Non-alcoholic fatty liver disease and insulin resistance: importance of risk factors and histological spectrum

Decrease in fasting insulin secretory function correlates with significant liver fibrosis in Japanese non-alcoholic fatty liver disease patients

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) is typically associated with metabolic syndrome and diabetes, and insulin resistance is involved in its pathogenesis. However, the relationship between insulin secretion and NAFLD is unclear. We aimed to characterize the relationship between fasting insulin secretory function (ISF), evaluated using the homeostatic model assessment‐beta cell function (HOMA‐β) and the severity of fibrosis during NAFLD.

Methods

A‐β was calculated in 188 patients with biopsy‐confirmed NAFLD, and the correlations between Log HOMA‐β and clinical parameters, including hepatic fibrosis, were calculated.

Results

Log HOMA‐β was significantly lower in NAFLD patients with significant fibrosis (stages 2–4) than in those in the early stages (stages 0–1) (median [interquartile range]) (2.1 [1.9–2.4] vs 2.0 [1.8–2.2], P = 0.04). The prevalence of significant fibrosis decreased with increasing Log HOMA‐β: it was 59.2% in participants with low ISF (Log HOMA‐β < 1.85), 43.6% in those with intermediate ISF (1.85 ≤ Log HOMA‐β < 2.25), and 68.0% in those with high ISF (Log HOMA‐β ≥ 2.25). Patients with lower Log HOMA‐β had lower current body mass index (BMI), BMI at 20 years of age, and peak lifetime BMI than patients with intermediate or high Log HOMA‐β.

Conclusions

Fasting ISF decreased alongside the development of liver fibrosis in NAFLD, suggesting that an impaired β cell function has a characteristic finding of significant liver fibrosis in relatively nonobese Japanese patients.

Erchen Decoction and Linguizhugan Decoction Ameliorate Hepatic Insulin Resistance by Inhibiting IRS-1Ser307 Phosphorylation In Vivo and In Vitro

Erchen decoction (ECD) and Linguizhugan decoction (LGZGD), both are Chinese herbal formula, have been used clinically for the treatment of nonalcoholic fatty liver disease (NAFLD). However, their therapeutic mechanisms are still unclear. Because insulin resistance (IR) is a key etiological factor in the pathology of high-fat diet- (HFD-) induced NAFLD, in this study, the protective effects of ECD and LGZGD on HFD-induced insulin resistance in rats were evaluated and their mechanisms were investigated by OGTT and Western blot. The results showed that treatment with ECD and LGZGD significantly improved insulin resistance and liver damage in rats, evidenced by supported serum aminotransferase levels and the histopathological examination. ECD and LGZGD also showed significant protective effects against HFD-induced hyperlipidemia and the inhibition of the hepatocyte proliferation by palmitate. Furthermore, supplementation of ECD and LGZGD decreased TNF-α, NF-κB, and IRS-1Ser307 phosphorylation expressions in vivo and in vitro. These results indicated that ECD and LGZGD have protective effects against HFD-induced liver IR and their underlying mechanisms involve the TNF-α and insulin pathway. These findings would be beneficial for understanding of the therapeutic effects of ECD and LGZGD in treatment of NAFLD.

Nonalcoholic fatty liver disease in patients with coronary disease from a Brazil northeast area

Background Nonalcoholic fatty liver disease (NAFLD) is the most frequent chronic liver injury around the world. It is associated with metabolic syndrome and cardiovascular diseases. Objective To evaluate the frequency and relevance of NAFLD in patients with coronary artery disease (CAD). Methods Patients from a Brazil Northeast area, who underwent elective coronary angiography (CAG) from 2009 to 2010 were included. All of them had suspicion of CAD. Criteria to CAD: presence of obstructive lesions in the epicardial coronary arteries, or in their major branches. NAFLD criteria: presence of hepatic steatosis on ultrasound; exclusion of other liver diseases; ethanol intake ≤ 20g/day. Statistics analysis included Independent t-test, Mann-Whitney and Pearson's chi-squared test. Multivariate regression analysis measured the relationship between the risk factors and the concomitant presence of CAD and NAFLD. Results A total of 244 patients were evaluated: 63.5% had CAD and 42.2% had NAFLD. NAFLD was observed in 43.9% of the CAD patients. The regression analysis showed that the relationship between CAD and NAFLD was positively correlated with HOMA-IR ≥3.0 or insulin resistance and overweight/obesity. Conclusion NAFLD was frequent among CAD patients; insulin resistance and overweight/obesity were the most relevant risk factors related to the association NAFLD and CAD. The results suggest that patients with CAD should be evaluated for NAFLD.

Fatty liver in adults receiving antiepileptic medications: relationship to the metabolic risks

This study aimed to determine the frequency of fatty liver disease (FLD) induced by antiepileptic drugs (AEDs) and its relationship to the metabolic profile. This study included 130 patients (valproate or VPA = 75; carbamazepine or CBZ = 40; lamotrigine or LTG = 15). Liver ultrasonography (US) was done. Serum lipids, uric acid, free fatty acids (FFAs), glucose, insulin and leptin were measured. Compared to controls and patients on CBZ or LTG, higher BMI; TC, TG, LDL-c, uric acid, FFAs, glucose, insulin and leptin concentrations and enlarged liver lobes volume and span and insulin resistance (45%) were reported with VPA. With FLD, significant correlations were reported between BMI with leptin (r = 0.390;p < 0.01), insulin (r = 0.655;p < 0.001) and FFAs (r = 0.570;p < 0.001) and insulin with leptin (r = 0.355;p < 0.01). In multivariate analysis, with FLD, liver span was correlated with BMI (OR:4.50;95%CI:1.54-13.3,p = 0.01) and leptin concentrations (OR:2.55;95%CI:1.04-6.27,p = 0.045). We conclude that VPA therapy is a risk for FLD and is correlated with the associated adverse metabolic profile.

