Association between sub-clinical inflammation and non-alcoholic fatty liver disease (NAFLD) has not been studied in Asian Indians. In this case-control study, we aimed to analyse association of NAFLD with the sub-clinical inflammation and metabolic profile in Asian Indians in north India.
Ultrasound diagnosed 120 cases of NAFLD were compared to 152 healthy controls without NAFLD. Anthropometric profile [body mass index (BMI), waist circumference (WC), hip circumference (HC)], high-sensitivity C-reactive protein (hs-CRP), metabolic profile [fasting blood glucose (FBG), lipid profile] and hepatic function tests [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)] were recorded.
Metabolic parameters [FBG, total cholesterol (TC), serum triglycerides (TG),low-density lipoprotein (LDL-c)], hs-CRP and prevalence of the metabolic syndrome were higher in cases as compared to controls (p-value<0.05 for all). The median (range) of hs-CRP (mg/L) for cases [2.6(0.2–13.4)] were significantly higher than in controls [1.4(0.03–11.4), p = 0.01]. Similarly, higher values of hs-CRP were obtained when subgroups of cases with obesity, abdominal obesity and the metabolic syndrome were compared to controls [2.75 (0.03–14.3) vs. 1.52 (0.04–14.3), p = 0.0010; 2.8 (0.03–14.3) vs. 1.5 (0.06–14.3), p = 0.0014 and 2.7 (0.5–14.3) vs. 1.6 (0.06–8.5), p = 0.0013, respectively. On multivariate logistic regression analysis BMI (p = 0.001), WC (p = 0.001), FBG (p = 0.002), TC (p = 0.008), TG (p = 0.002), blood pressure (p = 0.005), metabolic syndrome (p = 0.001) and hs-CRP (p = 0.003) were significantly and independently associated with NAFLD. After adjusting for significant variables, the association between high hs-CRP and NAFLD remained large and statistically significant [adjusted OR = 1.17, 95% confidence interval (CI) = 1.05–1.29]. An increase in 1 mg/dl of hs-CRP level calculated to increase the risk of developing NAFLD by 1.7 times as compared to controls after adjusting for significant variables associated with NAFLD.
In this cohort of Asian Indians in North India, presence of NAFLD showed independent relationships with sub-clinical inflammation.
Citation: Nigam P, Bhatt SP, Misra A, Vaidya M, Dasgupta J, et al. (2013) Non-Alcoholic Fatty Liver Disease Is Closely Associated with Sub-Clinical Inflammation: A Case-Control Study on Asian Indians in North India. PLoS ONE 8(1): e49286. doi:10.1371/journal.pone.0049286
Editor: Cordula M. Stover, University of Leicester, United Kingdom
Received: August 1, 2012; Accepted: October 8, 2012; Published: January 11, 2013
Copyright: © 2013 Nigam et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was fully supported by a grant from the Indian Council of Medical Research (No. 5/9/70/2008-RHM) Government of India. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
High sensitivity C-reactive protein (hs-CRP), synthesized in hepatocytes, is an acute-phase reactant that increases non-specifically in bacterial infections, immuno-inflammatory diseases and malignant disorders. Obesity, particularly abdominal adiposity, is characterised by low-grade systemic inflammation. In prospective studies, high hs-CRP levels have been shown to predict the metabolic syndrome , type 2 diabetes mellitus (T2DM)  and coronary heart disease (CHD) . Increased hs-CRP levels have been shown to correlate with generalised and abdominal adiposity in Asian Indians .
The development of non-alcoholic fatty liver disease (NAFLD) is strongly associated with the presence of the metabolic syndrome . Current understanding of pathogenesis of NAFLD and non-alcoholic steato-hepatitis (NASH) involves a two-hit hypothesis wherein first, hepatic insulin resistance causes steatosis, and second, pathogenic stimulus causes oxidative stress and cytokines production leads to hepatic inflammation. Interestingly, systemic sub-clinical inflammation could be contributed by hepatic inflammation as well as from visceral adipose tissue. Recent data also show that hs-CRP is a biomarker for NAFLD in some ethnic groups (Japanese)  while no association has been shown by others (Europeans) .
Asian Indians are highly predisposed to develop insulin resistance, the metabolic syndrome, T2DM and CHD; more than white Caucasians , . Asian Indians have abnormal body composition consisting of high body fat and abdominal adiposity that may partially explain the high prevalence of these clinical disorders . Further, they have higher hs-CRP levels than white Caucasians , . Our previous studies have shown high hs-CRP levels in urban Asian Indian adolescents living in India . Further, we also showed that accumulation of fat in other ectopic sites (soleus muscles; intra-myocellular triglycerides) showed correlation with hs-CRP but not insulin resistance .
