Fatty liver, carotid disease and gallstones: A study of age-related associations

Relation between non-alcoholic fatty liver disease and carotid artery intimal media thickness as a surrogate for atherosclerosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis without heavy alcohol consumption or other chronic conditions, encompasses a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis leading to cirrhosis. This analysis aimed to investigate the correlation between NAFLD and carotid intimal media thickness (C-IMT), a non-invasive surrogate for atherosclerosis.

METHODOLOGY

Database searches, including PubMed, EMBASE and Cochrane Library, yielded studies up to April 2023. Included were studies exploring the NAFLD-C-IMT relationship in populations aged >18 years. Exclusions comprised non-English papers, those involving animals or pediatric populations and studies lacking control groups.

RESULTS

No statistical significance was noted between mild and moderate NAFLD compared to the control group regarding C-IMT [95% confidence intervals (CI): -0.03, 0.12] and (95% CI: -0.03, 0.21), respectively. There was a statistically significant difference only in the Severe NAFLD group ( P value 0.03). NAFLD with and without metabolic syndrome showed statistically significant differences compared to control regarding C-IMT (95% CI: 0.04, 0.12) and (95% CI: 0.01, 0.07), respectively. Fifty-nine studies were mentioned without classification of NAFLD severity and revealed a high statistically significant difference between NAFLD and controls regarding C-IMT with (95% CI: 0.09, 0.12, P < 0.00001). Stratified analysis according to sex was done in two studies and revealed statistical differences between NAFLD and control regarding C-IMT in both groups.

CONCLUSION

This meta-analysis underscores a significant association between NAFLD and increased C-IMT, emphasizing the importance of assessing C-IMT in NAFLD patients to identify cardiovascular risk and tailor therapeutic interventions for improved patient outcomes.

Nomogram for predicting the risk of nonalcoholic fatty liver disease in older adults in Qingdao, China: A cross-sectional study

BACKGROUND AND OBJECTIVES

To explore the risk factors for non-alcoholic fatty liver disease (NAFLD) and to establish a non-invasive tool for the screening of NAFLD in an older adult population.

METHODS AND STUDY DESIGN

A total of 131,161 participants were included in this cross-sectional study. Participants were randomly divided into training and validation sets (7:3). The least absolute shrinkage and selection operator method was used to screen risk factors. Multivariate logistic regression was employed to develop a nomogram, which was made available online. Receiver operating characteristic curve analysis, calibration plots, and decision curve analysis were used to validate the discrimination, calibration, and clinical practicability of the nomogram. Sex and age subgroup analyses were conducted to further validate the reliability of the model.

RESULTS

Nine variables were identified for inclusion in the nomogram (age, sex, waist circumference, body mass index, exercise frequency, systolic blood pressure, fasting plasma glucose, alanine aminotransferase, and low-density lipoprotein cholesterol). The area under the receiver operating characteristic curve values were 0.793 and 0.790 for the training set and the validation set, respectively. The calibration plots and decision curve analyses showed good calibration and clinical utility. Subgroup analyses demonstrated consistent discriminatory ability in different sex and age subgroups.

CONCLUSIONS

This study established and validated a new nomogram model for evaluating the risk of NAFLD among older adults. The nomogram had good discriminatory performance and is a non-invasive and convenient tool for the screening of NAFLD in older adults.

Hepatic Huwe1 loss protects mice from non-alcoholic fatty liver disease through lipid metabolic rewiring

Non-alcoholic fatty liver disease (NAFLD) is the most pervasive liver pathology worldwide. Here, we demonstrate that the ubiquitin E3 ligase Huwe1 is vital in NAFLD pathogenesis. Using mass spectrometry and RNA sequencing, we reveal that liver-specific deletion of Huwe1 (Huwe1LKO) in 1-year-old mice (approximately middle age in humans) elicits extensive lipid metabolic reprogramming that involves downregulation of de novo lipogenesis and fatty acid uptake, upregulation of fatty acid β-oxidation, and increased oxidative phosphorylation. ChEA transcription factor prediction analysis inferred these changes result from attenuated PPARɑ, LXR, and RXR activity in Huwe1LKO livers. Consequently, Huwe1LKO mice fed chow diet exhibited significantly reduced hepatic steatosis and superior glucose tolerance compared to wild-type mice. Huwe1LKO also conferred protection from high-fat diet-induced hepatic steatosis by 6-months of age, with increasingly robust differences observed as mice reached middle age. Together, we present evidence that Huwe1 plays a critical role in the development of age- and diet-induced NAFLD.

