Gender and racial differences in nonalcoholic fatty liver disease

Pharmacogenomic and personalized approaches to tackle nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a raising liver disease with increasing prevalence due to the epidemics of obesity and diabetes, with end points in cirrhosis or hepatocellular carcinoma. A multitude of genetic and metabolic perturbations, together with environmental factors, likely drive the disease. However, to date only a few genes, primarily PNPLA3 and TM6SF2, associate with NAFLD and there is no specific treatment. In this review we focus on the therapeutical aspects of NAFLD, taking into account drugs and lifestyle interventions. Sex also influences disease progression and treatment outcomes. Lastly, we discuss the present and potential future of personalized approaches to tackle NAFLD and how the known polymorphisms of NAFLD associated genes influence the choice and success of therapy.

Sex and Gender Differences in Risk, Pathophysiology and Complications of Type 2 Diabetes Mellitus

The steep rise of type 2 diabetes mellitus (T2DM) and associated complications go along with mounting evidence of clinically important sex and gender differences. T2DM is more frequently diagnosed at lower age and body mass index in men; however, the most prominent risk factor, which is obesity, is more common in women. Generally, large sex-ratio differences across countries are observed. Diversities in biology, culture, lifestyle, environment, and socioeconomic status impact differences between males and females in predisposition, development, and clinical presentation. Genetic effects and epigenetic mechanisms, nutritional factors and sedentary lifestyle affect risk and complications differently in both sexes. Furthermore, sex hormones have a great impact on energy metabolism, body composition, vascular function, and inflammatory responses. Thus, endocrine imbalances relate to unfavorable cardiometabolic traits, observable in women with androgen excess or men with hypogonadism. Both biological and psychosocial factors are responsible for sex and gender differences in diabetes risk and outcome. Overall, psychosocial stress appears to have greater impact on women rather than on men. In addition, women have greater increases of cardiovascular risk, myocardial infarction, and stroke mortality than men, compared with nondiabetic subjects. However, when dialysis therapy is initiated, mortality is comparable in both males and females. Diabetes appears to attenuate the protective effect of the female sex in the development of cardiac diseases and nephropathy. Endocrine and behavioral factors are involved in gender inequalities and affect the outcome. More research regarding sex-dimorphic pathophysiological mechanisms of T2DM and its complications could contribute to more personalized diabetes care in the future and would thus promote more awareness in terms of sex- and gender-specific risk factors.

Comparison of the Phenotype and Approach to Pediatric vs Adult Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the main chronic noncommunicable diseases in Westernized societies; its worldwide prevalence has doubled during the last 20 years. NAFLD has serious health implications not only for adults, but also for children. However, pediatric NAFLD is not only an important global problem in itself, but it is likely to be associated with increases in comorbidities, such as metabolic syndrome and cardiovascular diseases. There are several differences between NAFLD in children and adults, and it is not clear whether the disease observed in children is the initial phase of a process that progresses with age. The increasing prevalence of pediatric NAFLD has serious implications for the future adult population requiring appropriate action. Studies of NAFLD progression, pathogenesis, and management should evaluate disease phenotypes in children and follow these over the patient's lifetime. We review the similarities and differences of NAFLD between children and adults.

Abdominal Obesity, Race and Chronic Kidney Disease in Young Adults: Results from NHANES 1999-2010

OBJECTIVE

Kidney dysfunction in obesity may be independent of and may precede the development of hypertension and/or diabetes mellitus. We aimed to examine if abdominal obesity is associated with early markers of CKD in a young healthy population and whether these associations differ by race and/or ethnicity.

METHODS

We analyzed data from the NHANES 1999-2010 for 6918 young adults ages 20-40 years. Abdominal obesity was defined by gender criteria of waist circumference. CKD markers included estimated glomerular filtration rate and albuminuria ≥30 mg/g. Race stratified analyses were done overall and in subgroups with normal blood pressures, normoglycemia and normal insulin sensitivity. Awareness of CKD was assessed in participants with albuminuria.

RESULTS

Abdominal obesity was present in over one-third of all young adults and was more prevalent among non-Hispanic blacks (45.4%) versus Mexican-Americans (40.6%) or non-Hispanic whites (37.4%) (P-value = 0.004). Mexican-American young adults with abdominal obesity had a higher odds of albuminuria even among those with normal blood pressure, normal glucose, and normal insulin sensitivity [adjusted odds ratio 4.5; 95% confidence interval (1.6-12.2), p = 0.004]. Less than 5% of young adults with albuminuria of all races and ethnicities had been told they had kidney disease.

CONCLUSION

Abdominal obesity in young adults, especially in Mexican-Americans, is independently associated with albuminuria even with normal blood pressures, normoglycemia and normal insulin levels. Greater awareness of CKD is needed to protect this young population from long-standing exposure to abdominal obesity and early progressive renal disease.

Associations between whole peripheral blood fatty acids and DNA methylation in humans

Fatty acids (FA) modify DNA methylation in vitro, but limited information is available on whether corresponding associations exist in vivo and reflect any short-term effect of the diet. Associations between global DNA methylation and FAs were sought in blood from lactating infants (LI; n = 49) and adult males (AMM; n = 12) equally distributed across the three conventional BMI classes. AMM provided multiple samples at 2-hour intervals during 8 hours after either a single Western diet-representative meal (post-prandial samples) or no meal (fasting samples). Lipid/glucose profile, HDAC4 promoter and PDK4 5’UTR methylation were determined in AMM. Multiple regression analysis revealed that global (in LI) and both global and PDK4-specific DNA methylation (in AMM) were positively associated with eicosapentaenoic and arachidonic acid. HDAC4 methylation was inversely associated with arachidonic acid post-prandially in AMM. Global DNA methylation did not show any defined within-day pattern that would suggest a short-term response to the diet. Nonetheless, global DNA methylation was higher in normal weight subjects both post-prandially and in fasting and coincided with higher polyunsaturated relative to monounsaturated and saturated FAs. We show for the first time strong associations of DNA methylation with specific FAs in two human cohorts of distinct age, diet and postnatal development stage.

