Obesity and alcoholic liver disease

Independent and additive effects of binge drinking and obesity on liver enzymes: a cross-sectional analysis using the Korean National Health Insurance Service data

Background

Binge drinking (BD) has been associated with elevated liver enzymes, but the joint association of BD and adiposity with liver enzymes is understudied. We aimed to examine the combined association of BD and obesity with elevated liver enzymes.

Methods

Data were obtained from 285,600 patients in the Korean National Health check-up program during 2009-2015. Level I BD (BD I) was defined as alcohol consumption of >60 g (men) or >40 g (women) on one occasion in the previous year. High-intensity BD (HIBD) corresponded to at least two times the BD I levels. General and abdominal obesity were defined by body mass index and waist circumference. Logistic regression was used to examine the independent and joint associations of BD and obesity with elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) levels. Relative excess risk (RERI), attributable proportion (AP), and synergy index (SI) were calculated to estimate the additive interaction effects.

Results

The mean age was 42.1 ± 0.03 years and 50.2% were women. Elevated ALT [odds ratio (OR) 1.09, 95% confidence interval (CI) 1.02-1.16], AST (OR 1.16, 95% CI 1.11-1.23), and GGT (OR 1.84, 95% CI 1.05-1.94) were associated with HIBD. Higher odds of elevated ALT (OR 3.57, 95% CI 3.43-3.71), AST (OR 3.47, 95% CI 3.37-3.58), and GGT (OR 2.10, 95% CI 1.98-2.12) were observed in individuals with general obesity. A similar trend was observed for abdominal obesity. The RERI, AP, and SI for the interaction effect of BD and general obesity were 23%, 7%, and 13% for elevated AST levels, and 67%, 24%, and 58% for elevated GGT levels, respectively. Similar effects were observed for the interaction between BD and abdominal obesity.

Conclusions

Obesity aggravated the odds of elevated liver AST and GGT levels in HIBD.

mTORC1 inhibition uncouples lipolysis and thermogenesis in white adipose tissue to contribute to alcoholic liver disease

BACKGROUND

Adipose tissue thermogenic activities use fatty acids from lipolysis for heat generation. Therefore, a tight coupling between lipolysis and thermogenesis is physiologically imperative in maintaining not only body temperature but also lipids homeostasis. Adipose tissue dysfunction contributes to alcoholic liver disease (ALD). Here, studies were conducted to examine how alcohol intake affects adipose tissue thermogenic activities and whether altered adipose tissue thermogenesis contributes to ALD.

METHODS

Both the Lieber-DeCarli and the NIAAA mouse models of ALD were used. Denervation surgery in epididymal fat pads was performed. CL316,243, a selective β3-adrenoceptor agonist, SR59230A, a selective β3 adrenoceptor (ADRB3) antagonist, and rapamycin, a selective mechanistic target of rapamycin complex 1 (mTORC1) inhibitor, were administrated through i.p. injection. Adipocyte-specific Prdm16 knockout mice were subjected to alcohol-containing diet chronically.

RESULTS

Chronic alcohol consumption, which enhances adipose tissue lipolysis, inhibits thermogenic activities of beige adipocytes in inguinal white adipose tissue (WAT), leading to an uncoupling status between lipolysis and thermogenesis in WAT at both basal and ADRB3 stimulation states. CL316,243 administration exacerbates liver pathologies of ALD. Alcohol intake inhibits mTORC1 activities in WAT. In mice, mTORC1 inhibition by rapamycin inhibits the thermogenesis of iWAT, whereas enhancing WAT lipolysis. Further investigations using adipocyte-specific Prdm16 knockout mice revealed that functional deficiency of beige adipocytes aggravates liver pathologies of ALD, suggesting that the inhibitory effect of alcohol on WAT browning/thermogenesis contributes to ALD pathogenesis.

CONCLUSION

Chronic alcohol consumption induces an "uncoupling status" between lipolysis and browning/thermogenesis in WAT by inhibiting mTORC1 activation. Diminished WAT browning/thermogenesis, concomitant with enhanced lipolysis, contributes to ALD pathogenesis.

The Impact of Metabolic Syndrome on the Prognosis of High-Risk Alcoholic Hepatitis Patients: Redefining Alcoholic Hepatitis

Background

Alcoholic hepatitis (AH) is characterized by acute symptomatic hepatitis associated with heavy alcohol use. This study was designed to assess the impact of metabolic syndrome on high-risk patients with AH with discriminant function (DF) score ≥ 32 and its effect on mortality.

Methods

We searched the hospital database for ICD-9 diagnosis codes of acute AH, alcoholic liver cirrhosis, and alcoholic liver damage. The entire cohort was categorized into two groups: AH and AH with metabolic syndrome. The effect of metabolic syndrome on mortality was evaluated. Also, an exploratory analysis was used to create a novel risk measure score to assess mortality.

Results

A large proportion (75.5%) of the patients identified in the database who had been treated as AH had other etiologies and did not meet the American College of Gastroenterology (ACG)-defined diagnosis of acute AH, thus had been misdiagnosed as AH. Such patients were excluded from analysis. The mean body mass index (BMI), hemoglobin (Hb), hematocrit (HCT), and alcoholic liver disease/non-alcoholic fatty liver disease index (ANI) were significantly different between two groups (P < 0.05). The results of a univariate Cox regression model showed that age, BMI, white blood cells (WBCs), creatinine (Cr), international normalized ratio (INR), prothrombin time (PT), albumin levels, albumin < 3.5, total bilirubin, Na, Child-Turcotte-Pugh (CTP), model for end-stage liver disease (MELD), MELD ≥ 21, MELD ≥ 18, DF score, and DF ≥ 32 had a significant effect on mortality. Patients with a MELD greater than 21 had a hazard ratio (HR) (95% confidence interval (CI) of 5.81 (2.74 - 12.30) (P < 0.001). The adjusted Cox regression model results showed that age, Hb, Cr, INR, Na, MELD score, DF score, and metabolic syndrome were independently associated with high patient mortality. However, the increase in BMI and mean corpuscular volume (MCV) and sodium significantly reduced the risk of death. We found that a model including age, MELD ≥ 21, and albumin < 3.5 was the best model in identifying patient mortality. Our study showed that patients admitted with a diagnosis of alcoholic liver disease with metabolic syndrome had an increased mortality risk compared to patients without metabolic syndrome, in high-risk patients with DF ≥ 32 and MELD ≥ 21. A bivariate correlation analysis revealed that patients with AH with metabolic syndrome were more likely to have infection (43%) compared to AH (26%) with correlation coefficient of 0.176 (P = 0.03, CI: 0.018 - 1.0).

Conclusion

In clinical practice, the diagnosis of AH is inaccurately applied. Metabolic syndrome significantly increases the mortality risk in high-risk AH. It signifies that the presence of features of metabolic syndrome modifies the behavior of AH in acute settings, warranting different therapeutic strategies. We propose that in defining AH, patients overlapping with metabolic syndrome may need to be excluded as their outcome is different with regard to risk of renal dysfunctions, infections and death.

Periplaneta americana extract alleviates steatohepatitis in a mouse model by modulating HMGB1-mediated inflammatory response

Alcoholic abuse and obesity are the most common lifestyle implications of chronic liver injury, and always act synergistically to increase the risk of mortality. Periplaneta americana has a long history of being applied in medicine, including wound healing, antitumor, antibacterial, antiviral, antifibrotic, and cardiomyocyte-protecting. Ganlong capsule (GLC), a natural prescription drug extracted from Periplaneta americana, has been widely used in HBV-related symptoms. However, the anti-steatohepatitis efficacy and mechanisms of GLC have not yet been characterized. Here, we found the protective effect of GLC on the development of hepatic steatosis, oxidative stress, and inflammation in vivo under alcohol exposure combined with a high-fat and high-cholesterol diet (HFHC). Consistently, GLC exhibited a hepatoprotective property by preventing hepatocytes from oxidative stress injury and lipid accumulation in vitro. In addition, it exerted an anti-inflammation characteristic by reducing macrophage recruitment and decreasing the expression of pro-inflammatory genes in vivo and in vitro. Mechanically, GLC serum, isolated from GLC-treated mice, reduced extracellular high-mobility group box 1 (HMGB1) of dying hepatocytes; and suppressed subsequent M1 polarization of macrophages in the co-culture system. Furthermore, GLC serum inhibited inflammatory response via suppressing the HMGB1 release and blocking the downstream TLR4/NF-kB pathway. Collectively, GLC alleviates steatohepatitis induced by alcohol consumption and obesity through inhibition of the HMGB1-mediated inflammatory cascade. GLC might be a therapeutic candidate for the treatment of steatohepatitis developed by alcohol abuse and metabolic disorders.

