Ultrasonographic hepatic steatosis increases prediction of mortality risk from elevated serum gamma-glutamyl transpeptidase levels

Extra-hepatic manifestations and complications of nonalcoholic fatty liver disease

This review article aims to synthesize the evidence regarding nonalcoholic fatty liver disease (NAFLD) as a systemic disorder. We critically discuss the metabolic syndrome and its components; the cardiovascular and the endocrine system; chronic respiratory disorders; the musculoskeletal system; the skin; and extra-hepatic tumors. We conclude that, while some of these extra-hepatic conditions clearly predispose to the development of secondary forms of NAFLD (typically hypothyroidism-induced NAFLD), others result from pre-existent NAFLD (e.g., certain extra-hepatic tumors) and others (such as Type 2 Diabetes) have, with NAFLD, mutual and bidirectional associations. Analyzed data imply that NAFLD is not merely a hepatic disease. It is also and possibly more importantly, a systemic disorder requiring a special awareness, a multidisciplinary approach and a multidimensional vision.

Nonalcoholic fatty liver disease and mortality from all causes, cardiovascular disease, and cancer: a meta-analysis

Whether nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of mortality remains controversial. The present study aimed to clarify this issue. A systematic search of PubMed and Embase was conducted through October 2018. Studies providing risk estimates of NAFLD and mortality were included. A random-effects model was employed to calculate summary risk estimates. Subgroup analyses were performed to identify potential effect modifiers. Fourteen studies, involving 498501 subjects and 24234 deaths, were included. Patients with NAFLD were found to be at an elevated risk of all-cause mortality compared with those without [hazard ratio (HR) = 1.34; 95% confidence interval (CI) 1.17-1.54)]. The significantly positive association between NAFLD and all-cause mortality could not be modified by age, sex, follow-up duration, and adjustment for body mass index, diabetes, smoking or hypertension (all Pinteraction > 0.05), and remained in sensitivity analyses. No significant associations of NAFLD with CVD (HR = 1.13; 95% CI 0.92-1.38) and cancer (HR = 1.05; 95% CI 0.89-1.25) mortality were found. In conclusion, NAFLD is a predictor of increased all-cause mortality but not CVD and cancer mortality. These findings have important implications for decision making in public health and clinical practice, and highlight the urgency of developing effective treatments for NAFLD.

Drug-induced liver steatosis in patients with HIV infection

Drug-induced liver injury (DILI) due to the use of prescription and non-prescription medication by HIV-positive and HIV-negative patients is one of the main causes of acute liver failure and transplantation in Western countries and, although rare, has to be considered a serious problem because of its unforeseeable nature and possibly fatal course. Drug-induced steatosis (DIS) and steatohepatitis (DISH) are infrequent but well-documented types of DILI. Although a number of commonly used drugs are associated with steatosis, it is not always easy to identify them as causative agents because of the weak temporal relationship between the administration of the drug and the clinical event, the lack of a confirmatory re-challenge, and the high prevalence of non-alcoholic fatty liver disease (NAFLD) in the general population, which often makes it difficult to make a differential diagnosis of DIS and DISH. The scenario is even more complex in HIV-positive patients not only because of the underlying disease, but also because the various anti-retroviral regimens have different effects on liver steatosis. Given the high prevalence of liver steatosis in HIV-positive patients and the increasing use of drugs associated with a potential steatotic risk, the identification of clinical signs suggesting liver damage should help to avoid the possible misdiagnosis of "primary" NAFLD in a patient with DIS or DISH. This review will therefore initially concentrate on the current diagnostic criteria for DIS/DISH and their differential diagnosis from NAFLD. Subsequently, it will consider the different clinical manifestations of iatrogenic liver steatosis in detail, with specific reference to HIV-positive patients. Finally, the last part of the review will be dedicated to the possible effects of liver steatosis on the bioavailability of antiretroviral and other drugs.

Elevated liver enzymes and cardiovascular mortality: a systematic review and dose-response meta-analysis of more than one million participants

Gamma glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) are commonly used liver function markers. We performed a dose-response meta-analysis to investigate the association between liver enzymes and cardiovascular disease (CVD) mortality in prospective cohort studies. We conducted a systematic search up to April 2018 in Medline/PubMed, Scopus, Cochrane, and Embase databases. Combined hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a random-effects model as described by DerSimonian and Laird. Dose-response analysis was also carried out. Twenty-three studies with 1 067 922 participants reported association between GGT and CVD mortality and were included in our analysis. Pooled results showed a significant association between GGT and risk of CVD mortality (HR: 1.62; 95% CI: 1.47-1.78, P=0.001, P-heterogeneity=0.001) and it was HR: 0.87; 95% CI: 0.73-1.07; P=0.221, P-heterogeneity=0.028, for ALT. There was a direct association between baseline levels of ALP and AST/ALT ratio with CVD mortality (HR: 1.45; 95% CI: 1.11-1.89; P=0.005, P-heterogeneity=0.026, and HR: 2.20; 95% CI: 1.60-3.04; P=0.001, P-heterogeneity=0.540, respectively). Pooled results did not show any significant association between AST and the risk of CVD mortality (HR: 1.20; 95% CI: 0.83-1.73; P=0.313, P-heterogeneity=0.024). Moreover, there was a significant nonlinear association between GGT and ALP levels and the risk of CVD mortality (P=0.008 and 0.016, respectively). Our dose-response meta-analysis revealed a direct relationship between GGT and ALP levels and the risk of CVD mortality. High levels of GGT, ALP and AST/ALT were associated with an increased CVD mortality rate.

The correlation between fatty liver disease and chronic kidney disease

BACKGROUND/PURPOSE

The impact of non-alcoholic fatty liver disease (NAFLD) on the prevalence of chronic kidney disease (CKD) is not fully elucidated. We aimed to assess the correlation between NAFLD and CKD in a large population study.

METHODS

We included consecutive subjects who had received health check-up service at Taipei Veterans General Hospital from 2002 to 2009. NAFLD was diagnosed with abdominal ultrasound, and advanced liver fibrosis was determined with NAFLD fibrosis score (NAFLD-FS). CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m².

RESULTS

Among the 29,797 subjects enrolled in this study, NAFLD and CKD were diagnosed in 44.5% and 20.2% of the population, respectively. Subjects with NAFLD had a higher proportion of CKD compared to those without NAFLD (24.1% vs. 17.1%, p < 0.001). However, NAFLD was not related to CKD with an odds ratio (OR) of 1.015 (95% confidence interval [CI] 0.954-1.081, p = 0.630) after multivariate analyses. Nevertheless, further analyses revealed that among patients with NAFLD, those with advanced fibrosis were more likely to have CKD after adjusting for confounding factors (OR 2.284, 95% CI 1.513-3.448, p < 0.001).

CONCLUSION

NAFLD per se was not a risk factor for CKD, but NAFLD patients with advanced fibrosis faced a higher possibility of CKD. Hence, patients with NAFLD and advanced fibrosis should be screened for CKD and prompted to receive treatment if the diagnosis was made.