Non alcoholic fatty liver disease in a Nigerian population with type II diabetes mellitus

Introduction

Worldwide, Non-alcoholic fatty liver disease (NAFLD) has become an important cause of chronic liver disease and cardiovascular morbidity, even more so in subjects with Type II Diabetes Mellitus (T2DM). The aim of this study was to determine the prevalence and risk factors of NAFLD in an African population with Type II Diabetes Mellitus.

Methods

We performed a case control study and evaluated anthropometric and biochemical risk factors for NAFLD in 336 subjects (T2DM and non-diabetic controls). Parameters assessed included estimation of BMI (Body Mass Index), measurement of waist circumference (WC), serum cholesterol including HDL-C, LDL-C and triglyceride and serum transaminases (ALT and AST). Hepatitis B and C viral antibody screening was also performed. The diagnosis of NAFLD was confirmed by identification of hepatic steatosis on abdominal ultrasound scan evaluation and exclusion of significant alcohol consumption.

Results

NAFLD was identified in 16.7% (28 of 168) patients with T2DM compared with 1.2% (2 of 168) non-diabetic controls (Odds Ratio 16.6; p < 0.001). Central obesity (WC > 102cm) and dyslipidaemia (HDL-c < 40mg/dl) were independently associated with NAFLD in male subjects with T2DM (p = 0.03 and p = 0.04 respectively).

Conclusion

NAFLD occurred more frequently in patients with T2DM than controls and was associated with central obesity and dyslipidaemia. The diabetic subjects with NAFLD will require more intensive therapy to decrease the risk of hepatic, cardiovascular and other adverse events.

Global Epidemiology of Nonalcoholic Fatty Liver Disease and Perspectives on US Minority Populations

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome predicted to be the next global epidemic affecting millions of people worldwide. The natural course of this disease including its subtype, non-alcoholic steatohepatitis (NASH), is not clearly defined especially in the African-American segment of the US population.

AIMS

To conduct a review of the global epidemiology of NAFLD with emphasis on US minority populations.

METHODS

A thorough search of evidence-based literature was conducted using the Pubmed database and commercial web sources such as Medscape and Google Scholar.

RESULTS

NAFLD and its subtype NASH are becoming the principal cause of chronic liver disease across the world. In the US, Hispanics are the most disproportionately affected ethnic group with hepatic steatosis, and elevated aminotransferase levels, whereas African-Americans are the least affected. Genetic disparities involved in lipid metabolism seem to be the leading explanation for the lowest incidence and prevalence of both NAFLD and NASH in African-Americans.

CONCLUSIONS

The unprecedented rise in the prevalence of NAFLD globally requires an initiation of population cohort studies with long-term follow-up to determine the incidence and natural history of NAFLD and its underrepresentation in African-Americans. Future studies should also focus on the delineation of the interplay between genetic and environmental factors that trigger the development of NAFLD and NASH.

Global Epidemiology of Nonalcoholic Fatty Liver Disease and Perspectives on US Minority Populations

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome predicted to be the next global epidemic affecting millions of people worldwide. The natural course of this disease including its subtype, non-alcoholic steatohepatitis (NASH), is not clearly defined especially in the African-American segment of the US population.

AIMS

To conduct a review of the global epidemiology of NAFLD with emphasis on US minority populations.

METHODS

A thorough search of evidence-based literature was conducted using the Pubmed database and commercial web sources such as Medscape and Google Scholar.

RESULTS

NAFLD and its subtype NASH are becoming the principal cause of chronic liver disease across the world. In the US, Hispanics are the most disproportionately affected ethnic group with hepatic steatosis, and elevated aminotransferase levels, whereas African-Americans are the least affected. Genetic disparities involved in lipid metabolism seem to be the leading explanation for the lowest incidence and prevalence of both NAFLD and NASH in African-Americans.

CONCLUSIONS

The unprecedented rise in the prevalence of NAFLD globally requires an initiation of population cohort studies with long-term follow-up to determine the incidence and natural history of NAFLD and its underrepresentation in African-Americans. Future studies should also focus on the delineation of the interplay between genetic and environmental factors that trigger the development of NAFLD and NASH.

Nonalcoholic Fatty Liver Disease in Canadian First Nations and Non-First Nations Patients

Background. Features of nonalcoholic fatty liver disease (NAFLD) have yet to be described in the Canadian First Nations (FN) population. The aim of this study was to compare the prevalence, severity, and outcome of NAFLD in FN versus non-FN patients at an urban, tertiary care centre. Methods. Adults with NAFLD and no additional liver disease were identified in a prospectively derived database at the University of Manitoba. Demographic, clinical, laboratory, imaging, and histologic data were analyzed. Results. 482 subjects fulfilled diagnostic criteria for NAFLD, including 33 (7%) FN. Aside from rural residence, diabetes and cholestasis being more common in FN patients, the ages, gender distributions, clinical and radiologic features, and liver enzyme/function test results were similar in the two cohorts. Noninvasive tests of fibrosis (APRI and NAFLD fibrosis scores) were also similar in the two cohorts. There were no significant differences in liver enzyme or function tests in either cohort after approximately three years of follow-up. Conclusion. Compared to the prevalence of FN persons in the general population of this study site (10-15%), FN patients were underrepresented in this NAFLD population. The severity and progression of liver disease in FN patients appear to be similar to those in non-FN patients.

Gender-based differences in the relationship between fatty liver disease and atherosclerosis

Background

Carotid intima–media thickness (CIMT) is a surrogate of subclinical atherosclerosis. Fatty liver disease is also linked to increased risk of cardiovascular events. The aim of this study was to evaluate the association between fatty liver disease and CIMT according to gender.

Methods

Patients who had undergone carotid and abdominal ultrasound between June 2011 and December 2013 were retrospectively evaluated. The differences between the CIMT values measured in the common carotid artery and the prevalence of carotid plaque in patients with fatty liver disease and those with normal livers were investigated.

