Prevalence of nonalcoholic fatty liver among administrative officers in Shanghai: an epidemiological survey

Epidemiology and risk factors of nonalcoholic fatty liver disease (NAFLD)

The nonalcoholic fatty liver disease (NAFLD) is defined as the presence of hepatic steatosis, determined by either imaging or histology, in the absence of secondary causes of hepatic fat accumulation. Nonalcoholic fatty liver is defined as the presence of hepatic steatosis with no evidence of hepatocellular injury in the form of ballooning of the hepatocytes or fibrosis. NASH is defined as the presence of hepatic steatosis and inflammation with hepatocyte injury (ballooning) with or without fibrosis. Although initial epidemiological studies have focused on its prevalence in the Western countries, it is becoming increasingly clear that NAFLD is highly prevalent in the Asia Pacific region, and there may be important distinctions in its phenotype between Asia Pacific and Western countries. Of particular interest are "lean NAFLD" and the "urban-rural divide," which will be discussed in this review article. Obesity, dyslipidemia, type 2 diabetes and metabolic syndrome are established risk factors for developing NAFLD. Many other risk factors (e.g., hypothyroidism, polycystic ovary syndrome, obstructive sleep apnea, hypopituitarism and hypogonadism) for NAFLD have been described in the Western countries, but these associations are yet to be investigated adequately in the Asia Pacific region.

Risk factors of non-alcoholic fatty liver disease in patients with inflammatory bowel disease

BACKGROUND

Metabolic risk factors are associated with non-alcoholic fatty liver disease (NAFLD), but they are less frequent in inflammatory bowel disease (IBD).

AIM

This study evaluates the frequency of NAFLD and its risk factors among IBD patients including anti-TNF-α therapy.

METHODS

IBD patients who underwent abdominal imaging from January, 2009 to December, 2010 were analyzed in this nested, case-controlled study. IBD patients with NAFLD by imaging were compared with those who had no evidence of NAFLD (control).

RESULTS

Among 928 IBD patients, 76 (8.2%) had evidence of NAFLD by imaging, and were compared to 141 patients without NAFLD evaluated (study: control ratio=~1:2). NAFLD patients were older (46.0 ± 13.3 vs. 42.0 ±14.1 years; p=0.018) and had a later onset of IBD compared to the control group (37.2 ± 15.3 vs. 28.7 ± 23.8 years; p=0.002). Metabolic syndrome was present in 29.0% of NAFLD patients, with a median Adult Treatment Panel risk factor of 2 [Interquartile range 1,3]. Patients not receiving anti-TNF-α therapy had a higher occurrence of NAFLD (p=0.048). In multivariate analysis, hypertension (OR=3.5), obesity (OR=2.1), small bowel surgeries (OR=3.7), and use of steroids at the time of imaging (OR=3.7) were independent factors associated with NAFLD.

CONCLUSION

NAFLD occurred in 8.2% of the IBD population. NAFLD patients were older and had a later onset of IBD disease. IBD patients develop NAFLD with fewer metabolic risk factors than non-IBD NAFLD patients. It is also less common among patients who received anti-TNF-α therapy.

Non-B, non-C hepatocellular carcinoma (Review)

Although most hepatocellular carcinoma (HCC) is related to viral infection, there is a substantial population of HCC patients (5-20%) who are negative for both markers of hepatitis B virus and hepatitis C virus infection [non-B, non-C (NBNC) hepatitis] in Japan and the incidence of NBNC-HCC has recently tended to increase. The most common cause of liver disease in developed countries is non‑alcoholic fatty liver disease (NAFLD), which includes non‑alcoholic steatohepatitis (NASH) and its related complications. Increased body mass index and diabetes mellitus are associated with developing NAFLD and NASH, which is a severe form of NAFLD. Furthermore, increasing clinical evidence supports the fact that NAFLD and NASH can progress to liver cirrhosis and even HCC. A detailed understanding of the epidemiology, etiology, molecular mechanism, clinical features and prognosis of NBNC-HCC could improve our screening and therapy of this disease. In this review, we primarily focus on clinical aspects of NBNC-HCC and refer to our current knowledge of this cancer.

Epidemiology of alcoholic and nonalcoholic fatty liver disease in China

The prevalence of patients presenting with fatty liver disease (FLD) in China has approximately doubled over the past two decades. At present, FLD, which is typically diagnosed by imaging, is highly prevalent (≈ 27% urban population) in China and is mainly related to obesity and metabolic syndrome (MetS). However, the percentage of alcoholic liver disease (ALD) among patients with chronic liver diseases in clinic is increasing as well, and a synergetic effect exists between heavy alcohol drinking and obesity in ALD. Prevalence figures reveal regional variations, with a median prevalence of ALD and nonalcoholic FLD (NAFLD) of 4.5% and 15.0%, respectively. The prevalence of NAFLD in children is 2.1%, although the prevalence increases to 68.2% among obese children. With the increasing pandemic of obesity and MetS in the general population, China is likely to harbor an increasing reservoir of patients with FLD. The risk factors for FLD resemble to those of Caucasian counterparts, but the ethnic-specific definitions of obesity and MetS are more useful in assessment of Chinese people. Therefore, FLD/NAFLD has become a most common chronic liver disease in China. Public health interventions are needed to halt the worldwide trend of obesity and alcohol abuse to ameliorate liver injury and to improve metabolic health.

Prevalence and associated metabolic factors of fatty liver disease in the elderly

OBJECTIVE

The aim of this study was to investigate the metabolic risk factors for fatty liver disease in the elderly, and determine the prevalence of fatty liver disease in the elderly in Wuhan, central China.

METHODS

The study was a case-control study based on all 4226 adults above 60 years of age from a cohort investigated in 2010-11 at the medical examination center of Zhongnan hospital, using 3145 randomly selected adults under 60 years of age from the same cohort as controls. Fatty liver disease (FLD) was identified with ultrasound imaging. The risk factors measured were body mass index (BMI), and plasma concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low density lipoprotein (LDL) and serum uric acid (SUA). The probability of steatohepatitis with advanced fibrosis was predicted using a score based on BMI, age, ALT, and TG (BAAT),and using AST/ALT ratio (AAR).

RESULTS

FLD was higher in the elderly (26.7%) than in the non-elderly (22.8%) and similar in the elderly between men and women (26.6% vs 27.0%, p>0.05). BMI, TC, TG, LDL, SUA, AST and ALT were all significantly higher in FLD, whereas the level of HDL was markedly lower. Multiple regression analyses showed that obesity, high TC, TG, SUA, low HDL, and elevated ALT, AAR<1 were closely related to the elderly FLD, while male sex, obesity, high TC, TG, low HDL, elevated ALT, AST and AAR<1 were closely related to the non-elderly FLD. The prevalence of steatohepatitis with advanced fibrosis estimated as BAAT index≥3 was 2.4% in all subjects, and was higher in the elderly FLD patients than in the non-elderly FLD patients.

CONCLUSION

The prevalence of FLD is higher in the elderly, and is broadly related to the same metabolic risk factors as in the non-elderly. However, female-sex is no longer protective with increasing age, and the prevalence of steatohepatitis with advanced fibrosis is estimated to be considerably higher in the elderly FLD patients than in the non-elderly FLD controls.

Non alcoholic fatty liver disease in southern Iran: a population based study

BACKGROUND

Population based studies on prevalence and risk factors of NAFLD in Iranian population are few. The prevalence of NAFLD and non alcoholic steatohepatitis (NASH) in Iranians varies from 2.9% to 7.1% in general population and 55.8% in patients with type 2 diabetes mellitus.

OBJECTIVES

To determine the prevalence and determinants of non alcoholic fatty liver disease (NAFLD) in a sample of adult Iranian general population.

PATIENTS AND METHODS

This was a cross-sectional study being performed in Shiraz, southern Iran during a 10-month period from November 2010 to September 2011 through cluster random sampling of Iranian general population in Shiraz region. All individuals undergone anthropometric, blood pressure measurements, thorough medical history and physical examinations. Laboratory measurements included fasting blood glucose (FBS), lipid profile, complete blood count (CBC) and liver function tests. NAFLD was diagnosed by transabdominal ultrasonography.

