Zbigniew Konopski

Metformin in patients with non-alcoholic fatty liver disease: A randomized, controlled trial

Objective. The antidiabetic agent metformin is regularly discussed as a promising treatment for non-alcoholic fatty liver disease (NAFLD), which is characterized by insulin resistance. However, the evidence for its beneficial effects is limited, and conflicting reports have been published. The purpose of this study was to conduct a randomized, double-blind, placebo-controlled trial to test whether metformin improves liver histology in patients with non-alcoholic fatty liver disease. Material and methods. Forty-eight patients with biopsy-proven NAFLD were randomized to treatment with metformin (n=24) or placebo (n=24) for 6 months. A second liver biopsy was obtained in all subjects who completed the trial (n=44). Data analyses are restricted to this group (per-protocol analyses). The primary outcome was changes in histologically assessed liver steatosis. Secondary outcomes were changes in NAFLD activity (NAS)-score, liver steatosis assessed by computed tomography (CT), liver transaminases, body-weight, metabolic variables and inflammatory markers. Results. No significant differences between treatment with metformin or placebo were observed for changes in liver steatosis, assessed either histologically or by CT, NAS-score, liver transaminases or on markers of insulin resistance or inflammation. In contrast, beneficial effects of metformin were observed on changes in body-weight (p<0.001), serum levels of cholesterol (p=0.004), LDL-cholesterol (p<0.001), glucose (p=0.032) and on HbA1c (p=0.020). Conclusions. Treatment with metformin for 6 months was no better than placebo in terms of improvement in liver histology in patients with NAFLD. Nevertheless, the use of metformin could still be beneficial in this group as it is associated with a reduction in serum levels of lipids and glucose. (ClinicalTrials.gov number, NCT00303537)

Fetuin A in nonalcoholic fatty liver disease: in vivo and in vitro studies

OBJECTIVE Fetuin A has been associated with insulin resistance and the metabolic syndrome. We therefore explored the role of fetuin A in nonalcoholic fatty liver disease (NAFLD). DESIGN Cross-sectional and intervention studies. METHODS We included 111 subjects with histologically proven NAFLD of whom 44 participated in a randomized, controlled trial with metformin. One hundred and thirty-one healthy subjects and 13 subjects undergoing hepatic surgery for metastatic cancer served as controls. Main outcome variables were circulating levels of fetuin A according to the presence of NAFLD, hepatic gene expression of fetuin A and key enzymes in glucose and lipid metabolism, and the effect of metformin on fetuin A levels in vivo and in vitro (HepG2 cells). RESULTS Fetuin A levels were significantly higher in NAFLD patients compared with controls (324 ± 98 vs 225 ± 75 mg/l, P<0.001). NAFLD was a significant predictor of elevated fetuin A levels (β=174 (95% confidence interval: 110-234)) independent of body mass index, age, sex, fasting glucose, and triglycerides. Hepatic fetuin A mRNA levels correlated significantly with hepatic mRNA levels of key enzymes in lipid (sterol regulatory element-binding protein 1c, carnitine palmitoyltransferase 1) and glucose (phosphoenol pyruvate kinase 1, glucose-6-phosphatase) metabolism. Plasma fetuin A levels decreased significantly after metformin treatment compared with placebo (-40 ± 47 vs 15 ± 82 mg/l, P = 0.008). Metformin induced a dose-dependent decrease in fetuin A secretion in vitro. CONCLUSIONS Fetuin A levels were elevated in NAFLD. Hepatic expression of fetuin A correlated with key enzymes in glucose and lipid metabolism. Metformin decreased fetuin A levels in vitro.

Abnormal glucose tolerance is a predictor of steatohepatitis and fibrosis in patients with non-alcoholic fatty liver disease.

