The interaction between current smoking and hemoglobin on the risk of advanced fibrosis in patients with biopsy-proven nonalcoholic fatty liver disease.

BACKGROUND: Higher hemoglobin levels have been associated with an increased risk for nonalcoholic fatty liver disease. Although the mechanism underlying this association is elusive, smoking has been previously related to both higher hemoglobin concentrations and an increased risk of fibrosis in nonalcoholic fatty liver disease. The present study was conducted to investigate formally the interaction among current smoking, hemoglobin levels, and risk for advanced fibrosis in patients with biopsy-proven nonalcoholic fatty liver disease. PATIENTS AND METHODS: We examined 433 Turkish patients with biopsy-proven nonalcoholic fatty liver disease. Advanced fibrosis (F ≥ 3) was identified on liver biopsy in 80 cases, whereas 84 patients were current smokers. Logistic regression models were used to evaluate the effect of current smoking on risk for advanced fibrosis, after adjusting for the effects of age, sex, BMI, diabetes, and metabolic syndrome. RESULTS: Preliminary analyses revealed the presence of substantial statistical interaction between current smoking and hemoglobin levels (P < 0.001). In separate multivariable analyses conducted in the entire cohort and in the subgroups of patients with high and low hemoglobin levels (according to median value in the study cohort: 14.4 g/l), current smoking was associated with increased risk for advanced fibrosis in patients with high hemoglobin (odds ratio: 3.32, 95% confidence interval: 1.23-7.21, P < 0.01) but neither in those with low hemoglobin (odds ratio: 0.71, 95% confidence interval: 0.28-1.81, P = 0.52) nor in the entire study cohort (odds ratio: 1.18, 95% confidence interval: 0.73-2.14, P = 0.79). CONCLUSION: Hemoglobin acts as a modifier in the association between current smoking and advanced fibrosis in nonalcoholic fatty liver disease.

Characterization of Patients with Biopsy-Proven Non-Alcoholic Fatty Liver Disease and Normal Aminotransferase Levels.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of abnormal liver function tests in hepatology practice. However, not all patients with NAFLD have increased aminotransferase levels. The aim of this study was to compare the clinical and histologic characteristics of patients with biopsyproven NAFLD showing normal versus elevated aminotransferase levels. METHODS: We retrospectively reviewed 515 patients with biopsy-proven NAFLD. Patients with ALT ≤ 40 U/L and AST ≤ 37 U/L were considered as having normal liver enzymes. A histological fibrosis score F ≥ 3 was used to define advanced fibrosis. RESULTS: Of the 515 study participants, 107 (20.8%) had normal liver enzymes. Compared with patients showing elevated liver enzymes, those with normal aminotransferase levels were older and most commonly women. Moreover, they had a higher body mass index and more frequently showed metabolic risk factors (metabolic syndrome, diabetes mellitus, hypertension, higher waist and hip circumferences). Although liver histology tended to be less severe in patients with normal liver enzymes, the prevalence of advanced fibrosis was similar in the two groups. Diabetes mellitus (odds ratio [OR] = 2.12, 95% confidence interval [CI] = 1.46-3.91, p < 0.001) and age (OR = 1.14, 95% CI = 1.07-1.24, p < 0.05) were identified as independent predictors of advanced fibrosis in patients with normal aminotransferase levels. CONCLUSIONS: NAFLD with normal aminotransferase levels is characterized by a severe metabolic profile and a prevalence of advanced fibrosis similar to that identified in cases with elevated aminotransferase levels.

Impaired Gallbladder Motility and Increased Gallbladder Wall Thickness in Patients with Nonalcoholic Fatty Liver Disease.

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Along with the increase in the incidence of NAFLD and associated obesity, an increase in gallbladder disease (GD) has been noted. This has led to the identification of a new disease entity called fatty GD. There is a gap in the literature on the dynamics of gallbladder function in patients with NAFLD. METHODS: An observational case-control study, a total of 50 patients with biopsy proven NAFLD without gallbladder stone/sludge and 38 healthy comparison subjects were enrolled. Fasting, postprandial gallbladder volumes (PGV), gallbladder ejection fraction (GEF), and fasting gallbladder wall thickness (FGWT) were measured by real-time 2-dimensional ultrasonography. RESULTS: Fasting gallbladder wall thickness, fasting gallbladder volumes and PGV were significantly higher in patients with NAFLD than control subjects (P < 0.001, P = 0.006, and P < 0.001, respectively). Gallbladder ejection fraction was significantly lower in the NAFLD group than the controls (P = 0.008). The presence of NAFLD was an independent predictor for GEF, PGV, and FGWT. Also, steatosis grade was an independent predictor for GEF, and GEF was significantly lower in the nonalcoholic steatohepatitis (NASH) subgroup than the controls. CONCLUSIONS: Gallbladder dysfunction and increase in gallbladder wall thickness exists in asymptomatic (without stone/sludge and related symptoms) patients with NAFLD and are useful in identifying fatty GD. Measurement of these variables in NAFLD patients may be useful in identifying those at higher risk for GD.