Results

Out of a total of 1 121 patients, the men had more fatty liver disease than the women. The mean CIMT of the men was significantly higher than that of the women, and the men had more plaque than the women. The women with fatty liver disease had a significantly higher mean CIMT value and more plaque than the women with normal livers. The differences between the men with fatty liver and those with normal livers in mean CIMT values and in the prevalence of plaque were not significant. In the women, multivariate analysis showed that fatty liver disease was independently associated with subclinical atherosclerosis [adjusted hazards ratio (HR) 1.65, 95% confidence interval (CI) 1.007–2.697, p = 0.047].

Conclusions

The men had more fatty liver disease, carotid plaque and higher CIMT values than the women. Fatty liver disease was a useful predictor of atherosclerosis, especially for the female study patients.

Body Mass Index and Risk of Nonalcoholic Fatty Liver Disease: Two Electronic Health Record Prospective Studies

CONTEXT

The relationship between rising body mass index (BMI) and prospective risk of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is virtually absent.

OBJECTIVE

Determine the extent of the association between BMI and risk of future NAFLD diagnosis, stratifying by sex and diabetes.

DESIGN

Two prospective studies using Humedica and Health Improvement Network (THIN) with 1.54 and 4.96 years of follow-up, respectively.

SETTING

Electronic health record databases.

PARTICIPANTS

Patients with a recorded BMI measurement between 15 and 60 kg/m(2), and smoking status, and 1 year of active status before baseline BMI. Patients with a diagnosis or history of chronic diseases were excluded.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Recorded diagnosis of NAFLD/NASH during follow-up (Humedica International Classification of Diseases, Ninth Revision code 571.8, and read codes for NAFLD and NASH in THIN).

RESULTS

Hazard ratios (HRs) were calculated across BMI categories using BMI of 20-22.5 kg/m(2) as the reference category, adjusting for age, sex, and smoking status. Risk of recorded NAFLD/NASH increased linearly with BMI and was approximately 5-fold higher in Humedica (HR = 4.78; 95% confidence interval, 4.17-5.47) and 9-fold higher in THIN (HR = 8.93; 7.11-11.23) at a BMI of 30-32.5 kg/m(2) rising to around 10-fold higher in Humedica (HR = 9.80; 8.49-11.32) and 14-fold higher in THIN (HR = 14.32; 11.04-18.57) in the 37.5- to 40-kg/m(2) BMI category. Risk of NAFLD/NASH was approximately 50% higher in men and approximately double in those with diabetes.

CONCLUSIONS

These data quantify the consistent and strong relationships between BMI and prospectively recorded diagnoses of NAFLD/NASH and emphasize the importance of weight reduction strategies for prevention and management of NAFLD.

Association of polymorphisms within the Renin-Angiotensin System with metabolic syndrome in a cohort of Chilean subjects

OBJECTIVE

Metabolic syndrome (MetS) is associated with hypertension, obesity and dyslipidemia. Thus, genetic variants related with these conditions may modulate its development. We evaluated the effect of polymorphisms in the renin-angiotensin system (RAS) on metabolic syndrome risk in a cohort of Chilean subjects.

SUBJECTS AND METHODS

A total of 152 subjects, 83 with MetS (51.2 ± 9.6 years) and 69 without MetS (49.5 ± 9.3 years) of both genders were included, according to the ATP III update criteria. The rs4340 Insertion/Deletion (I/D), rs699 (T>C) and rs5186 (A>C) of the ACE, AGT and AGTR1 genes, respectively, were genotyped.

RESULTS

After adjusting for age and gender, we observed the DD genotype of rs4340 associated with MetS (p = 0.02). Specifically, the DD genotype was associated with MetS risk in women (OR = 4.62, 95%CI, 1.41 - 15.04; p < 0.01). In males, the AA genotype for rs5186 variant was associated with an increased risk for developing MetS when compared with women carrying the same genotype (OR = 3.2; 95%CI, 1.03 - 9.89; p = 0.04). In subjects without MetS, DD genotype was associated with increased waist circumference (p = 0.023) while subjects with MetS carrying the rs5186 TT genotype showed higher levels of HDL-cholesterol (p = 0.031).

CONCLUSION

The present study contributes data highlighting the role for RAS polymorphisms in predisposing to metabolic syndrome in Chilean subjects.

Time-dependent behavioral, neurochemical, and metabolic dysregulation in female C57BL/6 mice caused by chronic high-fat diet intake

High-fat diet (HFD) induced obesity is associated not only with metabolic dysregulation, e.g., impaired glucose homeostasis and insulin sensitivity, but also with neurological dysfunction manifested with aberrant behavior and/or neurotransmitter imbalance. Most studies have examined HFD's effects predominantly in male subjects, either in the periphery or on the brain, in isolation and after a finite feeding period. In this study, we evaluated the time-course of selected metabolic, behavioral, and neurochemical effects of HFD intake in parallel and at multiple time points in female (C57BL/6) mice. Peripheral effects were evaluated at three feeding intervals (short: 5-6 weeks, long: 20-22 weeks, and prolonged: 33-36 weeks). Central effects were evaluated only after long and prolonged feeding durations; we have previously reported those effects after the short (5-6 weeks) feeding duration. Ongoing HFD feeding resulted in an obese phenotype characterized by increased visceral adiposity and, after prolonged HFD intake, an increase in liver and kidney weights. Peripherally, 5 weeks of HFD intake was sufficient to impair glucose tolerance significantly, with the deleterious effects of HFD being greater with prolonged intake. Similarly, 5 weeks of HFD consumption was sufficient to impair insulin sensitivity. However, sensitivity to insulin after prolonged HFD intake was not different between control, low-fat diet (LFD) and HFD-fed mice, most likely due to age-dependent decrease in insulin sensitivity in the LFD-fed mice. HFD intake also induced bi-phasic hepatic inflammation and it increased gut permeability. Behaviorally, prolonged intake of HFD caused mice to be hypoactive and bury fewer marbles in a marble burying task; the latter was associated with significantly impaired hippocampal serotonin homeostasis. Cognitive (short-term recognition memory) function of mice was unaffected by chronic HFD feeding. Considering our prior findings of short-term (5-6 weeks) HFD-induced central (hyperactivity/anxiety and altered ventral hippocampal neurochemistry) effects and our current results, it seems that in female mice some metabolic/inflammatory dysregulations caused by HFD, such as gut permeability, appear early and persist, whereas others, such as glucose intolerance, are exaggerated with continuous HFD feeding; behaviorally, prolonged HFD consumption mainly affects locomotor activity and anxiety-like responses, likely due to the advanced obesity phenotype; neurochemically, the serotonergic system appears to be most sensitive to continued HFD feeding.