There is paucity of data regarding sub-clinical inflammation and NAFLD in Asian Indians. We hypothesized that sub-clinical inflammation is closely correlated with NAFLD among Asian Indians. To test this hypothesis we designed a case (subjects with NAFLD) and controls (subjects without NAFLD) by analyzing anthropometric and metabolic profiles and hs-CRP levels.
Subjects and Methods
This study has been done in Northern part of India at Fortis Hospital, New Delhi from February 2006 to June 2008 after approval from the institutional ethics committee. All subjects gave written informed consent. Subjects were recruited from the outpatient department of Fortis Hospital.
Subjects with significant alcohol intake (>20 g/day) type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD), presence of other liver diseases (alcoholic liver disease, viral hepatitis, autoimmune hepatitis, primary biliary cirrhosis, biliary obstruction, drug-induced liver damage etc.), severe end organ damage, human immunodeficiency virus infection, pregnancy and lactation, were excluded from the study. A detailed history (demographic and social economic profiles, history of smoking, and alcohol intake and physical activity patterns) and family history (T2DM, overweight, hypertension, liver disease, and CVD) were obtained. Clinical, demographic and socioeconomic profiles of 272 apparently healthy subjects were studied.
For measurement of weight, subject was instructed to stand still in the platform, with the body weight evenly distributed between both the feet. After removing heavy clothing weight was measured to the nearest of 0.1 kg. Height was measured using stadiometer with head held in Frankfort plane to the nearest of 0.1 cm. Body mass index (BMI) was calculated by the following formula; weight (kg)/height (m2). Waist circumference (WC) was measured mid way between iliac crest and lowermost margin of the ribs, in quiet breathing. Hip circumference (HC) was measured at the maximum protruding part of buttocks at the level of the greater trochanter with the patient wearing minimal clothing and with feet together. Mid-thigh circumference was taken at the point in anterior midline of the thigh, midway between the inguinal ligament and base of patella to the nearest of 0.1 mm. Pulse rate was recorded after 5 minutes of rest. Blood pressure was also recorded after at least 5 minutes of rest in a chair, with feet on the floor, and arm supported at heart level, using a mercury sphygmomanometer. An appropriate-sized cuff (cuff bladder encircling at least 80% of the arm) was used to ensure accuracy. Systolic blood pressure was measured at the point where the first of two or more sounds was heard (phase 1), and diastolic blood pressure before the disappearance of sounds (phase 5).
Biochemical Analysis and hs-CRP Assay
Estimations for fasting blood glucose (FBG), total cholesterol (TC), serum triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were done as previously described .
Levels of hs-CRP were measured using ELISA kit (Biocheck Inc., CA, USA). In this assay system unique monoclonal antibody was directed against a distinct antigenic determinant on the CRP molecule and it is attached to the surface of microtitre wells on the ELISA plate. A horseradish peroxidase-conjugated goat anti-CRP antibody was used as the secondary antibody was used as the secondary antibody. The test sample was allowed to react simultaneously with the antibodies resulting in sandwiching of CRP molecules between solid phase and enzyme linked antibodies. Intensity of the blue color following addition of tetramethylbenzidine substrate is directly proportional to the concentrations of CRP in the sample. According to the manufacturers, the normal CRP concentration using this assay ranged from 0.068 to 8.2 mg/l, the lowest detectable limit being 0.005 mg/l. The intra-assay variation determined using duplicate samples was 1.7–3.3%.
Ultrasound Imaging of Liver
Liver ultrasound was carried out using 3.5 MHz curvilinear probe (Siemens-G 60 S 2004, Germany) by a trained radiologist with post graduate qualifications, who followed the standardized procedure. A complete examination required both sub-costal and inter-costal scanning. The definition of fatty liver was based on a comparative assessment of image brightness relative to the kidneys, according to previously reported diagnostic criteria –. Severity of fatty liver was classified according to the brightness compared to kidneys, blurring of gall bladder wall and attenuation of hepatic veins. Liver span was measured in the mid-clavicular line by marking upper and lower limit of liver using ultrasonic probe. The radiologist performing the ultrasound was blinded to the clinical data.