Non-Alcoholic Steatohepatitis (NASH): Risk Factors in Morbidly Obese Patients

The aim was to investigate the prevalence of non-alcoholic steatohepatitis (NASH) and risk factors for hepatic fibrosis in morbidly obese patients submitted to bariatric surgery. This retrospective study recruited all patients submitted to bariatric surgery from January 2007 to December 2012 at a reference attendance center of Southern Brazil. Clinical and biochemical data were studied as a function of the histological findings of liver biopsies done during the surgery. Steatosis was present in 226 (90.4%) and NASH in 176 (70.4%) cases. The diagnosis of cirrhosis was established in four cases (1.6%) and fibrosis in 108 (43.2%). Risk factors associated with NASH at multivariate analysis were alanine aminotransferase (ALT) >1.5 times the upper limit of normal (ULN); glucose ≥ 126 mg/dL and triglycerides ≥ 150 mg/dL. All patients with ALT ≥1.5 times the ULN had NASH. When the presence of fibrosis was analyzed, ALT > 1.5 times the ULN and triglycerides ≥ 150 mg/dL were risk factors, furthermore, there was an increase of 1% in the prevalence of fibrosis for each year of age increase. Not only steatosis, but NASH is a frequent finding in MO patients. In the present study, ALT ≥ 1.5 times the ULN identifies all patients with NASH, this finding needs to be further validated in other studies. Moreover, the presence of fibrosis was associated with ALT, triglycerides and age, identifying a subset of patients with more severe disease.

Recreational Anabolic-Androgenic Steroid Use Associated With Liver Injuries Among Brazilian Young Men

BACKGROUND

The recreational use of anabolic-androgenic steroids (AAS) has reached alarming levels among healthy people. However, several complications have been related to consumption of these drugs, including liver disorders.

OBJECTIVE

To evaluate the prevalence of liver injuries in young Brazilian recreational AAS users.

METHODS

Between February/2007 and May/2012 asymptomatic bodybuilders who were ≥18 years old and reported AAS use for ≥6 months were enrolled. All had clinical evaluations, abdominal ultrasound (AUS), and blood tests.

RESULTS

182 individuals were included in the study. The median age (interquartile range) was 26.0 years (22.0-30.0) and all were male. Elevated liver enzyme levels were observed in 38.5% (n = 70) of AAS users, and creatine phosphokinase was normal in 27.1% (n = 19) of them. Hepatic steatosis was observed by AUS in 12.1% of the sample. One individual had focal nodular hyperplasia and another had hepatocellular adenoma. One case each of hepatitis B and C virus infection was found. A diagnosis of toxic liver injury was suggested in 23 (12.6%) AAS users without a history of alcohol or other medications/drugs consumption, or evidence of other liver diseases.

CONCLUSIONS/IMPORTANCE

Young Brazilian recreational AAS users presented a wide spectrum of liver injuries that included hepatotoxicity, fatty liver, and liver neoplasm. They also presented risk factors for liver diseases such as alcohol consumption and hepatitis B and C virus infection. The results suggest that the risk of AAS use for the liver may be greater than the esthetic benefits, and demonstrate the importance of screening AAS users for liver injuries.

Methylenetetrahydrofolate reductase gene polymorphism and serum homocysteine levels in nonalcoholic fatty liver disease

BACKGROUND/AIMS

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder characterized by hepatic fat accumulation in the absence of alcohol consumption. Hyperhomocysteinemia is considered an independent risk factor for liver diseases, and the genetic polymorphisms C677T and A1298C in the MTHFR gene have been linked to hyperhomocysteinemia. The purpose of this study was to investigate serum homocysteine (Hcy) concentrations and the MTHFR C677T and A1298C polymorphisms as risk factors for the development of NAFLD.

METHODS

One hundred and thirty-four Brazilian patients with biopsy-proven NAFLD and 134 healthy controls were recruited. The MTHFR C677T and A1298C polymorphisms were detected through polymerase chain reaction restriction fragment length polymorphism. Serum Hcy levels were determined by chemiluminescence.

RESULTS

Serum Hcy levels were higher in NAFLD patients as compared to control subjects, but there were no differences between patients with steatosis and nonalcoholic steatohepatitis. The NAFLD and control groups did not differ in genotypic and allelic frequencies of the MTHFR C677T and A1298C polymorphisms, either. Elevated plasma Hcy levels were positively correlated with age in the NAFLD subjects.

CONCLUSION

The MTHFR C677T and A1298C polymorphisms are not genetic risk factors for the development of NAFLD. Higher Hcy levels exist in NAFLD subjects, but they are not associated with liver disease severity.