Less favorable body composition and adipokines in South Asians compared with other US ethnic groups: results from the MASALA and MESA studies

Background

Small studies have shown that South Asians (SAs) have more total body, subcutaneous, visceral and hepatic fat and abnormal adipokine levels compared to Whites. However, comprehensive studies of body composition and adipokines in SAs compared to other ethnic groups are lacking.

Methods

Using harmonized data, we performed a cross-sectional analysis of two community-based cohorts: Mediators of Atherosclerosis of South Asians Living in America (MASALA, n=906) and Multi-Ethnic Study of Atherosclerosis (MESA which included 2,622 Whites; 803 Chinese Americans; 1,893 African Americans; and 1,496 Latinos). General linear models were developed to assess ethnic differences in ectopic fat (visceral, intermuscular, and pericardial fat; and hepatic attenuation), lean muscle mass, and adipokines (adiponectin and resistin). Models were adjusted for age, sex, site, alcohol use, smoking, exercise, education, household income and BMI. Ectopic fat models were additionally adjusted for hypertension, diabetes, HDL, and triglycerides. Adipokine models were adjusted for subcutaneous, visceral, intermuscular, and pericardial fat; and hepatic attenuation.

Results

Compared to all ethnic groups in MESA (Whites, Chinese Americans, African Americans, and Latinos), SAs had greater intermuscular fat (pairwise comparisons to each MESA group, p < 0.01), lower hepatic attenuation (p < 0.001), and less lean mass (p < 0.001). SAs had greater visceral fat compared to Chinese Americans, African Americans and Latinos (p < 0.05) and greater pericardial fat compared to African Americans (p < 0.001). SAs had lower adiponectin levels compared to other ethnic groups (p < 0.01; except Chinese Americans) and higher resistin levels than all groups (p < 0.001), even after adjusting for differences in body composition.

Conclusion

There are significant ethnic differences in ectopic fat, lean mass, and adipokines. A less favorable body composition and adipokine profile in South Asians may partially explain the increased predisposition to cardiometabolic disease. The mechanisms that underlie these differences warrant further investigation.

Tools for Successful Weight Management in Primary Care

Obesity is one of the most pervasive and costly public health problems. Clinicians need effective tools to address weight management in primary care, including evaluation and communication methods, guideline-based weight management interventions and safe and effective weight loss medications and surgery. The objective of this Grand Rounds presentation is to provide practicing clinicians with the latest information regarding effective ways to care for and communicate with patients about weight loss; evidence-based guidelines for selecting weight management therapies and safety, efficacy and adverse effects of weight loss medications and surgery.

Increased prevalence of polycystic ovary syndrome in premenopausal women with nonalcoholic fatty liver disease

OBJECTIVE

Limited data exist concerning the presence of polycystic ovary syndrome (PCOS) in premenopausal women with nonalcoholic fatty liver disease (NAFLD). We aimed to investigate the prevalence of PCOS in overweight and obese premenopausal women with NAFLD.

DESIGN

Prospective, observational, and cross-sectional study.

METHODS

We studied 110 apparently healthy, overweight, and obese (BMI: 25.1-49.1 kg/m(2)) premenopausal women (age: 18-45 years) reporting no or minimal alcohol consumption for NAFLD with abdominal ultrasonography after excluding causes of secondary liver disease and for PCOS (Rotterdam criteria) with clinical examination, biochemical evaluation, and pelvic ultrasonography. Insulin resistance (IR) was assessed by homeostasis model assessment of IR (HOMA-IR), and free androgen index was calculated.

RESULTS

NAFLD was detected in 71/110 women (64.5%). Women with NAFLD compared to women without NAFLD were more commonly diagnosed with PCOS (43.7% vs 23.1%, respectively, P=0.04), metabolic syndrome (30.2% vs 5.3%, respectively, P=0.003), and abnormal lipid profile (81.1% vs 51.3%, P=0.002). All women with abnormal glucose metabolism had NAFLD (P=0.01). Although PCOS was associated with NAFLD (OR 2.6, 95% CI: 1.1-6.2, P=0.04), in a multivariate analysis higher HOMA-IR values (OR 2.2, 95% CI: 1.1-4.4, P=0.02) and triglyceride levels (OR 1.01, 95% CI: 1.00-1.02, P=0.04) independently predicted NAFLD, after adjusting for age, BMI, and waist-to-hip ratio.

CONCLUSIONS

These findings indicate an increased prevalence of PCOS in overweight and obese premenopausal women with NAFLD, although it is not supported that the syndrome is primarily involved in NAFLD. Evaluation for PCOS may be considered in these women.