Cheese Intake Exhibits an Alteration of Glycolipid Profile and Impacts on Non-Alcoholic Fatty Liver in Bahraini Older Adults

Background: Metabolic syndrome (MetS) is a multifactorial condition characterized by a complex interrelation between genetic and environmental factors that heighten the risk of cardiovascular diseases and all-cause mortality. It is hypothesized that diet may play an important role in the regulation of metabolic syndrome factors and influence the process. Therefore, the main objective of this study was to investigate the specific dietary patterns associated with metabolic syndrome markers and quantify the possible effects of dietary patterns among Bahrain older adults. Methods: This is a cross-sectional study that included 151 Bahraini patients diagnosed with MetS, 89 (58.7%) were females and 62 (41.3%) males. Results: The prevalence of Non-Alcoholic Fatty Liver was 89%. Statistically significant correlations were found between dairy products with low fat and SBP (r = 0.182, p < 0.001) body mass index (BMI) (r = −0.195; p < −0.01). Higher chicken consumption was associated with reduction of BMI (r = −0.273; p < −0.01). A higher consumption of ricotta and cheddar cheese (high in fat) was associated with higher levels of triglycerides (p < 0.01). Higher frequent consumption of rice (basmati) was associated with lower glucose levels (r = −0.200; p < −0.01). Fatty liver has been associated with high consumption of cream cheese (p < 0.01). Conclusion: In older Bahraini adults with metabolic syndrome, higher frequency of food consumption of full-fat cheese was linked with a derangement of lipid profile and Non-Alcoholic Fatty Liver. Positive effects on BMI have been recorded with higher-frequency consumption of basmati rice and chicken.

Alcohol drinking and risks of liver cancer and non-neoplastic chronic liver diseases in China: a 10-year prospective study of 0.5 million adults

BACKGROUND

Alcohol consumption is an important risk factor for hepatic neoplastic and non-neoplastic diseases. Questions remain, however, about the relevance to disease risk of drinking patterns and alcohol tolerability, which differ appreciably between Chinese and Western populations.

METHODS

The prospective China Kadoorie Biobank included 512,715 adults (41% men) aged 30-79 years recruited from ten areas during 2004-2008, recording alcohol intake, drinking patterns, and other characteristics. After median 10 years' follow-up, 2531 incident liver cancer, 2040 liver cirrhosis, 260 alcoholic liver disease (ALD), and 1262 non-alcoholic fatty liver disease (NAFLD) cases were recorded among 492,643 participants without prior cancer or chronic liver disease at baseline. Cox regression was used to estimate adjusted hazard ratios (HR) relating alcohol intake and drinking patterns to each disease.

RESULTS

Overall, 33% of men and 2% of women drank alcohol regularly (i.e. at least weekly) at baseline. Among male current regular drinkers, alcohol consumption showed positive dose-response associations with risks of several major chronic liver diseases, with HRs per 280 g/week (i.e. around four drinks/day) higher usual alcohol intake of 1.44 (95% CI 1.23-1.69) for liver cancer (n = 547), 1.83 (1.60-2.09) for liver cirrhosis (n = 388), 2.01 (1.77-2.28) for ALD (n = 200), 1.71 (1.35-2.16) for NAFLD (n = 198), and 1.52 (1.40-1.64) for total liver disease (n = 1775). The association with ALD appeared stronger among men reporting flushing (i.e., with low alcohol tolerance). After adjustment for the total amount of weekly alcohol consumption, daily drinkers had significantly increased risk of ALD (2.15, 1.40-3.31) compared with non-daily drinkers, and drinking without meals was associated with significantly greater risks of liver cancer (1.32, 1.01-1.72), liver cirrhosis (1.37, 1.02-1.85), and ALD (1.60, 1.09-2.33) compared with drinking with meals. Female current regular drinkers had significantly higher risk of ALD, but not other liver diseases, than female abstainers.

CONCLUSIONS

In Chinese men, alcohol intake was associated with significantly increased risks of several major chronic liver diseases, and certain drinking patterns (e.g. drinking daily, drinking without meals) may further exacerbate the disease risks.

Impact of body mass and alcohol consumption on all-cause and liver mortality in 240 000 adults in the United States

INTRODUCTION

Nationally representative studies of the combined impact of drinking and body mass (BMI) on mortality outcomes are unavailable. We investigate whether both act together to elevate risk of all-cause or liver mortality.

METHODS

We obtained self-reported histories of drinking and BMI from 129 098 women (mean age 47.2 years) and 102 568 men (mean age 45.6 years) ≥18 years interviewed from 1997 to 2004 in the National Health Interview Survey and related these data to the deaths that occurred by 31 December 2006 (women = 8486; men = 7819 deaths). Death hazards among current drinkers in different BMI groups were adjusted for age, education, race and smoking.

RESULTS

Obese (≥30 kg m-2 ) adults with consumption of >40 g day-1 (women) or >60 g day-1 (men) pure ethanol were at risk of increased mortality from all-cause and chronic liver disease (P trend <0.0001). For heavy drinkers with BMI ≥30 kg m-2 , each 5 kg m-2 higher BMI was associated with an elevated all-cause mortality in men (hazard ratios 1.27, 95% confidence interval [CI]: 1.16-1.40) and women (1.12, [1.02-1.24]). The excess risk due to interaction was more pronounced in men (7.30, [3.60-11.00]) than women (2.90, [0.50-5.30]).

DISCUSSION AND CONCLUSIONS

Obesity and excess alcohol are both related to all-cause and liver mortality-the latter with evidence of a supra-additive interaction between the risk factors. The presence of both factors in the same population and their impact should inform treatment, public health policies and research.

Beneficial effects of an endogenous enrichment in n3-PUFAs on Wnt signaling are associated with attenuation of alcohol-mediated liver disease in mice

Alcohol-associated liver disease (ALD) is a major human health issue for which there are limited treatment options. Experimental evidence suggests that nutrition plays an important role in ALD pathogenesis, and specific dietary fatty acids, for example, n6 or n3-PUFAs, may exacerbate or attenuate ALD, respectively. The purpose of the current study was to determine whether the beneficial effects of n3-PUFA enrichment in ALD were mediated, in part, by improvement in Wnt signaling. Wild-type (WT) and fat-1 transgenic mice (that endogenously convert n6-PUFAs to n3) were fed ethanol (EtOH) for 6 weeks followed by a single LPS challenge. fat-1 mice had less severe liver damage than WT littermates as evidenced by reduced plasma alanine aminotransferase, hepatic steatosis, liver tissue neutrophil infiltration, and pro-inflammatory cytokine expression. WT mice had a greater downregulation of Axin2, a key gene in the Wnt pathway, than fat-1 mice in response to EtOH and LPS. Further, there were significant differences between WT and fat-1 EtOH+LPS-challenged mice in the expression of five additional genes linked to the Wnt signaling pathway, including Apc, Fosl1/Fra-1, Mapk8/Jnk-1, Porcn, and Nkd1. Compared to WT, primary hepatocytes isolated from fat-1 mice exhibited more effective Wnt signaling and were more resistant to EtOH-, palmitic acid-, or TNFα-induced cell death. Further, we demonstrated that the n3-PUFA-derived lipid mediators, resolvins D1 and E1, can regulate hepatocyte expression of several Wnt-related genes that were differentially expressed between WT and fat-1 mice. These data demonstrate a novel mechanism by which n3-PUFAs can ameliorate ALD.

The combined effect of alcohol and body mass index on risk of chronic liver disease: A systematic review and meta-analysis of cohort studies

BACKGROUND & AIMS

Increasingly populations are both overweight/obese and consume alcohol. The risk of liver disease from the combination of these factors is unclear. We performed a systematic review and meta-analysis to address this important gap in evidence. Protocol registered with PROSPERO(CRD42016046508).

METHODS

We performed electronic searches of Ovid Medline, Embase Classic + Embase, until 17th June 2020 for cohort studies of adults without pre-existing liver disease. Primary outcome was morbidity/mortality from chronic liver disease. Exposures were alcohol consumption categorised as within or above UK recommended limits (14 units/112 g per week) and BMI categorised as normal, overweight or obese. Non-drinkers were excluded. A Poisson regression log-linear model was used to test for statistical interaction between alcohol and BMI and to conduct a one-stage meta-analysis.

RESULTS

Searches identified 3129 studies-16 were eligible. Of these, nine cohorts (1,121,514 participants) had data available and were included in the analysis. The Poisson model showed no significant statistical interaction between alcohol consumption and BMI on the risk of chronic liver disease. Compared to normal weight participants drinking alcohol within UK recommended limits, relative risk of chronic liver disease in overweight participants drinking above limits was 3.32 (95% CI 2.88 to 3.83) and relative risk in obese participants drinking above limits was 5.39 (95% CI 4.62 to 6.29).

CONCLUSIONS

This meta-analysis demonstrated a significantly increased risk of chronic liver disease in participants who were both overweight/obese and consumed alcohol above UK recommended limits. This evidence should inform advice given to patients and risk stratification by healthcare professionals.

Joint associations of adiposity and alcohol consumption with liver disease-related morbidity and mortality risk: findings from the UK Biobank

BACKGROUND

The incidence of both non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (ALD) are expected to grow as a consequence of the ongoing obesity and alcohol consumption trends.

OBJECTIVE

We examined the joint associations of adiposity (body mass index (BMI) and waist circumference (WC)) and alcohol consumption on ALD, NAFLD and liver disease incidence and mortality (n = 465,437).

METHODS

Alcohol consumption was categorised based on current UK guidelines (14 units/week). Data were analysed using Cox proportional hazard models. A total of 1090 liver disease deaths, 230 ALD deaths and 192 NAFLD deaths occurred over an average follow-up length of 10.5 ± 1.7 years.