Peroxisome proliferator-activated receptors alpha and gamma2 polymorphisms in nonalcoholic fatty liver disease: a study in Brazilian patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) refers to the accumulation of hepatic steatosis in the absence of excess alcohol consumption. The pathogenesis of fatty liver disease and steatohepatitis (NASH) is not fully elucidated, but the common association with visceral obesity, hyperlipidemia, hypertension and type 2 diabetes mellitus (T2DM) suggests that it is the hepatic manifestation of metabolic syndrome. Peroxisome proliferator-activated receptor PPARα and PPARγ are members of a family of nuclear receptors involved in the metabolism of lipids and carbohydrates, adipogenesis and sensitivity to insulin. The objective of this study was to analyze the polymorphisms Leu162Val of PPARα and Pro12Ala of PPARγ as genetic risk factors for the development and progression of NAFLD.

METHODS

One hundred and three NAFLD patients (89 NASH, 14 pure steatosis) and 103 healthy volunteers were included. Single nucleotide polymorphisms (SNPs) Leu162Val and Pro12Ala were analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).

RESULTS

NASH patients presented higher BMI, AST and prevalence of T2DM than patients with pure steatosis. A higher prevalence of 12Ala allele was observed in the NASH Subgroup when compared to Control Group. When we grouped NASH and Steatosis Subgroups (NAFLD), we found lower serum glucose and more advanced fibrosis in the Leu162Val SNP. On the other hand, there was no statistical difference in clinical, laboratorial and histological parameters according to the Pro12Ala SNP.

CONCLUSIONS

We documented a lower prevalence of 12Ala allele of gene PPARγ in the NASH Subgroup when compared to Control Group. In NAFLD patients, there were no associations among the occurrence of Pro12Ala SNP with clinical, laboratorial and histological parameters. We also documented more advanced fibrosis in the Leu162Val SNP. The obtained data suggest that Pro12Ala SNP may result in protection against liver injury and that Leu162Val SNP may be involved in the progression of NAFLD.

Sonographic hepatorenal ratio: a noninvasive method to diagnose nonalcoholic steatosis

PURPOSE

To evaluate the accuracy of the sonographic hepatorenal ratio (HRR) in the diagnosis and grading of nonalcoholic steatosis, using biopsy as the reference.

METHODS

Ultrasound (US) and liver biopsy were performed in 42 patients with nonalcoholic fatty liver disease. Forty healthy volunteers without steatosis at US and without risk factors for nonalcoholic fatty liver disease were also studied. The HRR was obtained by dividing the mean brightness level of region-of-interest pixels in hepatic parenchyma by that in renal parenchyma. Needle biopsy samples (hematoxylin-eosin stained) were classified as mild (5-33% fatty infiltration), moderate (>33-66%), or severe (>66%) steatosis. Spearman coefficient was used to evaluate the correlation between HRR and steatosis grade, analysis of variance for differences between subgroups, and receiver operating characteristic curve analysis for sensitivity and specificity.

RESULTS

Significant correlation was found between HRR and histologic steatosis (r = 0.80, p < 0.01). The HRR cutoff for predicting steatosis was ≥1.24 (sensitivity, 92.7%; specificity, 92.5%). The mean ± SD HRRs in controls and steatosis subgroups were control 1.09 ± 0.13, mild 1.46 ± 0.24, moderate 1.52 ± 0.27, severe 2.04 ± 0.3 and were significantly different from each other except between mild and moderate steatosis subgroups.

CONCLUSIONS

The HRR is a noninvasive, objective, and simple method that could be used to diagnose and grade hepatic steatosis.

Hepatic and biochemical repercussions of a polyunsaturated fat-rich hypercaloric and hyperlipidic diet in Wistar rats

CONTEXT

Non-alcoholic fatty liver disease is characterized by lipid deposits in the hepatocytes and has been associated with obesity, dyslipidemia and type-2 diabetes. It is considered a hepatic manifestation of the metabolic syndrome, of which the main component is insulin resistance leading to hyperinsulinemia and increased production of inflammatory cytokines. Saturated fat promotes hypertriglyceridemia and hyperinsulinemia, reduces levels of high-density cholesterol and increases levels of low-density cholesterol, while polyunsaturated fat is associated with hypolipidemic, antiinflammatory and imunoregulating action.

OBJECTIVE

To evaluate the hepatic and biochemical repercussions of a polyunsaturated fat-rich diet in Wistar rats.

METHODS

Twenty-two rats were distributed equally in two groups: GI - standard diet (Biobase Bio-tec Ratos e Camundongos®) providing 3.000 kcal/kg and GII - hypercaloric and hyperlipidic diet providing 4.250 kcal/kg (ω-6:ω-3 = 3:1). The animals were euthanized after 23 weeks of experiment. The weight, biochemical parameters and hepatohistological changes were registered.

RESULTS

Findings were submitted to variance analysis with the level of statistical significance at 5%. The average weight did not differ significantly between the groups at baseline (P = 0.711), but was greater in Group II by the end of the experiment (P = 0.000). The levels of triglycerides (P = 0.039), total cholesterol (P = 0.015) and HDL (P = 0.005) were higher in Group I than in Group II. Macrovesicular steatosis was significantly more common in Group II than in Group I (P = 0.03).

CONCLUSION

Hypercaloric and hyperlipidic diet rich in polyunsaturated fat promotes weight gain and favors the development of hepatic steatosis while reducing serum levels of triglycerides, total cholesterol and HDL.

Noninvasive predictors for liver fibrosis in patients with nonalcoholic steatohepatitis

AIM

To evaluate certain anthropometric, clinical and laboratory features indicating liver fibrosis in nonalcoholic steatohepatitis and to establish the noninvasive markers for liver fibrosis.