RESULTS

819 subjects were included in this study among which were 340 males (41.5%) and 479 females (58.5%) with the mean age of 43.1 ± 14.1 years. NAFLD was diagnosed in 176 (21.5%) subjects. Patients with NAFLD were significantly older (P < 0.001), had higher proportion of male gender (P = 0.004) and had higher BMI (P < 0.001). They also had higher prevalence of hypertension (P < 0.001), high FBS (P < 0.001), high cholesterol (P = 0.026), high triglyceride (P < 0.001) and high waist circumference (P < 0.001). Taking all these together, patients with NAFLD had significantly higher prevalence of metabolic syndrome when compared to healthy subjects (P < 0.001).

CONCLUSION

The prevalence of NAFLD in this group of Iranian adult general population is 21.5%. NAFLD in Iranian population is associated with male gender, old age, obesity, and features of metabolic syndrome.

Nonalcoholic fatty liver disease following liver transplantation

Post-transplant, nonalcoholic hepatic steatosis and steatohepatitis are increasingly recognized as a complication of liver transplantation, and the progression of the latter through fibrosis to cirrhosis has been clearly shown. Non-alcoholic steatohepatitis (NASH) is independently associated with an increased risk of death from cardiovascular and liver diseases. While optimal therapy is not yet available in the post-liver transplant setting, knowledge gained in the therapy of NASH in the non-transplant setting can be used to design therapeutic interventions. In addition, early recognition with protocol liver biopsies and an effective preventive strategy by modifying known risk factors implicated in the recurrence of NASH would be the most effective way to curtail the progression of NASH before an effective treatment can be found. Additional rigorous research aimed at elucidating the pathogenesis, natural history, and selection of immunosuppressants for NASH is clearly warranted.

Anti-inflammatory effects of total alkaloids from Rubus alceifolius Poir [corrected]. on non-alcoholic fatty liver disease through regulation of the NF-κB pathway

We aimed to explore the anti-inflammatory effects of total alkaloids inRubus alceifolius Poir [corrected]. (TARAP) on non-alcoholic fatty liver disease, and to investigate the possible molecular mechanisms. A rodent non-alcoholic fatty liver disease (NAFLD) model was established by administration of a modified high-fat diet ad libitum for 8 weeks. Rats were treated with polyene phosphatidylcholine (PP), TARAP low‑dose (0.72 g/kg body weight/day) and TARAP high-dose (1.44 g/kg body weight/day). The model group and the control group received distilled water. After treatment for 4 weeks, the blood samples were obtained from the abdominal aorta, and the levels of serum ALT, AST, GGT, ALP, TG, TC, HDL-C and LDL-C were measured. Changes in liver tissue morphology were evaluated by H&E staining. The expression levels of nuclear factor (NF)-κB, cyclooxygenase-2 (COX‑2), interleukin (IL)-6 and tumor necrosis factor (TNF)-α in rat livers were assayed by reverse transcription‑polymerase chain reaction (RT-PCR) and immunohistochemistry. Both TARAP and PP attenuated hepatic steatosis induced by the high-fat diet. The modified high-fat diet caused a significant increase in ALT, AST, GGT, ALP, TG, TC, LDL-C levels and a decrease in HDL-C levels. TARAP and PP treatment abrogated the increase in the levels of liver enzymes and the levels of TG, TC, LDL-C, as well as suppressed the increase in HDL-C levels. The results of RT-PCR and immunohistochemical assay showed that PP and TARAP treatment decreased the expression of NF-κB, COX-2, IL-6 and TNF-α. In conclusion, these results suggest that TARAP may protect against NAFLD through regulation of the NF-κB pathway.

[Steatohepatitis--a challenge?]

CLINICAL/METHODICAL ISSUE

With the increasing use of cross-sectional imaging techniques both diffuse and focal fat accumulations in the liver are frequent incidental findings. Focal fatty changes in particular, such as localized distribution disorders in steatohepatitis or focal fat deposition of the liver, can lead to difficulties in the correct diagnosis of patients with a history of malignant disease.

STANDARD RADIOLOGICAL METHODS

Ultrasound is used as the first imaging modality in most cases but has a relatively low sensitivity and specificity. In most cases a further diagnosis of diffuse fatty liver accumulations is possible with non-contrast computed tomography (CT) scanning and chemical shift imaging in magnetic resonance imaging (MRI) enabling an even further differential diagnostic distinction of fatty disorders of the liver.

PERFORMANCE

For the detection of generalized fatty liver disease ultrasound has a sensitivity and specificity of 60-100% and 77-95%, respectively. Non-contrast CT of the liver attains a sensitivity of between 43% and 95% with a specificity of 90%. Sensitivity and specificity for chemical shift imaging of MRI are 81% and 100%, respectively.

PRACTICAL RECOMMENDATIONS

For advanced differential diagnostic distinction of the different forms of fatty liver disorders and for the correct diagnosis of benign and malignant liver lesions the leading imaging modality is chemical shift imaging of MRI (in-phase and opposed-phase).

Association of nonalcoholic fatty liver disease with components of metabolic syndrome according to body mass index in Korean adults

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease, and its prevalence is much higher in obese individuals. NAFLD is closely related to metabolic syndrome (MetS); however, most concepts about the relationship between NAFLD and MetS have emphasized obesity, although NAFLD is not a rare disease in the non-obese population. In the present study, we aim to determine the association between NAFLD and MetS and to compare this association between non-obese and obese individuals.

METHODS

A total of 29,994 adults who underwent routine comprehensive health evaluations, including abdominal ultrasonography, were selected. We calculated the adjusted prevalence ratios (PRs) for components of MetS (high blood pressure (BP), impaired fasting glucose, low high-density lipoprotein cholesterol (HDL-C), and high triglycerides (TG)) according to NAFLD in non-obese and obese patients.

RESULTS

NAFLD was found in 12.6% of non-obese subjects and 50.1% of obese subjects. NAFLD was associated with most components of MetS in both obese and non-obese subjects. However, non-obese NAFLD patients had significantly higher PRs for certain components of MetS than did obese patients, especially among women. Adjusted PRs (95% confidence interval) for components of MetS in non-obese women vs. obese women were as follows: (1) high BP: 1.41 (1.31-1.51) vs. 1.05 (0.89-1.22) (2) impaired fasting glucose: 2.04 (1.95-2.75) vs. 1.37 (1.21-1.53) (3) low HDL-C: 2.00 (1.92-2.08) vs. 1.40 (1.26-1.55), and (4) high TG: 3.36 (3.24-3.47) vs. 1.97 (1.76-2.17).

CONCLUSIONS

NAFLD was associated with risk for components of MetS, and the association was stronger in non-obese than in obese individuals, especially in women. Therefore, NAFLD should be considered a meaningful predictor of metabolic diseases in the non-obese population.

Attenuating effect of Ginkgo biloba leaves extract on liver fibrosis induced by thioacetamide in mice

The purpose of this study is to investigate the effect of Ginkgo biloba leaves extract on experimental liver fibrosis induced by thioacetamide (TAA) in male albino mice. The experimental mice were divided into four groups. The mice of the first group were served as control. The experimental animals of the second group were given 150 mg/kg body weight of TAA by intraperitoneal injection, twice weekly, for 9 weeks. The mice of the third group were exposed to TAA and supplemented with G. biloba leaves extract. The animals of the fourth group were supplemented with G. biloba leaves extract. The levels of plasma alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, triglycerides, cholesterol, and low-density lipoprotein cholesterol were statistically increased while the levels of plasma total protein, albumin, glucose, and high-density lipoprotein cholesterol were significantly decreased. The levels of liver superoxide dismutase, glutathione, glycogen and total protein were notably declined, whereas the level of total lipid was increased in mice of the second group. Furthermore, microscopic examination of liver sections from mice treated with TAA showed an abnormal morphology characterized by nodular transformations in liver parenchyma which surrounded by fibrous septa. Administration of G. biloba leaves extract reduced extent and development of fibrous septa, liver cells change, and biochemical alterations in mice exposed to TAA. This study showed that G. biloba leaves extract has a potential activity against TAA-induced liver fibrosis and suggested that the chemical constituents of G. biloba are effective in modulation of oxidative stress induced by TAA.