RESULTS

In multivariate models, we observed greater point estimates for risk of ALD, NAFLD and liver disease incidence and mortality among overweight/obese participants who consumed alcohol at the same level as normal weight participants. We found that overweight/obese participants who reported alcohol consumption above the guidelines had a greater HR for liver disease incidence and mortality (HR 1.52, 95% CI 1.32, 1.75 and HR 2.20, 95% CI 1.41, 3.44, respectively) than normal weight individuals (HR 0.95, 95% CI 0.83, 1.09 and HR 1.24, 95% CI 0.8, 1.93, respectively). The results for the associations of alcohol consumption and WC with ALD, NAFLD and liver disease mortality were similar. Participants with high WC who reported alcohol consumption above the guidelines had a greater HR for liver disease incidence (HR 1.59, 95% CI 1.35, 1.87) than normal WC individuals (HR 0.85, 95% CI 0.72, 1.01).

CONCLUSIONS

We found evidence that being overweight/obese amplified the harmful effect of alcohol on the liver incidence and mortality.

Taxifolin ameliorate high-fat-diet feeding plus acute ethanol binge-induced steatohepatitis through inhibiting inflammatory caspase-1-dependent pyroptosis

Excessive alcohol drinking and a high-fat diet (HFD) promote steatohepatitis in the comorbidity of NAFLD and AFLD. Taxifolin (TAX) is a rich dihydroxyflavone compound found in onions, milk thistle and Douglas fir. We aimed to explore the intervention mechanism of TAX on chronic steatohepatitis induced by HFD feeding plus acute ethanol binge. We established an in vivo model by HFD feeding plus a single dose of ethanol binge, and established an in vitro model by oleic acid or palmitic acid on HepG2 cells to induce lipid accumulation. TAX regulated lipid synthesis by inhibiting the expression of SREBP1 and upregulating the PPARγ level. In addition, TAX inhibited the expression of P2X7R, IL-1β, and caspase-1. Moreover, TAX reduced the expression of caspase-1 activation; thereby inhibiting the recruitment of macrophages and neutrophils. TAX also improved the inflammatory response caused by caspase-1 activation in steatotic hepatocytes. TAX exhibited an inhibitory effect on lipid accumulation and caspase-1-related pyroptosis. Collectively, TAX has therapeutic potential as an intervention of steatohepatitis induced by alcohol combined with HFD and for preventing non-alcoholic fatty liver degeneration targeting caspase-1-dependent pyroptosis.

Genetic and lifestyle risk factors for advanced liver disease among men and women

BACKGROUND AND AIM

Liver disease is traditionally categorized as alcoholic and non-alcoholic. We studied various risk factors predictive of advanced non-viral liver disease in general population and analyzed the interaction between these factors and alcohol consumption.

METHODS

Persons without underlying liver disease who participated in the Health2000 or FINRISK studies 1992-2012 comprised a cohort of 41 260 individuals. Pattern of alcohol consumption and metabolic, lifestyle-related, and anthropometric parameters were analyzed with Cox regression analysis using severe liver disease hospitalization, cancer, or death as end-point. Viral liver diseases were excluded.

RESULTS

A total of 355 liver events occurred during the mean 12.4-year follow-up (511 789 person-years). In the multivariate model, age (hazard ratio [HR] 1.03, P = 0.0083 for men; HR 1.04, P = 0.0198 for women), waist-to-hip ratio (WHR) (HR 1.52, P = 0.0006 for men; HR 1.58, P = 0.0167 for women), patatin-like phospholipase-containing domain 3 mutations (HR 1.9, P = 0.024 for men; HR 2.7, P = 0.0109 for women), and weekly binge drinking (HR 2.4, P = 0.0024 for men; HR 7.4, P < 0.0001 for women) predicted development of severe liver disease. Among men, diabetes (HR 2.7, P = 0.0002), average alcohol consumption (HR for 10 g/day 1.1, P = 0.0022), non-married status (HR 1.9, P = 0.0397 for single; HR 2.4, P = 0.0002 for widowed/separated), and serum high-density lipoprotein (HR 2.2, P = 0.0022) and non-high-density lipoprotein cholesterol (HR 1.2, P = 0.0237) were additional risk factors. Alcohol intake increased the risk especially among persons with high WHR (P for interaction 0.009).

CONCLUSIONS

Age, patatin-like phospholipase-containing domain 3 haplotype, and WHR increase the risk for development of severe liver disease. We found strong synergism between alcohol and central obesity. Binge drinking is an additional risk factor.

Molecular and Pathological Events Involved in the Pathogenesis of Diabetes-Associated Nonalcoholic Fatty Liver Disease

Diabetes mellitus is a rising epidemic in most part of the world and is often associated with multiple organ disorders such as kidney, liver, and cardiovascular diseases. Liver is a major metabolic hub, and the metabolic disorders associated with diabetes result in liver dysfunctions culminating in spectrum of liver diseases such as fatty liver disorders, cirrhosis, and hepatocellular carcinoma. The intervention strategies to prevent diabetes-associated liver injury require an overall understanding of the key factors and molecular pathways which can be strategically targeted. The present review focuses on some of the key aspects of fatty acid metabolism, fetuin-A regulation, inflammatory pathways, and genetic factors associated with insulin resistance, dyslipidemia, hyperglycemia, oxidative stress, and so on involved in the nexus between diabetes and liver injury. Further recent interventions, pharmacological target, and newer therapeutic agents are discussed briefly for the better clinical management of diabetes-associated hepatic disorders.

Combined Association of Body Mass Index and Alcohol Consumption With Biomarkers for Liver Injury and Incidence of Liver Disease: A Mendelian Randomization Study

IMPORTANCE

Individually, higher body mass index (BMI) and alcohol consumption increase the risk of liver disease. Evidence of a joint association is mixed; however, previous studies have not used causal inference methods robust to confounding and reverse causation. Understanding any true effect is key to developing effective interventions to reduce liver disease.

OBJECTIVE

To investigate the joint association of BMI and alcohol consumption with liver injury biomarkers and incident liver disease using factorial mendelian randomization (MR).

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study (Copenhagen General Population Study) recruited a random sample of Copenhagen, Denmark, residents aged 20 years or older of white, Danish descent (N = 98 643) between November 25, 2003, and July 1, 2014. Data were also obtained from ongoing links to national registers, and then analyzed from September 30, 2016, to April 23, 2018.

EXPOSURES

High and low BMI and alcohol consumption categories from baseline-measured or self-reported observational data and genetic variants predicting BMI and alcohol consumption.

MAIN OUTCOMES AND MEASURES

Plasma biomarkers of liver injury (alanine aminotransferase [ALT] and γ-glutamyltransferase [GGT]) and incident cases of liver disease from hospital records were the outcomes.

RESULTS

Of the 98 643 individuals recruited, 91 552 (54 299 [45.2%] women; mean [SD] age, 58 [13.05] years) with no baseline liver disease were included in main analyses. Individuals had a mean (SD) BMI of 26.2 (4.3) and consumed a mean (SD) of 10.6 (10.2) U/wk of alcohol. In factorial MR analyses, considering the high BMI/high alcohol group as the reference, mean circulating ALT and GGT levels were lowest in the low BMI/low alcohol group (ALT: -2.32%; 95% CI, -4.29% to -0.35%, and GGT: -3.56%; 95% CI, -5.88% to -1.24%). Individuals with low BMI/high alcohol use and high BMI/low alcohol use also had lower mean circulating ALT levels (low BMI/high alcohol use: -1.31%; 95% CI, -1.88% to -0.73%, and high BMI/low alcohol use: -0.81%; 95% CI, -2.86% to 1.22%) and GGT levels (low BMI/high alcohol use: -0.91%; 95% CI, -1.60% to -0.22%, and high BMI/low alcohol use: -1.13%; 95% CI, -3.55% to 1.30%) compared with the high BMI/high alcohol use reference group. These patterns were similar in multivariable factorial analyses. For incident liver disease (N = 580), factorial MR results were less conclusive (odds ratio of liver disease vs high BMI/high alcohol group: 1.01; 95% CI, 0.84 to 1.18, for the low BMI/high alcohol group, 1.22; 95% CI, 0.56 to 1.88 for the high BMI/low alcohol group, and 0.99 (95% CI, 0.41 to 1.56 for the low BMI/low alcohol group).

CONCLUSIONS AND RELEVANCE

Interventions to reduce both BMI and alcohol consumption might reduce population levels of biomarkers of liver injury more than interventions aimed at either BMI or alcohol use alone. However, it is not clear whether this intervention will directly translate to a reduced risk of liver disease.