Effect of HLA-DPA1 alleles on chronic hepatitis B prognosis and treatment response.

OBJECTIVE: Chronic hepatitis B (CHB) is a major health problem. The outcome of hepatitis B virus (HBV) infection is associated with variations in HLA-DPA1 alleles. The aim of this study was to investigate possible associations of HLA-DPA1 alleles with treatment response and with hepatitis B virus e antigen (HBeAg) seroconversion. METHODS: Eight different HLA-DPA1 alleles from 246 CHB patients were genotyped by polymerase chain reaction with sequence-specific primers at high resolution to investigate the association of HLA-DPA1 alleles with treatment response, development of cirrhosis, HBeAg seroconversion, and disease reoccurrence upon HBeAg loss. RESULTS: There was no significant association between HLA-DPA1 alleles and treatment response, development of cirrhosis, or HBeAg seroconversion. However, HLA-DPA1*04:01 allele was significantly more frequently found in patients who redeveloped disease upon HBeAg seroconversion (100% vs 36.8%: p=0.037; Fisher's exact test). CONCLUSION: HLA-DPA1*04:01 allele may be a risk factor for reoccurrence of CHB after HBeAg seroconversion.

HLA DQB1 alleles are related with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease. NAFLD is a complex disease and inflammation is a crucial component in the disease pathogenesis. Recent genome wide association studies in hepatology area highlighted significant relations with human leukocyte antigen (HLA) DQ region and certain liver diseases. The previous animal models also emphasized the involvement of adaptive immune system in the liver damage pathways. To investigate possible polymorphisms in the HLA region that can contribute to the immune response affecting the NAFLD, we enrolled 93 consecutive biopsy proven NAFLD patients and a control group consisted of 101 healthy people and genotyped HLA DQB1 alleles at high resolution by sequence specific primers-polymerase chain reaction. The mean NAFLD activity score (NAS) was 5.2 ± 1.2, fibrosis score was 0.9 ± 0.9, ALT was 77 ± 47.4 U/L, AST was 49.4 ± 26.3 U/L. Among 13 HLA DQB1 alleles analyzed in this study, DQB1*06:04 was observed significantly at a more frequent rate among the NAFLD patients compared to that of healthy controls (12.9 vs. 2 % χ(2) = 8.6, P = 0.003, P c = 0.039, OR: 7.3 95 % CI 1.6-33.7). In addition, the frequency of DQB1*03:02 was significantly higher in the healthy control group than the NAFLD patients (24.8 vs. 7.5 %, χ(2) = 10.4, P = 0.001, P c = 0.013, OR: 0.2, 95 % CI 0.1-0.6). NAFLD patients were grouped according to their fibrosis score and NAS. The distribution of DQB1 alleles over stratified NAFLD patients did not reveal any statistically significant relation. Taken together, immune repertoire of individuals may have an effect on NAFLD pathogenesis and therefore, in NAFLD, adaptive immunity pathways should be investigated.

The effect of HLA-DQB1 alleles on virologic breakthroughs during chronic hepatitis B treatment with genetically low barrier drugs.

BACKGROUND: Chronic hepatitis B treatment with oral antiviral drugs is a long course. During this course, antiviral resistance is a serious issue, particularly, if genetically low barrier drugs are in use. Host immunity is accepted to have an effect on antiviral resistance development. The earliest clinical sign of drug resistance is virologic breakthrough. In this study, we aimed to investigate the relation between HLA-DQB1 alleles and virologic breakthrough events. SUBJECTS AND METHODS: The patient records at single institution hepatology clinic were reviewed. Local institution ethics committee approval was taken. The patients' demographic data, virologic parameters, treatment statues were noted. Patients who had received lamivudine or adefovir were recruited and grouped into two according to virologic breakthrough occurrence. Patients who were not compliant to the given treatment were excluded. Blood samples were taken for DNA extraction. HLA-DQB1 alleles were determined at high level by sequence-specific primers-polymerase chain reaction. The distribution of DQB1 alleles among groups was analyzed. RESULTS: One hundred ninety-eight patients were eligible for the study. Ninety-six of them had virologic breakthrough where 102 did not have. DQB1 0503 allele was more frequent in patients without breakthrough (28.4% vs. 12.4%, P=0.006). In univariate analysis, HBeAg seropositivity (P<0.001), absence of cirrhosis (P=0.007), younger age (P=0.002) and higher pretreatment logDNA (P<0.001) were related to breakthrough events. However, in multivariate analysis only logDNA (P<0.001) and DQB1*0503 (P=0.02) allele revealed statistically significant relation with breakthrough events. CONCLUSION: Host immunity may have an effect on outcome during treatment with oral antiviral drugs. A patient with better immunologic profile may suppress the viral replication better and this may cause less resistance occurrence during treatment with genetically low barrier drugs.