Non-alcoholic Fatty Liver Disease: East Versus West

Non-alcoholic fatty liver disease (NAFLD) is an important cause of liver disease worldwide with prevalence ranging from 10% to 30% in various countries. It has become an important cause of unexplained rise in transaminases, cryptogenic cirrhosis, and cryptogenic hepatocellular carcinoma. Pathogenesis is related to obesity, insulin resistance, oxidative stress, lipotoxicity, and resultant inflammation in the liver progressing to fibrosis. Pharmacological treatment in patients with NAFLD is still evolving and the treatment of these patients rests upon lifestyle modification with diet and exercise being the cornerstones of therapy. While there are many similarities between patients with NAFLD from Asia and the West, there are certain features which make the patients with NAFLD from Asia stand apart. This review highlights the data on NAFLD from Asia comparing it with the data from the West.

The efficacy of licorice root extract in decreasing transaminase activities in non-alcoholic fatty liver disease: a randomized controlled clinical trial

This study was performed to investigate the effects of licorice on non-alcoholic fatty liver disease (NAFLD). In this double blind randomized clinical trial, 66 patients were divided into case and control groups. All patients had elevated liver enzymes and had increased liver echogenicity (lipid accumulation) on sonography. The case group was treated with one capsule containing 2 g aqueous licorice root extract per day for 2 months while the control group was treated in the same manner with a placebo. Weight, body mass index (BMI) and liver transaminase levels were measured for each patient before and after the study. In the case group, the mean alanine aminotransferase (ALT) level decreased from 64.09 to 51.27 IU/mL and the aspartate aminotransferase (AST) level decreased from 58.18 to 49.45 IU/mL, which were statistically significant (p < 0.001 and p < 0.001). But in the control group, a drop in the ALT and AST levels was not statistically significant. The BMI difference before and after the study was not statistically significant in both groups. Despite the significant drop in liver enzymes following administration of licorice root extract, it is recommended that further studies that include histological examination are necessary.

Hepatocellular carcinoma in non-alcoholic steatohepatitis: Growing evidence of an epidemic?

The incidence of hepatocellular carcinoma in non-viral-related chronic liver disease has gradually increased in Japan. Obesity and diabetes mellitus type 2 have been established as a significant risk factor for hepatocellular carcinoma (HCC) by epidemiologic observations and experimental studies. The risks of these factors for HCC are likely conferred by two factors: the increased risk for development of non-alcoholic steatohepatitis (NASH) and the carcinogenic potential of themselves. Hepatocellular carcinoma in NASH is difficult to evaluate because histological diagnosis is required for diagnosis of NASH, which can lead selection bias. Furthermore, end-stage NASH is in effect "burned-out" NASH, for which the diagnosis of NASH cannot be made any more. At all events, previous studies on the etiology of Japanese HCC showed that non-alcoholic fatty liver disease accounts for 1-5% of all HCC (male predominant, median age 72 years). They have high prevalences of obesity and/or diabetes mellitus type 2 and 10-75% of the HCC arose from non-cirrhotic livers. HCC in NASH may be of multicentric origin, similar to HCC based on viral hepatitis. Regular screening for HCC is extremely important especially in cirrhotic NASH patients and recurrence should be warned. In western and Asian countries, the prevalence of non-alcoholic fatty liver disease in the general population is increasing dramatically. Therefore, there is an urgent need to elucidate pathogenesis and clinical features of HCC in NASH. In this review we summarize current concepts for HCC in NASH.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) refers to the accumulation of hepatic steatosis not due to excess alcohol consumption. The prevalence of NAFLD is up to 30% in developed countries and nearly 10% in developing nations, making NAFLD the most common liver condition in the world. The pathogenesis of NAFLD is related to insulin resistance and, thus, it is frequently found in individuals who have central obesity or diabetes. Insulin resistance and excess adiposity are associated with increased lipid influx into the liver and increased de novo hepatic lipogenesis, promoting hepatic triglyceride accumulation. Defects in lipid utilization via mitochondrial oxidation and lipid export may also contribute to hepatic lipid build-up. Adipocytokine alterations, lipotoxicity from saturated fatty acids and fructose have been all been implicated in causing hepatocyte injury in NAFLD through pathways involving oxidative and endoplasmic reticulum stress. Clinically, NAFLD is commonly asymptomatic and frequently detected incidentally by blood liver function tests or imaging performed for other reasons. Subjects with NAFLD have a higher mortality rate than the general population and are at increased risk of developing cardiovascular disease and diabetes in the future. Histologically, NAFLD occurs as a spectrum from mild hepatic steatosis only, to non-alcoholic steatohepatitis (NASH) characterized by hepatocellular injury and inflammation, to cirrhosis. A diagnosis of NASH with associated fibrosis heralds a more significant prognosis as it is more likely to progressive to cirrhosis with complications of hepatic failure and hepatocellular carcinoma. Currently, the diagnosis of NASH requires a liver biopsy, however, serum based markers of hepatocyte apoptosis such as cytokeratin-18 fragments offer promise as accurate non-invasive diagnostic tests. Treatment of NAFLD revolves around addressing concomitant metabolic risk factors and improving insulin resistance through weight loss measures and exercise. Insulin sensitizing agents such as pioglitazone and anti-oxidant agents such as vitamin E show some promise in improving liver histology in patients with NASH, however, the long-term benefit of these medications has not been demonstrated.

Non-alcoholic fatty liver disease: is iron relevant?

Non-alcoholic fatty liver disease (NAFLD) is a common and ubiquitous disorder (Bedogni et al. in Hepatology 42:44-52, 2005; Bellentani et al. in Ann Intern Med 132:112-117, 2000) which in a proportion of subjects leads to non-alcoholic steatohepatitis (NASH), advanced liver disease and hepatocellular carcinoma. Although the factors responsible for progression of disease are still uncertain, there is evidence that insulin resistance (IR) is a key operative mechanism (Angulo et al. in Hepatology 30:1356-1362, 1999) and that two stages are involved. The first is the accumulation of triglycerides in hepatocytes followed by a "second hit" which promotes cellular oxidative stress. Several factors may be responsible for the induction of oxidative stress but hepatic iron has been implicated in various studies. The topic is controversial, however, with early studies showing an association between hepatic iron (with or without hemochromatosis gene mutations) and the progression to hepatic fibrosis. Subsequent studies, however, could not confirm an association between the presence of hepatic iron and any of the histological determinants of NAFLD or NASH. Recent studies have reactivated interest in this subject firstly, with the demonstration that hepatic iron loading increases liver cholesterol synthesis with increased lipid deposition in the liver increasing the cellular lipid burden and secondly, a large clinical study has concluded that hepatocellular iron deposition is associated with an increased risk of hepatic fibrosis, thus, strongly supporting the original observation made over a decade ago. An improvement in insulin sensitivity has been demonstrated following phlebotomy therapy but a suitably powered controlled clinical trial is required before this treatment can be implemented.

Non-Alcoholic Fatty Liver Disease (NAFLD): new challenge for general practitioners and important burden for health authorities?

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of hepatic dysfunction encountered in general practice. A large proportion of individuals with type 2 diabetes and the metabolic syndrome develop NAFLD. NAFLD is associated with severe insulin resistance and increased risk of cardiovascular disease and can progress to non-alcoholic steato-hepatitis, liver cirrhosis and cancer. Currently the only known effective treatments for NAFLD are lifestyle changes including stable weight loss and a diet low in calories. General practitioners will increasingly play a key role in dealing with this evolving but serious epidemic of NAFLD and associated metabolic complications. However, success will depend on the appropriate systems and mechanisms being in place in primary care and the proper motivation, support and education of the patient. This review provides the primary care physician with: (a) a step-by step guide of how to identify NAFLD, (b) information to exclude common other causes of liver fat accumulation and (c) additional insight into relationships between NAFLD and other conditions such as obesity, cardiovascular disease and type 2 diabetes.

Nonalcoholic fatty liver disease in children living in the obeseogenic society

BACKGROUND

The problem of obesity in children has grown considerably in recent years in the United States as well as the rest of the world. This has resulted in a marked increase in the prevalence of nonalcoholic liver disease in the pediatric age group. Nonalcoholic fatty liver disease (NAFLD) is currently the most common hepatic disorder seen in pediatric hepatology practice.