METHODS

Eighty-one patients (40 male, 41 female) who were diagnosed with fatty liver by ultrasonographic examination and fulfilled the inclusion criteria participated in the study. Anamnesis, anthropometric, clinical and laboratory features of all cases were recorded and then liver biopsy was performed after obtaining patient consent. Steatosis, necroinflammation and liver fibrosis were examined according to age ≥ 45, gender, body mass index, central obesity, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) > 1, γ-glutamyltransferase (GGT)/ALT > 1, platelet count, insulin, c-peptide levels and the presence of hypertension, diabetes, hypertriglyceridemia and insulin resistance.

RESULTS

Eighty-one patients with non-alcoholic steatohepatitis (NASH) enrolled in the study. 69 of 81 patients were diagnosed with NASH, 11 were diagnosed with simple fatty liver and 1 was diagnosed with cirrhosis. AST/ALT > 1, GGT/ALT > 11, high serum ferritin and fasting insulin levels, the presence of diabetes, hypertension, hypertriglyceridemia and insulin resistance seemed to enhance the severity of steatosis, necroinflammation and fibrosis but these results were not statistically significant.

CONCLUSION

Liver steatosis and fibrosis can occur in individuals with normal weight. There was no significant concordance between severity of liver histology and the presence of predictors for liver fibrosis including metabolic risk factors.

Dopplerfluxometria da veia hepática em pacientes com esteatose não alcoólica

OBJETIVO: Avaliar a correlação entre a dopplerfluxometria da veia hepática direita e o grau de esteatose, inflamação e fibrose à biópsia na doença hepática gordurosa não alcoólica. MATERIAIS E MÉTODOS: Foi realizada ultrassonografia com Doppler em 80 pacientes, sendo 40 portadores de doença hepática gordurosa não alcoólica, também submetidos à biópsia. Quarenta controles normais saudáveis, sem fatores risco para doença hepática gordurosa não alcoólica foram submetidos a ultrassonografia com Doppler. O padrão ao Doppler da veia hepática direita foi classificado em trifásico, bifásico e monofásico. Os espécimes de biópsia foram classificados conforme o grau de esteatose, inflamação e fibrose. RESULTADOS: O fluxo foi trifásico em 38 (95%) dos controles e em 9 (56,3%) dos pacientes com esteatose discreta, enquanto nos com esteatose acentuada o padrão foi monofásico em 60%. Encontrou-se diferença significante na distribuição dos padrões ao Doppler (p < 0,01). Houve correlação negativa e significante entre o padrão ao Doppler da veia hepática direita e grau de esteatose (r = -0,57; p < 0,01). CONCLUSÃO: A alteração do padrão ao Doppler da veia hepática direita em pacientes com doença hepática gordurosa não alcoólica pode sugerir redução da complacência vascular consequente a infiltração gordurosa.

Nonalcoholic fatty liver disease in Brazil. Clinical and histological profile

BACKGROUND

The epidemiology and clinical characteristics of nonalcoholic fatty liver disease (NAFLD) in South America are not well known. Brazil is a largest country in this part of the world and the present study aimed to contribute with this information.

METHODS

This descriptive study included patients from medical centers around Brazil, who had diagnosis of NAFLD. They were selected from chart review and also prospectively in Hepatology out-clinics. Patients with history of alcohol intake and others liver diseases were excluded. Histological diagnosis included: steatosis or steatohepatitis (steatosis, ballooning of hepatocytes or fibrosis). The criteria to perform a liver biopsy was ALT or AST > 1.5 x normal levels.

RESULTS

A total of 1280 patients from 16 Brazilian centers and all five regions were included. The mean age was 49.68 ± 13.59 years; 53.3% were males and 85% were asymptomatic. Hyperlipidemia was observed in 66.8% cases, obesity in 44.7%, overweight in 44.4%, diabetes in 22.7%, and toxins exposure in 10%. Metabolic syndrome was observed in 41.3% cases. Elevated levels of ALT, AST and GGT were observed in 55.8%, 42.2% and 63.1% cases, respectively. Liver biopsy performed in 437 cases showed: isolate steatosis in 42% cases, steatohepatitis in 58% and 27% of them also presented fibrosis. Cirrhosis was observed in 15.4% and hepatocellular carcinoma in 0.7%.

CONCLUSIONS

NAFLD in Brazil is more frequent in asymptomatic males; steatohepatitis with fibrosis and cirrhosis were a significant diagnosis. The genetic predisposition and lifestyle should be influenced in the spectrum; however these findings deserve a future investigation.

Role of insulin resistance in the pathogenesis of nonalcoholic fatty liver disease

AIM: To investigate the role of insulin resistance (IR) in the pathogenesis of nonalcoholic fatty liver disease in rats.

METHODS: Spraque-Dawley rats were randomly divided into normal control group and model group. The model group was fed a high-fat cholesterol-rich diet for 8 wk to induce nonalcoholic fatty liver disease and insulin resistance. The model group was further divided randomly into two equal subgroups: model control subgroup and therapeutic subgroup. Physiological saline and rosiglitazone maleate were given to the model control subgroup and therapeutic subgroup for 4 wk, respectively. Hepatic histological changes were then observed. Fasting plasma glucose, fasting insulin, plasma ApoC II and ApoC III were determined to calculate insulin resistance index. The activity of lipoprotein lipase and hepatic lipase was measured, and the expression of ApoB-100 mRNA was detected.

