Hepatitis B virus infection and fatty liver in the general population

Hepatitis B virus infection and fatty liver in the general population Vincent Wai-Sun Wong1,2,Grace Lai-Hung Wong1,2,Winnie Chiu-Wing Chu1,3,⇑, Angel Mei-Ling Chim1,2,Arlinking Ong1,2,4,David Ka-Wai Yeung5,Karen Kar-Lum Yiu1,2, Shirley Ho-Ting Chu1,2,Hoi-Yun Chan1,2,Jean Woo2,Francis Ka-Leung Chan1,2,Henry Lik-Yuen Chan1,2,⇑1Institute of Digestive Disease,The Chinese University of Hong Kong,Hong Kong;2Department of Medicine and Therapeutics,The Chinese University of Hong Kong,Hong Kong;3Department of Imaging and Interventional Radiology,The Chinese University of Hong Kong, Hong Kong;4Department of Medicine,Section of Gastroenterology,University of Santo Tomas Hospital,Espana Manila,Philippines;5Departmentof Clinical Oncology,The Chinese University of Hong Kong,Hong KongBackground&Aims:In animal studies,expression of hepatitis B virus(HBV)proteins causes hepatic steatosis.We aimed to study the prevalence of fatty liver in people with and without HBV infection in the general population.Methods:We performed a cross-sectional population study in Hong Kong Chinese.Intrahepatic triglyceride content(IHTG) was measured by proton-magnetic resonance spectroscopy. Results:One thousand and thirteen subjects(91HBV patients and922controls)were recruited.The median IHTG was1.3% (0.2–33.3)in HBV patients and 2.1%(0–44.2)in controls(p <0.001).Excluding subjects with significant alcohol consumption, the prevalence of nonalcoholic fatty liver disease was13.5%(95% confidence interval[CI]6.4%,20.6%)in HBV patients and28.3% (95%CI25.3%,31.2%)in controls(p=0.003).The fatty liver prev-alence differed in HBV patients and controls aged40–59years but was similar in those aged60years or above.After adjusting for demographic and metabolic factors,HBV infection remained an independent factor associated with lower risk of fatty liver (adjusted odds ratio0.42;95%CI0.20,0.88;p=0.022).HBV patients also had a lower prevalence of metabolic syndrome (11.0%vs.20.2%;p=0.034),but the difference was mainly attrib-uted to lower triglyceride levels.Among HBV patients,viral geno-types,HBV DNA level and hepatitis B e antigen status were not associated with fatty liver.Conclusions:HBV infection is associated with a lower prevalence of fatty liver,hypertriglyceridemia and metabolic syndrome.Viral replication may affect lipid metabolism and this warrants further studies.Ó2011European Association for the Study of the Liver.Published by Elsevier B.V.All rights reserved.IntroductionChronic hepatitis B is estimated to affect more than350million people worldwide and is one of the leading causes of cirrhosis and hepatocellular carcinoma[1,2].Nonalcoholic fatty liver dis-ease(NAFLD)is another common chronic liver disease that affects20–40%of the general population[3,4].NAFLD is strongly associated with obesity and metabolic syndrome[5–8],and may result in cirrhosis and hepatocellular carcinoma[9,10].Since both chronic hepatitis B and NAFLD are common,many patients suffer from both conditions.However,the interaction between chronic hepatitis B and NAFLD is unclear.In a large cross-sectional study using transient elastography examination,chronic hepatitis B patients with metabolic syn-drome were more likely to have advancedfibrosis and cirrhosis than those without[11].In addition,type2diabetes and obesity have been found to be associated with hepatocellular carcinoma development in patients with viral hepatitis[12,13].On the other hand,several large histological series failed to demonstrate any association between hepatic steatosis andfibrosis in patients with chronic hepatitis B[14–16].Hepatic steatosis is associated with metabolic but not viral factors such as viral load and geno-type[16–22].Since most histological cohorts came from special-ized centers,it is uncertain if the observation may be influenced by a selection bias.For example,patients undergoing liver biop-sies are more likely to have abnormal liver function tests and radiological evidence of cirrhosis[23].Whether hepatitis B virus infection increases the risk of fatty liver is another area of controversy.In transgenic mouse and cell line models,hepatitis B X(HBx)protein expression results in hepatic steatosis and activation of the nuclear factorkappaBJournal of Hepatology2012vol.56j533–540Keywords:Nonalcoholic fatty liver disease;Nonalcoholic steatohepatitis;Obesity;Diabetes mellitus;Hypertriglyceridemia;Cross-sectional study.Received27May2011;received in revised form23August2011;accepted21September2011;available online23October2011⇑Corresponding authors.Addresses:Department of Imaging and InterventionalRadiology,Prince of Wales Hospital,30–32Ngan Shing Street,Shatin,Hong Kong.Tel.:+852********;fax:+852********(W.C.