DATA SOURCES

We have reviewed the most recent literature regarding the prevalence, pathogenesis as well as the most recent advances in the diagnostic and therapeutic modalities of NAFLD in children.

RESULTS

NAFLD affects a substantial portion of the population including children.

CONCLUSIONS

The rising incidence of NAFLD, nonalcoholic steatohepatitis (NASH) and cirrhosis emphasizes the need for effective treatment options. The lack of complete understanding of the pathogenesis of NAFLD still limits our ability to develop novel therapeutic modalities that can target the metabolic derangements implicated in the development of the disorder.

Development of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) after pancreaticoduodenectomy: proposal of a postoperative NAFLD scoring system

BACKGROUND

The main etiology of NAFLD and NASH after pancreatic resection is still unclear, and the therapeutic strategy has yet to be established. The focus of this review is how predict and prevent NAFLD/NASH after pancreaticoduodenectomy.

METHODS

From April 2005 to October 2008, 54 patients who underwent pancreaticoduodenectomy in our institution were enrolled in this study. From the pre-, intra- and postoperative risk factors, we identified the most influential risk factors of postoperative NAFLD by uni- and multivariate analyses. Moreover, a postoperative NAFLD scoring system was proposed based on these risk factors.

RESULTS

The incidence of postoperative NAFLD was 37.0% (20/54). Of these, 10% (2/20) of patients were diagnosed as having NASH by percutaneous liver biopsy. By multivariate analysis, pancreatic adenocarcinoma (p < 0.05), pancreatic resection line (p < 0.01) and postoperative diarrhea (p < 0.01) were identified as the most influential factors concerning postoperative NAFLD. Based on these results, we proposed a postoperative NAFLD scoring system (0-10) and evaluated the correlation between the score and decreasing rates of CT values, revealing a significant correlation (r = 0.829 p < 0.001). The prevalence of postoperative NAFLD in the patients with our scores of 0-3, 4-6 and 7-10 points was 0 (0/22), 35 (6/17) and 93% (14/15), respectively.

CONCLUSIONS

In conclusion, NAFLD develops frequently in patients who undergo PD, and some patients even progress to NASH. A postoperative NAFLD scoring system makes it possible to predict the occurrence of NAFLD after PD, and aggressive nutrition support is needed for patients with high scores.

Prevalence and risk factors for non-alcoholic fatty liver disease among adults in an urban Sri Lankan population

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is an emerging problem in the Asia-Pacific region. However, its prevalence and risk factors in Asian (especially South Asian) communities is poorly studied. In this study, the aim was to determine the community prevalence and risk factors for NAFLD among adults in an urban Sri Lankan population.

METHODS

The study population consisted of 35-64-year-old adults, selected by stratified random sampling. NAFLD was diagnosed on established ultrasound criteria for fatty liver, safe alcohol consumption (< 14 units/week for men, < 7 units/week for females) and absence of hepatitis B and C markers. Blood pressure (BP) and anthropometric measurements were made, and fasting glucose, glycosylated hemoglobin, serum lipids, fasting serum insulin and serum alanine aminotransferase (ALT) were determined.

RESULTS

Of the 2985 study participants, 974 (32.6%) had NAFLD (605 [62.1%] women, mean age 52.8 years [standard deviation, 7.3]). On multivariate analysis, obesity, acanthosis nigricans, insulin resistance, elevated diastolic BP, fasting plasma glucose, plasma triglycerides, and ALT twice the upper limit of the reference range or more were independently associated with NAFLD.

CONCLUSION

The prevalence of NAFLD among adults in this urban Sri Lankan community is high and is strongly associated with constituent features of the metabolic syndrome.

Influence of ethnicity on histological differences in non-alcoholic fatty liver disease

BACKGROUND/AIMS

Previous studies examining ethnic differences in non-alcoholic fatty liver disease (NAFLD) are limited by small sample sizes and the lack of liver biopsy as a diagnostic modality.

METHODS

We retrospectively examined the influence of ethnicity on the biochemical and liver histological differences in NAFLD patients.

RESULTS

The proportion of African Americans (AA) in the NAFLD sample (total 238 patients; 15.1% AA) was lower than in the base population (68.2%). Median ALT (47 IU/L; p=0.05) and triglyceride (134mg/dL, p=0.002) levels were lower in AA than other ethnicities. AA showed lower degrees of steatosis [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.22-0.89; p=0.02] than Whites. In contrast, Asians showed higher grades of ballooning than Whites (OR 2.67, 95% CI 1.03-6.93; p=0.04) and other ethnicities combined (OR 2.71, 95% CI 1.06-6.92; p=0.04). Hispanics showed a higher rate of Mallory bodies than Whites (OR 2.38, 95% CI 1.05-5.39; p=0.04) and other ethnicities combined (OR 2.41, 95% CI 1.09-5.34; p=0.03).

CONCLUSIONS

African Americans showed a lower degree of steatosis than Whites. In contrast, Asians and Hispanics showed higher grades of ballooning and Mallory bodies, respectively, than Whites and other ethnicities combined. These findings highlight the need for prospective studies to evaluate ethnic differences in NAFLD.

Long-term follow-up of patients with nonalcoholic fatty liver

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of conditions ranging from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH) convincingly. NASH is the only subtype of NAFLD that has been shown to progress relatively, although these findings were reported from studies with short follow-up periods. We assessed the long-term outcomes of a NAFLD cohort.

METHODS

Patients with NAFLD established by biopsy were identified in databases and categorized as NASH or non-NASH. Mortality data and causes of death were obtained from National Death Index Plus. The nonparametric Kaplan-Meier method with log-rank test and multivariate analyses with a Cox proportional hazard model were used to compare different NAFLD subtypes and to identify independent predictors of overall and liver-related mortality.

RESULTS

Of 173 NAFLD patients (age at biopsy, 50.2 +/- 14.5 y; 39.9% male; 80.8% Caucasian; 28.9% with type II diabetes), 72 (41.6%) had NASH and 101 (58.4%) had non-NASH NAFLD. Over the follow-up period, the most common causes of death were coronary artery disease, malignancy, and liver-related death. Although overall mortality did not differ between the NAFLD subtypes, liver-related mortality was higher in patients with NASH (P < .05). Independent predictors of liver-related mortality included histologic NASH, type II diabetes, older age at biopsy, lower albumin levels, and increased levels of alkaline phosphatase (P < .05).

CONCLUSIONS

This long-term follow-up evaluation of NAFLD patients confirms that NASH patients have increased liver-related mortality compared with non-NASH patients. In addition, patients with NAFLD and type II diabetes are especially at risk for liver-related mortality.

The Risk Factors for Ultrasound-diagnosed Non-alcoholic Fatty Liver Disease Among Adolescents

Introduction: Non-alcoholic fatty liver disease (NAFLD) is garnering increasing interest and acceptance as one of the most important causes of chronic liver disease. The aim of this study was to investigate the risk factors for NAFLD among selected adolescent students in Hualien City, Taiwan. Materials and Methods: A stratified random sampling scheme was carried out among 1724 adolescent students aged 12 or 13 years old in Hualien City. In total, 220 students (normal: overweight: obese = 97:48:75) agreed to join the study. They underwent physical examination, laboratory tests and ultrasonography examination of the liver. Diagnosis of NAFLD in this study was based on sonographic evidence of a fatty liver and testing negative for serum HBsAg and anti- HCV antibody. Results: Of the 220 participants, 4 were excluded because they tested positive for HBsAg or anti-HCV antibody. NAFLD was detected in 86 (39.8%) out of the 216 subjects. The rate of NAFLD in the adolescents increased progressively from 16.0% in the normal group to 50.5% in the overweight group, and 63.5% among the obese subjects. Compared to their normal counterparts, adolescents with NAFLD had a significantly higher weight, body mass index (BMI), waist circumference, levels of alanine aminotransferase (ALT), triglyceride and non- high-density-lipoprotein (non-HDL) cholesterol. However, among the participants with NAFLD, only 20 (23.3%) showed ALT abnormality but there was an increasing trend of ALT abnormality as the severity of fatty liver increased. In addition, the higher ALT, Homeostasis model assessment- insulin resistance (HOMA-IR), cholesterol, triglyceride, and non-HDL levels and lower HDL-C as the severity of fatty liver increased. In a stepwise logistic regression analysis, the most significant factor associated with the presence of NAFLD was weight category. When compared with their normal counterparts, overweight and obese adolescents had a 4.14 and 5.98 times the risk of having NAFLD, respectively. Elevated ALT was the second most important factor as adolescents with elevated ALT were more likely to have NAFLD (odds ratio = 3.32, 95% CI: 1.16 to 9.50). Non-HDL cholesterol level was the third most important factor associated with NAFLD with a 3.81-fold increase in risk incurred for every l n (1 mg/dL) increment. Conclusions: Obesity, ALT abnormality and elevated non-HDL-cholesterol are risk factors for NAFLD in adolescents. However, only 23.3% of the adolescents with NAFLD showed an abnormality for ALT. Therefore, ALT alone is not a sufficient indicator; and it is recommended that ultrasonog- raphy of the liver should be part of the routine health examination of obese adolescents. Key words: Adolescents, Non-alcoholic fatty liver disease, Obese, Risk factors

