When we calculated odd ratios (ORs) for metabolic syndrome prevalence of the highest quartiles in three markers using multivariate logistic regression analyses, ALT was associated most strongly with metabolic syndrome in both genders (OR 5.65 [95% CI, 3.80 to 8.40]; P<0.001 in men, OR 3.23 [95% CI, 2.15 to 4.86]; P<0.001 in women). The cut-off value for ALT using the ROC curve was 27 IU/L (area under the curve=0.717, sensitivity 62.5%, specificity 70.4%, P<0.001) in men and 18 IU/L (area under the curve=0.735, sensitivity 61.3%, specificity 72.3%, P<0.001) in women. In conclusion, ALT, WBC count, and uric acid play important role as an additional markers for metabolic syndrome. Among three markers, in overlap the multiple risk factors, ALT might have a strong association with metabolic syndrome in Korean adults.

Angiotensin receptor blockers in the treatment of NASH/NAFLD: could they be a first-class option?

Nonalcoholic fatty liver disease (NAFLD) is a condition pathogenically linked to metabolic syndrome (MS) by insulin resistance (IR), and characterized by hepatic steatosis in the absence of significant alcohol use, hepatotoxicity, and/or other known liver diseases.The principles of NAFLD therapy target IR: the key point of MS. As the renin-angiotensin system (RAS) plays a central role in IR, and subsequently in NAFLD and nonalcoholic steatohepatitis (NASH), an attempt to block the deleterious effects of RAS overexpression seems a logical target. While many potential therapies tested in NASH target only the consequences of this condition, or try to "get rid" of excessive fat, angiotensin receptor blockers (ARBs) could act as an elegant tool for adequate correction of the various imbalances that act in harmony in NASH/NAFLD. Indeed, by inhibiting RAS we can improve the intracellular insulin signaling pathway, better control adipose tissue proliferation and adipokine production, and produce more balanced local and systemic levels of various cytokines. At the same time, by controlling the local RAS in the liver we might be able to prevent at least fibrosis and also slow down the vicious cycle that links steatosis to necroinflammation. By targeting the pancreatic effects of angiotensin we should be able to preserve an adequate insulin secretion and acquire a better metabolic balance.In our opinion there are two major advantages of ARBs that make them a possible therapeutic option for treating NASH and MS: their specific antihypertensive effect, and their impact on liver fibrosis. In light of this, and based on the current evidence (including existent human studies), we can speculate that some ARBs like telmisartan, candesartan, and losartan can be beneficial in treating NASH/NAFLD and its consequences, and further larger controlled clinical trials will bring consistent data into this field.

Evaluation of vulnerable coronary plaques and non-alcoholic fatty liver disease (NAFLD) by 64-detector multislice computed tomography (MSCT)

BACKGROUND

Multislice computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also the characteristics of plaques in patients with coronary artery disease (CAD). Also, because of its potential to be a novel risk factor for cardiovascular disease, interest in non-alcoholic fatty liver disease (NAFLD) is increasing.

METHODS AND RESULTS

Participants comprised 298 consecutive patients who received MSCT to diagnose CAD. Patients with an alcohol intake exceeding 20 g/day or with a history of known liver disease were excluded from the study. Liver steatosis and 4 coronary artery findings, including remodeling lesions, lipid core plaques, calcified plaques and narrowing of lumen, were assessed. Liver steatosis was evaluated by computed tomography density of the liver and spleen. In the study, NAFLD was defined as having a liver and spleen (L:S) ratio of <1.1. The L:S ratios of patients with remodeling lesions or lipid core plaques were significantly lower than those without. NAFLD was related significantly to those findings, but there was no correlation between calcified plaques, narrowing of lumen and L:S ratios. Adjusted odds ratio of NAFLD for remodeling lesions was 2.41 (95% confidence interval (CI), 1.24-4.67; p=0.009), and those for lipid core lesions was 2.29 (95% CI, 1.15-4.56; p=0.018).

CONCLUSION

NAFLD is a novel risk factor for vulnerable plaques.

Association of liver enzymes with incident type 2 diabetes: A nested case control study in an Iranian population

BACKGROUND

To investigate the association of Aspartate aminotransferase (AST), Alanin aminotranferase (ALT) and Gamma glutamyl transferase (GGT) with incident type 2 diabetes.

METHODS

In a nested case-control study, AST, ALT, GGT as well as classic diabetes risk factors, insulin and C-reactive protein (CRP) were measured in 133 non-diabetic subjects at baseline of which 68 were cases and 65 were controls. Incident diabetes was defined by the WHO 1999 criteria. Conditional logistic regression was used to calculate the odds ratio (OR) of incident diabetes associated with different hepatic markers. We used factor analysis for clustering of classic diabetes risk factors.

RESULTS

In Univariate analysis both ALT and GGT were associated with diabetes with ORs of 3.07(1.21-7.79) and 2.91(1.29-6.53) respectively. After adjustment for CRP and insulin, ALT and GGT were still predictive of incident diabetes. When the model was further adjusted for anthropometric, blood pressure and metabolic factors, only ALT was independently associated with diabetes [OR = 3.18 (1.02-9.86)]. No difference was found between the area under the receiver operating characteristic curves of the models with and without ALT (0.820 and 0.802 respectively, P = 0.4)

CONCLUSION

ALT is associated with incident type 2 diabetes independent of classic risk factors. However, its addition to the classic risk factors does not improve the prediction of diabetes.

Adipokines and cytokines in non-alcoholic fatty liver disease

BACKGROUND

Several adipocytokines have been implicated in the pathogenesis non-alcoholic fatty liver disease (NAFLD).

AIM

To assess adipocytokines in NAFLD patients and controls.

METHODS

A total of 95 patients (26 non-alcoholic steatohepatitis (NASH), 19 simple steatosis (SS), 38 obese controls and 12 non-obese controls) were included. Fasting serum insulin, glucose, visfatin, resistin, adiponectin, tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and IL-6 were determined. Univariate and multivariate analyses were used to compare groups and determine associations.

RESULTS

Serum TNF-alpha and IL-8 were higher in NAFLD patients when compared with both obese and non-obese controls. Analysis involving all patients revealed a significant correlation between serum TNF-alpha and IL-8 (P < 6.319e-08), and between IL-6 and IL-8 (P < 5.271e-15). Homeostatic model assessment scores negatively correlated with adiponectin in NAFLD (P < 0.0032). Serum visfatin was higher in all three obese groups than in non-obese controls (P < 0.02, P < 0.002 and P < 0.008). Visfatin in NASH patients was lower than SS and obese controls. Although TNF-alpha was associated with NAFLD (P < 0.02), it was interdependent on visfatin. In comparison to SS, four factors were independently associated with NASH: age, alanine aminotransferase, IL-8 and adiponectin (P < 0.05). Multivariate analysis indicated that TNF-alpha was the only independent predictor of fibrosis in NASH (P < 0.0004).

CONCLUSION

These findings support a complex interaction between adipocytokines and the pathogenesis of NAFLD.