Lipoprotein Profiles in Class III Obese Caucasian and African American Women with Nonalcoholic Fatty Liver Disease

Triglyceride content in the liver is regulated by the uptake, production and elimination of lipoproteins, and derangements in these processes contribute to nonalcoholic fatty liver disease (NAFLD). Previous studies show a direct relationship between intrahepatic fat and production of apolipoprotein B100 (apoB100) containing particles, VLDL and LDL, but little consensus exists regarding changes in lipoprotein production in the development of simple steatosis (SS) versus nonalcoholic steatohepatitis (NASH). Further, ethnic variations in lipoproteins among SS and NASH are unknown as is how such variations might contribute to the differential prevalence of disease among Caucasians versus African Americans. In this study, we assessed plasma lipoprotein profiles by nuclear magnetic resonance (NMR) spectroscopy in 70 non-diabetic class III obese females recruited from the surgical weight loss clinic. Of these, 51 females were stratified by biopsy-staged NAFLD severity (histologically normal, SS, or NASH). NASH females displayed increased circulating triglycerides and increased VLDL particle number and size relative to those with histologically normal livers, while total and large LDL concentration decreased in SS versus NASH and correlated with increased insulin resistance (via HOMA2-IR). When Caucasian women were examined alone (n = 41), VLDL and triglycerides increased between normal and SS, while total LDL and apoB100 decreased between SS and NASH along with increased insulin resistance. Compared to Caucasians with SS, African American women with SS displayed reduced triglycerides, VLDL, and small LDL and a more favorable small to large HDL ratio despite having increased BMI and HOMA2-IR. These findings suggest that ApoB100 and lipoprotein subclass particle number and size can delineate steatosis from NASH in obese Caucasian females, but should be interpreted with caution in other ethnicities as African Americans with SS display relatively improved lipoprotein profiles. This may reflect variation in the relationship between dyslipidemia and NAFLD progression across gender and ethnicity.

Change in fatty liver status and 5-year risk of incident metabolic syndrome: a retrospective cohort study

INTRODUCTION

Fatty liver is associated with metabolic syndrome (MetS) but it may also occur without MetS. Whether resolution of fatty liver in the general population affects risk of MetS is unknown. Our aim was to determine whether a change in fatty liver status (either the development of new fatty liver or the resolution of existing fatty liver) would modify the risk of de novo MetS.

METHODS

Two thousand eighty-nine people without hypertension, diabetes, and MetS were examined at baseline and at 5-year follow-up using a retrospective cohort study design. Fatty liver status was assessed at baseline and at follow-up by ultrasonography. Adjusted hazard ratios (aHR) and 95 % confidence intervals (CIs) for de novo MetS at follow-up were calculated controlling for the potential confounders, compared to the reference group (people who never had fatty liver at baseline and follow-up).

RESULTS

During follow-up, fatty liver developed in 251 people and fatty liver resolved in 112 people. After the adjustment for multiple confounders, persisting fatty liver and incident fatty liver development were associated with de novo MetS, with aHR of 2.60 (95 % CIs [1.61,4.20]) and 3.31 (95 % CIs [1.99,5.51]), respectively. Risk of new MetS in resolved fatty liver group was attenuated with insignificant aHR of 1.29 accompanying 95 % CIs of 0.60 and 2.80.

DISCUSSION

Development or maintenance of fatty liver is positively associated with occurrence of new MetS. Resolution of fatty liver status has similar risk of de novo MetS with those who never had fatty liver. Therefore, cautious management is needed with those with fatty liver.

Perceptions of non-alcoholic fatty liver disease - an Asian community-based study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is closely related to metabolic syndrome and its risk factors. Worldwide, epidemiological studies have reported NAFLD prevalence rates of 5% to 30% depending on geographical variations. While epidemiological data suggest a progressively increasing prevalence of metabolic risk factors in Singapore, there are limited data about NAFLD per se in the community. We aim to explore the prevalence and perceptions of NAFLD in Singapore.

METHODS

Attendees at a gastroenterology public forum were enrolled in a cross-sectional observational study evaluating demographic, anthropometric and clinical information. The diagnosis of NAFLD was based on sonographic criteria. Metabolic syndrome was defined according to International Diabetes Federation guidelines. Perceptions of NAFLD were explored using a self-administered survey questionnaire.

RESULTS

A total of 227 subjects were recruited, with NAFLD being diagnosed in 40% of the cohort. Relative to those without NAFLD, subjects with NAFLD had higher male preponderance, older age, higher body mass index, waist circumference and more metabolic syndrome (all P < 0.05). Although 71.2% subjects had heard about NAFLD before, only 25.4% of them felt that they were at risk of NAFLD. Comparable responses were observed in subjects with no metabolic risk factors relative to subjects with one or more metabolic risk factors (P > 0.05). Of note, 75.6% of subjects with one or more metabolic risk factors did not think that they were at risk of NAFLD.

CONCLUSION

Our study suggests a significant local prevalence of NAFLD in the community including non-obese individuals. Considering the tendency to underestimate risk of NAFLD, enhanced public education about NAFLD is warranted to improve understanding.

Accuracy and the effect of possible subject-based confounders of magnitude-based MRI for estimating hepatic proton density fat fraction in adults, using MR spectroscopy as reference

PURPOSE

To determine the accuracy and the effect of possible subject-based confounders of magnitude-based magnetic resonance imaging (MRI) for estimating hepatic proton density fat fraction (PDFF) for different numbers of echoes in adults with known or suspected nonalcoholic fatty liver disease, using MR spectroscopy (MRS) as a reference.

MATERIALS AND METHODS

In this retrospective analysis of 506 adults, hepatic PDFF was estimated by unenhanced 3.0T MRI, using right-lobe MRS as reference. Regions of interest placed on source images and on six-echo parametric PDFF maps were colocalized to MRS voxel location. Accuracy using different numbers of echoes was assessed by regression and Bland-Altman analysis; slope, intercept, average bias, and R2 were calculated. The effect of age, sex, and body mass index (BMI) on hepatic PDFF accuracy was investigated using multivariate linear regression analyses.

RESULTS

MRI closely agreed with MRS for all tested methods. For three- to six-echo methods, slope, regression intercept, average bias, and R2 were 1.01-0.99, 0.11-0.62%, 0.24-0.56%, and 0.981-0.982, respectively. Slope was closest to unity for the five-echo method. The two-echo method was least accurate, underestimating PDFF by an average of 2.93%, compared to an average of 0.23-0.69% for the other methods. Statistically significant but clinically nonmeaningful effects on PDFF error were found for subject BMI (P range: 0.0016 to 0.0783), male sex (P range: 0.015 to 0.037), and no statistically significant effect was found for subject age (P range: 0.18-0.24).

CONCLUSION

Hepatic magnitude-based MRI PDFF estimates using three, four, five, and six echoes, and six-echo parametric maps are accurate compared to reference MRS values, and that accuracy is not meaningfully confounded by age, sex, or BMI.