Signal Transduction Mechanisms of Alcoholic Fatty Liver Disease: Emer ging Role of Lipin-1

Lipin-1, a mammalian phosphatidic acid phosphatase (PAP), is a bi-functional molecule involved in various signaling pathways via its function as a PAP enzyme in the triglyceride synthesis pathway and in the nucleus as a transcriptional co-regulator. In the liver, lipin-1 is known to play a vital role in controlling the lipid metabolism and inflammation process at multiple regulatory levels. Alcoholic fatty liver disease (AFLD) is one of the earliest forms of liver injury and approximately 8-20% of patients with simple steatosis can develop into more severe forms of liver injury, including steatohepatitis, fibrosis/ cirrhosis, and eventually hepatocellular carcinoma (HCC). The signal transduction mechanisms for alcohol-induced detrimental effects in liver involves alteration of complex and multiple signaling pathways largely governed by a central and upstream signaling system, namely, sirtuin 1 (SIRT1)-AMP activated kinase (AMPK) axis. Emerging evidence suggests a pivotal role of lipin-1 as a crucial downstream regulator of SIRT1-AMPK signaling system that is likely to be ultimately responsible for development and progression of AFLD. Several lines of evidence demonstrate that ethanol exposure significantly induces lipin-1 gene and protein expression levels in cultured hepatocytes and in the livers of rodents, induces lipin-1-PAP activity, impairs the functional activity of nuclear lipin-1, disrupts lipin-1 mRNA alternative splicing and induces lipin-1 nucleocytoplasmic shuttling. Such impairment in response to ethanol leads to derangement of hepatic lipid metabolism, and excessive production of inflammatory cytokines in the livers of the rodents and human alcoholics. This review summarizes current knowledge about the role of lipin-1 in the pathogenesis of AFLD and its potential signal transduction mechanisms.

Genetic and Epigenetic Modifiers of Alcoholic Liver Disease

Alcoholic liver disease (ALD), a disorder caused by excessive alcohol consumption is a global health issue. More than two billion people consume alcohol in the world and about 75 million are classified as having alcohol disorders. ALD embraces a wide spectrum of hepatic lesions including steatosis, alcoholic steatohepatitis (ASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). ALD is a complex disease where environmental, genetic, and epigenetic factors contribute to its pathogenesis and progression. The severity of alcohol-induced liver disease depends on the amount, method of usage and duration of alcohol consumption as well as on age, gender, presence of obesity, and genetic susceptibility. Genome-wide association studies and candidate gene studies have identified genetic modifiers of ALD that can be exploited as non-invasive biomarkers, but which do not completely explain the phenotypic variability. Indeed, ALD development and progression is also modulated by epigenetic factors. The premise of this review is to discuss the role of genetic variants and epigenetic modifications, with particular attention being paid to microRNAs, as pathogenic markers, risk predictors, and therapeutic targets in ALD.

Association between skirt size and chronic liver disease in post-menopausal women: a prospective cohort study within the United Kingdom Trial of Ovarian Cancer Screening (UKCTOCS)

Background

We investigated the association between self-reported skirt size (SS) and change in SS, and incidence of chronic liver disease (CLD) in a prospective cohort study of women recruited to the UKCTOCS trial.

Methods

Women recruited to UKCTOCS in England without documented CLD self-reported their current UK SS during trial participation and were asked to recall their SS when aged in 20s (via completion of a questionnaire 3–5 years after recruitment). Participants were followed up via electronic health record linkage and hazard ratios (HR) calculated for incident liver-related events (LRE).

Results

Three hundred twenty-two (0.3%) of 94,124 women experienced a first LRE. Compared to SS ≤ 16, rates of LRE were higher in the SS ≥ 18 groups (both when aged in 20s and at questionnaire completion). Event rates were higher if there was no change in SS or an increase in SS, compared to a decrease in SS.

In the models adjusted for potential confounders, HRs for LRE were higher in the groups of women reporting SS ≥ 18 both when aged in 20s (HR = 1.39 (95% CI; 0.87–2.23)) and at questionnaire completion (HR = 1.37 (95% CI; 1.07–1.75)). Compared to a decrease in SS, HRs were higher in the no change (HR = 1.78 (95% CI; 0.95–3.34)) and increase (HR = 1.80 (95% CI; 1.01–3.21)) groups.

Conclusion

CLD is associated with high SS and an increase in SS over time. These data suggest SS can be used in simple public health messages about communicating the risk of liver disease.

Trial Registration

UKCTOCS is registered as an International Standard Randomised Controlled Trial, number ISRCTN22488978. Registered 06/04/2000.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5308-x) contains supplementary material, which is available to authorized users.

Inflammation is independent of steatosis in a murine model of steatohepatitis

Obesity and alcohol consumption synergistically promote steatohepatitis, and neutrophil infiltration is believed to be associated with steatosis. However, the underlying mechanisms remain obscure. Peroxisome proliferator-activated receptor gamma (PPARγ) plays a complex role in lipid metabolism and inflammation; therefore, the purpose of this study was to dissect its role in regulating steatosis and neutrophil infiltration in a clinically relevant mouse steatohepatitis model of 3-month high-fat diet (HFD) feeding plus a binge of ethanol (HFD-plus-binge ethanol). Hepatocyte-specific Pparg disruption reduced liver steatosis but surprisingly increased hepatic neutrophil infiltration after HFD-plus-binge ethanol. Knockout or knockdown of the PPARγ target gene, fat-specific protein 27, reduced steatosis without affecting neutrophil infiltration in this model. Moreover, hepatocyte-specific deletion of the Pparg gene, but not the fat-specific protein 27 gene, markedly up-regulated hepatic levels of the gene for chemokine (C-X-C motif) ligand 1 (Cxcl1, a chemokine for neutrophil infiltration) in HFD-plus-binge ethanol-fed mice. In vitro, deletion of the Pparg gene also highly augmented palmitic acid or tumor necrosis factor alpha induction of Cxcl1 in mouse hepatocytes. In contrast, activation of PPARγ with a PPARγ agonist attenuated Cxcl1 expression in hepatocytes. Palmitic acid also up-regulated interleukin-8 (a key chemokine for human neutrophil recruitment) expression in human hepatocytes, which was attenuated and enhanced by cotreatment with a PPARγ agonist and antagonist, respectively. Finally, acute ethanol binge markedly attenuated HFD-induced hepatic PPARγ activation, which contributed to the up-regulation of hepatic Cxcl1 expression post-HFD-plus-binge ethanol.

CONCLUSION

Hepatic PPARγ plays an opposing role in controlling steatosis and neutrophil infiltration, leading to dissociation between steatosis and inflammation; acute ethanol gavage attenuates hepatic PPARγ activation and subsequently up-regulates hepatic CXCL1/interleukin-8 expression, thereby exacerbating hepatic neutrophil infiltration. (Hepatology 2017;66:108-123).

Treatment of severe alcoholic hepatitis: past, present and future

Alcoholic hepatitis (AH) manifests as a clinical syndrome characterized by recent jaundice and liver function deterioration in an actively drinking patient. The principal cause of AH is alcoholic steatohepatitis (ASH) defined histologically by the coexistence of steatosis, hepatocyte ballooning and satellitosis. While nonsevere AH usually responds to alcohol abstinence, severe AH, identified by Maddrey scoring ≥ 32, has a bad prognosis and is traditionally treated by a 28-day course of prednisone therapy. A recent trial, which showed no improvement of long-term survival but significant reduced mortality after 28 days of corticoid therapy compared to placebo, opens a debate on its efficacy. N-acetyl-cysteine supplementation combined with steroid therapy is also able to reduce the 28-day mortality compared to steroid alone. While guidelines recommend high-calorie intake and protein supplementation in decompensated liver diseases, intensive enteral nutrition together with corticoid treatment does not reduce mortality compared to corticoid alone in a recent study with ASH patients. Stimulation of liver regeneration through interleukin-22, granulocyte colony-stimulating factor or farnesoid X receptor agonists, inhibition of apoptosis, early liver transplantation and modulation of gut microbiota through antibiotic or faecal transplantation approaches constitute new therapeutic perspectives that are investigated in current clinical trials. Inhibition of oxidative stress, modulation of gut fungal populations and stimulation of progenitor cell proliferation and pro-regenerative inflammatory pathways constitute prospects for future human trials. For long-term survival, strategies for persistent alcohol abstinence remain the key of success, opening another large research field.

Risk of chronic liver disease in post-menopausal women due to body mass index, alcohol and their interaction: a prospective nested cohort study within the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)

Background

We investigated the risk of chronic liver disease (CLD) due to alcohol consumption and body mass index (BMI) and the effects of their interaction in a prospective cohort study of women recruited to the UKCTOCS trial.

Methods

95,126 post-menopausal women without documented CLD were stratified into 12 groups defined by combinations of BMI (normal, overweight, obese) and alcohol consumption (none, <1–15, 16–20 and ≥21 units/week), and followed for an average of 5.1 years. Hazard ratios (HR) were calculated for incident liver-related events (LRE).

Results

First LREs were reported in 325 (0.34%) participants. Compared to women with normal BMI, HR = 1.44 (95% CI; 1.10–1.87) in the overweight group and HR = 2.25 (95% CI; 1.70–2.97) in the obese group, adjusted for alcohol and potential confounders. Compared to those abstinent from alcohol, HR = 0.70 (95% CI; 0.55–0.88) for <1–15 units/week, 0.93 (95% CI; 0.50–1.73) for 16–20 units/week and 1.82 (95% CI; 0.97–3.39) for ≥21 units/week adjusted for BMI and potential confounders. Compared to women with normal BMI drinking no alcohol, HR for LRE in obese women consuming ≥21 units/week was 2.86 (95% CI; 0.67–12.42), 1.58 (95% CI; 0.96–2.61) for obese women drinking <1–15 units/week and 1.93 (95% CI; 0.66–5.62) in those with normal BMI consuming ≥21 units/week after adjustment for potential confounders. We found no significant interaction between BMI and alcohol.