High hs-CRP level was defined as >1 mg/L . Overweight/obesity was defined as BMI ≥23 kg/m2 . Waist circumference ≥90 cm for males and ≥80 cm for females was considered an indicator of abdominal obesity . Impaired fasting glucose (IFG) was diagnosed according to the diagnostic criteria of the American Diabetes Association . The metabolic syndrome was defined based on the consensus statement for diagnosis of obesity, abdominal obesity and metabolic syndrome for Asian Indians . Physical activity is defined as >20 minutes brisk walk per day. Any degree of current smoking was taken as definition of smoking.
Data were presented as either mean ± standard deviation (SD) or median (range) as appropriate. The differences in mean values of the variables between cases and controls were tested using student t-test. Chi square test was used to test the association between categorized variables and independent t-test was used to compare means of continuous variables. Wilcoxon rank-sum test was used to detect the differences in hs-CRP values between cases and controls with obesity, abdominal obesity, and metabolic syndrome. Multivariate logistic regression analysis was carried out with NAFLD as the dependent variable and smoking, family history of T2DM and CVD, age, BMI, WC, TC, FBG, HDL-c, LDL-c, ALT, AST and hs-CRP (after removing the outliers to achieve normality) as an independent variables to assess significant predictors and unadjusted odds ratio and 95% confidence interval (OR (95% CI). To assess the effect of hs-CRP on NAFLD, adjusted odds ratio estimated by controlling the other significant predictors of NAFLD. p-value<0.05 was considered as statistically significant. Various statistical measures evaluated with the help of statistical packages SPSS 11 for windows (SPSS, Inc., Chicago, IL, USA).
Among 272, 120 subjects (males 92) had NAFLD (“cases”) while 152 subjects (males 105) had normal liver ultrasonography (“controls”). Smoking and family history of T2DM and CVD were significantly higher among cases as compared to controls (Table 1). Prevalence of overweight, obesity, the metabolic syndrome, hs-CRP levels and IFG were significantly higher in cases than controls (Table 2). Significantly higher values of BMI, WC, HC, weight- to-height ratio, mid-thigh circumference, FBG, TC, TG, LDL-c, AST and ALT were recorded in cases than in controls (Table 3).
Table 1. Demographic and Lifestyle Profiles.doi:10.1371/journal.pone.0049286.t001
Table 2. Distribution of hs-CRP According to Presence of Impaired Fasting Glucose, Body Mass Index and the Metabolic Syndrome.doi:10.1371/journal.pone.0049286.t002
Table 3. Clinical and Biochemical Parameters.doi:10.1371/journal.pone.0049286.t003
The median (range) of hs-CRP (mg/dL) for cases [2.6 (0.2–13.4)] was significantly higher than controls [1.4 (0.03–11.4), p value = 0.01] (Table 3). Similarly, higher values of hs-CRP were obtained when subgroups of cases and controls with obesity, abdominal obesity and the metabolic syndrome were compared [2.75 (0.03–14.3) vs. 1.52 (0.04–14.3), p = 0.001; 2.8 (0.03–14.3) vs. 1.5 (0.06–14.3), p = 0.0014; and 2.7 (0.5–14.3) vs. 1.6 (0.06–8.5), p = 0.0013, respectively]. (Fig. 1)
Figure 1. Box plot representation of hs-CRP levels in subjects with non-alcoholic fatty liver disease and in controls having overweight and obesity (a), abdominal obesity (b), and the metabolic syndrome (c).
Each box comprises the values between the 25th and the 75th percentiles, and the bold horizontal line is the median value; the whiskers stretch from the 10th and to the 90th percentile. Circles represent individual outlier's value. Stars represent extremes value of individual.doi:10.1371/journal.pone.0049286.g001
On multivariate logistic regression analysis BMI (p = 0.001), WC (p = 0.001), FBG (p = 0.002), TC (p = 0.008), TG (p = 0.002), blood pressure (p = 0.005), the metabolic syndrome (p = 0.001) and hs-CRP (p = 0.003) were significantly and independently associated with NAFLD (Table 4). To assess the effect of hs-CRP on NAFLD, adjusted OR (95% CI) for hs-CRP was estimated after adjusting for significant variables. Unadjusted and adjusted OR (95% CI) for hs-CRP were 1.2 (1.09–1.38) and 1.7 (1.05–1.29), respectively. An increase in 1 mg/dl of hs-CRP level calculated to increase the risk of developing NAFLD by 1.7 times as compared to controls after adjusting for significant variables associated with NAFLD.
This is the first case-control study in which comprehensive analysis of hs-CRP, anthropometric and metabolic co-variates has been researched among Asian Indians in north India. In this study, the NAFLD was associated with hs-CRP in apparently healthy Asian Indians independent of obesity and abdominal obesity.