Objective. The majority of patients with non-alcoholic fatty liver disease (NAFLD) have simple steatosis. A minority, however, present with non-alcoholic steatohepatitis (NASH), a condition that can lead to advanced fibrosis and cirrhosis. The frequencies of NASH and fibrosis among patients with NAFLD and sustained elevation of liver function tests (LFT) are uncertain. Our aim was to estimate these frequencies. We characterize a population with NAFLD, with special emphasis on insulin resistance and the metabolic syndrome, and study possible predictors for different stages of the disease. Material and methods. All referred patients with sustained elevation of LFT, radiological evidence or clinical suspicion of fatty liver, and absence of other liver disease, were invited to participate in our study in the period June 2002 to December 2004. Results. Of 129 patients who met the inclusion criteria, 88 underwent liver biopsy. NAFLD was verified in 83 of them. Among these patients, 59 (71%) had the metabolic syndrome, 41 (49%) had NASH and 36 (43%) had fibrosis. Abnormal glucose tolerance (T2DM or impaired glucose tolerance) was the only independent risk factor for NASH (OR: 3.14; 95% CI: 1.20–8.23). Independent predictors for fibrosis were abnormal glucose tolerance (OR: 3.83; 95% CI: 1.29–11.40) and body mass index (OR: 1.20; 95% CI: 1.06–1.36) per kg/m2. Conclusions. Both NASH and fibrosis are frequently present among patients with NAFLD and sustained elevation of LFT. The probability of these potentially progressive stages of NAFLD increases with the presence of abnormal glucose tolerance.

Intracellular Nicotinamide Phosphoribosyltransferase Protects against Hepatocyte Apoptosis and Is Down-Regulated in Nonalcoholic Fatty Liver Disease

CONTEXT Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in Western and non-Western countries, but its pathogenesis is not fully understood. OBJECTIVE Based on the role of nicotinamide phosphoribosyltransferase (NAMPT) in fat and glucose metabolism and cell survival, we hypothesized a role for NAMPT/visfatin in the pathogenesis of NAFLD-related disease. DESIGN AND SETTING We conducted clinical studies at a referral medical center in well-characterized NAFLD patients (n = 58) and healthy controls (n = 27). In addition we performed experimental in vitro studies in hepatocytes. MAIN OUTCOME MEASURES We examined 1) the hepatic and systemic expression of NAMPT/visfatin in patients with NAFLD and control subjects, 2) the hepatic regulation of NAMPT/visfatin, and 3) the effect of NAMPT/visfatin on hepatocyte apoptosis. RESULTS Our main findings were as follows. 1) Patients with NAFLD had decreased NAMPT/visfatin expression both systemically in serum and within the hepatic tissue, with no difference between simple steatosis and nonalcoholic steatohepatitis. 2) By studying the hepatic regulation of NAMPT/visfatin in wild-type and peroxisome proliferators-activated receptor (PPAR)alpha(-/-) mice as well as in hepatocytes, we showed that PPARalpha activation and glucose may be involved in the down-regulation of hepatic NAMPT/visfatin expression in NAFLD. 4) Within the liver, NAMPT/visfatin was located to hepatocytes, and our in vitro studies showed that NAMPT/visfatin exerts antiapoptotic effects in these cells, involving enzymatic synthesis of nicotinamide adenine dinucleotide. CONCLUSION Based on these findings, we suggest a role for decreased NAMPT/visfatin levels in hepatocyte apoptosis in NAFLD-related disease.

Hepatitis C reinfection after sustained virological response

BACKGROUND & AIMS On-going risk behaviour can lead to hepatitis C virus (HCV) reinfection following successful treatment. We aimed to assess the incidence of persistent HCV reinfection in a population of people who inject drugs (PWID) who had achieved sustained virological response (SVR) seven years earlier. METHODS In 2004-2006 we conducted a multicentre treatment trial comprising HCV genotype 2 or 3 patients in Sweden, Norway and Denmark (NORTH-C). Six months of abstinence from injecting drug use (IDU) was required before treatment. All Norwegian patients who had obtained SVR (n=161) were eligible for participation in this long-term follow-up study assessing virological and behavioural characteristics. RESULTS Follow-up data were available in 138 of 161 (86%) individuals. Persistent reinfection was identified in 10 of 94 (11%) individuals with a history of IDU prior to treatment (incidence rate 1.7/100 person-years (PY); 95% CI 0.8-3.1) and in 10 of 37 (27%) individuals who had relapsed to IDU after treatment (incidence rate 4.9/100 PY; 95% CI 2.3-8.9). Although relapse to IDU perfectly predicted reinfection, no baseline factor was associated with reinfection. Relapse to IDU was associated with age <30 years (vs. ⩾40 years) at treatment (adjusted odds ratio [aOR] 7.03; 95% CI 1.78-27.8) and low education level (aOR 3.64; 95% CI 1.44-9.18). CONCLUSIONS Over time, persistent HCV reinfection was common among individuals who had relapsed to IDU after treatment. Reinfection should be systematically addressed and prevented when providing HCV care for PWID.