Conclusion

High BMI and alcohol consumption and abstinence are risk factors for CLD in post-menopausal women. However, BMI and alcohol do not demonstrate significant interaction in this group.

Trial registration

UKCTOCS is registered as an International Standard Randomised Controlled Trial, number ISRCTN22488978. Registered 06/04/2000.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4518-y) contains supplementary material, which is available to authorized users.

Emerging concepts in alcoholic hepatitis

Severe alcoholic hepatitis is implicated as a costly, worldwide public health issue with high morbidity and mortality. The one-month survival for severe alcoholic hepatitis is low with mortality rates high as 30%-50%. Abstinence from alcohol is the recommended first-line treatment. Although corticosteroids remain as the current evidence based option for selected patients with discriminant function > 32, improvement of short-term survival rate may be the only benefit. Identification of individuals with risk factors for the development of severe alcoholic hepatitis may provide insight to the diverse clinical spectrum and prognosis of the disease. The understanding of the complex pathophysiologic processes of alcoholic hepatitis is the key to elucidating new therapeutic treatments. Newer research describes the use of gut microbiota modification, immune modulation, stimulation of liver regeneration, caspase inhibitors, farnesoid X receptors, and the extracorporeal liver assist device to aid in hepatocellular recovery. Liver transplantation can be considered as the last medical option for patients failing conventional medical interventions. Although the preliminary data is promising in patients with low risk of recividism, controversy remains due to organ scarcity. This review article comprehensively summarizes the epidemiology, pathophysiology, risk factors, and prognostic indicators of severe alcoholic hepatitis with a focus on the current and emerging therapeutics.

Treatment of Alcohol Use Disorder in Patients with Alcoholic Liver Disease

Alcohol is a leading cause of liver disease worldwide. Although alcohol abstinence is the crucial therapeutic goal for patients with alcoholic liver disease, these patients have less access to psychosocial, behavioral, and/or pharmacologic treatments for alcohol use disorder. Psychosocial and behavioral therapies include 12-step facilitation, brief interventions, cognitive behavioral therapy, and motivational enhancement therapy. In addition to medications approved by the US Food and Drug Administration for alcohol use disorder (disulfiram, naltrexone, and acamprosate), recent efforts to identify potential new treatments have yielded promising candidate pharmacotherapies. Finally, more efforts are needed to integrate treatments across disciplines toward patient-centered approaches in the management of patients with alcohol use disorder and alcoholic liver disease.

The Association between Alcohol Consumption and β-Cell Function and Insulin Sensitivity in Korean Population

This cross-sectional study was performed to examine the association between alcohol consumption and insulin secretion and sensitivity using the Korean Genome and Epidemiology Study. Alcohol consumption levels were categorized into four groups: (i) abstainers, (ii) low (<5 g/day), (iii) intermediate (<30 g/day), and (iv) high (≥30 g/day) alcohol consumption. β-cell function and insulin sensitivity were estimated using the insulinogenic index (IGI60), and Matsuda insulin sensitivity index (ISI), respectively. IGI60 and ISI were dichotomized into high and low groups using median cut-off values and four groups were defined (G-I: high IGI60/high ISI; G-II: high IGI60/low ISI; G-III: low IGI60/high ISI; and G-IV: low IGI60/low ISI). Men consumed 26.5 g alcohol per day on average, whereas women only consumed 5.7 g/day, so women were excluded from subsequent analyses due to their low drinking levels. Alcohol consumption was positively associated with high-density lipoprotein (HDL) cholesterol, aspartate aminotransferase (AST), and triglycerides (TG) in men, but was negatively associated with IGI60 (p < 0.05). TG levels were only increased in individuals with decreased insulin sensitivity (G-II) or decreased β-cell function (G-III) with high alcohol consumption. In addition, alcohol consumption increased HDL cholesterol in the four groups (p < 0.001). In subjects with decreased insulin sensitivity (G-II), intermediate and high alcohol consumption increased the risk of high cholesterol and TG. In individuals with decreased β-cell function (G-III), alcohol consumption increased the risk of high TG and high AST levels. High alcohol consumption was significantly associated with reduced insulin secretion. In addition, alcohol consumption was related to some metabolic risk factors depending on insulin secretion or sensitivity.

Insulin resistance alters hepatic ethanol metabolism: studies in mice and children with non-alcoholic fatty liver disease

OBJECTIVE

Increased fasting blood ethanol levels, suggested to stem from an increased endogenous ethanol synthesis in the GI tract, are discussed to be critical in the development of non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to further delineate the mechanisms involved in the elevated blood ethanol levels found in patients with NAFLD.

DESIGN

In 20 nutritionally and metabolically screened children displaying early signs of NAFLD and 29 controls (aged 5-8 years), ethanol plasma levels were assessed. Ethanol levels along the GI tract, in vena cava and portal vein, intestinal and faecal microbiota, and activity of alcohol dehydrogenase (ADH) and cytochrome P450 2E1 (CYP2E1) were measured in wild-type, ob/ob and anti-TNFα antibody (aT) treated ob/ob mice.

RESULTS

Despite not differing in dietary pattern or prevalence of intestinal overgrowth, fasting ethanol levels being positively associated with measures of insulin resistance were significantly higher in children with NAFLD than in controls. Ethanol levels were similar in portal vein and chyme obtained from different parts of the GI tract between groups while ethanol levels in vena cava plasma were significantly higher in ob/ob mice. ADH activity was significantly lower in liver tissue obtained from ob/ob mice in comparison to wild-type controls and ob/ob mice treated with aT.

CONCLUSIONS

Taken together, our data of animal experiments suggest that increased blood ethanol levels in patients with NAFLD may result from insulin-dependent impairments of ADH activity in liver tissue rather than from an increased endogenous ethanol synthesis.

TRIAL REGISTRATION NUMBER

NCT01306396.

Current Management of Alcoholic Hepatitis and Future Therapies

Alcohol is one of the most common etiologies of liver disease, and alcoholic liver disease overall is the second most common indication for liver transplantation in the United States. It encompasses a spectrum of disease, including fatty liver disease, alcoholic hepatitis (AH), and alcoholic cirrhosis. AH can range from mild to severe disease, with severe disease being defined as: Discriminant Function (DF) ≥ 32, or Model for End-stage Liver Disease (MELD) ≥ 21, or presence of hepatic encephalopathy. Management of the mild disease consists mainly of abstinence and supportive care. Severe AH is associated with significant mortality. Currently, there is no ideal medical treatment for this condition. Besides alcohol cessation, corticosteroids have been used with conflicting results and are associated with an inherent risk of infection. Overall steroids have shown short term benefit when compared to placebo, but they have no obvious long term benefits. Pentoxifylline does not improve survival in patients with severe AH and is no longer recommended based on the results of the STOPAH (Steroid Or Pentoxifylline for Alcoholic Hepatitis) trial. Anti-tumor necrosis factor (TNF) agents are associated with increased risk of life threatening infections and death. Currently, early stage trials are underway, mainly targeting novel pathways based on disease pathogenesis, including modulation of innate immune system, inhibition of gut-liver axis and cell death pathways, and activation of transcription factor farnesyl X receptor (FXR). Future treatment may lie in human induced pluripotent stem cell (iPSC) technology, which is currently under investigation for the study of pathogenesis, drug discovery, and stem cell transplantation. Liver transplantation has been reported with good results in highly selected patients but is controversial due to limited organ supply.

Alcohol use among Native Americans compared to whites: Examining the veracity of the 'Native American elevated alcohol consumption' belief

BACKGROUND

This study uses national survey data to examine the veracity of the longstanding belief that, compared to whites, Native Americans (NA) have elevated alcohol consumption.

METHODS

The primary data source was the National Survey on Drug Use and Health (NSDUH) from 2009 to 2013: whites (n=171,858) and NA (n=4,201). Analyses using logistic regression with demographic covariate adjustment were conducted to assess differences in the odds of NA and whites being alcohol abstinent, light/moderate drinkers (no binge/heavy consumption), binge drinkers (5+ drinks on an occasion 1-4 days), or heavy drinkers (5+ drinks on an occasion 5+ days) in the past month. Complementary alcohol abstinence, light/moderate drinking and excessive drinking analyses were conducted using Behavioral Risk Factor Surveillance System (BRFSS) data from 2011 to 2013: whites (n=1,130,658) and NA (n=21,589).

RESULTS

In the NSDUH analyses, the majority of NA, 59.9% (95% CI: 56.7-63.1), abstained, whereas a minority of whites, 43.1% (CI: 42.6-43.6), abstained-adjusted odds ratio (AOR): 0.64 (CI: 0.56-0.73). Approximately 14.5% (CI: 12.0-17.4) of NA were light/moderate-only drinkers, versus 32.7% (CI: 32.2-33.2) of whites (AOR: 1.90; CI: 1.51-2.39). NA and white binge drinking estimates were similar-17.3% (CI: 15.0-19.8) and 16.7% (CI: 16.4-17.0), respectively (AOR: 1.00; CI: 0.83-1.20). The two populations' heavy drinking estimates were also similar-8.3% (CI: 6.7-10.2) and 7.5% (CI: 7.3-7.7), respectively (AOR: 1.06; CI: 0.85-1.32). Results from the BRFSS analyses generally corroborated those from NSDUH.