-W.Chu),Department ofMedicine and Therapeutics,Prince of Wales Hospital,30–32Ngan Shing Street,Shatin,Hong Kong.Tel.:+852********;fax:+852********(H.L.-Y.Chan).E-mail addresses:winnie@.hk(W.C.-W.Chu),hlychan@.hk(H.L.-Y.Chan).Abbreviations:Anti-HBe,antibody against hepatitis B e antigen;CI,confidenceinterval;HBeAg,hepatitis B e antigen;HBV,hepatitis B virus;HBx,hepatitis B X;NAFLD,nonalcoholic fatty liver disease;1H-MRS,proton-magnetic resonancespectroscopy.Research Articlepathway [24,25].On the other hand,two studies on ethnic Chinese population failed to demonstrate a positive correlation between hepatitis B infection and metabolic syndrome [26,27].The association with fatty liver has also not been adequately tested in large human studies.Recently,proton-magnetic resonance spectroscopy (1H-MRS)has been developed as a non-invasive test of hepatic steatosis.It quantifies hepatic steatosis by measuring proton signals from the acyl groups of hepatocyte triglyceride stores [28].The measure-ment is reproducible and correlates well with the degree of hepatic steatosis by histology [29–31].Using this new technique,it is now possible to evaluate hepatic steatosis in a large number of chronic hepatitis B patients and controls in the general population.In this study,we aimed to investigate the prevalence of fatty liver in people with and without chronic hepatitis B virus infec-tion in the general population.We also aimed at determining fac-tors associated with fatty liver and the interaction with viral factors.Patients and methodsPatientsThis was a cross-sectional study.Subjects from the general population were ran-domly selected from the census database of the Hong Kong Government,and were invited by mail and phone calls [32].We included subjects aged18–70years.Subjects with active malignancy,metallic implants or other contra-indications to magnetic resonance imaging,positive antibody against hepatitis C virus,secondary causes of fatty liver (e.g.consumption of systemic corticosteroids and tamoxifen)and decompensated liver disease (defined as bilirubin above 50l mol/L,albumin below 35g/L,platelet count below 150Â109/L,international normalized ratio above 1.3,or the presence of ascites or varices)were excluded.The study protocol was approved by the Clinical Research Ethics Committee of The Chinese University of Hong Kong.All subjects provided informed written consent.Clinical assessmentAt the clinic visit,drug history,alcohol intake,smoking and past medical history were recorded using a standardized questionnaire.Significant alcohol consump-tion was defined as alcohol intake of P 20g per day in men and P 10g per day in women [33].Anthropometric measurements included body weight,body height and waist circumference.Body mass index (BMI)was calculated as weight (kg)divided by height (m)squared.Waist circumference was measured at a level midway between the lower rib margin and the iliac crest with the tape all around the body in the horizontal position.Blood tests including liver biochemistry,glucose and lipids were performed after 8-h fasting.Metabolic syndrome was defined according to the ethnic-specific criteria by the International Diabetes Federation,which was modified from the National Cholesterol Education Program,Adult Treatment Panel III Guidelines:any three of the following:(1)central obesity (waist circumference P 90cm in men and P 80cm in women);(2)triglycerides >1.7mmol/L;(3)reduced high-density lipoprotein–cholesterol (<1.03mmol/L in men and <1.29mmol/L in women);(4)blood pressure P 130/85mmHg;and (5)fasting plasma glucose P 5.6mmol/L;or