Epidemiology of non-alcoholic fatty liver disease in China

Fatty liver (steatosis) is highly prevalent in China and is more often linked to obesity than to alcoholism. Among more affluent regions of China, the community prevalence of non-alcoholic fatty liver disease (NAFLD) is approximately 15%. With the increasing pandemic of obesity, the prevalence of NAFLD has approximately doubled in the past decade. The risk factors resemble those in other ethnic populations, but it is important to note that ethnic-specific definitions of central obesity, obesity and metabolic syndrome are more useful in assessment of Chinese people. The full range of histological manifestations of NAFLD has been demonstrated in Chinese patients, but to date hepatic severity is generally mild. In contrast to chronic hepatitis C, steatosis is less common in patients with chronic hepatitis B; it is associated with metabolic, and not viral factors and does not appear to affect disease severity. Although long-term outcomes of NAFLD in Chinese populations remain unclear, it may be a predictor of metabolic disorders, diabetes and cardiovascular disease. Public health interventions are therefore indicated to halt or reverse the national trend of obesity in China so as to improve liver as well as metabolic health.

Non-alcoholic fatty liver disease and its association with obesity, insulin resistance and increased serum levels of C-reactive protein in Hispanics

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder of the liver, which may progress to fibrosis or cirrhosis. Recent studies have shown a significant impact of ethnicity on susceptibility to steatosis-related liver disease.

AIMS

To estimate the prevalence of NAFLD among Chilean Hispanics as well as the clinical and biochemical variables associated with the disease.

METHODS

Population-based study among Chilean Hispanics. The diagnosis of NAFLD was made on the basis of ultrasound evidence of fatty liver and absence of significant alcohol consumption and hepatitis C virus infection.

RESULTS

A total of 832 Hispanic subjects were included. Ultrasound findings revealed diffuse fatty liver in 23% of the subjects. Variables associated with fatty liver in multivariate analysis were body mass index >26.9 [odds ratio (OR) 6.2; 95% confidence interval (CI) 3.3-11.5], abnormal aspartate aminotransferase levels (OR 14; 95% CI 8.2-23.7), presence of insulin resistance as measured by homoeostasis model assessment-insulin resistance (OR 3; 95% CI 1.8-4.8) and serum levels of high-sensitivity C-reactive protein (hs-CRP) greater than 0.86 mg/L (OR 2.9; 95% CI 1.6-5.2). Among subjects with NAFLD, levels of hs-CRP were similar regardless of the alanine aminotransferase (ALT) level.

CONCLUSIONS

Chilean Hispanics exhibit a high prevalence of NAFLD. Obesity, insulin resistance, abnormal aminotransferase levels and elevated hs-CRP were independently associated with the presence of NAFLD. ALT elevation underestimates the presence of ultrasonographical fatty liver, whereas hs-CRP is a sensitive independent marker of NAFLD, which may be useful for detecting fatty liver in the general population.

Dietary resveratrol alters lipid metabolism-related gene expression of mice on an atherogenic diet

BACKGROUND/AIMS

Resveratrol, a polyphenolic activator of the silent information regulation 2 homolog 1 (SIRT1), is known to extend lifespan and improve metabolic disease. The aim of the present study is to test whether resveratrol protects against metabolic steatohepatitis through the modulation of lipid metabolism-related genes.

METHODS

We used a mouse model in which steatohepatitis can be induced by an atherogenic diet (Ath diet) to evaluate the effects of resveratrol on steatotic hepatitis and hepatic gene expression.

RESULTS

The Ath diet induced excessive weight gain, hepatomegaly, dyslipidemia, and steatohepatitis after 8 weeks. The addition of resveratrol protected against Ath diet-induced changes and also alleviated steatohepatitis. Whole-genome expression analysis revealed that an Ath diet altered the hepatic expression of genes involved in lipid metabolism, and the addition of resveratrol to the diet reversed that effect. Real-time PCR and Western blot analysis confirmed the Ath diet up-regulated the levels of genes related to lipogenesis and down-regulated genes involved in lipolysis. Resveratrol clearly suppressed the Ath diet-induced alterations of the expression of genes related to lipid metabolism.

CONCLUSIONS

Resveratrol ameliorated dyslipidemia and steatohepatitis induced by the Ath diet, and its beneficial effects were associated with the altered expression of hepatic genes involved in lipid metabolism.

Relation between alanine aminotransferase concentrations and visceral fat accumulation among nondiabetic overweight Korean women

BACKGROUND

Alanine aminotransferase (ALT) is used as a surrogate marker for nonalcoholic fatty liver disease (NAFLD), which is frequently observed among obese subjects. Reported data were scanty about the relation between ALT concentrations and visceral fat accumulation measured by computed tomographic (CT) scanning in a large sample.

OBJECTIVE

We investigated the association between ALT concentrations and visceral fat accumulation measured by CT scanning, among nondiabetic overweight Korean women.

DESIGN

A cross-sectional study was performed in 903 nondiabetic overweight [body mass index (BMI; in kg/m(2)) > or = 25] Korean women aged 20-80 y. The area of abdominal visceral adipose tissue (VAT) was measured by CT scan. Anthropometric and cardiometabolic variables were measured.

RESULTS

Elevated ALT (> 40 IU/L) concentrations were found in 14.9% of the subjects. ALT concentrations were significantly correlated with all anthropometric and cardiometabolic variables after adjustment for age and alcohol consumption (P < 0.05). The adjusted odds ratios for elevated ALT concentrations according to the quartiles of VAT were 1.51 (95% CI: 0.83, 2.76), 3.16 (95% CI: 1.55, 6.49), and 15.15 (95% CI: 4.57, 50.00) in the second (76.9-102.6 cm(2)), the third (102.7-135.0 cm(2)), and the fourth (135.1-382.7 cm(2)) quartiles, respectively, compared with the first quartile (23.0-76.8 cm(2)) (P for trend < 0.001). In the multiple linear regression model, the VAT was significantly positively associated with ALT concentrations (standardized beta = 0.206, P < 0.001), whereas the regression coefficients of other anthropometric and cardiometabolic variables were not significant.

CONCLUSIONS

ALT concentrations have a strong association with visceral fat accumulation, and VAT is the main predictor of elevated ALT concentrations in the context of NAFLD among nondiabetic overweight Korean women.

Review article: epidemiology, pathogenesis and potential treatments of paediatric non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of paediatric liver disease. Similar to NAFLD in adults, NAFLD in children is associated with obesity and insulin resistance and requires liver histology for diagnosis and staging. However, significant histological differences exist between adult and paediatric NAFLD to warrant caution in extrapolation of adult data.

AIM

To review the available data on the epidemiology, pathogenesis, diagnosis and treatment of paediatric NAFLD.

METHODS

Relevant articles were identified by Medline searches using the keywords: nonalcoholic fatty liver disease, steatohepatitis, obesity and children.

RESULTS

The rise in childhood obesity has been accompanied by an increase in paediatric NAFLD. Age, gender and race/ethnicity are significant determinants of risk, and sex hormones, insulin sensitivity and adipocytokines are implicated in the pathogenesis of paediatric NAFLD. There is no consensus for treatment of NAFLD; however, data suggest that diet, exercise and some pharmacological therapies may be of benefit.