CONCLUSIONS

In contrast to the 'Native American elevated alcohol consumption' belief, Native Americans compared to whites had lower or comparable rates across the range of alcohol measures examined.

Obesity and the extent of liver damage among adult New Zealanders: findings from a national survey

Objective

Non‐alcoholic fatty liver disease (NAFLD), defined as excessive fat accumulation in hepatocytes when no other pathologic causes are present, is an increasingly common obesity‐related disorder. We sought to describe the prevalence of elevated liver enzymes, a marker of liver damage, among New Zealand adults, and high‐risk subgroups including those with an elevated body mass index and those with pre‐diabetes or diabetes, to gain a better understanding of the burden of liver disease.

Methods

A total of 4,721 New Zealanders aged 15+ years participated in a nationally representative nutrition survey. Liver enzymes, alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT) were measured in serum. Results were available for 3,035 participants, of whom 10.8% were Māori and 4.5% Pacific.

Results

Overall, the prevalence of elevated ALT and elevated GGT was 13.1% (95% confidence interval [CI]: 11.2 – 15.0) and 13.7% (95% CI: 12.0 – 15.4), respectively. Odds ratios for an elevated ALT or GGT markedly increased with increasing body mass index. Men with obesity had the highest elevated ALT prevalence (28.5%; 95% CI: 21.7–35.4), and women with diabetes had the highest elevated GGT prevalence (36.5%; 95% CI: 26.0–47.0). Adding alcohol consumption categories to each of the adjusted models did not meaningfully change any results, although for women, heavy alcohol consumption was associated with an elevated GGT (overall p = 0.03).

Conclusions

Obesity‐related liver disease is likely to increasingly burden the New Zealand health sector and contribute to health disparities unless effective obesity treatment and prevention measures are given high priority. © 2015 The Authors. Obesity Science & Practice published by John Wiley & Sons Ltd, World Obesity and The Obesity Society.

Alcoholic liver disease in Nepal: identifying homemade alcohol as a culprit

Background

Though the type of alcohol consumed is not thought to be associated with alcoholic liver disease (ALD), some studies have shown a beverage-specific effect. In the present study, we aim to study the effects of locally brewed alcoholic beverages on the development of liver disease.

Patients and methods

This cross-sectional study was conducted at the internal medicine department of a university hospital in Nepal. All patients classified as having either alcohol abuse or alcohol dependence by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition were evaluated for the presence of ALD.

Results

A total of 1,500 patients were screened, of which, 447 patients had ALD. Chronic liver disease (CLD) was detected in 144 patients (9.6%). Most of the patients consumed homemade locally brewed alcohol. On multivariate analysis, the following variables were found to be significantly associated with CLD: male sex (odds ratio [OR]: 1.81; 95% confidence interval [CI]: 1.12–2.94; P=0.02): rakshi consumption ≥30 units (OR: 2.53; 95% CI: 1.07–6.01; P=0.04); and tongba consumption (OR: 3.02; 95% CI: 1.22–7.50; P=0.02).

Conclusion

There was a significant increase in the risk of developing ALD with the consumption of rakshi and tongba after adjusting for total units consumed. The absence of striking differences between our patients with CLD and non-CLD patients with regards to the amount of alcohol consumed demonstrates that, although alcohol consumption is a prerequisite for the development of ALD, other factors like type of alcoholic beverage consumed may be involved.

Adipokines levels are associated with the severity of liver disease in patients with alcoholic cirrhosis

AIM: To investigate the adipokine levels of leptin, adiponectin, resistin, visfatin, retinol-binding protein 4 (RBP4), apelin in alcoholic liver cirrhosis (ALC).

METHODS: Forty non-diabetic ALC patients [median age: 59 years, males: 35 (87.5%), Child-Pugh (CP) score: median 7 (5-12), CP A/B/C: 18/10/12, Model for End-stage Liver Disease (MELD): median 10 (6-25), follow-up: median 32.5 mo (10-43)] were prospectively included. The serum adipokine levels were estimated in duplicate by ELISA. Somatometric characteristics were assessed with tetrapolar bioelectrical impedance analysis. Pearson’s rank correlation coefficient was used to assess possible associations with adipokine levels. Univariate and multivariate Cox regression analysis was used to determine independent predictors for overall survival.

RESULTS: Body mass index: median 25.9 (range: 20.1-39.3), fat: 23.4% (7.6-42.1), fat mass: 17.8 (5.49-45.4), free fat mass: 56.1 (39.6-74.4), total body water (TBW): 40.6 (29.8-58.8). Leptin and visfatin levels were positively associated with fat mass (P < 0.001/P = 0.027, respectively) and RBP4 with TBW (P = 0.025). Median adiponectin levels were significantly higher in CPC compared to CPA (CPA: 7.99 ± 14.07, CPB: 7.66 ± 3.48, CPC: 25.73 ± 26.8, P = 0.04), whereas median RBP4 and apelin levels decreased across the spectrum of disease severity (P = 0.006/P = 0.034, respectively). Following adjustment for fat mass, visfatin and adiponectin levels were significantly increased from CPA to CPC (both P < 0.001), whereas an inverse correlation was observed for both RBP4 and apelin (both P < 0.001). In the multivariate Cox regression analysis, only MELD had an independent association with overall survival (HR = 1.53, 95%CI: 1.05-2.32; P = 0.029).

CONCLUSION: Adipokines are associated with deteriorating liver function in a complex manner in patients with alcoholic liver cirrhosis.

Role of Nrf2 in chronic liver disease

Nuclear erythroid 2-related factor 2 (Nrf2) is a central regulator of antioxidative response elements-mediated gene expression. It has a significant role in adaptive responses to oxidative stress by interacting with the antioxidant response element, which induces the expression of a variety of downstream targets aimed at cytoprotection. Previous studies suggested oxidative stress and associated damage could represent a common link between different forms of diseases. Oxidative stress has been implicated in various liver diseases, including viral hepatitis, nonalcoholic fatty liver disease/steatohepatitis, alcoholic liver disease and drug-induced liver injury. Nrf2 activation is initiated by oxidative or electrophilic stress, and aids in the detoxification and elimination of potentially harmful exogenous chemicals and their metabolites. The expression of Nrf2 has been observed throughout human tissue, with high expression in detoxification organs, especially the liver. Thus, Nrf2 may serve as a major regulator of several cellular defense associated pathways by which hepatic cells combat oxidative stress. We review the relevant literature concerning the crucial role of Nrf2 and its signaling pathways against oxidative stress to protect hepatic cell from oxidative damage during development of common chronic liver diseases. We also review the use of Nrf2 as a therapeutic target to prevent and treat liver diseases.

Nuclear factor (erythroid-derived 2)-like 2 activation-induced hepatic very-low-density lipoprotein receptor overexpression in response to oxidative stress contributes to alcoholic liver disease in mice

Chronic alcohol consumption leads to hypertriglyceridemia, which is positively associated with alcoholic liver disease (ALD). However, whether and how it contributes to the development of fatty liver and liver injury are largely unknown. In this study we demonstrate that chronic alcohol exposure differently regulates the expression of very-low-density lipoprotein receptor (VLDLR) in adipose tissue and the liver. Whereas adipose tissue VLDLR is significantly down-regulated, its hepatic expression is dramatically increased after chronic alcohol feeding. While HepG2 cells stably overexpressing VLDLR manifests increased intracellular triglyceride accumulation, VLDLR-deficient mice are protective against fatty liver and liver injury after chronic alcohol exposure. Mechanistic investigations using both in vitro and in vivo systems reveal that oxidative stress-induced nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activation plays a critical role in alcohol-induced VLDLR up-regulation in hepatocytes, but not in adipocytes. Oxidative stress enhances VLDLR gene expression and protein abundance in primary hepatocytes, concomitant with the Nrf2 activation. Conversely, Nrf2 gene silencing abrogates oxidative stress-induced VLDLR up-regulation in the liver, but not in adipose tissue. In mice, alcohol exposure induces hepatic oxidative stress and Nrf2 activation. Supplementation of N-acetylcysteine alleviates fatty liver and liver injury induced by chronic alcohol exposure, which is associated with suppressed Nrf2 activation and attenuated VLDLR increase in the liver. Furthermore, in comparison to wild-type counterparts, Nrf2-deficient mice demonstrate attenuated hepatic VLDLR expression increase in response to chronic alcohol exposure.

CONCLUSION

Chronic alcohol consumption differently alters VLDLR expression in adipose tissue and the liver. Oxidative stress-induced Nrf2 activation is mechanistically involved in VLDLR overexpression in hepatocytes in response to chronic alcohol consumption. Hepatic VLDLR overexpression plays an important role in the pathogenesis of ALD.