receiving treatment for the above metabolic abnormalities [34].On the day of assessment,the subjects also completed a locally validated food-frequency questionnaire to document dietary intake over a 7-day period [35].This method has the advantage of adjusting for day-to-day variation and minimizing recall bias.Daily nutrient intake and food group consumption were calculated by Food Processor Nutrition Analysis and Fitness Software version 7.9(Esna Research,Salem,USA).Virological assaysEnzyme-linked immunosorbent assay (ELISA)kits were used to test hepatitis B surface antigen (Roche Diagnostics Corp.,Indianapolis,IN),hepatitis B e antigen (HBeAg)and antibody against HBeAg (anti-HBe)(SanofiDiagnostics,Pasteur,France).TaqMan real-time polymerase chain reaction assay was used to measure hepatitis B virus (HBV)DNA levels [36].The detection range was 102–109copies/ml.HBV genotyping was performed by restriction fragment length polymorphism at the initial visit,as previously described [37].Proton-magnetic resonance spectroscopy1H-MRS was performed to measure intrahepatic triglyceride content (IHTG)within 8weeks from the baseline visit.Whole-body 3.0T scanner with a single voxel point-resolved spectroscopy sequence and an echo time of 40ms and rep-etition time of 5000ms was used.A survey scan was first performed in the abdominal region to help positioning a volume measuring 20(AP)Â15(RL)Â40(FH)mm within the liver.The scanner’s built-in body coil was used for both signal transmission and reception.No-water-suppressed spectra were acquired using 32signal averages and the data were exported for offline spectral analysis.Water (4.65ppm)and lipid (1.3ppm)peak amplitudes were measured to determine vertebral marrow fat content,which was defined as the relative fat signal amplitude in terms of a percentage of the total signal amplitude (water and fat)and calculated according to the following equation:fat con-tent =[I fat /(I fat +I water )]Â100,where I fat and I water are the peak amplitudes of fat and water,respectively.Correction for relaxation loss was not applied because of the relatively long repetition time and short echo time.An IHTG of 5%was used to distinguish between patients with and without fatty liver [29,30,32].Transient elastographyLiver stiffness measurement by transient elastography was performed to estimate the degree of liver fibrosis during the baseline clinic visit according to the instruc-tions and training provided by the manufacturer.Ten successful acquisitions were performed on each subject.The success rate was calculated as the ratio of the number of successful acquisitions over the total number of acquisitions.TheResearch Article534Journal of Hepatology 2012vol.56j 533–540median value represented the liver elastic modulus.Liver stiffness measurements were considered reliable only if10successful acquisitions were obtained,the suc-cess rate was above60%,and the interquartile range-to-median ratio of the10 acquisitions was smaller than0.3.Liver stiffness was expressed in kiloPascal (kPa).The cutoff values of9.6kPa was used to estimate the number of subjects with advancedfibrosis.The cutoff value had specificity over90%in a previous val-idation study using liver histology as the reference standard[38].Statistical analysisAll statistical tests were performed using the Statistical Package for Social Sciences version16.0(Chicago,IL).Continuous variables were presented as mean±standard deviation or median(range),and compared between hepatitis B patients and controls using unpaired t test and Mann–Whitney U test as appro-priate.Categorical variables were compared using the Chi-squared test.The rela-tionship between fatty liver and HBV infection was adjusted for demographic and metabolic factors using the bivariate logistic regression model.Statistical signifi-cance was taken as a two-sided p value<0.05.ResultsFrom May2008to September2010,invitation letters were sent to3000randomly selected Hong Kong residents from the census database.One thousand and sixty-nine subjects responded,with a response rate of35.6%.After excluding subjects with contrain-dications to or failed1H-MRS examination and those with chronic hepatitis C,1013subjects were included in thefinal analysis (Fig.1).Ninety-one(9.0%)subjects had positive hepatitis B surface antigen,while922(91.0%)subjects with negative hepatitis B sur-face antigen served as controls.Overall,chronic hepatitis B patients and controls had similar demographics(Table1).The groups also did not differ in smoking and drinking habits.Two (2.2%)hepatitis B patients and30(3.3%)controls had alcoholContinuous variables were expressed as mean±standard deviation or median(range). HDL,high density lipoprotein;LDL,low density lipoprotein. 