Concentrations of connective tissue growth factor in patients with nonalcoholic fatty liver disease: association with liver fibrosis.

AIM: In this study, we aimed to investigate the relationship between the histological fibrosis stage of nonalcoholic fatty liver disease (NAFLD) and serum connective tissue growth factor (CTGF) to determine the usefulness of this relationship in clinical practice. METHODS: Serum samples were collected from 51 patients with biopsy-proven NAFLD and 28 healthy controls, and serum levels of CTGF were assayed by ELISA. RESULTS: Levels of CTGF were significantly higher in patients with NAFLD compared with controls (P=0.001). The serum CTGF levels were significantly increased, that correlated with histological fibrosis stage, in patients with NAFLD [in patients with no fibrosis (stage 0) 308.2 ± 142.9, with mild fibrosis (stage 1-2) 519.9 ± 375.2 and with advanced fibrosis (stage 3-4) 1353.2 ± 610 ng/l, P < 0.001]. Also serum level of CTGF was found as an independent predictor of histological fibrosis stage in patients with NAFLD (ß = 0.662, t=5.6, P <0.001). The area under the ROC curve was estimated 0.931 to separate patients with severe fibrosis from patients with other fibrotic stages. CONCLUSION: Serum levels of CTGF may be a clinical utility for distinguishing NAFLD patients with and without advanced fibrosis.

Relation of epicardial adipose tissue and carotid intima-media thickness in patients with nonalcoholic fatty liver disease.

OBJECTIVE: Currently, nonalcoholic fatty liver disease (NAFLD) itself has been accepted as an atherosclerotic risk factor and related to increased cardiovascular disease risk. In this study, we aimed to investigate the relationship of epicardial fat thickness (EFT), a parameter associated with atherosclerosis in recent years, with carotid artery intima-media thickness (C-IMT), another parameter of subclinical atherosclerosis. DESIGN AND METHODS: We investigated 57 patients with biopsy-proven NAFLD and 30 age-matched and sex-matched controls. EFT was obtained by transthoracic echocardiography and C-IMT was evaluated by an ultrasonographic measurement using a linear type B-mode probe. RESULTS: EFT and C-IMT were significantly higher in NAFLD patients compared with the controls (EFT: 0.58 ± 0.18 vs. 0.36 ± 0.17 cm, P<0.001 and C-IMT: 0.64 ± 0.1 vs. 0.52 ± 0.1 mm, P<0.001, respectively). We found a statistically significant correlation between EFT and BMI, C-IMT, waist circumference, homeostasis model assessment of insulin resistance, and nonalcoholic steatohepatitis scores in both groups. Stepwise regression analysis showed that C-IMT (ß=0.36, t=2.86, P=0.006) and waist circumference (ß=0.3, t=2.44, P=0.018), in the order they entered into the model, were independent predictors of EFT in patients with NAFLD. CONCLUSION: Our findings indicate that EFT and C-IMT were significantly higher in patients with NAFLD compared with the controls and waist circumference and C-IMT are independent predictors for EFT in patients with NAFLD.

Association of serum lipoprotein-associated phospholipase A2 level with nonalcoholic fatty liver disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and is one of the most common causes of chronic liver disease, worldwide. Lipoprotein-associated phospholipase A2 (Lp-PLA2) was recently characterized as a novel inflammatory biomarker that is correlated with several components constituting the metabolic syndrome. METHODS: In this study, we determined the serum levels of Lp-PLA2 in patients with definite nonalcoholic steatohepatitis (NASH, n=25), borderline NASH (n=22), simple fatty liver (n=10), and healthy controls without evidence of liver disease (n=38). The levels of Lp-PLA2 were measured by enzyme-linked immunosorbent assay and compared in the four study groups. Moreover, concentrations of Lp-PLA2 were assessed in relation to the general characteristics of the study participants and the results of liver biopsy. RESULTS: Concentrations of Lp-PLA2 were significantly higher in patients with definite NASH (161.8±0.9 µg/L, P<0.001), borderline NASH (135.4±47.7 µg/L, P=0.001), and simple fatty liver (132.4±46.2 µg/L, P=0.042) compared with healthy controls (86.2±40.7 µg/L). Furthermore, the serum Lp-PLA2 level was strongly associated to histological steatosis scores in patients with NAFLD (ß=0.32, t=2.50, P=0.016). CONCLUSION: Although subject to future confirmation, our data suggest that Lp-PLA2 levels are elevated in NAFLD.