RESULTS: Compared with the normal control group, the body mass, fasting plasma glucose, fasting insulin and insulin resistance index were significantly higher in the model control subgroup and therapeutic subgroup (fasting plasma glucose: 6.46 mmol/L ± 0.75 mmol/L, 6.61 mmol/L ± 0.45 mmol/L vs 5.48 mmol/L ± 0.47 mmol/L; fasting insulin: 78.82 mU/L ± 11.13 mU/L, 78.48 mU/L ± 12.94 mU/L vs 40.90 mU/L ± 7.76 mU/L; insulin resistance index: 22.48 ± 2.81, 22.98 ± 3.47 vs 9.85 ± 1.15; all P < 0.05). Histological analysis revealed that the rats of the model control subgroup and therapeutic subgroup met the diagnostic criteria for fatty liver. Compared with the model control subgroup, hepatic histological changes were milder in the therapeutic subgroup. Treatment with rosiglitazone maleate significantly lowered the fasting plasma glucose (6.01 mmol/L ± 0.56 mmol/L vs 6.43 mmol/L ± 0.47 mmol/L), fasting insulin (68.11 mU/L ± 10.52 mU/L vs 82.48 mU/L ± 15.20 mU/L), insulin resistance index (18.49 ± 2.44 vs 23.39 ± 3.16) and plasma ApoC III level, but increased plasma ApoC II level and the activity of lipoprotein lipase.

CONCLUSION: Improvement of insulin resistance in fatty liver rats can improve the activity of lipoprotein lipase and hepatic lipase by altering plasma ApoC II and ApoC III levels, promote the degradation of peripheral very low-density lipoprotein and triglycerides, up-regulate hepatic expression of ApoB-100 mRNA, facilitate the synthesis of very low-density lipoprotein in the liver and the transport of endogenous triglycerides, and lessen fatty infiltration of the liver.

[Hepatoprotective effect of diheptanoin and tritreptanoin chronic consumption against steatosis in rats]

OBJECTIVE

To evaluate the effect of chronic consumption of di- and triheptanoin on hepatic steatosis (HS) in rats.

METHODOLOGY

Wistar rats were submitted to a diet AIN-93 with 0, 30 or 50% of its oil substituted with an oil rich in di- and triheptanoin, groups TAGC(7)0, TAGC(7)30 and TAGC(7)50 respectively, for nine months. The control group received Labina(R). Liver histology, hepatic lesion and function proofs, glycemia and lipid profile, were performed. Variance analyses, F-test, Dunnet s test and uni- and multivariate regression analyses were performed (p<0.05).

RESULTS

TAGC(7)0, TAGC(7)30 and TAGC(7)50 developed HS; 80% of severe cases in TAGC(7)0, as against 40% in TAGC(7)50. The absolute (ALW) and relative (RLW) liver weights were higher in TAGC(7)0 and TAGC(7)30, and glycemia was greater in TAGC(7)30 and TAGC(7)50, than in the Control. Total cholesterol, LDL-c, LDL-c/HDL-c and total proteins were higher in the Control. The experimental oil reduced RLW and showed a tendency in the reduction of body weight, ALW, percentage of hepatic lipids and the severity of HS. The explanatory variables in relation to HS were final weight, glycemia, albumin, HDL-c, LDL-c, LDL-c/HDL-c, VLDL-c and alkaline phosphatase.

CONCLUSIONS

It is suggested that di- and triheptanoin have a hepatoprotector effect against HS, in rats, in a dose-dependent manner.

Synergistic effect of fatty liver and smoking on metabolic syndrome

AIM: To investigate the association of fatty liver and smoking on metabolic syndrome and its components.

METHODS: This cross-sectional study enrolled participants who attended annual health screening at Shin Kong Wu Ho-Su Memorial Hospital from January to December 2005. A total of 3455 (1981 men and 1474 women) subjects were included in final analyses. Fatty liver was diagnosed using abdominal ultrasonography by trained gastroenterologists. The modified National Cholesterol Education Program Adult Treatment Panel III was used to define metabolic syndrome. The associations between smoking, fatty liver and metabolic syndrome were analyzed using multiple logistic regression.

RESULTS: Subjects with fatty liver, and who smoked tobacco, had the highest odds ratios (ORs) for high waist circumference [OR, 4.5 (95% CI: 3.3-6.1), P < 0.05], hypertriglyceridemia [OR, 8.1 (95% CI: 6.0-10.9), P < 0.05], low serum high-density lipoprotein cholesterol (HDL-C) [OR, 8.3 (95% CI: 6.1-11.3), P < 0.05], and metabolic syndrome [OR, 9.5 (95% CI: 6.7-13.4), P < 0.05] compared to subjects without fatty liver who did not smoke tobacco. We also found that the ORs for hypertriglyceridemia, low serum HDL-C, and metabolic syndrome for subjects with fatty liver who smoked tobacco had greater than the sum of the ORs for subjects with fatty liver who did not smoke plus those who did not have fatty liver and who did smoke.

CONCLUSION: Fatty liver and smoking had a synergistic effect on metabolic syndrome and its components, especially for hypertriglyceridemia and low serum HDL-C.

Effects of light-to-moderate alcohol consumption on steatosis and steatohepatitis in severely obese patients

OBJECTIVES

The effect of light-to-moderate alcohol consumption (LMAC) in nonalcoholic fatty liver disease (NAFLD) remains a controversial subject. The aim of this study was to evaluate the relationship between LMAC and the severity of NAFLD in morbidly obese patients.