1Metabolic syndrome criteria by International DiabetesFederation.JOURNAL OF HEPATOLOGY Journal of Hepatology2012vol.56j533–540535consumption of P 20g per day in men and P 10g per day in women,up to 350g per week.During transient elastography examination,64subjects had less than 10successful acquisitions and 119subjects had inter-quartile-range-to-median ratio of the 10acquisitions greater than 0.3.As a result,830(81.9%)subjects (70hepatitis B patients and 760controls)had valid liver stiffness measurement.Subjects in both groups had low liver stiffness (Table 2).None of the hep-atitis B patients and 19(2.5%)controls had liver stiffness P 9.6kPa.Fatty liver and metabolic syndromeHepatitis B patients had significantly lower IHTG by 1H-MRS (Table 2).The prevalence of fatty liver was 14.3%(95%confidence interval [CI]7.1%,21.5%)in hepatitis B patients and 28.6%(95%CI 25.7%,31.6%)in controls (p =0.003).There was also a trend that fewer hepatitis B patients had IHTG P 11.0%,a level suggestive of grade 2or 3steatosis by histology [29].Excluding subjects with significant alcohol consumption,the prevalence of NAFLD was 13.5%(95%CI 6.4%,20.6%)in hepatitis B patients and 28.3%(95%CI 25.3%,31.2%)in controls (p =0.003).When stratified by age,hepatitis B patients aged 40–49years (7.1%vs.25.5%;p =0.035)and 50–59years (15.4%vs.32.3%;p =0.030)had significantly lower prevalence of fatty liver than controls (Fig.2).In both the hepatitis B and control groups,the prevalence of fatty liver increased with age and became similar above the age of 60.Hepatitis B patients and control subjects had similar blood pressure,BMI,waist-to-hip ratio and plasma glucose level (Table 1).However,hepatitis B patients had significantly lower total cholesterol and triglyceride levels.Since the two groups did not differ in high density lipoprotein–cholesterol and low density lipoprotein–cholesterol levels,the difference in total cholesterol was mainly explained by the lower triglyceride level in hepatitis B patients.The prevalence of metabolic syndrome was 11.0%(95%CI 4.6%,17.4%)in hepatitis B patients and 20.2%(95%CI 17.6%,22.8%)in controls (p =0.034).The median (range)number of metabolic syndrome criteria according to the International Diabetes Federation was 1(0–4)in hepatitis B patients and 1(0–5)in controls (p =0.051).When each criterion was analyzed separately,hepatitis B patients were less likely to have hypertri-glyceridemia (Table 1).On the other hand,the proportion of hep-atitis B patients and controls with central obesity,reduced high density lipoprotein–cholesterol,high blood pressure and hyper-glycemia was similar.In two multivariate models,HBV infection remained as an independent factor associated with lower risk of fatty liver,after adjusting for demographic and metabolic factors (Table 3).When analyzed separately,reduced high density lipoprotein–cholesterol level was independently associated with fatty liver in HBV patients.In contrast,male gender and all components of meta-bolic syndrome were independently associated with fatty liver in controls (Table 4).In the overall population,serum triglycerides had moderate correlation with IHTG (r =0.37,p <0.001).When analyzed sepa-rately,the positive correlation was observed in both HBV patients (r =0.31,p =0.003)and controls (r =0.38,p <0.001).In view of a significant difference in metabolic parameters between hepatitis B patients and controls,the dietary intake was further assessed by food-frequency questionnaires.The med-ian daily calorie intake was 2109kcal in hepatitis B patients and 2221kcal in controls (Table 5).The consumption of macronutri-ents was