Prevalence and risk factors for biopsy-proven non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in a prospective cohort of adult patients with gallstones.

BACKGROUND & AIMS: Relationship between gallstones and non-alcoholic fatty liver disease (NAFLD), and largely non-alcoholic steatohepatitis (NASH), is uncertain. AIM: To determine the prevalence, non-invasive fibrosis markers profile and risk factors for biopsy-proven NAFLD and NASH among patients with gallstones. METHODS: Anthropometric and laboratory evaluation, an abdominal ultrasound and a liver biopsy were performed to 215 consecutive patients with gallstones referred for cholecystectomy. RESULTS: Prevalence of NASH was 10.2% whereas that of simple steatosis (SS) was 41.4%. In the cohort of NAFLD patients, negative predictive values for advanced fibrosis of FIB-4 and NAFLD fibrosis score were 96 and 95% respectively. Gallstone patients with NASH had a higher mean homeostatic model assessment (HOMA) score than those with SS (P = 0.015). Noteworthy, NASH was 2.5-fold more frequent in patients with gallstones who had metabolic syndrome than in those who did not (P < 0.001). Fatty liver on ultrasound was observed in 90.9% of gallstone patients with NASH compared with 61.8% of those with SS (P = 0.044). Using multivariate logistic regression, increased HOMA score (OR, 3.47; 95% CI, 1.41-8.52; P = 0.007) and fatty liver on ultrasound (OR, 23.27; 95% CI, 4.15-130.55; P < 0.001) were the only factors independently associated with NASH. CONCLUSIONS: Prevalence of NASH among patients with gallstones is lower than estimated previously, but NASH is frequent particularly in those patients with concurrent metabolic syndrome. The combination of an increased HOMA score with fatty liver on ultrasound has a good accuracy for predicting NASH in patients with gallstones.

Increased hepatic CD36 expression with age is associated with enhanced susceptibility to nonalcoholic fatty liver disease.

CD36 has been associated with obesity and diabetes in human liver diseases, however, its role in age-associated nonalcoholic fatty liver disease (NAFLD) is unknown. Therefore, liver biopsies were collected from individuals with histologically normal livers (n=30), and from patients diagnosed with simple steatosis (NAS; n=26). Patients were divided into two groups according to age and liver biopsy samples were immunostained for CD36. NAFLD parameters were examined in young (12-week) and middle-aged (52-week) C57BL/6J mice, some fed with chow-diet and some fed with low-fat (LFD; 10% kcal fat) or high-fat diet (HFD; 60% kcal fat) for 12-weeks. CD36 expression was positively associated with age in individuals with normal livers but not in NAS patients. However, CD36 was predominantly located at the plasma membrane of hepatocytes in aged NAS patients as compared to young. In chow-fed mice, aging, despite an increase in hepatic CD36 expression, was not associated with the development of NAFLD. However, middle-aged mice did exhibit the development of HFD-induced NAFLD, mediated by an increase of CD36 on the membrane. Enhanced CD36-mediated hepatic fat uptake may contribute to an accelerated progression of NAFLD in mice and humans. Therapies to prevent the increase in CD36 expression and/or CD36 from anchoring at the membrane may prevent the development of NAFLD.

Increased soluble CD36 is linked to advanced steatosis in nonalcoholic fatty liver disease.

BACKGROUND: Soluble CD36 (sCD36) clusters with insulin resistance, but no evidence exists on its relationship with hepatic fat content. We determined sCD36 to assess its link to steatosis in nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) patients. MATERIALS AND METHODS: Two hundred and twenty-seven NAFLD, eighty-seven CHC, and eighty-five patients with histologically normal liver (NL) were studied. Steatosis was graded by Kleiner's histological scoring system. Serum sCD36 and hepatic CD36 expression was assessed by immunoassay and immunohistochemistry, respectively. RESULTS: In NAFLD, serum sCD36 levels were significantly higher in simple steatosis than in NL (361.4 ± 286.4 vs. 173.9 ± 137.4 pg/mL, respectively; P < 0.001), but not in steatohepatitis (229.6 ± 202.5 pg/mL; P = 0.153). In CHC, serum sCD36 levels were similar regardless of the absence (428.7 ± 260.3 pg/mL) or presence of steatosis (387.2 ± 283.6 pg/mL; P = 0.173). A progressive increase in serum sCD36 values was found in NAFLD depending on the histological grade of steatosis (P < 0.001), but not in CHC (P = 0.151). Serum sCD36 concentrations were independently associated with advanced steatosis in NAFLD when adjusted by demographic and anthropometric features [odds ratio (OR), 1.001; 95% confidence interval (CI), 1.000 to 1.002; P = 0.021] and by metabolic variables (OR, 1.002; 95% CI, 1.000 to 1.003; P = 0.001). Interestingly, a significant correlation was observed between hepatic CD36 and serum sCD36 (ρ = 0.499, P < 0.001). CONCLUSIONS: Increased serum sCD36 is an independent factor associated with advanced steatosis in NAFLD.