METHODS

We studied 132 patients undergoing liver biopsy during bariatric surgery. The patients were divided into three groups: G1: alcohol intake greater than 20 g/day and less than 40 g/day; G2: alcohol intake less than 20 g/day; G3: no alcohol intake. Insulin resistance was defined by the Homeostasis Model Assessment (>3). NAFLD was classified according to the Matteoni types: type I: steatosis alone; type II: steatosis with inflammation; types III-IV: steatosis with ballooning and/or fibrosis.

RESULTS

The mean age was 37.3+/-11 years. Sixty-three percent were females and body mass index was 43.9+/-5.6 kg/m. G1, G2, and G3 included 19, 56, and 57 patients, respectively. Histological diagnoses classified by levels of alcohol were: G1: 10.5% normal liver, 89.5% type III or IV; G2: 10.7% normal liver, 1.8% type I or II, and 87.5% grade III or IV; G3: 10.5% normal liver, 3.5% type I or II, and 86% type III or IV (one had cirrhosis). The presence of IR was similar in moderate and no alcohol consumption (81.3 and 78.7%) but significantly less in the light consumption group (54%, P<0.05).

CONCLUSION

The results suggest that LMAC may have a protection effect against IR in severely obese patients. However, it had no impact on the severity of activity and stage of liver disease.

Liver histology according to the presence of metabolic syndrome in nonalcoholic fatty liver disease cases

AIM: To investigate the histologic features of the liver in nonalcoholic fatty liver disease (NAFLD) cases according to the presence of metabolic syndrome or its individual components.

METHODS: We enrolled 81 patients (40 male, 41 female) who were diagnosed with fatty liver by ultrasonographic scan and fulfilled the inclusion criteria. First anamnesis, anthropometric, clinical, laboratory and imaging features of all participants were recorded and then liver biopsy was performed after gaining consent from patients. Diagnosis of metabolic syndrome was dependent on patients having 3 or more out of 5 risk criteria defined by the WHO. Biopsy specimens were assessed according to Brunt et al’s classification.

RESULTS: Sixty-nine of the 81 patients had nonalcoholic steatohepatitis (NASH), 11 had simple fatty liver and 1 had cirrhosis according to histologic evaluation. Comparisons were made between two groups of NASH patients, those with and without metabolic syndrome. We did not detect statistically significant differences in liver histology between NASH patients with and without metabolic syndrome.

CONCLUSION: NASH can progress without metabolic risk factors or the presence of metabolic syndrome.

Nonalcoholic fatty liver disease in HIV-infected patients referred to a metabolic clinic: prevalence, characteristics, and predictors

BACKGROUND

The prevalence and predictors of nonalcoholic fatty liver disease (NAFLD) in human immunodeficiency virus (HIV)-infected highly active antiretroviral therapy-experienced patients and the association of NAFLD with risk of cardiovascular disease and subclinical atherosclerosis are unknown.

METHODS

We performed a cross-sectional observational study. NAFLD was defined by liver-spleen attenuation values of <1.1 on computed tomography in persons who had neither evidence of chronic viral hepatitis nor a significant history of alcohol consumption.

RESULTS

We enrolled 225 patients; 163 (72.4%) were men. Mean (+/-SD) HIV infection duration was 145 +/- 60 months, and mean (+/-SD) body mass index (calculated as weight in kilograms divided by the square of height in meters) was 23.75 +/- 3.59. NAFLD was diagnosed in 83 patients (36.9% of the total cohort). The following variables were significantly associated with NAFLD in univariate analyses: sex, waist circumference, body mass index, cumulative exposure to nucleoside reverse-transcriptase inhibitors, visceral adipose tissue, homeostasis model assessment of insulin resistance index, serum alanine and aspartate aminotransferase levels, and ratios of total serum cholesterol to high-density lipoprotein cholesterol. Coronary artery calcium scores and a diagnosis of diabetes were not associated with NAFLD. In multivariable logistic regression analyses, factors associated (P<0.001) with NAFLD were higher serum alanine to aspartate ratio (odds ratio, 4.59; 95% confidence interval, 2.09-10.08), male sex (odds ratio, 2.49; 95% confidence interval, 1.07-5.81), greater waist circumference (odds ratio, 1.07; 95% confidence interval, 1.03-1.11), and longer nucleoside reverse-transcriptase inhibitor exposure (odds ratio, 1.12 per year of exposure; 95% confidence interval, 1.03-1.22).

CONCLUSIONS

NAFLD is common among HIV-infected persons who have the traditional risk factors for NAFLD (elevations in serum alanine level, male sex, and increased waist circumference) apparent. Exposure to nucleoside reverse-transcriptase inhibitors was an independent risk factor for NAFLD, with an 11% increase in the odds ratio for each year of use.

Fatty liver disease in severe obese patients: Diagnostic value of abdominal ultrasound

AIM: To evaluate the sensitivity and specificity of abdominal ultrasound (US) for the diagnosis of hepatic steatosis in severe obese subjects and its relation to histological grade of steatosis.

METHODS: A consecutive series of obese patients, who underwent bariatric surgery from October 2004 to May 2005, was selected. Ultrasonography was performed in all patients as part of routine preoperative time and an intraoperative wedge biopsy was obtained at the beginning of the bariatric surgery. The US and histological findings of steatosis were compared, considering histology as the gold standard.