also similar between the two groups.Virological factors and fatty liverAmong patients with chronic hepatitis B,29(32%)patients were infected by HBV genotype B,32(35%)by HBV genotype C and 2(2%)by mixed HBV genotypes B and C.Twenty-eight (31%)patients could not be genotyped for HBV because of low viral load.IHTG level was 3.5±4.1%, 3.5±6.2%and 1.4±0.6%in patients infected with HBV genotype B,genotype C and mixed genotypes,respectively (p =0.86).Fatty liver was detected in 5(17%)patients with HBV genotype B,5(16%)with genotype C,and 0patients with mixed genotypes (p =0.81).Fourteen (15%)patients had positive HBeAg and 77(85%)had negative HBeAg.IHTG level was 2.7±3.9%in HBeAg-positive patients and 3.0±5.0%in HBeAg-negative patients (p =0.82).Two (14%)HBeAg-positive patients and 11(14%)HBeAg-negative patients had fatty liver (p =1.0).The mean HBV DNA level was 3.1±1.5log IU/ml.There was no significant correlation between HBV DNA level and IHTG (r =À0.009,p =0.93).HBV DNA level was 3.0±1.6log IU/ml in patients with fatty liver and 3.1±1.5log IU/ml in those without (p =0.86).Table 2.Intrahepatic triglyceride content and liver stiffness in subjects withIHTG,intrahepatic triglyceride.1Included 830subjects with valid liver stiffness measurements by transient elastography.Research Article536Journal of Hepatology 2012vol.56j 533–540Since virological factors might represent different phases of disease over time,the association between these factors and fatty liver was further evaluated with adjustment for age and gender. By multivariate analysis,HBV genotypes,HBeAg status and HBV DNA level were not associated with fatty liver(Table6).There was no significant difference in liver stiffness by transient elastography in patients with HBV genotype B(5.0±1.2kPa)and genotype C(5.0±1.5kPa;p=0.86).Patients with positive and negative HBeAg also had similar liver stiffness(5.2±1.4kPa vs.4.9±1.4kPa;p=0.42).In contrast,HBV DNA level had positive correlation with liver stiffness(r=0.28,p=0.020).DiscussionIn this large community-based study,hepatitis B patients had lower prevalence of fatty liver than uninfected controls.The neg-ative association remained robust after adjustment for alcohol consumption,demographic,and metabolic factors.In addition, HBV infection was associated with lower prevalence of metabolic syndrome.The effect was mainly explained by a lower prevalence of hypertriglyceridemia.The relationship between HBV infection and fatty liver has long been a matter of controversy.Overexpression of HBx1Metabolic syndrome criteria by International Diabetes Federation.1Metabolic syndrome criteria by International Diabetes Federation.JOURNAL OF HEPATOLOGYJournal of Hepatology2012vol.56j533–540537induces hepatic lipid accumulation in HepG2–HBx stable cells and HBx-transgenic mice [24].HBx upregulates sterol regulatory element binding protein 1[24],and enhances cyclo-oxygenase 2expression,leading to endoplasmic reticulum stress [39].In another animal model,HBsAg-transgenic mice accumulate more hepatic fat than wild-type mice when exposed to methionine–choline-deficient diet [40].HBV-transgenic mice on normal diet have also altered control in oxidative stress and lipid metabolism [41].In HepG2–HBV-stable cells,HBV replication upregulates adipogenic genes and adiponectin can stimulate viral replication [42].On the other hand,data on the association are more conflict-ing in human studies.Although some studies showed that chronic hepatitis C patients have higher prevalence of fatty liver than chronic hepatitis B patients,a considerable proportion of the latter patients still harbor hepatic steatosis [43,44].In chronic hepatitis B patients,the degree of hepatic steatosis and insulin resistance is mainly attributed to metabolic factors but not viro-logical factors [14–16,20,22,45].Treatment response to peginter-feron and lamivudine is also not affected by hepatic steatosis [46].Nevertheless,the previous histological studies were limited by the lack of a comparable control arm and selection bias of chronic hepatitis B patients with active disease and high preva-lence of fibrosis or cirrhosis.In this study,both HBV patients and uninfected controls came