Hepatic fatty acid translocase CD36 upregulation is associated with insulin resistance, hyperinsulinaemia and increased steatosis in non-alcoholic steatohepatitis and chronic hepatitis C.

BACKGROUND: Fatty acid translocase CD36 (FAT/CD36) mediates uptake and intracellular transport of long-chain fatty acids in diverse cell types. While the pathogenic role of FAT/CD36 in hepatic steatosis in rodents is well-defined, little is known about its significance in human liver diseases. OBJECTIVE: To examine the expression of FAT/CD36 and its cellular and subcellular distribution within the liver of patients with non-alcoholic fatty liver disease (NAFLD) and chronic hepatitis C virus (HCV) infection. PATIENTS: 34 patients with non-alcoholic steatosis (NAS), 30 with non-alcoholic steatohepatitis (NASH), 66 with HCV genotype 1 (HCV G1) and 32 with non-diseased liver (NL). METHODS: Real-time PCR and western blot analysis were used to assess hepatic FAT/CD36 expression. Computational image analysis of immunostained liver biopsy sections was performed to determine subcellular distribution and FAT/CD36 expression index. RESULTS: Compared with NL, hepatic mRNA and protein levels of FAT/CD36 were significantly higher in patients with NAS (median fold increase 0.84 (range 0.15-1.61) and 0.66 (range 0.33-1.06), respectively); NASH (0.91 (0.22-1.81) and 0.81 (0.38-0.92), respectively); HCV G1 without steatosis (0.30 (0.17-1.59) and 0.33 (0.29-0.52), respectively); and HCV G1 with steatosis (0.85 (0.15-1.98) and 0.87 (0.52-1.26), respectively). In contrast to NL, FAT/CD36 was predominantly located at the plasma membrane of hepatocytes in patients with NAFLD and HCV G1 with steatosis. A significant correlation was observed between hepatic FAT/CD36 expression index and plasma insulin levels, insulin resistance (HOMA-IR) and histological grade of steatosis in patients with NASH (r=0.663, r=0.735 and r=0.711, respectively) and those with HCV G1 with steatosis (r=0.723, r=0.769 and r=0.648, respectively). CONCLUSIONS: Hepatic FAT/CD36 upregulation is significantly associated with insulin resistance, hyperinsulinaemia and increased steatosis in patients with NASH and HCV G1 with fatty liver. Translocation of this fatty acid transporter to the plasma membrane of hepatocytes may contribute to liver fat accumulation in patients with NAFLD and HCV.

Obesidad y enfermedad hepática / Obesity and liver disease

La obesidad se asocia a un mayor riesgo de tener una enfermedad hepática por depósito de grasa no relacionada con el abuso de alcohol (EHGNA) y contribuye a la progresión de hepatopatías de diferentes etiologías, como la hepatitis crónica por el virus de hepatitis C (VHC). El descubrimiento de que el tejido adiposo es un tejido sometido a un estado de inflamación crónica capaz de secretar adipoquinas ha permitido establecer un nexo de unión entre las alteraciones metabólicas que conducen al acúmulo de triglicéridos y a la inflamación hepática, y ha reforzado el papel de la lipotoxicidad hepatocelular en la patogenia de la enfermedad hepática por depósito de grasa no relacionada con el abuso de alcohol. Por otro lado, aunque el genotipo 3 del VHC induce esteatosis, actualmente se considera que la obesidad y sus alteraciones metabólicas asociadas, como la resistencia a la insulina, están implicadas en la progresión de la enfermedad hepática mediada por el VHC así como de otras hepatopatías crónicas de diversas etiologías (AU)

Obesity is associated with a higher risk of developing non-alcoholic fatty liver disease (NAFLD) and contributes to the progression of liver diseases of distinct etiologies such as chronic hepatitis C virus (HCV) infection. The discovery that adipose tissue is submitted to a state of chronic inflammation able to secrete adipokines has allowed a connection to be established between the metabolic alterations that lead to triglyceride accumulation and liver inflammation, reinforcing the role of hepatocellular lipotoxicity in the pathogenesis of NAFLD. In addition, although HCV genotype 3 induces steatosis, it is currently believed that obesity and its associated alterations, such as insulin resistance, are involved in progression of HCV-mediated liver disease, as well as that of other chronic liver diseases of diverse etiologies (AU)

[Obesity and liver disease]. / Obesidad y enfermedad hepática.

Obesity is associated with a higher risk of developing non-alcoholic fatty liver disease (NAFLD) and contributes to the progression of liver diseases of distinct etiologies such as chronic hepatitis C virus (HCV) infection. The discovery that adipose tissue is submitted to a state of chronic inflammation able to secrete adipokines has allowed a connection to be established between the metabolic alterations that lead to triglyceride accumulation and liver inflammation, reinforcing the role of hepatocellular lipotoxicity in the pathogenesis of NAFLD. In addition, although HCV genotype 3 induces steatosis, it is currently believed that obesity and its associated alterations, such as insulin resistance, are involved in progression of HCV-mediated liver disease, as well as that of other chronic liver diseases of diverse etiologies.