RESULTS: The study included 105 patients. The mean age was 37.2 ± 10.6 years and 75.2% were female. The histological prevalence of steatosis was 89.5%. The sensitivity and specificity of US in the diagnosis of hepatic steatosis were, respectively, 64.9% (95% CI: 54.9-74.3) and 90.9% (95% CI: 57.1-99.5). The positive predictive value and negative predictive value were, respectively, 98.4% (95% CI: 90.2-99.9) and 23.3% (95% CI: 12.3-39.0). The presence of steatosis on US was associated to advanced grades of steatosis on histology (P = 0.016).

CONCLUSION: Preoperative abdominal US in our series has not shown to be an accurate method for the diagnosis of hepatic steatosis in severe obese patients. Until another non-invasive method demonstrates better sensitivity and specificity values, histological evaluation may be recommended to these patients undergoing bariatric surgery.

HIV-positive patients with nonalcoholic fatty liver disease have a lower body mass index and are more physically active than HIV-negative patients

OBJECTIVE

To determine whether the clinical and metabolic features associated with nonalcoholic fatty liver disease (NAFLD) are similar between HIV-positive and HIV-negative male subjects.

METHODS

Twenty-six HIV-positive and 25 HIV-negative subjects with liver biopsy-proven NAFLD were compared for liver histology (extent of steatosis, steatosis grading, and fibrosis staging), blood biochemistry (glucose, insulin, C-peptide, hemoglobin A1c, and lipid profile), insulin resistance (IR) using a homeostasis model assessment, anthropometry (body mass index [BMI], waist circumference, and arm muscle area), dietary intake, and physical activity.

RESULTS

The 2 groups were similar for age, liver histology, and IR. HIV-positive patients had a lower BMI (26.3 +/- 0.5 vs. 30.2 +/- 1.0 kg/m; P = 0.001) and lower percentage of fat mass (19.4 +/- 0.9 vs. 22.7 +/- 1.2; P = 0.026) when compared with HIV-negative patients. Although caloric intake was similar between groups, HIV-positive patients had a higher physical activity level (8.3 +/- 1.6 vs. 4.1 +/- 0.8 units of exercise per day; P = 0.029). Blood triglycerides were significantly higher (3.14 +/- 0.39 vs. 1.86 +/- 0.20 mmol/L; P = 0.006) in HIV-positive patients.

CONCLUSION

Although NAFLD was similar between the 2 groups, HIV-positive patients had a lower BMI and were more physically active compared with HIV-negative patients. This may suggest that in HIV, NAFLD is associated with factors other than those related to body fatness, such as HIV infection and treatment.

Microarray analyses and molecular profiling of steatosis induction in immortalized human hepatocytes

Hepatic steatosis is an important risk factor for the development of inflammation, fibrosis and impaired liver regeneration. The factors regulating lipid accumulation and driving hepatic steatosis toward inflammation, fibrosis and impaired regeneration are largely unknown. The aim of this study was to identify major alterations in gene expression occurring in steatotic hepatocytes, and to analyze how these changes impact cellular processes associated with steatosis. Microarray gene chips and RT-PCR were performed to analyze changes in gene expression induced in fatty human immortalized hepatocytes after treatment with 50 muM oleic acid for 7 days. Lipid metabolism and triglyceride accumulation in these cells was examined by Oil-Red-O staining, thin-layer chromatography (TLC) and immunofluorescence. Caspase 3 activity, BrdU incorporation and trypan blue exclusion were used to study apoptosis, proliferation and cell viability. Finally, quantitative analysis of signalling induced by insulin was performed by Western blot. Characterization of steatosis in three hepatocyte-derived cell lines indicated that the immortalized human hepatocytes (IHH) line was the most appropriate cell line for this study. Gene expression analysis showed significant alterations in the transcription of two major classes of genes involved either in cholesterol and fatty acid biosynthesis, as well as lipid export, or in apoptosis and cell proliferation. Such changes were functionally relevant, since TLC indicated that synthesis and accumulation of triglycerides were increased in steatotic cells, while synthesis of cholesterol and fatty acids were decreased. Lipid accumulation in IHH was associated with an increased apoptosis and an inhibition of cell proliferation and viability. No detectable changes in genes associated with insulin resistance were observed in steatotic cells, but signalling induced by insulin was more efficient in steatotic IHH as compared to control cells. We conclude that IHH represent a new valuable model of steatosis, not associated with insulin resistance, to study at both the genetic and functional level factors involved in the process of lipid accumulation and steatosis-associated liver injury.

A systems biology approach to the pathogenesis of obesity-related nonalcoholic fatty liver disease using reverse phase protein microarrays for multiplexed cell signaling analysis

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. Omental adipose tissue, a biologically active organ secreting adipokines and cytokines, may play a role in the development of NAFLD. We tested this hypothesis with reverse-phase protein microarrays (RPA) for multiplexed cell signaling analysis of adipose tissue from patients with NAFLD. Omental adipose tissue was obtained from 99 obese patients. Liver biopsies obtained at the time of surgery were all read by the same hepatopathologist. Adipose tissue was exposed to rapid pressure cycles to extract protein lysates. RPA was used to investigate intracellular signaling. Analysis of 54 different kinase substrates and cell signaling endpoints showed that an insulin signaling pathway is deranged in different locations in NAFLD patients. Furthermore, components of insulin receptor-mediated signaling differentiate most of the conditions on the NAFLD spectrum. For example, PKA (protein kinase A) and AKT/mTOR (protein kinase B/mammalian target of rapamycin) pathway derangement accurately discriminates patients with NASH from those with the non-progressive forms of NAFLD. PKC (protein kinase C) delta, AKT, and SHC phosphorylation changes occur in patients with simple steatosis. Amounts of the FKHR (forkhead factor Foxo1)phosphorylated at S256 residue were significantly correlated with AST/ALT ratio in all morbidly obese patients. Furthermore, amounts of cleaved caspase 9 and pp90RSK S380 were positively correlated in patients with NASH. Specific insulin pathway signaling events are altered in the adipose tissue of patients with NASH compared with patients with nonprogressive forms of NAFLD.