Individual and joint impacts of ethanol use, BMI, age and gender on serum gamma-glutamyltransferase levels in healthy volunteers

Excessive ethanol consumption, obesity and increasing age may all lead to increased serum levels of gamma-glutamyltransferase (GGT) enzyme, which plays a key role in the metabolism of extracellular reduced glutathione. However, as yet, the interactions between the various modulators of GGT activities have remained poorly defined. We analyzed data from 15,617 apparently healthy individuals (7254 men and 8363 women, mean age 46 ± 13 years, range 25–74 years) who participated in a national cross-sectional health survey in Finland between 1997 and 2007. All subjects underwent detailed clinical examinations and interviews, including the amount of ethanol use and smoking habits. GGT levels were measured from all participants, and the individual and joint impacts of the different study variables on GGT levels were assessed. Significant individual effects were noted for ethanol use (p < 0.001), body mass index (BMI) (p < 0.001), age (p < 0.001) and smoking (p < 0.001). In men, significant two-factor interactions occurred between ethanol use and age (p < 0.020). Among those over 40 years of age, ethanol consumption was found to be a stronger determinant of increased GGT levels than in men below 40 years, whereas in the latter age group, BMI was found to predominate. In women, a significant two-factor interaction occurred between ethanol and BMI (p = 0.010), whereas it did not with ethanol use and age. The data underscores the role of ethanol consumption and age as major determinants of increased GGT levels in men, whereas in women, a relatively stronger impact was noted for ethanol intake and BMI. In light of the ability of GGT enzyme to modulate crucial redox-sensitive functions, the present findings also support the use of GGT as a biomarker of oxidative stress.

Ethanol administration exacerbates the abnormalities in hepatic lipid oxidation in genetically obese mice

Alcohol consumption synergistically increases the risk and severity of liver damage in obese patients. To gain insight into cellular or molecular mechanisms underlying the development of fatty liver caused by ethanol-obesity synergism, we have carried out animal experiments that examine the effects of ethanol administration in genetically obese mice. Lean wild-type (WT) and obese (ob/ob) mice were subjected to ethanol feeding for 4 wk using a modified Lieber-DeCarli diet. After ethanol feeding, the ob/ob mice displayed much more pronounced changes in terms of liver steatosis and elevated plasma levels of alanine aminotransferase and aspartate aminotransferase, indicators of liver injury, compared with control mice. Mechanistic studies showed that ethanol feeding augmented the impairment of hepatic sirtuin 1 (SIRT1)-AMP-activated kinase (AMPK) signaling in the ob/ob mice. Moreover, the impairment of SIRT1-AMPK signaling was closely associated with altered hepatic functional activity of peroxisome proliferator-activated receptor γ coactivator-α and lipin-1, two vital downstream lipid regulators, which ultimately contributed to aggravated fatty liver observed in ethanol-fed ob/ob mice. Taken together, our novel findings suggest that ethanol administration to obese mice exacerbates fatty liver via impairment of the hepatic lipid metabolism pathways mediated largely by a central signaling system, the SIRT1-AMPK axis.

Systemic immune modulation induced by alcoholic beverage intake in obese-diabetes (db/db) mice

Alcohol over-consumption is generally immunosuppressive. In this study, the effects of single or repetitive alcohol administration on the systemic immunity of db/db mice were observed to clarify the possible mechanisms for the increased susceptibility of obese individuals to alcohol-related immunological health problems. Alcohol (as a form of commercially available 20% distilled-alcoholic beverage) was orally administered one-time or seven times over 2 weeks to db/db mice and normal C57BL/6J mice. Immunologic alterations were analyzed by observation of body weight and animal activity, along with proportional changes of splenocytes for natural killer cells, macrophages, and T and B lymphocytes. Modulation of plasma cytokine level and immune-related genes were also ascertained by micro-bead assay and a microarray method, respectively. The immune micro-environment of db/db mice was an inflammatory state and adaptive cellular immunity was significantly suppressed. Low-dose alcohol administration reversed the immune response, decreasing inflammatory responses and the increment of adaptive immunity mainly related to CD4(+) T cells, but not CD8(+) T cells, to normal background levels. Systemic immune modulation due to alcohol administration in the obese-diabetic mouse model may be useful in the understanding of the induction mechanism, which will aid the development of therapeutics for related secondary diseases.

The epidemiology, pathogenesis and histopathology of fatty liver disease

Fatty liver disease includes non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD), each of which is increasing in prevalence. Each represents a histological spectrum that extends from isolated steatosis to steatohepatitis and cirrhosis. NAFLD is associated with obesity, diabetes, and insulin resistance, and is considered to be the liver manifestation of the metabolic syndrome. The pathogenesis of NAFLD and ALD involves cytokines, adipokines, oxidative stress, and apoptosis. Histopathology is the gold standard for assessing the severity of liver damage in NAFLD and ALD. We have reviewed the literature, and described and compared the epidemiology, natural disease history, pathogenesis and histopathology of NAFLD and ALD.

Temporal relationships between overweight and obesity and DSM-IV substance use, mood, and anxiety disorders: results from a prospective study, the National Epidemiologic Survey on Alcohol and Related Conditions

OBJECTIVE

To present nationally representative findings on the prospective relationships between overweight and obesity and DSM-IV substance use, mood, and anxiety disorders.

METHOD

A nationally representative sample of 34,653 US adults was interviewed in Wave 1 (2001-2002) and Wave 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions. The target population was the civilian population residing in households and group quarters, with gathered data adjusted to be representative of the civilian population of the United States on the basis of the 2000 Decennial Census. The main outcome measures were the incidence of DSM-IV substance use, mood, and anxiety disorders and changes in body mass index status during the 3-year follow-up period.

RESULTS

Regression analyses that controlled for a wide array of covariates showed that overweight and obese women were at increased risk (P < .05) for incident major depressive disorder during the follow-up period (adjusted OR [AOR] = 1.3 [95% CI, 1.02-1.56] and AOR = 1.2 [95% CI, 1.02-1.51], respectively). Overweight men and obese men were at decreased risk (P < .05) of incident drug abuse and alcohol dependence (AOR = 0.7 [95% CI, 0.44-0.96] and AOR = 0.7 [95% CI, 0.52-0.97]), respectively. Obese women had a decreased risk (P < .05) of incident alcohol abuse and drug dependence (AOR = 0.6 [95% CI, 0.45-0.88] and AOR = 0.4 [95% CI, 0.21-0.91], respectively). Men with drug dependence and women with specific phobia had a decreased risk (P < .05) of becoming overweight or obese during the follow-up period (AOR = 0.4 [95% CI, 0.19-0.99] and AOR = 0.8 [95% CI, 0.66-0.95], respectively).

CONCLUSIONS

Increased risk of major depressive disorder among overweight and obese women could be attributed to stigma and greater body dissatisfaction among women in Western cultures. Overweight and obesity may serve as protective factors against developing incident substance use disorders, possibly due to shared neural functions in the brain underlying addictions to numerous substances. Results are discussed in terms of their clinical implications, including the need to update treatment guidelines for the management of overweight, obesity, and major depressive disorder.

Synergistic effect of alcohol consumption and body mass on serum concentrations of cytokeratin-18

BACKGROUND

Cytokeratin-18 is an essential component of the cytoskeleton of epithelial cells (including hepatocytes). Serum concentrations of cytokeratin-18 (tissue polypeptide-specific antigen [TPS]) are used as a marker of epithelial neoplasms. Here, we investigated the potential interaction between alcohol and obesity in relation to serum TPS concentrations.

METHODS

Alcohol consumption, body mass index, and components of metabolic syndrome were measured in a random sample (n = 420) of the adult population (aged 18 to 92 years, 45% men) from a single municipality. Regular alcohol intake of >20 g/d (women) or >30 g/d (men) was considered risky drinking. Serum TPS was measured with a commercial immunoassay.

RESULTS

Risky drinking was associated with increased serum concentrations of TPS, which was particularly evident among obese individuals. Among individuals without risky drinking, TPS concentrations were similar for all levels of body mass. Conversely, among risky drinkers, serum TPS concentrations increased in parallel with body mass (p = 0.002). The odds ratio of a high (>100 U/l) TPS concentration for the combination of risky drinking and obesity was greater than the additive effect of the 2 separate factors, after adjusting for age and sex. A similar interaction was observed between risky drinking and abdominal adiposity, a major component of the metabolic syndrome. Serum TPS concentrations were correlated with markers of liver damage. Serum TPS was not superior to standard markers (gamma-glutamyl transferase and red blood cell mean volume) for the detection of risky drinking.

CONCLUSIONS

There is a synergism between risky alcohol consumption and common metabolic disorders (particularly obesity) in relation to serum concentrations of cytokeratin-18 (TPS), which probably reflect liver disease.

Post-translational modifications of mitochondrial aldehyde dehydrogenase and biomedical implications

Aldehyde dehydrogenases (ALDHs) represent large family members of NAD(P)+-dependent dehydrogenases responsible for the irreversible metabolism of many endogenous and exogenous aldehydes to the corresponding acids. Among 19 ALDH isozymes, mitochondrial ALDH2 is a low Km enzyme responsible for the metabolism of acetaldehyde and lipid peroxides such as malondialdehyde and 4-hydroxynonenal, both of which are highly reactive and toxic. Consequently, inhibition of ALDH2 would lead to elevated levels of acetaldehyde and other reactive lipid peroxides following ethanol intake and/or exposure to toxic chemicals. In addition, many East Asian people with a dominant negative mutation in ALDH2 gene possess a decreased ALDH2 activity with increased risks for various types of cancer, myocardial infarct, alcoholic liver disease, and other pathological conditions. The aim of this review is to briefly describe the multiple post-translational modifications of mitochondrial ALDH2, as an example, after exposure to toxic chemicals or under different disease states and their pathophysiological roles in promoting alcohol/drug-mediated tissue damage. We also briefly mention exciting preclinical translational research opportunities to identify small molecule activators of ALDH2 and its isozymes as potentially therapeutic/preventive agents against various disease states where the expression or activity of ALDH enzymes is altered or inactivated.