Pathological implications of cadherin zonation in mouse liver

Both acute and chronic liver diseases are associated with ample re-modeling of the liver parenchyma leading to functional impairment, which is thus obviously the cause or the consequence of the disruption of the epithelial integrity. It was, therefore, the aim of this study to investigate the distribution of the adherens junction components E- and N-cadherin, which are important determinants of tissue cohesion. E-cadherin was expressed in periportal but not in perivenous hepatocytes. In contrast, N-cadherin was more enriched towards the perivenous hepatocytes. In agreement, β-catenin, which links both cadherins via α-catenin to the actin cytoskeleton, was expressed ubiquitously. This zonal expression of cadherins was preserved in acute liver injury after treatment with acetaminophen or partial hepatectomy, but disrupted in chronic liver damage like in non-alcoholic steatohepatitis (NASH) or α1-antitrypsin deficiency. Hepatocyte proliferation during acetaminophen-induced liver damage was predominant at the boundary between the damaged perivenous and the intact periportal parenchyma indicating a minor contribution of periportal hepatocytes to liver regeneration. In NASH livers, an oval cell reaction was observed pointing to massive tissue damage coinciding with the gross impairment of hepatocyte proliferation. In the liver parenchyma, metabolic functions are distributed heterogeneously. For example, the expression of phosphoenolpyruvate carboxykinase and E-cadherin overlapped in periportal hepatocytes. Thus, during liver regeneration after acute damage, the intact periportal parenchyma might sustain essential metabolic support like glucose supply or ammonia detoxification. However, disruption of epithelial integrity during chronic challenges may increase susceptibility to metabolic liver diseases such as NASH or vice versa. This might suggest the regulatory integration of tissue cohesion and metabolic functions in the liver.

Inflammasome activation and function in liver disease

Inflammation contributes to the pathogenesis of most acute and chronic liver diseases. Inflammasomes are multiprotein complexes that can sense danger signals from damaged cells and pathogens and assemble to mediate caspase-1 activation, which proteolytically activates the cytokines IL-1β and IL-18. In contrast to other inflammatory responses, inflammasome activation uniquely requires two signals to induce inflammation, therefore setting an increased threshold. IL-1β, generated upon caspase-1 activation, provides positive feed-forward stimulation for inflammatory cytokines, thereby amplifying inflammation. Inflammasome activation has been studied in different human and experimental liver diseases and has been identified as a major contributor to hepatocyte damage, immune cell activation and amplification of liver inflammation. In this Review, we discuss the different types of inflammasomes, their activation and biological functions in the context of liver injury and disease progression. Specifically, we focus on the triggers of inflammasome activation in alcoholic steatohepatitis and NASH, chronic HCV infection, ischaemia-reperfusion injury and paracetamol-induced liver injury. The application and translation of these discoveries into therapies promises novel approaches in the treatment of inflammation in liver disease.

Toxicity profile of repeated doses of PEG-asparaginase incorporated into a pediatric-type regimen for adult acute lymphoblastic leukemia

Despite having been long regarded as too toxic for adult patients, pediatric-like regimens containing L-asparaginase have resulted in improved outcomes for adults with acute lymphoblastic leukemia (ALL). To characterize the spectrum of toxicity of repeated doses of polyethylene glycolated-asparaginase (PEG-asp) in adults, we reviewed all doses (2000 IU/m(2) ) administered as part of a pediatric-inspired regimen in adult ALL at our center. Subjects aged 18-60 yr with ALL (n = 152, 69.1% male) contributed 522 dose cycles to the study. Hepatotoxicity was the most common adverse event: grades 3-4 transaminitis and hyperbilirubinemia occurred in 53.9% and 23.7% of subjects, respectively. Hepatotoxicity was reversible; no cases of fulminate hepatic failure were observed. Other toxicities affecting at least 5% of subjects were grades 3-4 triglyceridemia in 50.9%, hypofibrinogenemia (<100 mg/dL) in 47.9%, clinical pancreatitis in 12.6%, venous thromboembolism in 11.2%, allergic reaction in 7.2%, and any grade bleeding in 5.3%. PEG-asp was always discontinued after grades 3-4 pancreatitis or allergic reaction. Otherwise, toxicities did not preclude administration of additional cycles of the drug. Our results suggest that repeated PEG-asp dosing is safe in adults aged 18-60 yr, even after occurrence of a drug-related toxicity.

Burden of nonalcoholic fatty liver disease and advanced fibrosis in a Texas Hispanic community cohort

AIM: To investigate the potential burden of nonalcoholic steatohepatitis (NASH) and advanced fibrosis in a hispanic community.

METHODS: Four hundred and forty two participants with available ultrasonography data from the Cameron County Hispanic Cohort were included in this study. Each participant completed a comprehensive questionnaire regarding basic demographic information, medical history, medication use, and social and family history including alcohol use. Values of the nonalcoholic fatty liver disease fibrosis score (NFS), FIB4 index, BARD score, and Aspartate aminotransferase to Platelet Ratio Index (APRI) were computed using the blood samples collected within 6 mo of liver ultrasonography from each participant. Hepatic steatosis was determined by ultrasonography. As part of univariable analysis, for continuous variables, comparisons among groups were performed with student-t test, one way analysis of variance, and Mann-Whitney test. Pearson χ² and the Fisher exact test are used to assess differences in categorical variables. For multivariable analyses, logistic regression analyses were performed to identify characteristics associated with hepatic steatosis. All reported P values are based two-sided tests, and a P value of less than 0.05 was considered to indicate statistical significance.