Several studies have suggested the association of NAFLD with obesity, abdominal obesity, dysglycemia and various components of the metabolic syndrome . However, limited data show elevation of serum hs-CRP levels. The current study has also shown higher hs-CRP levels in NAFLD as compared to those without NAFLD. Our observations are important in the light of the information that hs-CRP levels are higher in Asian Indians than in White Caucasians , . The findings of present study are in line with previous data on cross-sectional association between the hs-CRP and NAFLD in Japanese and Korean Asians , . In the cross-sectional study by Park et al , elevated hs-CRP level was associated with NAFLD in apparently healthy non-obese Korean men.
Elevation of serum hs-CRP usually reflects its synthesis in response to a pathological process . In vivo release of interleukin-6 (IL-6), linked closely to hs-CRP pathway, but not tumor necrosis factor-α (TNF-α), which is related to insulin resistance, has been reported in human subcutaneous adipose tissue (SAT) . We speculate that relatively larger SAT mass (truncal and peripheral SAT) in Asian Indians as compared to white Caucasians as has been shown in several studies , , is likely to generate relatively higher amounts of hs-CRP and preferentially drive this pathway rather than the insulin resistance pathway, although both appear to be interlinked. This is in line with our previous study  wherein triceps skin fold thickness (indicative of peripheral SAT) was an independent risk factor associated with elevated hs-CRP level. Importantly, when compared with white Caucasians and blacks, triceps skin fold thickness was significantly thicker in Asian Indians . Further, hepatic triglycerides appear to be higher in Asian Indians as compared to white Caucasians. By using proton magnetic resonance spectroscopy, Shulman et al  measured hepatic triglyceride (HTG) content and plasma IL-6 concentrations in different ethnic groups in USA. Interestingly, these authors reported that the HTG content and plasma IL-6 concentrations were nearly 2-fold higher in Asian Indians as compared to white Caucasians. Whether this increased hepatic HTG content could lead to increased hs-CRP levels in Asian Indians has not been investigated.
While the pathophysiology of NAFLD remains incompletely understood, accumulation of triglycerides in hepatocytes in presence of oxidative stress, lipid peroxidation, pro-inflammatory cytokines (e.g. TNF-α, IL-6) appears to be important . In the patients with NAFLD and NASH, liver biopsies have revealed hepatic distribution (mRNA) of the inflammatory cytokine TNF-α with its receptors  and the adiponectin with its receptors . As showed in animal studies, the increased amount of fatty acids present in the liver may mediate hepatic production of TNF-α, causing increased systemic levels of TNF-α . When hepatocytes get damaged, liver-specific macrophages (‘Kupffer Cells’) get activated and secrete more TNF-α and IL-6 into the blood . TNF-α and IL-6 are considered to induce hepatic production of the acute phase protein hs-CRP .
A limitation of this study was that the diagnosis of NAFLD was based on liver ultrasonography. It has been argued that other methods; magnetic resonance spectroscopy and liver biopsy are better tools for defining NAFLD, and could be considered as “gold standards”. Conversely, ultrasonography is by far the most common method of diagnosing NAFLD in clinical practice and has a fair sensitivity (87%) and specificity (94%) in detecting hepatic steatosis . It is simple to perform, non-invasive, cost-effective and does not entail any radiation hazard, and could also be used in the epidemiological studies. Previous publications in reference to hs-CRP in NAFLD have also relied either exclusively or substantially on ultrasound-based imaging for diagnosis of hepatic steatosis . Hence, although not “gold standard”, this method of investigation provides reasonable alternative to more expensive and difficult-to-perform diagnostic methods of NAFLD.
In summary, we demonstrate the association of inflammatory response (hs-CRP) with NAFLD in Asian Indians in north India for the first time. High hs-CRP levels, dysglycemia, obesity, and abdominal obesity were found to be independent predictors of NAFLD.
Conceived and designed the experiments: PN AM MV DSC. Performed the experiments: PN SPB. Analyzed the data: PN JD. Contributed reagents/materials/analysis tools: PN SPB JD. Wrote the paper: PN AM.
- 1. Ridker PM, Buring JE, Cook NR, Rifai N (2003) C-reactive protein, the metabolic syndrome, and risk of incident cardiovascular events: an 8-year follow-up of 14 719 initially healthy American women. Circulation 107: 391–7.