The changing epidemiology of liver diseases in the Asia-Pacific region

This Review presents current epidemiological trends of the most common liver diseases in Asia-Pacific countries. Hepatitis B virus (HBV) remains the primary cause of cirrhosis; despite declining prevalence in most Asian nations, this virus still poses a severe threat in some territories and regions. Mortality resulting from HBV infection is declining as a result of preventive measures and antiviral treatments. The epidemiological transition of hepatitis C virus (HCV) infection has varied in the region in the past few decades, but the medical burden of infection and the prevalence of its related cancers are increasing. The lack of licensed HCV vaccines highlights the need for novel treatment strategies. The prevalence of nonalcoholic fatty liver disease (NAFLD) has risen in the past decade, mostly owing to increasingly urbanized lifestyles and dietary changes. Alternative herbal medicine and dietary supplements are major causes of drug-induced liver injury (DILI) in some countries. Complications arising from these chronic liver diseases, including cirrhosis and liver cancer, are therefore emerging threats in the Asia-Pacific region. Key strategies to control these liver diseases include monitoring of at-risk populations, implementation of national guidelines and increasing public and physician awareness, in concert with improving access to health care.

Screening of Cardiovascular Disease in Nonalcoholic Fatty Liver Disease: Whom and How?

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. Patients with NAFLD are at a higher risk of developing cardiovascular disease (CVD). In fact, CVD-related mortality is more common in patients with NAFLD in comparison to liver-related mortality. This association is related to the common metabolic risk factors such as obesity, dyslipidemia, diabetes, and hypertension shared by both NAFLD and CVD, and also there is independent association of NAFLD with CVD because of risk factors such as insulin resistance, systemic inflammation, and atherogenic dyslipidemia. While there is abundant literature on association of NAFLD with CVD, there is sparse literature regarding the screening for CVD in patients with NAFLD. In the current review article, we discuss as to which patients with NAFLD to screen and how to screen for CVD.

Reducing NAFLD-screening time: A comparative study of eight diagnostic methods offering an alternative to ultrasound scans

BACKGROUND & AIMS

The use of ultrasound scan (US) in non-alcoholic fatty liver disease (NAFLD) screening overloads US waiting lists. We hypothesized and tested a hybrid two-step method, consisting of applying a formula, to exclude subjects at low risk, before US.

METHODS

The sample included 2970 males and females (937 with NAFLD) diagnosed by US. We selected eight formulas: Fatty Liver Index (FLI), Hepatic Steatosis Index (HIS), body mass index (BMI), waist circumference (WC), Abdominal Volume Index (AVI), waist-to-height ratio (WHtR), waist/height^0.5 (WHT.5R) and Body Roundness Index (BRI), and calculated their performance in the two-step method evaluating percentage reduction of the number of liver US (US reduction percentage), percentage of false negative and percentage of NAFLD identified.

RESULTS

The US reductions percentage were 52.2% (WHtR), 52.1% (HIS), 51.8% (FLI), 50.8% (BRI), 50.7% (BMI and WHt_5R), 46.5% (WC) and 45.2% (AVI). The false negative percentage were 8.5% (WHtR), 7.9% (BRI), 7.3% (WHt_5R), 7.2% (BMI), 6.7% (HIS), 6.6% (FLI), 5.6% (WC) and 5.2% (AVI). The best percentage of NALFD identified was obtained using AVI (83.6%) before US, then WC (82.2%), FLI (79%), HIS (78.9%), BMI (77.3%), WHt_5R (76.9%), BRI (74.8%) and WHtR (73%).

CONCLUSION

The best formula to use in two-step diagnostic NAFLD screening was AVI, which showed a low false negative rate and a higher percentage of identified NAFLD. Other studies evaluating the economic advantages of this screening method are warranted.

Increased Serum Uric Acid over five years is a Risk Factor for Developing Fatty Liver

The prevalence of fatty liver disease (FLD) is increasing. To clarify risk factors for developing FLD, we analyzed a database from healthy Japanese adults who had annual medical check-ups in 2004 and reexamined in 2009. We used the fatty liver index (FLI) to classify participants as FLD (FLI ≥60), borderline FLD (30≤ FLI <60), and normal liver (FLI <30). Subjects with hepatitis B or C virus infection and subjects with FLD at the baseline were excluded. The cumulative incidence of FLD from normal liver and from borderline FLD over five years were 0.65% (52/8,025) and 12.9% (244/1,888), respectively. After multiple adjustments, higher serum uric acid (SUA) (OR:1.92; 95% CI:1.40–2.63) and increased SUA change (OR:3.734; 95% CI:2.57–5.42) became risk factors for developing FLD from normal liver, as well as younger age and higher body mass index. The risk factors for developing FLD from borderline FLD were similar. Not only higher baseline SUA but also increased SUA change became independent risks for developing FLD.

NAFLD and cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is an important cause of chronic hepatic disease and liver transplant in Western societies. The increasing prevalence is related to dietary changes and sedentarism and follows the increasing frequency of obesity and type 2 diabetes mellitus.

Growing evidence of association of NAFLD with cardiovascular diseases (CVD), independent of cardiovascular risk factors, has prompted the clarification of whether the liver is mainly a key-effector or a target-organ of the metabolic disarrangements in the metabolic syndrome. The therapeutic strategies able to alter liver disease progression and, through this, reduce the cardiovascular risk have also been tested in the last 2 decades.

This review focus on the possible interactions between hepatic disease, metabolic syndrome, and CVD, and on their implications for clinical practice.

NAFLD/NASH in patients with type 2 diabetes and related treatment options

Type 2 diabetes may reduce life expectancy and patients' quality of life due to its micro- and macro-vascular complications and to the higher risk of several types of cancer. An emerging important factor is represented by the hepatic involvement; it is recognized that excessive hepatic fat accumulation represents a typical feature of diabetic patients and that it also plays an important pathogenic role. It is now evident that non-alcoholic fatty liver disease (NAFLD), generally perceived as a benign condition, may have on the contrary an important deleterious impact for diabetic patients increasing the risk to develop cardiovascular complications but also serious hepatic diseases, in particular non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Lifestyle intervention, bariatric surgery and several drug therapies have now accumulated evidence of efficacy in treating NASH. On the other hand, their durability and safety in the long-term is yet to be proven and their use may be sometimes associated with side effects or higher risk of adverse events limiting the regular administration or contraindicating it. Professional health care providers, building awareness about the importance of these hepatic complications, should put more efforts in primary prevention using a behavioral therapy needing a multidisciplinary approach, in secondary prevention applying on a regular basis in the clinical setting available predictive algorithms to identify the patients at higher cardiovascular and hepatologic risk, and in tertiary prevention treating, when not contraindicated, the diabetic patients preferentially with drugs with proven benefit on NAFLD/NASH.

Hypertension, diabetes, atherosclerosis and NASH: Cause or consequence?

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common forms of chronic liver disease worldwide and its prevalence is expected to continue rising. NAFLD has traditionally been considered a consequence of metabolic syndrome (MetS). However, the link between NAFLD and MetS components, especially type 2 diabetes mellitus (T2DM), hypertension (HTN), and cardiovascular disease (CVD) is more complex than previously thought. Indeed, the adverse effects of NAFLD extend far beyond the liver, with a large body of clinical evidence now suggesting that NAFLD may precede and/or promote the development of T2DM, HTN and atherosclerosis/CVD. The risk of developing these cardiometabolic diseases parallels the underlying severity of NAFLD. Accumulating evidence suggests that the presence and severity of NAFLD is associated with an increased risk of incident T2DM and HTN. Moreover, long-term prospective studies indicate that the presence and severity of NAFLD independently predicts fatal and nonfatal CVD events. In this review, we critically discuss the rapidly expanding body of clinical evidence that supports the existence of a bi-directional relationship between NAFLD and various components of MetS, particularly T2DM and HTN, as well as the current knowledge regarding a strong association between NAFLD and CVD morbidity and mortality. Finally, we discuss the most updated putative biological mechanisms through which NAFLD may contribute to the development of HTN, T2DM and CVD.

Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention

NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.

Severity of nonalcoholic fatty liver disease on sonography and risk of coronary heart disease

PURPOSE

To evaluate the relationship between nonalcoholic fatty liver disease (NAFLD) on sonography (US) and the risk of coronary heart disease (CHD) as well as the predictive value of US-diagnosed NAFLD to determine intermediate/high CHD risk compared with as well as in combination on with NAFLD fibrosis score (NFS).

METHODS

This retrospective study included 1,276 patients examined between November 2015 and August 2016. NAFLD was categorized as absent, mild, moderate, or severe based on liver-to-kidney echogenicity, visibility of intrahepatic vessel walls, and the diaphragm. The Framingham risk score (FRS) and NFS were used to predict CHD risk and hepatic fibrosis severity. Spearman correlation test, multivariate-adjusted logistic regression analysis, and receiver operating characteristic curves were used for statistical evaluation.

RESULTS

FRS increased as NAFLD severity increased, and US-determined NAFLD severity and FRS were highly positively correlated (r = 0.683, p < 0.001). The odds ratios for intermediate/high CHD risk increased with increasing NAFLD severity. The predictive performance of US-determined NAFLD severity for determining intermediate/high CHD risk in NAFLD patients was 0.738. There was no significant difference between US-determined NAFLD severity and NFS in terms of identifying intermediate/high CHD risk (p = 0.88). However, the combination of US-determined NAFLD severity and NFS significantly improved the ability to distinguish intermediate/high CHD risk compared with that of US-determined NAFLD severity or NFS alone (p < 0.001 for both).

CONCLUSIONS

US-determined NAFLD severity was well correlated with FRS and associated with the prevalence of intermediate/high CHD risk. The combination of US-determined NAFLD severity and NFS may be useful for predicting CHD risk. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:391-399, 2017.

Prevalence of elevated liver enzymes in adults with type 1 diabetes: A multicentre analysis of the German/Austrian DPV database

AIMS

To assess the prevalence of elevated liver enzymes in adults with type 1 diabetes mellitus (T1DM) in routine clinical care and the association with cardiovascular risk profile in the Diabetes-Prospective-Documentation (DPV) network in Germany and Austria.

SUBJECTS AND METHODS

This cross sectional observational study from the DPV registry includes data from 45 519 adults with T1DM at 478 centres up to September 2016. Liver enzyme measurements were available in 9226 (29%) patients at 270 centres and were analysed for increased alanine aminotransferase (ALT; men >50 U/L, women >35U/L) and/or aspartate aminotransferase (AST; men >50 U/L, women >35U/L) and/or gamma-glutamyltransferase (GGT; men >60U/L, women >40 U/L). A subgroup analysis in patients for whom 2 or more ALT measurements were available (n = 2335, 25%) and whose ALT was increased at least twice (men >30 U/L, women >19U/L) was performed. Associations with glycaemic control, cardiovascular risk factors and late complications were investigated with multiple regression analyses.

RESULTS

Twenty percent (19.8%, n = 1824) had increased liver enzyme(s) on one or more occasions. Increased liver enzymes were associated with worse glycaemic control and higher BMI (both P < .0001), dyslipidemia (OR, 1.75; 95% CI, 1.54-2.0), hypertension (OR, 1.48; 95% CI: 1.31-1.68), myocardial infarction (OR, 1.49; 95% CI, 1.17-1.91) and end stage renal disease (OR, 1.59; 95% CI, 1.17-2.17). ALT was increased twice in 29% and was associated with worse glycaemic control (P < .0001), higher BMI (P < .0001), hypertension (OR, 1.58; 95% CI, 1.26-1.97) and dyslipidemia (OR, 1.89; 95% CI, 1.51-2.37).

CONCLUSIONS

In this clinical audit in adults with T1DM, elevated liver enzymes on routine assessment were associated with a less favourable cardiovascular risk profile and with poorer glycaemic control.

Metabolomic characteristics of cholesterol-induced non-obese nonalcoholic fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD) in non-obese patients remains a clinical condition with unclear etiology and pathogenesis. Using a metabolomics approach in a mouse model that recapitulates almost all the characteristic features of non-obese NAFLD, we aimed to advance mechanistic understanding of this disorder. Mice fed high fat, high cholesterol, cholate (HFHCC) diet for three weeks consistently developed hepatic pathology similar to NAFLD and nonalcoholic steatohepatitis (NASH) without changes to body weight or fat pad weights. Gas- and liquid chromatography/mass spectrometry-based profiling of lipidomic and primary metabolism changes in the liver and plasma revealed that systemic mechanisms leading to steatosis and hepatitis in this non-obese NAFLD model were driven by a combination of effects directed by elevated free cholesterol, cholesterol esters and cholic acid, and associated changes to metabolism of sphingomyelins and phosphatidylcholines. These results demonstrate that mechanisms underlying cholesterol-induced non-obese NAFLD are distinct from NAFLD occurring as a consequence of metabolic syndrome. In addition, this investigation provides one of the first metabolite reference profiles for interpreting effects of dietary and hepatic cholesterol in human non-obese NAFLD/NASH patients.

Non-alcoholic fatty liver disease and its relationship with cardiovascular disease and other extrahepatic diseases

Key physiological functions of the liver, including glucose and lipid metabolism, become disturbed in the setting of non-alcoholic fatty liver disease (NAFLD) and may be associated with a systemic inflammatory 'milieu' initiated in part by liver-secreted cytokines and molecules. Consequently, the pathophysiological effects of NAFLD extend beyond the liver with a large body of clinical evidence demonstrating NAFLD to be independently associated with both prevalent and incident cardiovascular disease (CVD), chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The magnitude of risk of developing these extrahepatic diseases parallels the underlying severity of NAFLD, such that patients with non-alcoholic steatohepatitis (NASH) appear to be at greater risk of incident CVD, CKD and T2DM than those with simple steatosis. Other modifiers of risk may include genetic variants (eg, patatin-like phospholipase domain-containing 3 and trans-membrane 6 superfamily member 2 polymorphisms), visceral adipose tissue accumulation, dietary intake and the gut microbiome. Emerging data also suggest that NAFLD may be a risk factor for colonic neoplasia and reduced bone mineral density, especially among men. Importantly, improvement/resolution of NAFLD is associated with a reduced incidence of T2DM and improved kidney function, adding weight to causality and suggesting liver focused treatments may reduce risk of extrahepatic complications. Awareness of these associations is important for the clinicians such that CVD risk factor management, screening for T2DM and CKD are part of the routine management of patients with NAFLD.