from the general community with low prevalence of cirrhosis.With various multivariate models and stratified analysis,we demonstrated that HBV infection was associated with a lower prevalence of fatty liver.We believe that the association between the expression of HBV proteins and hepatic steatosis in laboratory models likely stems from the induction of endoplasmic reticulum stress in artificial situations.The theoretical rationale behind the experiments is not strong or supported by clinical observations.The current study is also in keeping with data from Taiwan and China indicating that HBV-infected patients have reduced tri-glyceride level and a lower prevalence of metabolic syndrome overall [26,27].The observation is consistent across these large population studies and unlikely to be due to chance.However,the underlying mechanism is currently unknown.In human stud-ies,HBV infection affects the secretion of various adipokines and may alter the lipid profile [16,18].As an analogy,lipid metabo-lism has been implicated in hepatitis C viral entry,replication and response to treatment [47].Further studies on the mecha-nism linking lipid metabolism and HBV replicative cycle may shed light on new treatment targets.One possible explanation of the lower metabolic risk and fatty liver prevalence in hepatitis B patients is that they may be more health conscious and lead a healthier lifestyle.Previous studies have highlighted the importance of dietary habits in NAFLD development [48].However,in our study,the total calorie intake of hepatitis B patients and controls was similar.There was also no significant difference in the consumption of the major macronu-trients.This suggests that the observation cannot be explained by a difference in lifestyle habits.In our study,high HBV DNA was associated with increased liver stiffness.In patients with chronic hepatitis B,high viralResearch Article538Journal of Hepatology 2012vol.56j 533–540load is usually associated with active disease and histological progression in the long run.Patients with high HBV DNA are more likely to have advanced liverfibrosis or cirrhosis[49,50]. Besides,large epidemiological studies confirmed that patients with high viral load are at increased risk of hepatocellular car-cinoma[2,51,52].Our study has a few limitations.First,IHTG was measured once and we cannot exclude the possibility that the value may change with time.However,a previous study in college students showed that while short-term increase in food intake might change the metabolic profile and ALT levels,the effect on IHTG was modest[53].The minor change in IHTG level would unlikely affect the majorfindings of this study.Second,the number of hepatitis B patients was relatively small.However,the negative association between HBV infection and fatty liver was consistent across different age groups and remained robust in multivariate analysis.These suggest the observation was genuine.Third,most hepatitis B patients in our study had inactive disease and normal liver stiffness since they were asymptomatic people from the general population.Ourfindings could not represent chronic hep-atitis B patients with advanced disease.While our data clearly indicate a lower prevalence of fatty liver in hepatitis B patients, the effect of active necroinflammation andfibrosis on the meta-bolic profile and lipid metabolism warrants further studies. Fourth,the assessment of hepatic steatosis andfibrosis was based on non-invasive tests with imperfect accuracies.However,the use of non-invasive tests allowed for large scale screening in asymptomatic individuals in the general population.Our study also adopted state-of-the-art1H-MRS and transient elastography that have been validated in histological series[23,29,30,38,54]. Finally,it is unclear if subjects with and without HBV infection had similar response rate to the study invitation.However,the proportion of subjects with HBV infection in this study(9.0%) was similar to the local prevalence.In conclusion,HBV infection is associated with a lower preva-lence of fatty liver,hypertriglyceridemia and metabolic syn-drome.Viral replication may affect lipid metabolism and this