CONCLUSIONS

To evaluate and effectively treat paediatric NAFLD, the pathophysiology and natural history of the disease should be clarified and non-invasive methods for screening, diagnosis, and longitudinal assessment developed. Randomized, controlled, double-blind trials of pharmacological therapies in children with biopsy-proven disease are necessary.

Evolving trends in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common etiologies of chronic liver disease worldwide. NALFD encompasses a continuum of histological findings ranging from steatosis alone, to nonalcoholic steatohepatitis (NASH) with steatosis, inflammation, hepatocyte ballooning, fibrosis and eventually liver cirrhosis. The pathogenesis of NAFLD might be related to a deregulated cross-talk between liver and visceral adipose tissue, originating an impairment of normal insulin signaling. A better comprehension of the immunologic and metabolic roles of adipose tissue in modulating inflammatory pathways will enhance our understanding of the molecular mechanisms leading to progression of fatty liver disease. These insights, moreover, will suggest new strategies to improve insulin sensitivity and reduce obesity-associated morbidities and mortality.

The effect of QuYuHuaTanTongLuo Decoction on the non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the most common cause of cryptogenic cirrhosis, is becoming more prevalent in China. However, there is as yet no clearly established therapy for reversing fatty liver. Our aim is to explore the effect of traditional Chinese herbs QuYuHuaTanTongLuo Decoction (QYHTTLD) on non-alcoholic steatohepatitis. Sixty-nine non-alcoholic steatohepatitis patients were randomly divided into two groups. One group of 35 patients were treated by QYHTTLD, another group of 34 patients were treated by Ursodeoxycholic acid (UDCA). The TNF-alpha, IL-8, MDA level, SOD activity and liver function, as well as B ultrasonic image were detected before and after being treated. The results showed: after 6 months treatment, MBI of the treatment group was obviously decreased (p<0.05). The levels of TC, TG and LDL-C were significantly decreased whereas the level of HDL-C increased (p<0.01, p<0.05, p<0.05, and p<0.05, respectively) in the treatment group, the levels of TC, TG, LDL-C and HDL-C had no significant difference in the control group (p>0.05). The levels of TNF-alpha, IL-8 and MDA were significantly decreased whereas SOD activity was significantly increased (p<0.01, p<0.05, p<0.01, and p<0.01, respectively) in the treatment group, the level of MDA was significantly decreased in the control group (p<0.05). B ultrasonic images were ameliorated in different degree (p<0.01 and p<0.01, respectively). Both QYHTTLD and UDCA had the effect in improving the scores of symptoms and signs of patients, however, the difference value of the scores in treatment group were significantly higher than that in control group after being treated for 6 months (p<0.05).

CONCLUSION

QYHTTLD is effective for treating non-alcoholic steatohepatitis, and its effect seems to relate with the ways of QYHTTL down-regulating inflammation cytokine IL-8 level and relieving lipid peroxidation of liver.

Prevalence of non-alcoholic fatty liver and characteristics in overweight adolescents in the general population

Overweight and obesity among children and adolescents are increasing. Fatty liver disease (FLD) is an emerging problem in this age group. We investigated prevalence of overweight and non-invasive FLD and associated clinical characteristics in a representative population-based sample of 378 children and adolescents aged 12-20 years who were randomly selected from the general population in Leutkirch, Southern Germany. Overweight was defined as having a body mass index above the 90th percentile for the respective age and sex. About 15% of female (29 out of 194) and 12% of male participants (22/182) were overweight. Among females, only one non-overweight individual showed signs of FLD but in more than one third of the overweight males (8/22) signs of FLD were present. Overweight subjects in general had an unfavourable lipid profile and abnormal concentrations of obesity-related hormones such as significantly lower concentrations of adiponectin and increased levels of inflammatory markers including C-reactive protein and fibrinogen. Overweight males with signs of FLD showed even more severe altered metabolic responses compared to those who were overweight without signs of liver injury. FLD was not explained by alcohol consumption or other chronic liver disease. In this sample of children and adolescents representative of the general population a high prevalence of non-alcoholic fatty liver disease (NAFLD) is found in overweight males. These individuals showed the most severe metabolic alterations compared to non-overweight and overweight individuals without NAFLD indicating even higher risk for future overweight and obesity-related diseases such as type 2 diabetes and cardiovascular disease.

Liver: an alarm for the heart?

BACKGROUND/AIMS

Fatty liver (FL) and coronary artery disease (CAD) have several risk factors in common, which are usually considered to account for their frequent coexistence. The independent association between FL and angiographic CAD was assessed in this case-control study by considering the contribution of their shared risk factors.

METHODS

Three hundred and seventeen adult patients who underwent elective coronary angiography (CAG) were recruited immediately after CAG and classified into either of the two groups A (normal or mildly abnormal CAG; n=85) or B (clinically relevant CAD; n=232). A liver sonography was performed on the same day as CAG.

RESULTS

The groups were significantly different in terms of gender, fasting blood glucose, low-density lipoproteins, diabetes (DM), hypertension and FL. In binary logistic regression, FL was the strongest independent predictor of CAD [P<0.001, odds ratio (OR)=8.48%, 95% confidence interval (CI)=4.39-16.40], followed by DM (P=0.002, OR=2.94) and male gender (P=0.014, OR=2.31). This pattern of associations did not change after clinically significant variables (waist-to-hip ratio, body mass index, triglycerides and high-density lipoproteins) were added to analysis.

CONCLUSION

Fatty liver seems to be a strong independent alarm for the presence of significant CAD.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) refers to the presence of hepatic steatosis not associated with a significant intake of ethanol. Insulin resistance is central to the pathogenesis of NAFLD; thus obesity, diabetes, and the metabolic syndrome are frequently associated with the disease. Consequently, as these metabolic conditions emerge as major health problems in Western society, it is now recognized that NAFLD is the most common chronic liver condition in the Western world. NAFLD is generally asymptomatic, although a minority of patients may present with evidence of progressive liver injury with complications of cirrhosis, liver failure, and hepatocellular carcinoma. Despite being common and potentially serious, relatively little is known about the natural history or prognostic significance of NAFLD. Although diabetes, obesity, and age are recognized risk factors for advanced liver disease, other significant factors leading to progressive liver injury remain to be identified. The treatment of NAFLD focuses upon modifying metabolic risk factors. Insulin-sensitizing and hepatoprotective drugs have been subjected to study trials, but as yet, no agent has conclusively been demonstrated to prevent disease progression. Management is further complicated by the inability to predict which patients will develop liver-related morbidity and thus benefit from treatment.

Evaluation and management of obesity-related nonalcoholic fatty liver disease

The clinicopathologic spectrum of nonalcoholic fatty liver disease (NAFLD) ranges from simple steatosis to nonalcoholic steatohepatitis (NASH). Simple steatosis has a relatively benign clinical course, but NASH can progress to cirrhosis and hepatocellular carcinoma. NAFLD occurs in the absence of significant alcohol use and is considered to be the hepatic manifestation of metabolic syndrome. NAFLD affects approximately 30% of the US population and the incidence seems to be rising as the obesity epidemic continues. At present, the most accurate modality for the diagnosis of NASH is liver biopsy; however, many patients do not have a liver biopsy, and in the absence of more-accurate imaging technologies and serum markers, the diagnosis is frequently one of exclusion. As yet there is no convincingly effective treatment for NAFLD--a multimodal treatment plan that targets obesity, insulin resistance, hyperlipidemia and hypertension might be the best option for these patients.

How common is non-alcoholic fatty liver disease in the Asia-Pacific region and are there local differences?

Risk factors for development of non-alcoholic steatohepatitis include obesity, especially central adiposity, glucose intolerance or type 2 diabetes mellitus (T2DM), and dyslipidemia. Non-alcoholic fatty liver disease (NAFLD) is now considered a manifestation of metabolic syndrome. During the last two decades, NAFLD has become the most common chronic liver disease in North America and Europe, but until recently was thought to be uncommon (perhaps due to the lack of study) in Asia. Fatty liver can be identified on imaging modalities (ultrasonography, computed tomography scans, and magnetic resonance imaging) with high sensitivity, but steatohepatitis and fibrosis cannot be distinguished. Thus, an inherent drawback in studying the epidemiology of NAFLD is the lack of definitive laboratory tests, no uniform definition-with different studies using cut-off values of alcohol consumption from <20 g/week to 210 g/week, and case selections where biopsy was used for definition. In studies outside the region, the prevalence of NAFLD varies from 16% to 42% by imaging, and 15-39% of liver biopsies. The major risk factors for NAFLD, central obesity, T2DM, dyslipidemia, and metabolic syndrome, are now widely prevalent and are increasing geometrically in the Asia-Pacific region. It is therefore not surprising that NAFLD is common in this region. Estimates of current prevalence range from 5% to 30%, depending on the population studied. Central obesity, diabetes, and metabolic syndrome are the major risk factors. To date, however, data on the natural history and impact of NAFLD causing serious significant chronic liver disease are lacking and there is a need for prospective, cooperative studies.