Plasma fibrinogen-like protein 2 levels in patients with non-alcoholic fatty liver disease.

BACKGROUND/AIMS: Fibrinogen-like protein 2 (fgl2), has recently been identified as a new member of the fibrinogen-like family of proteins. In this study we assayed plasma levels of fgl2 in patients with biopsy proven non-alcoholic fatty liver disease (NAFLD) and examined their association with clinical, biochemical and histological phenotypes. METHODOLOGY: Levels of plasma fgl2 were measured by enzyme linked immunosorbent assay and compared between the study groups. Moreover, concentrations of fgl2 were assessed in relation to the general characteristics of the study participants and the results of the liver biopsy. RESULTS: Levels of fgl2 were significantly higher in patients with definite non-alcoholic steatohepatitis (NASH) (788±190pg/mL, p<0.001) and borderline NASH (710 ± 140pg/mL, p<0.001) compared with controls (515±174pg/mL). No significant differences were found in patients with simple steatosis (649 ± 162pg/mL) as compared with controls. There were no associations between the plasma fgl2 levels with the fibrosis stage and steatosis grade. CONCLUSIONS: Although subject to future confirmation, our data suggest that fgl2 levels are elevated in the more severe forms of NAFLD.

SIRT1 as a potential therapeutic target for treatment of nonalcoholic fatty liver disease.

Sirtuins are members of the silent information regulator 2 (Sir2) family, a group of Class III histone/protein deacetylases. There are 7 different sirtuins in mammals (SIRT1-7), of which SIRT1 is the best known and most studied. SIRT1 is responsible for the regulation of protein activation by means of deacetylating a variety of proteins that play important roles in the pathophysiology of metabolic diseases. Recently, it has been shown that SIRT1 plays key roles in the regulation of lipid and glucose homeostasis, control of insulin secretion and sensitivity, antiinflammatory effects, control of oxidative stress and the improvements in endothelial function that result due to increased mitochondrial biogenesis and ß-oxidation capacity. Nonalcoholic fatty liver disease (NAFLD) is currently the most common liver disease, and it has been accepted as the hepatic component of metabolic syndrome. Recent studies have shown that SIRT expression in the liver is significantly decreased in an NAFLD model of rats fed a high-fat diet, and moderate SIRT1 overexpression protects mice from developing NAFLD. In addition to resveratrol, a natural SIRT1 activator, small-molecule pharmacologic SIRT1 activators have positive effects on metabolic diseases. These effects are particularly promising in the case of diabetes mellitus, for which phase studies are currently being performed. With this information, we hypothesized that the pharmacologic activation of SIRT1, which has been implicated in the pathogenesis of NAFLD, will be a potential therapeutic target for treating NAFLD. In this paper, we review the metabolic effects of SIRT1 and its association with the pathophysiology of NAFLD.

Orlistat accelerates gastric emptying and attenuates GIP release in healthy subjects.

Orlistat, an inhibitor of digestive lipases, is widely used for the treatment of obesity. Previous reports on the effect of orally ingested orlistat together with a meal on gastric emptying and secretion of gut peptides that modulate postprandial responses are controversial. We investigated the effect of ingested orlistat on gastric emptying and plasma responses of gut peptides in response to a solid mixed meal with a moderate energy load. In healthy subjects, gastric emptying was determined using scintigraphy and studies were performed without and with 120 mg of orlistat in pellet form in random order. Orlistat shortened t lag and t half and decreased the area under the gastric emptying curve. Orlistat significantly attenuated the secretion of glucose-dependent insulinotropic polypeptide (GIP) but did not alter the plasma responses of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), pancreatic polypeptide (PP), and insulin. There was no peptide YY (PYY) response. Area under the curve of gastric emptying was positively correlated with integrated secretion of GIP (r=0.786) in orlistat and was negatively correlated with integrated plasma response of GLP-1 (r=-0.75) in control experiments, implying that inhibition of fat absorption modifies determinants of gastric emptying of a meal. Orlistat administered similar to its use in obesity treatment accelerates gastric emptying of a solid mixed meal with a moderate energy load and profoundly attenuates release of GIP without appreciably altering plasma responses of CCK, GLP-1, and PP. Since GIP is being implemented in the development of obesity, its role in weight control attained by orlistat awaits further investigation.