warrants further studies.Conflict of interestVincent Wong is an advisory board member of Roche Pharmaceu-tical,Abbott,Gilead and Otsuka,and is a speaker for Echosens, Bristol-Myers Squibb and Novartis Pharmaceutical.Grace Wong is a speaker for Echosens.Henry Chan is an advisory board member of Abbott,Novartis Pharmaceutical,Merck,Bristol-Myers Squibb and Roche.Financial supportThe study was supported by a grant from the Health and Health Services Research Fund sponsored by the Government of Hong Kong SAR(Reference No.:07080081).AcknowledgmentsWe would like to thank the following students and research assistants in helping with data collection:Andrew Hayward, Catherine Hayward,Mandy Law,Mia Li,and April Wong.References[1]Chan HL,Sung JJ.Hepatocellular carcinoma and hepatitis B virus.Semin LiverDis2006;26:153–161.[2]Wong VW,Chan SL,Mo F,Chan TC,Loong HH,Wong GL,et al.Clinical scoringsystem to predict hepatocellular carcinoma in chronic hepatitis B carriers.J Clin Oncol2010;28:1660–1665.[3]Amarapurkar DN,Hashimoto E,Lesmana LA,Sollano JD,Chen PJ,Goh KL.How common is non-alcoholic fatty liver disease in the Asia-Pacific region and are there local differences?J Gastroenterol Hepatol2007;22:788–793.[4]Williams CD,Stengel J,Asike MI,Torres DM,Shaw J,Contreras M,et al.Prevalence of nonalcoholic fatty liver disease and nonalcoholic steatohep-atitis among a largely middle-aged population utilizing ultrasound and liver biopsy:a prospective study.Gastroenterology2011;140:124–131.[5]Wong VW,Chan HL,Hui AY,Chan KF,Liew CT,Chan FK,et al.Clinical andhistological features of non-alcoholic fatty liver disease in Hong Kong Chinese.Aliment Pharmacol Ther2004;20:45–49.[6]Wong VW,Hui AY,Tsang SW,Chan JL,Tse AM,Chan KF,et al.Metabolic andadipokine profile of Chinese patients with nonalcoholic fatty liver disease.Clin Gastroenterol Hepatol2006;4:1154–1161.[7]Wong VW,Hui AY,Tsang SW,Chan JL,Wong GL,Chan AW,et al.Prevalenceof undiagnosed diabetes and postchallenge hyperglycaemia in Chinese patients with non-alcoholic fatty liver disease.Aliment Pharmacol Ther 2006;24:1215–1222.[8]Wong VW,Wong GL,Yip GW,Lo AO,Limquiaco J,Chu WC,et al.Coronaryartery disease and cardiovascular outcomes in patients with non-alcoholic fatty liver disease.Gut2011;60:1721–1727.[9]Ascha MS,Hanouneh IA,Lopez R,Tamimi TA,Feldstein AF,Zein NN.Theincidence and risk factors of hepatocellular carcinoma in patients with nonalcoholic steatohepatitis.Hepatology2010;51:1972–1978.[10]Wong VW,Wong GL,Choi PC,Chan AW,Li MK,Chan HY,et al.Diseaseprogression of non-alcoholic fatty liver disease:a prospective study with paired liver biopsies at3years.Gut2010;59:969–974.[11]Wong GL,Wong VW,Choi PC,Chan AW,Chim AM,Yiu KK,et al.Metabolicsyndrome increases the risk of liver cirrhosis in chronic hepatitis B.Gut 2009;58:111–117.[12]Chen CL,Yang HI,Yang WS,Liu CJ,Chen PJ,You SL,et al.Metabolic factorsand risk of hepatocellular carcinoma by chronic hepatitis B/C infection:a follow-up study in Taiwan.Gastroenterology2008;135:111–121.[13]Yu MW,Shih WL,Lin CL,Liu CJ,Jian JW,Tsai KS,et al.Body-mass index andprogression of hepatitis B:a population-based cohort study in men.J Clin Oncol2008;26:5576–5582.[14]Peng D,Han Y,Ding H,Wei L.Hepatic steatosis in chronic hepatitis Bpatients is associated with metabolic factors more than viral factors.J Gastroenterol Hepatol2008;23:1082–1088.[15]Shi JP,Fan JG,Wu R,Gao XQ,Zhang L,Wang H,et al.Prevalence and riskfactors of hepatic steatosis and its impact on liver injury in Chinese patients with chronic hepatitis B infection.J Gastroenterol Hepatol 2008;23:1419–1425.[16]Wong VW,Wong GL,Yu J,Choi PC,Chan AW,Chan HY,et al.Interaction ofadipokines and hepatitis B virus on histological liver injury in the Chinese.Am J Gastroenterol2010;105:132–138.[17]Altlparmak E,Koklu S,Yalinkilic M,Yuksel O,Cicek B,Kayacetin E,et al.Viraland host causes of fatty liver in chronic hepatitis B.World J Gastroenterol 2005;11:3056–3059.[18]Hui CK,Zhang HY,Lee NP,Chan W,Yueng YH,Leung KW,et al.Serumadiponectin is increased in advancing liverfibrosis and declines with reduction infibrosis in chronic hepatitis B.J Hepatol2007;47:191–202. 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