CONCLUSION

These findings provide evidence for the role of omental fat in the pathogenesis, and potentially, the progression of NAFLD.

Non-alcoholic steatohepatitis and metabolic syndrome

PURPOSE OF REVIEW

Non-alcoholic steatohepatitis is part of a disease spectrum, non-alcoholic fatty liver disease, ranging from simple steatosis to cirrhosis, which is the most frequent cause of abnormal liver tests. There is clinical and epidemiological evidence that non-alcoholic fatty liver disease is the hepatic manifestation of the metabolic syndrome, having in common insulin resistance.

RECENT FINDINGS

The interest in the metabolic syndrome concept has been questioned. Insulin resistance, oxidative stress, mitochondrial dysfunction, immune deregulation and adipokines seem to be crucial in the pathogenesis of non-alcoholic fatty liver disease. The main treatment continues to rely on lifestyle changes, including weight loss strategies. Bariatric surgery in morbidly obese patients and insulin-sensitizing agents seem to be beneficial.

SUMMARY

There is strong evidence of the association of non-alcoholic steatohepatitis with the features of the metabolic syndrome, with its increased cardiovascular risk. Population interventions in order to change lifestyles and diet patterns that constitute risk factors for both situations are urgently needed. There is, however, evidence that in the presence of other risk factors, insulin resistance may be less important. These secondary forms of non-alcoholic steatohepatitis must be recognized, as they are potentially treatable by withdrawing the steatogenic factor.

Regulation of lipid metabolism by soy protein and its implication in diseases mediated by lipid disorders

Soybeans have a high-quality protein that has been consumed for approximately 5000 years in Oriental countries. The awareness that soy products are healthy has increased their consumption in Western countries. Substantial data from epidemiological surveys and nutritional interventions in humans and animals indicate that soy protein reduces serum total and low-density lipoprotein (LDL) cholesterol and triglycerides as well as hepatic cholesterol and triglycerides. This review examines the evidence on the possible mechanisms for which soy protein has beneficial effects in diabetes, obesity and some forms of chronic renal disease. Consumption of soy protein due to low methionine content reduces serum homocysteine concentration, decreasing the risk of acquiring a cardiovascular disease. On the other hand, soy protein reduces the insulin/glucagon ratio, which in turn down-regulates the expression of the hepatic transcription factor sterol regulatory element binding protein (SREBP)-1. The reduction of this factor decreases the expression of several lipogenic enzymes, decreasing in this way serum and hepatic triglycerides as well as LDL cholesterol and very LDL triglycerides in diabetes and obesity, reducing lipotoxicity in the liver. Soy protein intake also reduces hepatic lipotoxicity by maintaining the number of functional adipocytes, preventing the transfer of fatty acids to extra adipose tissues. Furthermore, soy protein isoflavones stimulate the transcription factor SREBP-2, increasing serum cholesterol clearance. The reduction of serum cholesterol and triglyceride concentrations by soy protein intake produces beneficial effects in the kidney preventing the inflammatory response, increasing the renal flow by releasing endothelial nitric oxide (NO) synthase from the caveolae, facilitating the synthesis of NO. Thus, soy protein consumption may reduce the clinical and biochemical abnormalities in diseases mediated by lipid disorders.

Body mass index and waist circumference in non-alcoholic fatty liver disease

OBJECTIVE

To evaluate the association of anthropometric indexes (body mass index and waist circumference) in patients with non-alcoholic fatty liver disease (NAFLD), and its association with insulin resistance (IR), metabolic syndrome (MS) and histological findings.

METHODS

From August 2003 to July 2004 a case series of 81 outpatients with clinic and/or histological diagnosis of NAFLD were selected at the Bahia University Gastro-Hepatology Clinic, Brazil. Liver function tests, lipid profile, glucose and insulin were performed in all patients. Body mass index (BMI) and waist circumference (WC) were determined according to WHO criteria. IR was measured by means of the homeostasis model assessment (HOMA) and IR was considered with HOMA > or =3. MS was defined according to the Adult Treatment Panel III (ATP III). Liver biopsy was performed in 37 cases.

RESULTS

Body mass index > or = 30 kg m(-2) (obesity) was found in 39% of the cases and BMI > or = 25-29.9 kg m(-2) (overweight) in 53%. BMI was correlated with IR (r = 0.29; P = 0.02) and WC with ALT (r = 0.02; P = 0.03). Increased WC also was related to IR and to MS. The presence of steatohepatitis with fibrosis on liver biopsy was associated with overweight (68%) and increase of WC (41%).

CONCLUSIONS

Body mass index and WC are frequent associated with MS, IR and histological findings (steatohepatitis and fibrosis) in patients with NAFLD.