NAFLD as a Sexual Dimorphic Disease: Role of Gender and Reproductive Status in the Development and Progression of Nonalcoholic Fatty Liver Disease and Inherent Cardiovascular Risk

Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatis, cirrhosis, and hepatocellular carcinoma (HCC) associated with striking systemic features and excess cardiovascular and liver-related mortality. The pathogenesis of NAFLD is complex and multifactorial. Endocrine derangements are closely linked with dysmetabolic traits. For example, in animal and human studies, female sex is protected from dysmetabolism thanks to young individuals' ability to partition fatty acids towards ketone body production rather than very low density lipoprotein (VLDL)-triacylglycerol, and to sex-specific browning of white adipose tissue. Ovarian senescence facilitates both the development of massive hepatic steatosis and the fibrotic progression of liver disease in an experimental overfed zebrafish model. Consistently, estrogen deficiency, by potentiating hepatic inflammatory changes, hastens the progression of disease in a dietary model of nonalcoholic steatohepatitis (NASH) developing in ovariectomized mice fed a high-fat diet. In humans, NAFLD more often affects men; and premenopausal women are equally protected from developing NAFLD as they are from cardiovascular disease. It would be expected that early menarche, definitely associated with estrogen activation, would produce protection against the risk of NAFLD. Nevertheless, it has been suggested that early menarche may confer an increased risk of NAFLD in adulthood, excess adiposity being the primary culprit of this association. Fertile age may be associated with more severe hepatocyte injury and inflammation, but also with a decreased risk of liver fibrosis compared to men and postmenopausal status. Later in life, ovarian senescence is strongly associated with severe steatosis and fibrosing NASH, which may occur in postmenopausal women. Estrogen deficiency is deemed to be responsible for these findings via the development of postmenopausal metabolic syndrome. Estrogen supplementation may at least theoretically protect from NAFLD development and progression, as suggested by some studies exploring the effect of hormonal replacement therapy on postmenopausal women, but the variable impact of different sex hormones in NAFLD (i.e., the pro-inflammatory effect of progesterone) should be carefully considered.

Non-alcoholic fatty liver disease and cardiovascular risk

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with insulin resistance and metabolic syndrome. The spectrum of disease ranges from simple steatosis to steatohepatitis and progression to cirrhosis. Compelling evidence over the past several years has substantiated a significant link between NAFLD and cardiovascular disease ranging from coronary artery disease to subclinical carotid atherosclerosis. Close follow up, treatment of risk factors for NAFLD, and cardiovascular risk stratification are necessary to predict morbidity and mortality in this subset of patients.

Effect of non-alcoholic fatty liver disease on left ventricular diastolic function and geometry in the Korean general population

AIM

Previous studies showed that non-alcoholic fatty liver disease (NALFD) could be related to subclinical left ventricular (LV) diastolic dysfunction and remodeling. However, this association is still equivocal in the general population. Thus, this study was carried out to examine whether NAFLD is associated with the risk for LV diastolic dysfunction and remodeling.

METHODS

A cross-sectional study was carried out for 20 821 Korean men and women who received a health checkup including echocardiography from 2011 to 2012. The study population was divided into three groups of normal, mild and moderate-to-severe NAFLD detected by ultrasonography. Using multivariable logistic regression analysis, the odd ratios of abnormal LV relaxation and remodeling were analyzed according to the degree of NAFLD. Additionally, adjusted mean values of LV diastolic functional and structural parameters were evaluated in the three groups.

RESULTS

Compared with the normal group, the mild and moderate-to-severe NAFLD groups had higher odd ratios for abnormal LV relaxation (mild group 1.29, 95% confidence interval 1.15-1.46; moderate-to-severe group 1.95, 95% confidence interval 1.61-2.35) and increased relative wall thickness (>0.42; mild group 1.26, 95% confidence interval 1.05-1.52; moderate-to-severe group 1.46, 95% confidence interval 1.08-1.95). Analyzing adjusted mean values of LV parameters also showed the significant association between the degree of NAFLD and impaired LV diastolic function and concentric LV remodeling.

CONCLUSIONS

The risk for LV diastolic dysfunction and remodeling proportionally increased according to the degree of NAFLD. NAFLD is significantly associated with LV functional and structural alteration.

Individual patient data meta-analysis of controlled attenuation parameter (CAP) technology for assessing steatosis

BACKGROUND & AIMS

The prevalence of fatty liver underscores the need for non-invasive characterization of steatosis, such as the ultrasound based controlled attenuation parameter (CAP). Despite good diagnostic accuracy, clinical use of CAP is limited due to uncertainty regarding optimal cut-offs and the influence of covariates. We therefore conducted an individual patient data meta-analysis.

METHODS

A review of the literature identified studies containing histology verified CAP data (M probe, vibration controlled transient elastography with FibroScan®) for grading of steatosis (S0-S3). Receiver operating characteristic analysis after correcting for center effects was used as well as mixed models to test the impact of covariates on CAP. The primary outcome was establishing CAP cut-offs for distinguishing steatosis grades.

RESULTS

Data from 19/21 eligible papers were provided, comprising 3830/3968 (97%) of patients. Considering data overlap and exclusion criteria, 2735 patients were included in the final analysis (37% hepatitis B, 36% hepatitis C, 20% NAFLD/NASH, 7% other). Steatosis distribution was 51%/27%/16%/6% for S0/S1/S2/S3. CAP values in dB/m (95% CI) were influenced by several covariates with an estimated shift of 10 (4.5-17) for NAFLD/NASH patients, 10 (3.5-16) for diabetics and 4.4 (3.8-5.0) per BMI unit. Areas under the curves were 0.823 (0.809-0.837) and 0.865 (0.850-0.880) respectively. Optimal cut-offs were 248 (237-261) and 268 (257-284) for those above S0 and S1 respectively.

CONCLUSIONS

CAP provides a standardized non-invasive measure of hepatic steatosis. Prevalence, etiology, diabetes, and BMI deserve consideration when interpreting CAP. Longitudinal data are needed to demonstrate how CAP relates to clinical outcomes.

LAY SUMMARY

There is an increase in fatty liver for patients with chronic liver disease, linked to the epidemic of the obesity. Invasive liver biopsies are considered the best means of diagnosing fatty liver. The ultrasound based controlled attenuation parameter (CAP) can be used instead, but factors such as the underlying disease, BMI and diabetes must be taken into account. Registration: Prospero CRD42015027238.

Gamma-glutamyltransferase and risk of cardiovascular mortality: A dose-response meta-analysis of prospective cohort studies

BACKGROUND

Serum gamma-glutamyltransferase (GGT) elevation likely contributes to cardiovascular (CV) mortality, however it has remained unknown whether a dose-response relationship exists between serum GGT and CV mortality.

METHODS

We searched the PubMed, EMBASE, and Cochrane library databases for prospective cohort studies published up to October 2, 2016. Summary hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) were calculated using a fixed effects model.

FINDINGS

Nine prospective studies, including 527,589 participants and more than 7,011 cases, were included in this meta-analysis. For the moderate, high, and highest levels of GGT, the pooled HRs of CV mortality were 1.11 (95% CI = 1.04-1.19), 1.29 (95% CI = 1.21-1.38) and 1.59 (95% CI = 1.47-1.72), respectively (all p < 0.05 as compared to the lowest levels of GGT). Additionally, the HR per incremental increase of GGT by 10 U/L was 1.10 (95% CI = 1.08-1.11). Evidence of a positive relationship with nonlinear trend for GGT elevation with CV mortality in females was found (P = 0.04 for nonlinearity). However, a linear model was better fit to illustrate the GGT-CV mortality among males (P = 0.304 for nonlinearity).

CONCLUSIONS

These findings indicate that serum GGT activity within the reference interval is positively associated with increased risk of CV mortality in a dose-response manner.

Non-alcoholic fatty liver disease is associated with early left ventricular dysfunction in childhood acute lymphoblastic leukaemia survivors

BACKGROUND

Childhood acute lymphoblastic leukaemia (ALL) survivors have an increased risk of metabolic and cardiovascular disease. We aimed to assess the presence of non-alcoholic fatty liver disease (NAFLD) in childhood ALL and if it is associated with early cardiovascular dysfunction.

METHODS

In total, 53 childhood ALL survivors and 34 controls underwent auxological evaluation, biochemical assay, liver, heart and vascular ultrasound study.