What are the risk factors and settings for non-alcoholic fatty liver disease in Asia-Pacific?

The risk factors and settings for non-alcoholic fatty liver disease (NAFLD) in Asians are reviewed comprehensively. Based particularly on large community-based studies using ultrasonography, case-control series and prospective longitudinal studies, the prevalence of NAFLD in Asia is between 12% and 24%, depending on age, gender, locality and ethnicity. Further, the prevalence in China and Japan has nearly doubled in the last 10-15 years. A detailed analysis of these data shows that NAFLD risk factors for Asians resemble those in the West for age at presentation, prevalence of type 2 diabetes mellitus (T2DM) and hyperlipidemia. The apparent differences in prevalence of central obesity and overall obesity are related to criteria used to define waist circumference and body mass index (BMI), respectively. The strongest associations are with components of the metabolic syndrome, particularly the combined presence of central obesity and obesity. Non-alcoholic fatty liver disease appears to be associated with long-standing insulin resistance and likely represents the hepatic manifestation of metabolic syndrome. Not surprisingly therefore, Asians with NAFLD are at high risk of developing diabetes and cardiovascular disease. Conversely, metabolic syndrome may precede the diagnosis of NAFLD. The increasing prevalence of obesity, coupled with T2DM, dyslipidemia, hypertension and ultimately metabolic syndrome puts more than half the world's population at risk of developing NAFLD/non-alcoholic steatohepatitis/cirrhosis in the coming decades. Public health initiatives are clearly imperative to halt or reverse the global 'diabesity' pandemic, the underlying basis of NAFLD and metabolic syndrome. In addition, a perspective of NAFLD beyond its hepatic consequences is now warranted; this needs to be considered in relation to management guidelines for affected individuals.

The importance of metabolic factors for the increasing prevalence of fatty liver in Shanghai factory workers

BACKGROUND AND AIM

To evaluate changes in the prevalence rates of ultrasonographic fatty liver (FL) in a specific population.

METHODS

An analysis of the medical records of BaoSteel Group (Shanghai, China) employees was done to evaluate the prevalence of FL in this population, in which health examinations were performed biennially between 1995 and 2002.

RESULTS

The study reviewed a database of 59 131 employees, of which 27.1% received medical check-ups four times within the study period, 26.6% three times, and 24.0% twice. The prevalence rates of obesity and metabolic disorders were high at baseline and increased significantly with time. The prevalence of ultrasonographic FL increased from 3.87% to 14.04% in the overall population, while there was an increase from 4.44% to 14.64% in men and 1.56% to 11.37% in women over the 6-year study period. Increased rates of FL were also noted, from 25.88% to 51.39%, among patients with elevated serum alanine aminotransferase (ALT) levels (> 40 U/L). The highest overall prevalence rates of FL were found in individuals aged 50-60 years, with all age-associated prevalence significantly higher in males than females.

CONCLUSION

The prevalence of FL increased rapidly over the study period with increased rates of obesity and metabolic disorders; FL is becoming a major cause of abnormal ALT levels in the specific population.

Prevalence of nonalcoholic fatty liver disease in women with polycystic ovary syndrome

BACKGROUND & AIMS

Insulin resistance has been implicated in the pathogenesis of both nonalcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS). We hypothesized that NAFLD would be common in both obese and nonobese women with PCOS. The aim of this study was to estimate the prevalence of and identify associated factors for hepatic steatosis in women with PCOS.

METHODS

This is a retrospective study of 88 consecutive premenopausal women with PCOS. Clinical history, height, weight, and laboratory values were obtained. Fasting measurements of serum glucose and insulin were used to calculate homeostasis model assessment of insulin resistance (HOMA-IR). Abdominal ultrasonography was used to determine the presence and severity of hepatic steatosis.

RESULTS

Of the 88 women (median age, 31.4 years), 48 (55%) had steatosis; 15 (39%) of them were lean women. The presence of steatosis was associated with a greater body mass index (BMI) (P = .005) and HOMA-IR (P = .033), a lower fasting high-density lipoprotein (P = .003), and a greater prevalence of impaired fasting glucose, impaired glucose tolerance, and diabetes mellitus (P = .013). Only 7 (15%) subjects with hepatic steatosis had abnormal liver chemistries.

CONCLUSIONS

Fatty liver was identified in 55% of subjects with PCOS, nearly 40% of whom were lean women. High BMI and insulin resistance appeared to be important associated factors. Early recognition of NAFLD in this group of young patients is warranted, and further investigation including liver biopsy might be indicated.

Restriction of dietary calories, fat and iron improves non-alcoholic fatty liver disease

BACKGROUND

The pathogenesis of non-alcoholic steatohepatitis (NASH) is unclear. Recent studies suggested that oxidative stress plays an important role in the mechanism of NASH. Excessive accumulation of iron in the liver causes oxidative stress. The aim of the present study was to evaluate the grade of hepatic iron accumulation and the therapeutic response to restriction of calories, fat and iron in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

Twenty-seven NAFLD patients were enrolled. The patients were categorized into two groups: 17 patients with NASH and 10 with simple steatosis. Twelve NAFLD patients (NASH, n = 9; simple steatosis, n = 3) were given a dietary prescription including restriction of energy, fat and iron.

RESULTS

Positive iron staining was observed in 71% and 50% of patients with NASH and simple steatosis, respectively. The average energy intake, fat energy fraction and iron intake decreased significantly 6 months after the beginning of the diet in all patients. In addition, the levels of serum transaminase and ferritin were significantly decreased.

CONCLUSION

Dietary restriction of calories, fat and iron improved NAFLD. Reduced serum ferritin levels appear to reduce oxidative stress in the liver.

Open-label pilot study of folic acid in patients with nonalcoholic steatohepatitis

BACKGROUND/AIMS

Folate deficiency disturbs hepatic methionine metabolism and promotes the development of steatohepatitis in animal models. Our aims were (1) to determine the safety and efficacy of folic acid treatment in patients with nonalcoholic steatohepatitis (NASH) on changes in liver biochemistries, and (2) to investigate the presence of subclinical folate deficiency in this population.

METHODS

Patients with biopsy-proven NASH were treated with folic acid 1 mg/day for 6 months. Liver enzymes and adverse events were monitored every 3 months until completion.

RESULTS

Ten patients (one male and nine females) with a median age of 54 years were enrolled in this study. At baseline, the median steatosis grade was 2 (range 1-3), the median necroinflammatory grade was 1 (1-3), and the median fibrosis stage was 2 (0-4). The median level of red cell folate was 526 ng/ml (range 99-708); the normal level was 268-616 ng/ml. One compensated cirrhotic patient had folate deficiency. No serious adverse events occurred. After 6 months of therapy, no significant reductions in serum aspartate and alanine aminotransferase levels (60+/-25 vs. 54+/-29, P=0.5 and 86+/-29 vs. 83+/-42, P=0.6, respectively), were observed. Serum levels of bilirubin, alkaline phosphatase, albumin, and prothrombin time remained in the normal range during treatment in all patients.

CONCLUSION

Six months of therapy with folic acid at a dose of 1 mg/day, although safe and well tolerated, does not lead to a significant biochemical improvement in patients with NASH. In a small number of patients, folate deficiency was present in only a cirrhotic patient.