RESULTS: The mean age and body mass index (BMI) of the study participants were 49.1 years and 31.3 kg/m², respectively. Among them, 65.6% were females, 52% had hepatic steatosis, 49.5% had metabolic syndrome, and 29% had elevated aminotransferases. Based on established cut-offs for diagnostic panels, between 17%-63% of the entire cohort was predicted to have NASH with indeterminate or advanced fibrosis. Participants with hepatic steatosis had significantly higher BMI (32.9 ± 5.6 kg/m²vs 29.6 ± 6.1 kg/m², P < 0.001) and higher prevalence rates of elevation of ALT (42.2% vs 14.6%, P < 0.001), elevation of aspartate aminotransferase (38.7% vs 18.9%, P < 0.001), and metabolic syndrome (64.8% vs 33%, P < 0.001) than those without hepatic steatosis. The NFS scores (P = 0.002) and the APRI scores (P = 0.002) were significantly higher in those with steatosis but the scores of the FIB4 index and BARD were similar between the two groups. After adjusting for age, gender and BMI, elevated transaminases, metabolic syndrome and its components, intermediate NFS and APRI scores were associated hepatic steatosis in multivariable analysis.

CONCLUSION: The burden of NASH and advanced fibrosis in the Hispanic community in South Texas may be more substantial than predicted from referral clinic studies.

Effect of enforced physical inactivity induced by 60-day of bed rest on hepatic markers of NAFLD in healthy normal-weight women

BACKGROUND & AIMS

Physical inactivity leads to a cluster of metabolic disorders that have been associated with non-alcoholic fatty liver diseases. We tested whether physical inactivity increases hepatic biomarkers of NAFLDs.

METHODS

Sixteen normal-weight healthy women (body mass index = 21.2 ± 0.5 kg/m(2) ) were studied under controlled energy balance conditions during a previous 60-day bed rest with (n = 8) or without (n = 8) a combined aerobic/resistive exercise protocol. Stored samples were retrospectively used to measure plasma hepatic markers, i.e. steatosis-related alanine and aspartate transaminases, cytokeratin 18 and angiopoietin-like 3, at baseline, after 30 and 60 days of bed rest. Fasting insulin and triglycerides were measured at baseline and after 30 days of bed rest. Two indexes were calculated, one combining alanine and aspartate transaminase and cytokeratin 18 and another cytokeratin 18, homeostasis model assessment of insulin resistance and aspartate aminotransferase.

RESULTS

Sixty days of bed rest increased all hepatic markers (P < 0.05 for all) and the two indexes (P < 0.01 for both). Exercise significantly reduced the elevation in aspartate transaminase, cytokeratin 18 and both indexes (P < 0.02 for all) but not the increase in alanine transaminase and angiopoietin-like 3. Changes between baseline and 30 days of bed rest in triglycerides were positively associated with changes in aspartate transaminase (R(2) = 0.28, P = 0.04) suggesting a role of hypertriglyceridaemia in the alteration of liver metabolism under inactive conditions.

CONCLUSION

Physical inactivity increases, independent of fat mass, hepatic markers of steatosis and steatohepatitis. Regular exercise can limit these physical inactivity-induced metabolic alterations. Future studies need to elucidate the underlying mechanisms.

Composite prognostic models across the non-alcoholic fatty liver disease spectrum: Clinical application in developing countries

Heterogeneity in clinical presentation, histological severity, prognosis and therapeutic outcomes characteristic of non-alcoholic fatty liver disease (NAFLD) necessitates the development of scientifically sound classification schemes to assist clinicians in stratifying patients into meaningful prognostic subgroups. The need for replacement of invasive liver biopsies as the standard method whereby NAFLD is diagnosed, graded and staged with biomarkers of histological severity injury led to the development of composite prognostic models as potentially viable surrogate alternatives. In the present article, we review existing scoring systems used to (1) confirm the presence of undiagnosed hepatosteatosis; (2) distinguish between simple steatosis and NASH; and (3) predict advanced hepatic fibrosis, with particular emphasis on the role of NAFLD as an independent cardio-metabolic risk factor. In addition, the incorporation of functional genomic markers and application of emerging imaging technologies are discussed as a means to improve the diagnostic accuracy and predictive performance of promising composite models found to be most appropriate for widespread clinical adoption.

Association Between Pulmonary Function and Nonalcoholic Fatty Liver Disease in the NHANES III Study

Emerging evidence indicates that nonalcoholic fatty liver disease (NAFLD) is associated with a wide variety of extrahepatic complications. However, the potential association between impaired pulmonary function and NAFLD has been less investigated. This study examined the relationship between pulmonary function and hepatic steatosis in 9976 adults participating in a cross-sectional analysis of the Third National Health and Nutrition Examination Survey (NHANES III). NAFLD was defined as hepatic steatosis presented on ultrasound examinations in the absence of other known liver diseases. The associations between predicted forced expiratory volume in 1 second (FEV1)% or predicted forced vital capacity (FVC)% and NAFLD were examined using multivariable linear regression while controlling for confounders. The association between obstructive or restrictive spirometry patterns and NAFLD was also evaluated using multivariable logistic regression analysis. After adjustment for multiple covariates, predicted FEV1% and FVC% were significantly and inversely associated with the degree of hepatic steatosis (P for trend <0.001 for both). The restrictive lung pattern was significantly related to participants with moderate and severe hepatic steatosis as compared with those without steatosis (OR 1.65, 95% CI 1.14-2.39 and OR 1.85, 95% CI 1.13-2.82), whereas the obstructive lung pattern was not associated with the presence of hepatic steatosis. Individuals with a greater degree of hepatic steatosis were at greater risk for poor pulmonary function, especially in restrictive pattern. These novel findings demonstrate that impaired pulmonary function is also an extrahepatic complication of NAFLD.

Management and diagnosis of fatty liver disease

Nonalcoholic fatty liver disease is a common cause of chronic liver disease and has been an increasingly studied topic of research as the obesity epidemic has been growing. There is a significant morbidity and mortality with uncontrolled steatohepatitis, which can progress to fibrosis, cirrhosis and hepatocellular carcinoma. The prevalence of this disease has been estimated to be roughly one-third of the western population, thought to be largely due to diet and sedentary lifestyle. Several treatments have been studied including vitamin E, insulin-sensitizing agents and ursodeoxycholic acid; however, the only treatment shown to improve the histologic changes of nonalcoholic fatty liver disease is weight loss. Given the proven benefit of weight loss, there may be reason to screen at-risk populations; however, limited availability of other disease-modifying treatments may limit the cost-benefit ratios. A better understanding of the diagnosis and management of this condition is required to alter the course of this modifiable disease.