RESULTS

NAFLD was more frequent in ALL patients than in controls (39.6% vs 11.7%, P < 0.01). Patients with NAFLD were more obese and insulin resistant than patients without NAFLD. Flow-mediated dilatation and interventricular septum were lower in the ALL group than those in the control group (P < 0.001 for both). The patients with NAFLD showed lower left ventricular ejection fraction than those without NAFLD (P = 0.011). In ALL survivors, BMI-SDS and subcutaneous fat were the strongest predictors of NAFLD, whereas preperitoneal adipose tissue and C-reactive protein were the strongest predictors of left ventricular ejection fraction.

CONCLUSIONS

Childhood ALL survivors had higher prevalence of NAFLD than healthy controls, which is associated with early left ventricular impairment. In the case of fatty liver, a comprehensive heart evaluation is mandatory. We strongly recommend to prevent visceral adiposity in ALL survivors, to search for metabolic syndrome or its components and to reinforce the need of intervention on diet and lifestyle during the follow-up of these patients.

Non-alcoholic fatty liver disease and progression of coronary artery calcium score: a retrospective cohort study

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of the metabolic syndrome, was associated with subclinical atherosclerosis in many cross-sectional studies, but the prospective association between NAFLD and the progression of atherosclerosis has not been evaluated. This study was conducted to evaluate the association between NAFLD and the progression of coronary atherosclerosis.

METHODS

This retrospective cohort study included 4731 adult men and women with no history of cardiovascular disease (CVD), liver disease or cancer at baseline who participated in a repeated regular health screening examination between 2004 and 2013. Fatty liver was diagnosed by ultrasound based on standard criteria, including parenchymal brightness, liver-to-kidney contrast, deep beam attenuation and bright vessel walls. Progression of coronary artery calcium (CAC) scores was measured using multidetector CT scanners.

RESULTS

The average duration of follow-up was 3.9 years. During follow-up, the annual rate of CAC progression in participants with and without NAFLD were 22% (95% CI 20% to 23%) and 17% (16% to 18%), respectively (p<0.001). The multivariable ratio of progression rates comparing participants with NAFLD with those without NAFLD was 1.04 (1.02 to 1.05; p<0.001). The association between NAFLD and CAC progression was similar in most subgroups analysed, including in participants with CAC 0 and in those with CAC >0 at baseline.

CONCLUSIONS

In this large cohort study of adult men and women with no history of CVD, NAFLD was significantly associated with the development of CAC independent of cardiovascular and metabolic risk factors. NAFLD may play a pathophysiological role in atherosclerosis development and may be useful to identify subjects with a higher risk of subclinical disease progression.

Fatty Liver Index and Lipid Accumulation Product Can Predict Metabolic Syndrome in Subjects without Fatty Liver Disease

Background. Fatty liver index (FLI) and lipid accumulation product (LAP) are indexes originally designed to assess the risk of fatty liver and cardiovascular disease, respectively. Both indexes have been proven to be reliable markers of subsequent metabolic syndrome; however, their ability to predict metabolic syndrome in subjects without fatty liver disease has not been clarified. Methods. We enrolled consecutive subjects who received health check-up services at Taipei Veterans General Hospital from 2002 to 2009. Fatty liver disease was diagnosed by abdominal ultrasonography. The ability of the FLI and LAP to predict metabolic syndrome was assessed by analyzing the area under the receiver operating characteristic (AUROC) curve. Results. Male sex was strongly associated with metabolic syndrome, and the LAP and FLI were better than other variables to predict metabolic syndrome among the 29,797 subjects. Both indexes were also better than other variables to detect metabolic syndrome in subjects without fatty liver disease (AUROC: 0.871 and 0.879, resp.), and the predictive power was greater among women. Conclusion. Metabolic syndrome increases the cardiovascular disease risk. The FLI and LAP could be used to recognize the syndrome in both subjects with and without fatty liver disease who require lifestyle modifications and counseling.

The epidemiology of non-alcoholic fatty liver disease

The increase in Non-alcoholic Fatty Liver Disease (NAFLD) and the imminent disappearance of chronic viral hepatitis thanks to new and effective therapies is motivating hepatologists to change their clinical approach to chronic liver disease. NAFLD-cirrhosis or NAFLD-Hepatocellular Carcinoma (HCC) are now the second cause of liver transplantation in the USA. This short-review is focused to the epidemiology of NAFLD/Non-alchoholic Steatohepatitis (NASH), including the definition of this disease which should be revised as well discussing the prevalence, risk factors for progression, natural history and mortality. NAFLD is considered to be the hepatic manifestation of the metabolic syndrome (MS). It affects 25-30% of the general population and the risk factors are almost identical to those of MS. The natural history involves either the development of cardiovascular diseases or cirrhosis and HCC. HCC can also develop in NASH in the absence of cirrhosis (45% of cases). We conclude that an international consensus conference on the definition, natural history, policies of surveillance and new pharmacological treatments of NAFLD and NASH is urgently needed.

Gamma-glutamyl transferase and cardiovascular disease

Gamma-glutamyl transferase (GGT) is an enzyme located on the external surface of cellular membranes. GGT contributes in maintaining the physiological concentrations of cytoplasmic glutathione and cellular defense against oxidative stress via cleavage of extracellular glutathione and increased availability of amino acids for its intracellular synthesis. Increased GGT activity is a marker of antioxidant inadequacy and increased oxidative stress. Ample evidence suggests that elevated GGT activity is associated with increased risk of cardiovascular disease (CVD) such as coronary heart disease (CHD), stroke, arterial hypertension, heart failure, cardiac arrhythmias and all-cause and CVD-related mortality. The evidence is weaker for an association between elevated GGT activity and acute ischemic events and myocardial infarction. The risk for CVD or CVD-related mortality mediated by GGT may be explained by the close correlation of GGT with conventional CVD risk factors and various comorbidities, particularly non-alcoholic fatty liver disease, alcohol consumption, oxidative stress, metabolic syndrome, insulin resistance and systemic inflammation. The finding of GGT activity in atherosclerotic plaques and correlation of intra-plaque GGT activity with histological indexes of plaque instability may suggest a participation of GGT in the pathophysiology of CVD, particularly atherosclerosis. However, whether GGT has a direct role in the pathophysiology of CVD or it is an epiphenomenon of coexisting CVD risk factors or comorbidities remains unknown and Hill's criteria of causality relationship between GGT and CVD are not fulfilled. The exploration whether GGT provides prognostic information on top of the information provided by known cardiovascular risk factors regarding the CVD or CVD-related outcome and exploration of molecular mechanisms of GGT involvement in the pathophysiology of CVD and eventual use of interventions to reduce circulating GGT activity remain a duty of future studies.

Cardiovascular Risk Reduction in Patients with Nonalcoholic Fatty Liver Disease: The Potential Role of Ezetimibe

Nonalcoholic fatty liver disease (NAFLD) is widely considered to be the hepatic manifestation of the metabolic syndrome and is closely linked to dyslipidemia, obesity, and insulin resistance. Patients with NAFLD have increased mortality when compared to the general population, primarily related to cardiovascular disease or malignancy. The biologic mechanisms that link NAFLD to cardiovascular disease include expansion of visceral adipose tissue, atherogenic dyslipidemia, impaired insulin signaling, systemic inflammation, and endothelial dysfunction. Currently, there are no approved therapies for NAFLD. It has recently been hypothesized that reducing the delivery of dietary cholesterol using the hypolipidemic agent, ezetimibe, could benefit patients with NAFLD. By potently inhibiting the Niemann-Pick C1-Like 1 (NPC1L1) sterol receptor on intestinal enterocytes and within the liver, ezetimibe blocks exogenous cholesterol absorption and has been shown to improve biochemical markers of NAFLD, improve insulin sensitivity and decrease hepatic steatosis. This review summarizes the clinical and epidemiological evidence for the relationship between NAFLD and cardiovascular risk and examines the potential therapeutic role of ezetimibe.