A Complex Role of Activin A in Non-Alcoholic Fatty Liver Disease

OBJECTIVES:Recent studies suggest that activin A, a member of the transforming growth factor (TGF) superfamily, is involved in the pathogenesis of liver disorders. We sought to explore its possible role in non-alcoholic fatty liver disease (NAFLD).METHODS:Serum levels of activin A and its natural inhibitor, follistatin, were measured in patients with NAFLD (n=70) and in control subjects (n=30). Gene expression was quantified in liver biopsies obtained from patients with NAFLD (n=13) and controls (n=6). Effects of activin A were examined in Huh7 (human hepatoma cell line) hepatocytes.RESULTS:Patients with NAFLD had significantly elevated serum levels of activin A and follistatin compared with healthy controls. In patients with non-alcoholic steatohepatitis (NASH, n=38), there were particularly high levels of activin A that were significantly related to the degree of hepatic fibrosis. Liver biopsies from NAFLD patients showed a markedly increased activin A–follistatin mRNA ratio, indicating increased hepatic activin A activity. In hepatocytes, activin A enhanced the expression of collagen and TGF-β1, promoted matrix metalloproteinase activity, induced mitochondrial β-oxidation, downregulated fatty acid (FA) synthase activity, promoted decreased weight percentage of saturated FAs, and altered the composition of polyunsaturated FAs.CONCLUSIONS:Our findings support the complex role of activin A in the pathogenesis of NAFLD, involving effects on fibrosis and lipid accumulation.

Incidence rates and causes of cirrhosis in a Norwegian population

Objective. To investigate the incidence rate and causes of cirrhosis in a Norwegian population. We also sought to assess the degree of underreporting of cirrhosis to the Norwegian Death Registry. Material and methods. All 1264 patients treated at Aker University Hospital in the period January 1999 to March 2004 who were given a diagnosis indicating cirrhosis, chronic liver disease or symptoms possibly attributable to cirrhosis were screened retrospectively. A search of the registry of histological diagnoses at Department of Pathology was also carried out. Based on the results of histological examinations and non-histological criteria, cirrhosis was confirmed in 194 patients. Calculations of the incidence rate of cirrhosis and frequencies of the various etiologies were based on 93 patients living in the catchment area of the hospital. Causes of death were retrieved from the Norwegian Death Registry. Results. The incidence rate of cirrhosis was 134 per million per year. The majority of cases were due to alcoholic liver disease (53%), followed by viral liver disease (12%), various autoimmune liver diseases (12%), hemochromatosis (4%) and non-alcoholic steatohepatitis (NASH) (3%). No etiology was established in 16%, a group with a high prevalence of diabetes mellitus, indicating that some of these cases were possibly caused by NASH. Among 105 deaths in this cohort of 194 cirrhotic patients, the diagnosis of cirrhosis was absent in the Norwegian Death Registry in 30% of cases. Conclusions. The incidence of cirrhosis in Norway is relatively low, with alcohol as the most important etiologic factor. Significant underreporting to the Norwegian Death Registry was observed.

ASAT/ALAT ratio provides prognostic information independently of Child-Pugh class, gender and age in non-alcoholic cirrhosis