Gender-based disparities in access to and outcomes of liver transplantation

Despite comprising 35% of transplants, the number of female transplant recipients has continued to decline. Accordingly, there is a growing attention to the issue of access to and outcomes of liver transplantation in women. The purpose of this review is to critically evaluate the published literature on etiologies contributing to gender-based disparities in liver transplantation focusing on the steps from chronic liver disease through transplantation including disparities in liver disease prevalence, access to liver transplant centers and transplant waiting list, receipt of liver transplantation once listed and disparities in post-liver transplantation outcomes. Our review finds factors contributing to this disparity may include gender differences in the etiology of underlying liver disease and patient and physician referral patterns, lifestyle and health care, but also utilization of an imperfect organ allocation system based on the model for end stage liver disease score and donor-recipient liver size matching. The review also highlights the need for further research in the area of gender disparity in order to develop appropriate approaches to address it and to improve allocation of this precious resource in the future.

Association between platelet count as a noninvasive marker and ultrasonographic grading in patients with nonalcoholic Fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease has become a worldwide challenge. Liver biopsy remains the single most reliable approach to determine the severity of this disease. As patients with nonalcoholic fatty liver disease require close follow-up, performing this invasive method repeatedly seems impractical; therefore, designing a noninvasive system to follow up patients has become a common interest.

OBJECTIVES

We intended to investigate the association between platelet counts of patients with nonalcoholic fatty liver disease and the severity of their disease based on serum levels of liver enzymes and grade of fatty liver on ultrasonography.

PATIENTS AND METHODS

One thousand, three hundred and five patients with nonalcoholic fatty liver disease were included in this descriptive study. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and platelet counts of patients were measured. The grade of fatty liver was determined by abdominal ultrasonography.

RESULTS

Of our study population, 54.3% (n = 708) were women. Patients with mild fatty liver on ultrasonography had lower platelet counts than those with moderate and severe fatty liver. However, no cutoff value of platelet count could reliably distinguish different grades of fatty liver. We found no significant association between platelet counts and serum levels of AST, ALT or ALP. However, we showed that male patients with abnormal levels of ALT had higher platelet counts.

CONCLUSIONS

Platelet count in nonalcoholic fatty liver disease can serve as a clue to the severity of disease, but it cannot be considered as a sole test to follow up patients.

Association between nonalcoholic fatty liver disease and colorectal adenoma: a systematic review and meta-analysis

BACKGROUND AND AIMS

Several existing studies indicated that nonalcoholic fatty liver disease (NAFLD) may be associated with colorectal adenoma, but the results and risk factors are controversial. A systematic review of studies was conducted to explore these issues by meta-analysis.

METHODS

We searched the Pubmed, Embase, Cochrane library, Medline and Web of Science databases for studies published before May 30(th), 2014. A statistical analysis was performed using RevMan 5.2 software.

RESULTS

Seven studies involving 11,905 participants from different regions were included. Among them, five trials carried out subgroup of NAFLD patients in colorectal adenoma population. The result showed NAFLD was significantly correlated with adenoma of colon (Odds ratio [OR] = 1.56, 95% confidence interval [CI]: 1.22-1.99, P = 0.0003). It could be found in stratified analysis that patients had more chance to get multiple adenomas when they suffered NAFLD (Rate ratio [RR]: 1.52, 95% CI: 1.08-2.13, P = 0.02). Such risk factors of NAFLD as age, waist circumference, body mass index (BMI), disorder of lipid metabolism, hyperglycemia and high blood pressure (HBP) increased risk of colorectal adenoma (Age: mean difference [MD]: 2.81, 95% CI: 0.33-5.28; Waist: MD: 2.84, 95% CI: 2.14-3.54; BMI: MD: 0.85, 95% CI: 0.69-1.01; High-density lipoprotein: MD: -2.46, 95% CI: -3.68 to -1.24; Triglyceride: MD: 16.12, 95% CI: 8.89-23.36; Low-density lipoprotein: MD: 6.04, 95% CI: 3.60-8.48; Cholesterol: MD: 4.25, 95% CI: 0.87-7.63; Fasting glucose: MD: 2.27, 95% CI: 1.24-3.30; HBP: OR = 1.51, 95% CI: 1.22-1.88), while diabetes had no significant association with it (OR = 1.43, 95% CI: 0.94-2.17, P = 0.09). Besides, NAFLD didn't affect the location, size and advanced type of colorectal adenoma (P > 0.05).

CONCLUSION

The present systematic review and meta-analysis demonstrated NAFLD was closely associated with great risk of colorectal adenoma and its number, but not with its location, size and advanced type. Waist, obesity, lipid profiles, glucose, hypertension played roles in the process of colorectal adenoma.

Systematic review on intervention with prebiotics/probiotics in patients with obesity-related nonalcoholic fatty liver disease

BACKGROUND

The gut microbiota is modulated by metabolic derangements, such as nutrition overload and obesity.

AIM

The aim of this systematic review is to summarize the role of these gut modifiers in nonalcoholic fatty liver disease (NAFLD) and obesity.

METHODS

A systematic search of MEDLINE (from 1946), PubMed (from 1946) and EMBASE (from 1949) databases through May 2014 was carried out to identify relevant articles. The search terms were 'probiotic' AND 'NAFLD', 'prebiotic' AND 'NAFLD', 'antibiotic' AND 'NAFLD', 'probiotics' AND 'obesity', 'prebiotic' AND 'obesity' or 'antibiotic' AND 'obesity'; these terms were searched as text word in 'clinical trials' and as exploded medical subject headings where possible.

RESULTS

The evidence in the literature is scant, due to the scarcity of appropriately powered, randomized, controlled clinical trials, involving various centers and population of different origin.

CONCLUSION

Although probiotics and prebiotics have been proposed in the treatment and prevention of patients with obesity-related NAFLD, their therapeutic use is not supported by high-quality clinical studies.