Fatty liver is associated with an increased risk of diabetes and cardiovascular disease - Evidence from three different disease models: NAFLD, HCV and HIV

Fatty liver, which frequently coexists with necro-inflammatory and fibrotic changes, may occur in the setting of nonalcoholic fatty liver disease (NAFLD) and chronic infections due to either hepatitis C virus (HCV) or human immunodeficiency virus (HIV). These three pathologic conditions are associated with an increased prevalence and incidence of cardiovascular disease (CVD) and type 2 diabetes (T2D). In this multidisciplinary clinical review, we aim to discuss the ever-expanding wealth of clinical and epidemiological evidence supporting a key role of fatty liver in the development of T2D and CVD in patients with NAFLD and in those with HCV or HIV infections. For each of these three common diseases, the epidemiological features, pathophysiologic mechanisms and clinical implications of the presence of fatty liver in predicting the risk of incident T2D and CVD are examined in depth. Collectively, the data discussed in this updated review, which follows an innovative comparative approach, further reinforce the conclusion that the presence of fatty/inflamed/fibrotic liver might be a shared important determinant for the development of T2D and CVD in patients with NAFLD, HCV or HIV. This review may also open new avenues in the clinical and research arenas and paves the way for the planning of future, well-designed prospective and intervention studies.

Nonalcoholic fatty liver disease - A multisystem disease?

Non-alcoholic fatty liver disease (NAFLD) is one of the most common comorbidities associated with overweight and metabolic syndrome (MetS). Importantly, NAFLD is one of its most dangerous complications because it can lead to severe liver pathologies, including fibrosis, cirrhosis and hepatic cellular carcinoma. Given the increasing worldwide prevalence of obesity, NAFLD has become the most common cause of chronic liver disease and therefore is a major global health problem. Currently, NAFLD is predominantly regarded as a hepatic manifestation of MetS. However, accumulating evidence indicates that the effects of NAFLD extend beyond the liver and are negatively associated with a range of chronic diseases, most notably cardiovascular disease (CVD), diabetes mellitus type 2 (T2DM) and chronic kidney disease (CKD). It is becoming increasingly clear that these diseases are the result of the same underlying pathophysiological processes associated with MetS, such as insulin resistance, chronic systemic inflammation and dyslipidemia. As a result, they have been shown to be independent reciprocal risk factors. In addition, recent data have shown that NAFLD actively contributes to aggravation of the pathophysiology of CVD, T2DM, and CKD, as well as several other pathologies. Thus, NAFLD is a direct cause of many chronic diseases associated with MetS, and better detection and treatment of fatty liver disease is therefore urgently needed. As non-invasive screening methods for liver disease become increasingly available, detection and treatment of NAFLD in patients with MetS should therefore be considered by both (sub-) specialists and primary care physicians.

The role of microRNAs in liver injury at the crossroad between hepatic cell death and regeneration

The liver fulfills critical metabolic functions, such as controlling blood sugar and ammonia levels, and is of central importance for lipid metabolism and detoxification of environmental and chemical agents, including drugs. Liver injuries of different etiology can elicit a spectrum of responses. Some hepatocytes initiate molecular programs resulting in cell death, whereas others undergo cellular divisions to regenerate the damaged organ. Interestingly, recent research indicates that microRNAs serve as very rapid as well as long-term regulators in these processes. In this review, we discuss their importance in liver disease etiology and progression as well as for therapy with particular focus on metabolic and inflammatory conditions. Furthermore, we highlight the central role of microRNAs in controlling hepatocyte differentiation and plasticity, which are required for successful regeneration, but under certain conditions, such as chronic liver insults, can result in the formation of hepatocellular carcinoma.

Accuracy of Liver Fat Quantification With Advanced CT, MRI, and Ultrasound Techniques: Prospective Comparison With MR Spectroscopy

OBJECTIVE

The purpose of this study was to prospectively evaluate the accuracy of proton-density fat-fraction, single- and dual-energy CT (SECT and DECT), gray-scale ultrasound (US), and US shear-wave elastography (US-SWE) in the quantification of hepatic steatosis with MR spectroscopy (MRS) as the reference standard.

SUBJECTS AND METHODS

Fifty adults who did not have symptoms (23 men, 27 women; mean age, 57 ± 5 years; body mass index, 27 ± 5) underwent liver imaging with un-enhanced SECT, DECT, gray-scale US, US-SWE, proton-density fat-fraction MRI, and MRS for this prospective trial. MRS voxels for the reference standard were colocalized with all other modalities under investigation. For SECT (120 kVp), attenuation values were recorded. For rapid-switching DECT (80/140 kVp), monochromatic images (70-140 keV) and fat density-derived material decomposition images were reconstructed. For proton-density fat fraction MRI, a quantitative chemical shift-encoded method was used. For US, echogenicity was evaluated on a qualitative 0-3 scale. Quantitative US shear-wave velocities were also recorded. Data were analyzed by linear regression for each technique compared with MRS.

RESULTS

There was excellent correlation between MRS and both proton-density fat-fraction MRI (r² = 0.992; slope, 0.974; intercept, -0.943) and SECT (r² = 0.856; slope, -0.559; intercept, 35.418). DECT fat attenuation had moderate correlation with MRS measurements (r² = 0.423; slope, 0.034; intercept, 8.459). There was good correlation between qualitative US echogenicity and MRS measurements with a weighted kappa value of 0.82. US-SWE velocity did not have reliable correlation with MRS measurements (r² = 0.004; slope, 0.069; intercept, 6.168).

CONCLUSION

Quantitative MRI proton-density fat fraction and SECT fat attenuation have excellent linear correlation with MRS measurements and can serve as accurate noninvasive biomarkers for quantifying steatosis. Material decomposition with DECT does not improve the accuracy of fat quantification over conventional SECT attenuation. US-SWE has poor accuracy for liver fat quantification.

Non-alcoholic fatty liver disease and risk of incident cardiovascular disease: A meta-analysis

BACKGROUND & AIMS

There have been many studies of the effects of non-alcoholic fatty liver disease (NAFLD) and the risk of cardiovascular disease (CVD), but these have produced conflicting results. We performed a meta-analysis of these studies to quantify the magnitude of the association between NAFLD (and NAFLD severity) and risk of CVD events.

METHODS

We searched PubMed, Google scholar, and Web of Science databases using terms "NAFLD", "cardiovascular events", "cardiovascular mortality", "prognosis" and their combinations to identify observational studies published through January 2016. We included only observational studies conducted in adults >18years and in which NAFLD was diagnosed on imaging or histology. Data from selected studies were extracted and meta-analysis was then performed using random effects modelling.

RESULTS

A total of 16 unique, observational prospective and retrospective studies with 34,043 adult individuals (36.3% with NAFLD) and approximately 2,600 CVD outcomes (>70% CVD deaths) over a median period of 6.9years were included in the final analysis. Patients with NAFLD had a higher risk of fatal and/or non-fatal CVD events than those without NAFLD (random effect odds ratio [OR] 1.64, 95% CI 1.26-2.13). Patients with more 'severe' NAFLD were also more likely to develop fatal and non-fatal CVD events (OR 2.58; 1.78-3.75). Sensitivity analyses did not alter these findings. Funnel plot and Egger's test did not reveal significant publication bias.