- 2. Barzilay JI, Abraham L, Heckbert SR, Cushman M, Kuller LH, et al. (2001) The relation of markers of inflammation to the development of glucose disorders in the elderly: the Cardiovascular Health Study. Diabetes 50: 2384–9.
- 3. Ridker PM, Rifai N, Cook NR, Bradwin G, Buring JE (2005) Non-HDL cholesterol, apolipoproteins A-I and B100, standard lipid measures, lipid ratios, and CRP as risk factors for cardiovascular disease in women. Jama 294: 326–33.
- 4. Vikram NK, Misra A, Dwivedi M, Sharma R, Pandey RM, et al. (2003) Correlations of C-reactive protein levels with anthropometric profile, percentage of body fat and lipids in healthy adolescents and young adults in urban North India. Atherosclerosis 168: 305–13.
- 5. Socha P, Wierzbicka A, Neuhoff-Murawska J, Wlodarek D, Podlesny J, et al. (2007) Nonalcoholic fatty liver disease as a feature of the metabolic syndrome. Rocz Panstw Zakl Hig 58: 129–37.
- 6. Uchihara M, Izumi N (2006) [High-sensitivity C-reactive protein (hs-CRP): a promising biomarker for the screening of non-alcoholic steatohepatitis (NASH)]. Nippon Rinsho 64: 1133–8.
- 7. Haukeland JW, Damas JK, Konopski Z, Loberg EM, Haaland T, et al. (2006) Systemic inflammation in nonalcoholic fatty liver disease is characterized by elevated levels of CCL2. J Hepatol 44: 1167–74.
- 8. Misra A, Khurana L (2008) Obesity and the metabolic syndrome in developing countries. J Clin Endocrinol Metab 93: S9–30.
- 9. Misra A, Khurana L (2009) The metabolic syndrome in South Asians: epidemiology, determinants, and prevention. Metab Syndr Relat Disord 7: 497–514.
- 10. Chambers JC, Eda S, Bassett P, Karim Y, Thompson SG, et al. (2001) C-reactive protein, insulin resistance, central obesity, and coronary heart disease risk in Indian Asians from the United Kingdom compared with European whites. Circulation 104: 145–50.
- 11. Chandalia M, Cabo-Chan AV Jr, Devaraj S, Jialal I, Grundy SM, et al. (2003) Elevated plasma high-sensitivity C-reactive protein concentrations in Asian Indians living in the United States. J Clin Endocrinol Metab 88: 3773–6.
- 12. Sinha S, Misra A, Rathi M, Kumar V, Pandey RM, et al. (2009) Proton magnetic resonance spectroscopy and biochemical investigation of type 2 diabetes mellitus in Asian Indians: observation of high muscle lipids and C-reactive protein levels. Magn Reson Imaging 27: 94–100.
- 13. Bajaj S, Nigam P, Luthra A, Pandey RM, Kondal D, et al. (2009) A case-control study on insulin resistance, metabolic co-variates & prediction score in non-alcoholic fatty liver disease. Indian J Med Res 129: 285–92.
- 14. Hsiao PJ, Kuo KK, Shin SJ, Yang YH, Lin WY, et al. (2007) Significant correlations between severe fatty liver and risk factors for metabolic syndrome. J Gastroenterol Hepatol 22: 2118–23.
- 15. Hamer OW, Aguirre DA, Casola G, Lavine JE, Woenckhaus M, et al. (2006) Fatty liver: imaging patterns and pitfalls. Radiographics 26: 1637–53.
- 16. Saadeh S, Younossi ZM, Remer EM, Gramlich T, Ong JP, et al. (2002) The utility of radiological imaging in nonalcoholic fatty liver disease. Gastroenterology 123: 745–50.
- 17. Pearson TA, Mensah GA, Alexander RW, Anderson JL, Cannon RO 3rd, et al. (2003) Markers of inflammation and cardiovascular disease: application to clinical and public health practice: A statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation 107: 499–511.
- 18. Misra A, Chowbey P, Makkar BM, Vikram NK, Wasir JS, et al. (2009) Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management. J Assoc Physicians India 57: 163–70.
- 19. Grundy SM, Cleeman JI, Daniels SR, Donato KA, Eckel RH, et al. (2005) Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation 112: 2735–52.
- 20. Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (2003) Report of the expert committee on the diagnosis and classification of diabetes mellitus. Diabetes Care 26 Suppl 1: S5–20.
- 21. Marchesini G, Bugianesi E, Forlani G, Cerrelli F, Lenzi M, et al. (2003) Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome. Hepatology 37: 917–23.