Objective. The aspartate amino transferase/alanine amino transferase (ASAT/ALAT) ratio is increased in cirrhosis. Some studies indicate that the ratio may provide prognostic information as well. The purpose of this study was to further elucidate the role of the ASAT/ALAT ratio as a predictor of survival by assessing it together with classical risk factors such as age, gender and Child-Pugh (CP) class in a mixed cohort of patients with cirrhosis. Material and methods. Eighty-nine patients with alcoholic cirrhosis and 81 patients with non-alcoholic cirrhosis treated at Aker University Hospital between 1999 and 2004 were identified retrospectively. Survival data from these patients per August 2006 were retrieved from the Norwegian Death Registry. Clinical and biochemical data at time of diagnosis were assessed as predictors of survival using the Kaplan-Meier method and Cox regression models. Results. Median ASAT/ALAT ratio was significantly higher in alcoholic cirrhosis (2.42) as compared with non-alcoholic cirrhosis (1.42). In both groups, a ratio above the median was predictive of poor outcome, p=0.024 and p=0.032, respectively. Other significant predictors of death were CP class (p<0.001), clinical decompensation (p<0.001) and age (p=0.001). Cox regression analyses showed that the ASAT/ALAT ratio was a predictor of death independently of CP class, gender and age in non-alcoholic, but not in alcoholic cirrhosis. The estimated increased hazard (risk of dying) in non-alcoholic cirrhosis was 5% (CI: 1–8%) per 0.10 increase in ASAT/ALAT ratio. Conclusions. A high ASAT/ALAT ratio is associated with increased mortality in cirrhosis. In non-alcoholic patients the ratio may provide prognostic information independently of classical risk factors.

Low liver stiffness among cirrhotic patients with hepatitis B after prolonged treatment with nucleoside analogs

Abstract Objective. Case reports and short-term clinical trials have suggested that treatment for chronic hepatitis B (CHB) may lead to improvement of cirrhosis. The aim of the present study was to measure liver stiffness in patients diagnosed with advanced fibrosis or cirrhosis prior to prolonged treatment with nucleoside or nucleotide analogs (NUCs) for CHB. Materials and methods. Patients with CHB and advanced fibrosis or cirrhosis prior to treatment with NUCs for at least 1 year were offered inclusion in the study. We measured liver stiffness using transient elastography (TE) at follow-up. TE cut-off levels to Metavir classification for fibrosis stage F2, F3 and F4 were ≥7.2 kPa, ≥8.1, and ≥11.0 kPa, respectively. Results. Among 66 patients with a successful TE examination at follow-up, 53 patients (80%) had cirrhosis and 13 had (20%) advanced fibrosis (F3) prior to treatment. Median treatment duration was 50.5 months. Among patients with cirrhosis prior to treatment, 26 (49%) had liver stiffness below 11.0 kPa at follow-up, suggesting regression of cirrhosis. Among patients with advanced fibrosis (F3) prior to treatment, 10 (77%) had liver stiffness below 8.1 kPa after treatment, suggesting improvement of fibrosis. Conclusion. Transient elastography examinations demonstrate that prolonged treatment with NUCs in patients with CHB results in low liver stiffness, suggesting regression of fibrosis in a majority of patients with advanced fibrosis or cirrhosis.

Combining transient elastography with FIB4 enhances sensitivity in detecting advanced fibrosis of the liver

Abstract Objective. To evaluate the predictive value of transient elastography (TE), easy available biochemical scores and a combination of these to detect advanced liver fibrosis (i.e. fibrosis stage ≥F3) in patients with chronic liver disease of different etiologies. Material and methods. A valid TE was obtained in 418 patients with chronic liver disease of mixed etiologies during the period of 2007–2010. Reliable fibrosis staging and biochemical data for calculation of APRI, FIB4, and AST/ALT-ratio (AAR) were available in 187 cases of which 50 had clinical obvious cirrhosis. Logistic regression analyses were performed to investigate if biochemical scores were significant predictors of advanced fibrosis independent of TE. Results. In the whole group, TE correlated significantly with APRI and FIB4 but not with AAR. In patients with TE ≥7 kPa, a new formula combining TE and FIB4 improved the accuracy for detecting advanced fibrosis. Area under the receiver operating characteristic curve (AUROC) and sensitivity for the combined formula was 0.94 and 0.92, respectively, as opposed to 0.90 and 0.87 for TE alone. After exclusion of cases with clinical obvious cirrhosis, only FIB4 was a significant predictor of advanced liver fibrosis independent of TE. A combined formula gave a marginally improved AUROC in this group. Conclusions. Our findings suggest that the combination of TE and FIB4 is useful in the prediction of advanced fibrosis. The effect of this combination was marginal when only asymptomatic patients were included. Larger studies are needed to see if this effect is statistically significant and to detect possible differences according to etiology.