CONCLUSIONS

NAFLD is associated with an increased risk of fatal and non-fatal CVD events. However, the observational design of the studies included does not allow to draw definitive causal inferences.

LAY SUMMARY

The data on whether NAFLD by itself is associated with increased cardiovascular events and death remains an issue of debate. The findings of this updated and large meta-analysis of observational studies indicate that NAFLD is significantly associated with an increased risk of fatal and non-fatal cardiovascular events. However, the observational design of the studies included does not allow us to prove that NAFLD causes cardiovascular disease. Clinicians who manage patients with NAFLD should not focus only on liver disease but should also consider the increased risk of cardiovascular disease and undertake early, aggressive risk factor modification.

Non-alcoholic fatty liver disease and risk of cardiovascular disease

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases worldwide, causing considerable liver-related mortality and morbidity. During the past decade, it has also become increasingly evident that NAFLD is a multisystem disease that affects many extra-hepatic organ systems, including the heart and the vascular system. In this updated clinical review, we discuss the rapidly expanding body of clinical and epidemiological evidence that supports a strong association of NAFLD with cardiovascular diseases (CVDs) and other functional and structural myocardial abnormalities. We also discuss some recently published data that correlate NAFLD due to specific genetic polymorphisms with the risk of CVDs. Finally, we briefly examine the assessment tools for estimating the global CVD risk in patients with NAFLD as well as the conventional and the more innovative pharmacological approaches for the treatment of CVD risk in this group of patients.

The Natural Course of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease in the world, paralleling the epidemic of obesity and Type 2 diabetes mellitus (T2DM). NAFLD exhibits a histological spectrum, ranging from “bland steatosis” to the more aggressive necro-inflammatory form, non-alcoholic steatohepatitis (NASH) which may accumulate fibrosis to result in cirrhosis. Emerging data suggests fibrosis, rather than NASH per se, to be the most important histological predictor of liver and non-liver related death. Nevertheless, only a small proportion of individuals develop cirrhosis, however the large proportion of the population affected by NAFLD has led to predictions that NAFLD will become a leading cause of end stage liver disease, hepatocellular carcinoma (HCC), and indication for liver transplantation. HCC may arise in non-cirrhotic liver in the setting of NAFLD and is associated with the presence of the metabolic syndrome (MetS) and male gender. The MetS and its components also play a key role in the histological progression of NAFLD, however other genetic and environmental factors may also influence the natural history. The importance of NAFLD in terms of overall survival extends beyond the liver where cardiovascular disease and malignancy represents additional important causes of death.

Extrahepatic Complications of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is an important cause of liver disease that is often associated with the metabolic syndrome. There is a growing awareness that extrahepatic complications occur in individuals with NAFLD, especially an increased risk of cardiovascular disease. Development of diabetes mellitus, chronic kidney disease, colorectal cancer, and endocrinopathies has been linked to NAFLD. This article reviews the extrahepatic complications affecting individuals with NAFLD and the pathogenesis underlying their development.

Cardiovascular Disease and Myocardial Abnormalities in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in many developed countries, affecting an estimated 30 % of the adult population. In this updated clinical review, we summarize the current knowledge regarding the strong association between NAFLD and the risk of coronary heart disease (CHD) and other functional, structural, and arrhythmic cardiac complications (e.g., left ventricular dysfunction, heart valve diseases and atrial fibrillation). We also briefly discuss the putative biological mechanisms linking NAFLD with these important extra-hepatic complications. To date, a large body of evidence has suggested that NAFLD is not simply a marker of CHD and other functional, structural, and arrhythmic cardiac complications, but also may play a part in the development and progression of these cardiac complications. The clinical implication of these findings is that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions aimed at decreasing the risk of CHD and other cardiac and arrhythmic complications.

Fatty Liver, Insulin Resistance, and Obesity: Relationships With Increase in Coronary Artery Calcium Over Time

BACKGROUND

Nonalcoholic fatty liver disease, insulin resistance (IR), and obesity frequently coexist with type 2 diabetes mellitus (DM), but it is uncertain whether these risk factors for vascular disease contribute to a change in atherosclerosis over time, independently of DM status.

HYPOTHESIS

We hypothesized that the combination of fatty liver, IR, and obesity would be associated with an increase in coronary artery calcium (CAC) score over time, independently of DM status, other cardiovascular risk factors, and medications.

METHODS

Data were analyzed from a South Korean occupational cohort of 2175 people. The outcome was increase in cardiac computed tomography CAC score between baseline and follow-up. Insulin resistance was defined by homeostatic model assessment of insulin resistance (HOMA-IR) ≥75th percentile and fatty liver by ultrasound.

RESULTS

In 592 (27.2%) participants, CAC score increased from baseline (mean ± SD; mean age at baseline, 44.8 ± 5.5 years); and in 1583 subjects, CAC did not change or improved during follow-up (mean age, 41.6 ± 5.6 years). Diabetes mellitus, HOMA-IR, fatty liver, and obesity prevalence were all higher (all P < 0.001) in participants whose CAC score increased from baseline. Adjusting for DM and potential confounders, the combination of IR, obesity, and fatty liver was independently associated with increase in CAC score over time (hazard ratio: 2.46, 95% confidence interval: 1.50-4.03).

CONCLUSIONS

The combination of fatty liver, IR, and obesity is associated with progression of atherosclerosis over time independently of DM, cardiovascular risk factors, and all medications for cardiovascular disease and DM.

Biomarker-Based Approaches for Assessing Alcohol Use Disorders

Although alcohol use disorders rank among the leading public health problems worldwide, hazardous drinking practices and associated morbidity continue to remain underdiagnosed. It is postulated here that a more systematic use of biomarkers improves the detection of the specific role of alcohol abuse behind poor health. Interventions should be initiated by obtaining information on the actual amounts of recent alcohol consumption through questionnaires and measurements of ethanol and its specific metabolites, such as ethyl glucuronide. Carbohydrate-deficient transferrin is a valuable tool for assessing chronic heavy drinking. Activities of common liver enzymes can be used for screening ethanol-induced liver dysfunction and to provide information on the risk of co-morbidities including insulin resistance, metabolic syndrome and vascular diseases. Conventional biomarkers supplemented with indices of immune activation and fibrogenesis can help to assess the severity and prognosis of ethanol-induced tissue damage. Many ethanol-sensitive biomarkers respond to the status of oxidative stress, and their levels are modulated by factors of life style, including weight gain, physical exercise or coffee consumption in an age- and gender-dependent manner. Therefore, further attention should be paid to defining safe limits of ethanol intake in various demographic categories and establishing common reference intervals for biomarkers of alcohol use disorders.

Presence of diabetes mellitus and steatosis is associated with liver stiffness in a general population: The Rotterdam study

Given that little is known about the prevalence of, and factors associated with, liver fibrosis in the general population, we aimed to investigate this in a large, well-characterized cohort by means of transient elastography (TE). This study was part of the Rotterdam Study, a population-based study among individuals ≥45 years. All participants underwent abdominal ultrasound and TE. Liver stiffness measurement (LSM) ≥8.0 kilopascals (kPa) was used as a cutoff suggesting clinically relevant fibrosis. Of 3,041 participants (age, 66.0 ± 7.6 years) with reliable LSM, 169 (5.6%) participants had LSM ≥8.0 kPa. Age (odds ratio [OR]: 2.40; 95% confidence interval [CI]: 1.72-3.36; P < 0.001), alanine aminotransferase (ALT; OR, 1.24; 95% CI: 1.12-1.38; P < 0.001), smoking (OR, 1.77; 95% CI: 1.16-2.70; P = 0.008), spleen size (OR, 1.23; 95% CI: 1.09-1.40; P = 0.001), hepatitis B surface antigen, or anti-hepatitis C virus positivity (OR, 5.38; 95% CI: 1.60-18.0; P = 0.006), and combined presence of diabetes mellitus (DM) and steatosis (OR, 5.20; 95% CI: 3.01-8.98; P < 0.001 for combined presence) were associated with LSM ≥8.0 kPa in multivariable analyses. The adjusted predicted probability of LSM ≥8.0 kPa increased per age decade, with probabilities ranging from 1.4% (0.9-3.6) in participants ages 50-60 years to 9.9% (6.8-14.5) in participants >80 years. Participants with both DM and steatosis had the highest probabilities of LSM ≥8.0 kPa (overall probability: 17.2% [12.5-23.4]; this probability did not increase with age [P = 0.8]).