Obesity, diabetes mellitus, and liver fibrosis

Obesity is a global epidemic with more than 1 billion overweight adults and at least 300 million obese patients worldwide. Diabetes is characterized by a defect in insulin secretion or a decrease in sensitivity to insulin, which results in elevated fasting blood glucose. Both obesity and elevated fasting glucose are risk factors for nonalcoholic fatty liver disease, a disease spectrum that includes hepatic steatosis (nonalcoholic fatty liver), nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Increased adiposity and insulin resistance contribute to the progression from NASH to fibrosis through the development of a profibrotic mileau in the liver, including increased hepatocellular death, increased reactive oxygen species generation, and an altered adipokine/cytokine balance. This review will summarize recent advances in our understanding of the pathological interactions among excessive fat accumulation, insulin resistance, and hepatic fibrogenesis and discuss specific molecular pathways that may be of interest in the development of therapeutic interventions to prevent and/or reverse hepatic fibrosis.

Antioxidative status of patients with alcoholic liver disease in southeastern Taiwan

AIM: To investigate the antioxidative status of patients with alcoholic liver disease (ALD) in southeastern Taiwan.

METHODS: Our study comprised 27 patients with ALD recruited from Taitung Mackay Memorial Hospital, located in southeastern Taiwan. Patients with ALD included 12 non-aborigines (12 men) and 15 aborigines (11 men and 4 women). According to the severity of ALD, patients with ALD included 10 with hepatitis (9 men and 1 woman) and 17 with cirrhosis (14 men and 3 women). Twenty-two age- and gender-matched healthy adults served as the control group in this study. Venous blood (10 mL) of each subject was drawn into EDTA-containing tubes after 8 h overnight fasting.

RESULTS: Compared to the control group, patients with ALD showed significantly lower erythrocytic catalase (11.1 ± 0.7 U/mg Hb vs 8.0 ± 0.7 U/mg Hb, P < 0.05) and superoxide dismutase (9.5 ± 1.6 U/mg Hb vs 3.0 ± 0.2 U/mg Hb, P < 0.05) activities. Furthermore, the erythrocytic reduced glutathione/oxidized glutathione ratio was significantly lower in ALD patients than that in the control group (38.1 ± 5.4 vs 15.7 ± 1.9, P < 0.05). The results revealed that patients with ALD experienced more oxidative stress than those in the control group. The non-aboriginal, but not the aboriginal, ALD group had higher erythrocytic glutathione peroxidase (GPX) activity than that in the control group (46.1 ± 7.8 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05). Hepatitis, but not cirrhosis, ALD patients had higher erythrocytic GPX activity than that in the control group (44.3 ± 8.6 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05).

CONCLUSION: Our results indicate that both ethnicity and the severity of ALD may cause different erythrocytic antioxidative enzyme activities especially GPX activity.

Rat strain differences in susceptibility to alcohol-induced chronic liver injury and hepatic insulin resistance

The finding of more severe steatohepatitis in alcohol fed Long Evans (LE) compared with Sprague Dawley (SD) and Fisher 344 (FS) rats prompted us to determine whether host factors related to alcohol metabolism, inflammation, and insulin/IGF signaling predict proneness to alcohol-mediated liver injury. Adult FS, SD, and LE rats were fed liquid diets containing 0% or 37% (calories) ethanol for 8 weeks. Among controls, LE rats had significantly higher ALT and reduced GAPDH relative to SD and FS rats. Among ethanol-fed rats, despite similar blood alcohol levels, LE rats had more pronounced steatohepatitis and fibrosis, higher levels of ALT, DNA damage, pro-inflammatory cytokines, ADH, ALDH, catalase, GFAP, desmin, and collagen expression, and reduced insulin receptor binding relative to FS rats. Ethanol-exposed SD rats had intermediate degrees of steatohepatitis, increased ALT, ADH and profibrogenesis gene expression, and suppressed insulin receptor binding and GAPDH expression, while pro-inflammatory cytokines were similarly increased as in LE rats. Ethanol feeding in FS rats only reduced IL-6, ALDH1-3, CYP2E1, and GAPDH expression in liver. In conclusion, susceptibility to chronic steatohepatitis may be driven by factors related to efficiency of ethanol metabolism and degree to which ethanol exposure causes hepatic insulin resistance and cytokine activation.

A cohort study of the effect of alcohol consumption and obesity on serum liver enzyme levels

OBJECTIVE

To conduct a cohort study of the effect of alcohol and obesity on liver enzymes in China.

METHODS

To study 500 individuals of liver enzymes normality randomly in the 1999-year epidemiological survey, and liver enzyme levels (461 complete data) in 2006.

RESULTS

Logistic-regression analysis showed a daily alcohol intake of at least 40 g, duration of drinking at least 10 years, and obesity, which were closely related to abnormality in liver enzyme levels; the relative risk (95% confidence interval) was 2.014 (1.108-3.662), 2.085 (1.106-3.928), and 1.772 (1.140-2.754), respectively (all P<0.05). According to the value of daily alcohol intake/duration of drinking and body mass index (BMI) to categorize, seven-year cumulative incidence of liver enzymes levels abnormality for the daily alcohol intake at least 40 g and obesity group or the duration of drinking at least 10 years and obesity group was the highest, 51.47 and 47.12%, respectively. No significant dose-response relationship was found between daily alcohol intake/duration of drinking and liver enzyme level abnormalities.

CONCLUSION

The risk of alcohol consumption and obesity-inducing liver injury together is far greater than the risk of a single factor inducing liver injury. An alcoholic threshold effect may be more important than a dose-response effect on liver enzyme levels.

Effect of body mass index and alcohol consumption on liver disease: analysis of data from two prospective cohort studies

OBJECTIVE

To investigate whether alcohol consumption and raised body mass index (BMI) act together to increase risk of liver disease.

DESIGN

Analysis of data from prospective cohort studies.

SETTING

Scotland.

PARTICIPANTS

Data were from two of the Midspan prospective cohort studies (9559 men): "Main" study 1965-8, participants from workplaces across central belt of Scotland, population of island of Tiree, and mainland relatives, and "Collaborative" study, 1970-3, participants from 27 workplaces in Glasgow, Clydebank, and Grangemouth. Follow-up was to 31 December 2007 (median 29 years, range 0.13-42). We divided participants into nine groups based on measures of body mass index (BMI) (underweight/normal weight <25, overweight 25 to <30, and obese >or=30) and alcohol consumption (none, 1-14, and >or=15 units per week).

MAIN OUTCOME MEASURES

Liver disease morbidity and mortality.

RESULTS

80 (0.8%) men died with liver disease as the main cause and 146 (1.5%) with liver disease as any cause. In the Collaborative study, 196 men (3.3%) had liver disease defined by a death, admission, or cancer registration. BMI and alcohol consumption were strongly associated with liver disease mortality in analyses adjusted for other confounders (P=0.001 and P<0.0001 respectively). Drinkers of 15 or more units per week in any BMI category and obese drinkers had raised relative rates for all definitions of liver disease, compared with underweight/normal weight non-drinkers. Drinkers of 15 or more units per week had adjusted relative rates for liver disease mortality of 3.16 (95% confidence interval 1.28 to 7.8) for underweight/normal weight men, 7.01 (3.02 to 16.3) for overweight, and 18.9 (6.84 to 52.4) for obese men. The relative rate for obese men who consumed 1-14 units per week was 5.3 (1.36 to 20.7). The relative excess risk due to interaction between BMI and alcohol consumption was 5.58 (1.09 to 10.1); synergy index=2.89 (1.29 to 6.47).

CONCLUSIONS

Raised BMI and alcohol consumption are both related to liver disease, with evidence of a supra-additive interaction between the two. The occurrence of both factors in the same populations should inform health promotion and public health policies.

Serotonin reuptake transporter (SERT) plays a critical role in the onset of fructose-induced hepatic steatosis in mice

Elevated dietary fructose intake, altered intestinal motility, and barrier function may be involved in the development of nonalcoholic fatty liver disease (NAFLD). Because intestinal motility and permeability are also regulated through the bioavailability of serotonin (5-HT), we assessed markers of hepatic injury in serotonin reuptake transporter knockout (SERT(-/-)) and wild-type mice chronically exposed to different monosaccharide solutions (30% glucose or fructose solution) or water for 8 wk. The significant increase in hepatic triglyceride, TNF-alpha, and 4-hydroxynonenal adduct as well as portal endotoxin levels found in fructose-fed mice was associated with a significant decrease of SERT and the tight-junction occludin in the duodenum. Similar effects were not found in mice fed glucose. In contrast, in SERT(-/-) mice fed glucose, portal endotoxin levels, concentration of occludin, and indices of hepatic damage were similar to those found in wild-type and SERT(-/-) mice fed fructose. In fructose-fed mice treated with a 5-HT3 receptor antagonist, hepatic steatosis was significantly attenuated. Our data suggest that a loss of intestinal SERT is a critical factor in fructose-induced impairment of intestinal barrier function and subsequently the development of steatosis.