Epidemiology and natural history of NAFLD and NASH

Understanding of the epidemiology and natural history of non-alcoholic fatty liver disease (NAFLD) has increased; it is the most common form of chronic liver disease in the Western world and increasing in importance in other parts of the world. Prevalence is expected to increase as obesity and diabetes epidemics evolve. The natural history of NAFLD depends on the histologic subtype. Those who have simple hepatic steatosis or nonspecific inflammation generally have a benign long-term prognosis, whereas non-alcoholic steatohepatitis (NASH) can progress to cirrhosis. NASH-related cirrhosis may have a similar prognosis as cirrhosis from other causes, leading to liver failure or hepatocellular carcinoma.

Non-alcoholic fatty liver disease in Malaysia: a demographic, anthropometric, metabolic and histological study

BACKGROUND AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is increasing rapidly in the Asia-Pacific region. There has been a paucity of studies from the region. The aims of this study were to define the demographic, anthropometric, metabolic and histological characteristics of patients with NAFLD in our local population and to determine independent predictors of severe liver fibrosis.

METHODS

Patients with persistently raised liver enzymes and/or fatty liver detected on ultrasonography with exclusion of other liver disorders were prospectively recruited. Their insulin resistance was assessed using the homeostasis model assessment of insulin resistance score. A liver biopsy was performed in all cases for grading (for steatohepatitis) and staging (for fibrosis) of NAFLD. Independent risk factors for fibrosis were determined using multiple logistic regression analysis.

RESULTS

Seventy-five patients were recruited: 39 men (52%) and 36 women (48%). The mean age of the patients was 47.0+/-12.2 years. Of these, 58 patients (77.3%) were centrally obese, 29 patients (38.7%) were diabetic and 15 patients (20.0%) had impaired glucose tolerance. Insulin resistance was diagnosed in 62 out of 64 (96.9%) patients. Benign steatosis, nonalcoholic steatohepatitis and cirrhosis were diagnosed in three (4.3%), 59 (84.3%) and eight (11.4%) of 70 patients, respectively. Significant independent predictors of liver fibrosis were; male sex (P=0.019, OR=5.55, CI=1.33-23.18) and Indian race (P=0.013, OR=8.21, CI=1.56-43.16).

CONCLUSIONS

The full histological spectrum of NAFLD was seen in our patients. The majority of patients were insulin resistant, centrally obese and either diabetic or had impaired glucose tolerance. The predictors of severe liver fibrosis were male sex and Indian race.

Prevalence and risk factors of gallstone disease in an adult population of Taiwan: an epidemiological survey

BACKGROUND AND AIMS

The aim of this study was to determine the prevalence and risk factors of gallstone disease (GSD) in an adult population of Taiwan through a population-based screening study.

METHODS

A cross-sectional community study in a rural village of Taiwan was conducted in 3333 Chinese adults (aged > or = 18 years) undergoing ultrasonography. A questionnaire on personal history was completed to ascertain whether the removed gallbladder contained stones in all cholecystectomized subjects, the dietary habits (vegetarian/non-vegetarian diet), the history of GSD in the participant's first-degree relatives, the history of gastrointestinal surgery (vagotomy, gastrectomy for peptic ulcer disease, or ileal resection), parity, and use of oral contraceptives. The demographic characteristics and biochemical parameters were recorded.

RESULTS

The overall prevalence of GSD was 5.0% (4.6% in men, 5.4% in women) with no significant sex differences (men/women: odds ratio [OR] 0.71, 95% confidence interval [CI] 0.50-1.01, P = 0.058). Logistic regression analysis showed that increasing age (men: 40-64 years, OR 7.38, 95% CI 2.59-21.01, P < 0.001 and > or = 65 years, OR 14.16, 95% CI 4.84-41.47, P < 0.001; women: 40-64 years, OR 4.08, 95% CI 1.90-8.75, P < 0.001 and > or = 65 years, OR 6.78, 95% CI 2.97-15.46, P < 0.001) and the presence of fatty liver evidenced by ultrasonography (men: OR 2.24, 95% CI 1.32-3.80, P = 0.003; women: OR 2.13, 95% CI 1.33-3.42, P = 0.002) were risk factors for GSD. Additionally, fasting plasma glucose > or = 126 mg/dL (OR 2.11, 95% CI 1.16-3.83, P = 0.014), history of GSD in the first-degree relatives (OR 7.47, 95% CI 2.22-25.12, P = 0.001), and use of oral contraceptives (OR 10.71, 95% CI 3.06-37.49, P < 0.001) were risk factors for GSD in women, but fasting plasma glucose > or = 126 mg/dL was only correlated to GSD without controlling for other confounding factors in men. Other demographic characteristics and biochemical parameters, such as high body mass index (> or = 25 kg/m2), increased parity, hypercholesterolemia, hypertriglyceridemia, hyperuricemia, hepatitis C infection and cirrhosis, did not exhibit any correlation to GSD in logistic regression analysis, although they appeared to be related to GSD in women in univariate analysis.

CONCLUSIONS

Age and fatty liver in both sexes were found to be risk factors for GSD in the study population. The finding of a correlation between fatty liver and GSD is an important addition to the literature concerning the risk factors of GSD. Diabetes mellitus, history of GSD in the first-degree relatives, and use of oral contraceptives were also risk factors for GSD in women.

Fatty Liver: Imaging Patterns and Pitfalls

Fat accumulation is one of the most common abnormalities of the liver depicted on cross-sectional images. Common patterns include diffuse fat accumulation, diffuse fat accumulation with focal sparing, and focal fat accumulation in an otherwise normal liver. Unusual patterns that may cause diagnostic confusion by mimicking neoplastic, inflammatory, or vascular conditions include multinodular and perivascular accumulation. All of these patterns involve the heterogeneous or nonuniform distribution of fat. To help prevent diagnostic errors and guide appropriate work-up and management, radiologists should be aware of the different patterns of fat accumulation in the liver, especially as they are depicted at ultrasonography, computed tomography, and magnetic resonance imaging. In addition, knowledge of the risk factors and the pathophysiologic, histologic, and epidemiologic features of fat accumulation may be useful for avoiding diagnostic pitfalls and planning an appropriate work-up in difficult cases.

Prevalence and risk factors of nonalcoholic fatty liver disease in an adult population of taiwan: metabolic significance of nonalcoholic fatty liver disease in nonobese adults

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) is rarely reported in Taiwan.

GOALS

To determine the prevalence and risk factors of NAFLD in an adult population of Taiwan.

STUDY

The cross-sectional community study examined 3245 adults in a rural village of Taiwan. The diagnostic criteria for NAFLD included no excessive alcohol intake, no chronic viral hepatitis, no known etiologies of liver disease, and ultrasonography consistent with fatty liver.

RESULTS

The prevalence of NAFLD was 11.5% (372/3245). The risk factors for NAFLD in the general population were male sex [odds ratio (OR), 1.44; 95% confidence interval (CI), 1.09-1.90], elevated alanine aminotransferase (ALT) (OR, 5.66; 95% CI, 3.99-8.01), obesity (OR, 7.21; 95% CI, 5.29-9.84), fasting plasma glucose > or =126 mg/dL (OR, 2.08; 95% CI, 1.41-3.05), total cholesterol > or =240 mg/dL (OR, 1.50; 95% CI, 1.06-2.13), triglyceride > or =150 mg/dL (OR, 1.76; 95% CI, 1.32-2.35), and hyperuricemia (OR, 1.53; 95% CI, 1.16-2.01). Age > or =65 years was inversely related to NAFLD (OR, 0.53; 95% CI, 0.36-0.77). The only NAFLD risk factors among nonobese subjects were age between 40 and 64 years (OR, 2.35; 95% CI, 1.34-4.11, P=0.003), elevated ALT (OR, 15.45; 95% CI, 8.21-29.09, P<0.001), and triglyceride > or =150 mg/dL (OR, 2.48; 95% CI, 1.42-4.32, P=0.001). In subjects with NAFLD, the prevalence of elevated ALT in the presence of each metabolic risk factor, such as obesity, fasting plasma glucose > or =126 mg/dL, total cholesterol > or =240 mg/dL, triglyceride > or =150 mg/dL, and hyperuricemia, did not differ from that of subjects with normal ALT levels.

CONCLUSIONS

NAFLD is closely associated with elevated ALT, obesity, diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, and hyperuricemia. Among the metabolic disorders, only hypertriglyceridemia was related to NAFLD in nonobese subjects. Serum ALT level was not a good predictor of metabolic significance in subjects with NAFLD.