CONCLUSION

In this large population-based study of older adults, LSM ≥8.0 kPa, suggestive of clinically relevant fibrosis, was present in 5.6% and was strongly associated with steatosis and DM. In the context of an aging population and an increased prevalence of DM and obesity, this study illustrates that liver fibrosis may become a more prominent public health issue in the near future.

Nonalcoholic Fatty Liver Disease and Mean Platelet Volume: A Systemic Review and Meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is linked to obesity, metabolic syndrome, and cardiovascular disease. Increased mean platelet volume (MPV), a marker of platelet activity, is associated with acute myocardial infarction, stroke, thrombosis, and increased mortality after myocardial infarction. The purpose of this study was to perform a meta-analysis to investigate the relationship between NAFLD and MPV.

METHODOLOGY

A systematic search of MEDLINE (Ovid), PubMed, and CINAHL databases from 1950 to May 2014, complemented with manual review of references of published articles for studies comparing MPV in patients with and without NAFLD was done. Results were pooled using both fixed and random effects model.

RESULTS

Our analysis from pooling of data from 8 observational studies including 1428 subjects (NAFLD=842 and non-NAFLD=586) showed that MPV was significantly higher in patients with NAFLD than those without. The standardized mean difference in MPV between NAFLD and controls was 0.457 (95% confidence interval: 0.348-0.565, P<0.001) using fixed and 0.612 (95% confidence interval: 0.286-0.938, P<0.001) using random effects model.

CONCLUSIONS

This study suggests that MPV is significantly higher in patients with NAFLD, indicating the presence of increased platelet activity in such patients. Future research is needed to investigate whether this increased MPV is associated with increased cardiovascular disease in patients with NAFLD.

Epidemiological modifiers of non-alcoholic fatty liver disease: Focus on high-risk groups

An improved understanding of non-alcoholic fatty liver disease epidemiology would lead to identification of individuals at high risk of developing chronic liver disease and extra-hepatic complications, thus contributing to more effective case finding of non-alcoholic fatty liver disease among selected groups. We aimed to illustrate the epidemiology of non-alcoholic fatty liver disease in high-risk groups, which were identified based on existing literature. To this end, PubMed was searched to retrieve original articles published until May 2015 using relevant and pertinent keywords "nonalcoholic fatty liver disease" and "diabetes", "obesity", "hyperlipidaemia", "familial heterozygous hypobetalipoproteinaemia", "hypertension", "metabolic syndrome", "ethnicity", "family history" or "genetic polymorphisms". We found that age, sex and ethnicity are major physiological modifiers of the risk of non-alcoholic fatty liver disease, along with belonging to "non-alcoholic fatty liver disease families" and carrying risk alleles for selected genetic polymorphisms. Metabolic syndrome, diabetes, obesity, mixed hyperlipidaemia and hypocholesterolaemia due to familial hypobetalipoproteinaemia are the major metabolic modifiers of non-alcoholic fatty liver disease risk. Compared with these metabolic conditions, however, arterial hypertension appears to carry a relatively more modest risk of non-alcoholic fatty liver disease. A better understanding of the epidemiology of non-alcoholic fatty liver disease may result in a more liberal policy of case finding among high-risk groups.

Prevalence of Nonalcoholic Fatty Liver Disease and Economy

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a growing health issue around the world.

AIM

This study is to investigate whether adult prevalence of NAFLD correlates with national economic status.

METHODS

Literature search on PubMed database was conducted to identify eligible records fully published before September 2014. Gross national income (GNI) per capita was chosen to evaluate national economic status. Pearson coefficient, linear regression, and unpaired t test were performed in the statistical analyses.

RESULTS

Twenty-one population-based surveys (seven in East Asia, five in South Asia, three in Middle East, and six in Europe) were included. The pooled prevalence of NAFLD was 24.24%, and the global prevalence was positively correlated with GNI per capita (r = 0.4782, P = 0.0283). Europe witnessed a higher prevalence (28.04%) than Middle East (12.95%, P = 0.0092) and East Asia (19.24%, P = 0.0083). Male presented a higher prevalence than female (P = 0.019), especially in Europe (P = 0.0132) and in Caucasians (P = 0.0383). Furthermore, male prevalence and rural prevalence individually were correlated with economic status (r = 0.5725, P = 0.0257 and r = 0.7389, P = 0.0060). Lastly, the urban (23.93%) witnessed a higher prevalence than the rural or the urban + rural (12.65%, P = 0.0141) in the countries of GNI per capita <$10,000.

CONCLUSIONS

This study suggested that countries with higher economic status tend to present a higher prevalence of NAFLD. It is believed to provide a distinctive epidemiologic perspective to global situation of NAFLD.

Nonalcoholic fatty liver disease - current status and future directions

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide with a reported prevalence ranging 6-33%, depending on the studied populations. It encompasses a spectrum of liver manifestations ranging from simple steatosis (also known as nonalcoholic fatty liver, NAFL) to nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, which may ultimately progress to hepatocellular carcinoma. NAFLD is strongly associated with the components of metabolic syndrome, mainly obesity and type 2 diabetes mellitus. NAFLD patients are at increased risk of liver-related as well as cardiovascular mortality. Current paradigm suggests a benign course for NAFL whereas NASH is considered to be the progressive phenotype. Although previously under-recognized accumulating evidence suggests that NAFL may also progress, suggesting a higher number of patients at risk than previously appreciated. Liver biopsy remains the gold standard for definitive diagnosis, but the majority of patients can be diagnosed accurately by noninvasive methods. Approved therapies for NAFLD are still lacking and lifestyle modifications aiming at weight loss remain the mainstay of NAFLD treatment. Intensive research could identify insulin resistance, lipotoxicity and dysbiosis of the gut microbiota as major pathophysiological mechanisms, leading to the development of promising targeted therapies which are currently investigated in clinical trials. In this review we summarized the current knowledge of NAFLD epidemiology, natural history, diagnosis, pathogenesis and treatment and considered future directions.

Treatment of Nonalcoholic Fatty Liver Disease: The Role of Medical, Surgical, and Endoscopic Weight Loss

Nonalcoholic fatty liver disease (NAFLD) represents a rapidly growing cause of chronic liver disease in the United States and is associated with significant morbidity and mortality, including progression to liver cirrhosis and hepatocellular carcinoma. NAFLD comprises a spectrum of liver conditions, ranging from simple steatosis to steatosis with inflammation (steatohepatitis) and progressive fibrosis. Weight loss represents a first line therapeutic modality for the management of NAFLD. Herein, we review the evidence base for medical, surgical, and endoscopic approaches to weight loss and their potential impact on the natural history of NAFLD.