- 22. Chambers JCES, Bassett P, Karim Y, Thompson SG, Gallimore JR, et al. (2001) C-reactive protein, insulin resistance, central obesity, and coronary heart disease risk in Indian Asians from the United Kingdom compared with European whites. Circulation 104: 145–50.
- 23. Yoneda M, Mawatari H, Fujita K, Iida H, Yonemitsu K, et al. (2007) High-sensitivity C-reactive protein is an independent clinical feature of nonalcoholic steatohepatitis (NASH) and also of the severity of fibrosis in NASH. J Gastroenterol 42: 573–82.
- 24. Riquelme A, Arrese M, Soza A, Morales A, Baudrand R, et al. (2009) Non-alcoholic fatty liver disease and its association with obesity, insulin resistance and increased serum levels of C-reactive protein in Hispanics. Liver Int 29: 82–8.
- 25. Park SH, Kim BI, Yun JW, Kim JW, Park DI, et al. (2004) Insulin resistance and C-reactive protein as independent risk factors for non-alcoholic fatty liver disease in non-obese Asian men. J Gastroenterol Hepatol 19: 694–8.
- 26. Kao PC, Shiesh SC, Wu TJ (2006) Serum C-reactive protein as a marker for wellness assessment. Ann Clin Lab Sci 36: 163–9.
- 27. Mohamed-Ali V, Goodrick S, Rawesh A, Katz DR, Miles JM, et al. (1997) Subcutaneous adipose tissue releases interleukin-6, but not tumor necrosis factor-alpha, in vivo. J Clin Endocrinol Metab 82: 4196–200.
- 28. Vikram NK, Misra A, Pandey RM, Dwivedi M, Luthra K, et al. (2006) Association between subclinical inflammation & fasting insulin in urban young adult north Indian males. Indian J Med Res 124: 677–82.
- 29. Misra A, Vikram NK, Arya S, Pandey RM, Dhingra V, et al. (2004) High prevalence of insulin resistance in postpubertal Asian Indian children is associated with adverse truncal body fat patterning, abdominal adiposity and excess body fat. Int J Obes Relat Metab Disord 28: 1217–26.
- 30. Petersen KF, Dufour S, Feng J, Befroy D, Dziura J, et al. (2006) Increased prevalence of insulin resistance and nonalcoholic fatty liver disease in Asian-Indian men. Proc Natl Acad Sci U S A 103: 18273–7.
- 31. Duvnjak M, Lerotic I, Barsic N, Tomasic V, Virovic Jukic L, et al. (2007) Pathogenesis and management issues for non-alcoholic fatty liver disease. World J Gastroenterol 13: 4539–50.
- 32. Crespo J, Cayon A, Fernandez-Gil P, Hernandez-Guerra M, Mayorga M, et al. (2001) Gene expression of tumor necrosis factor alpha and TNF-receptors, p55 and p75, in nonalcoholic steatohepatitis patients. Hepatology 34: 1158–63.
- 33. Kaser S, Moschen A, Cayon A, Kaser A, Crespo J, et al. (2005) Adiponectin and its receptors in non-alcoholic steatohepatitis. Gut 54: 117–21.
- 34. Feldstein AE, Werneburg NW, Canbay A, Guicciardi ME, Bronk SF, et al. (2004) Free fatty acids promote hepatic lipotoxicity by stimulating TNF-alpha expression via a lysosomal pathway. Hepatology 40: 185–94.
- 35. Wieckowska A, Papouchado BG, Li Z, Lopez R, Zein NN, et al. (2008) Increased hepatic and circulating interleukin-6 levels in human nonalcoholic steatohepatitis. Am J Gastroenterol 103: 1372–9.
- 36. Blake GJ, Ridker PM (2002) Inflammatory bio-markers and cardiovascular risk prediction. J Intern Med 252: 283–94.
- 37. Mathiesen UL, Franzen LE, Aselius H, Resjo M, Jacobsson L, et al. (2002) Increased liver echogenicity at ultrasound examination reflects degree of steatosis but not of fibrosis in asymptomatic patients with mild/moderate abnormalities of liver transaminases. Dig Liver Dis 34: 516–22.
- 38. Kogiso T, Moriyoshi Y, Shimizu S, Nagahara H, Shiratori K (2009) High-sensitivity C-reactive protein as a serum predictor of nonalcoholic fatty liver disease based on the Akaike Information Criterion scoring system in the general Japanese population. J Gastroenterol 44: 313–21.