The association between hypertension and the risk of gallstone disease: a cross-sectional study

BACKGROUND

To explore the association between hypertension and the risk of gallstone disease.

METHODS

We collected the data about the subjects receiving physical examination. Gallstone disease was diagnosed by abdominal ultrasound. Multivariable logistic regression was used to study the association between blood pressure and the risk of gallstone disease. SPSS version 23.0 was used for statistical analysis, and two-tailed P < 0.05 was defined as statistically significant.

RESULTS

A total of 318,403 people were included in the study and 171,276 (53.8%) of them were men and 147,127 (46.2%) were women. Among them, 27,463 (8.6%) were diagnosed with gallstone disease on ultrasound examination, with 12,452 (3.9%) cases of gallstones and 15,017 (4.7%) cases of cholecystectomy. Multivariable logistic regression showed that hypertension was significantly associated with the risk of gallstone disease (OR = 1.05; 95% CI: 1.02-1.10; P = 0.03) and gallstones (OR = 1.12; 95% CI: 1.06-1.19; P < 0.01) and the association between hypertension and gallstone disease was stronger in women than in men. However, hypertension was not significantly correlated with cholecystectomy (OR = 0.99; 95% CI: 0.95-1.04; P = 0.85). Additionally, results showed that with the severity of hypertension increased, the risk of gallstone disease was also marked elevated (P for trend < 0.001).

CONCLUSIONS

The gallstone disease was prevalent and hypertension is significantly associated with the gallstone disease risk with a significant dose-response association. This study showed that the association between hypertension and cholecystectomy was not statistically significant, maybe hypertension correlated with gallstones but not with symptomatic gallstone disease which would require cholecystectomy.

Impact of aging on primary liver cancer: epidemiology, pathogenesis and therapeutics

Aging involves progressive physiological and metabolic reprogramming to adapt to gradual deterioration of organs and functions. This includes mechanisms of defense against pre-malignant transformations. Thus, certain tumors are more prone to appear in elderly patients. This is the case of the two most frequent types of primary liver cancer, i.e., hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Accordingly, aging hallmarks, such as genomic instability, telomere attrition, epigenetic alterations, altered proteostasis, mitochondrial dysfunction, cellular senescence, exhaustion of stem cell niches, impaired intracellular communication, and deregulated nutrient sensing can play an important role in liver carcinogenesis in the elders. In addition, increased liver fragility determines a worse response to risk factors, which more frequently affect the aged population. This, together with the difficulty to carry out an early detection of HCC and iCCA, accounts for the late diagnosis of these tumors, which usually occurs in patients with approximately 60 and 70 years, respectively. Furthermore, there has been a considerable controversy on what treatment should be used in the management of HCC and iCCA in elderly patients. The consensus reached by numerous studies that have investigated the feasibility and safety of different curative and palliative therapeutic approaches in elders with liver tumors is that advanced age itself is not a contraindication for specific treatments, although the frequent presence of comorbidities in these individuals should be taken into consideration for their management.

NAFLD in the Elderly

Non-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent disease globally. Current estimates are that 24% of the adult population, thus, one billion individuals worldwide, are affected. Interestingly, the prevalence of fatty liver seems to peak between 40─50 years of age in males and 60─69 years in females, often slightly decreasing in older (>70 years) cohorts. Furthermore, several risk factors for NAFLD development, such as hypertension, diabetes, hyperlipidemia, and obesity are higher in older adults. The diagnosis and management strategies in older adults are sometimes challenging, and certain age-specific factors have to be taken into account by healthcare professionals. In this review, we provide an overview of considerations relevant to the management and diagnosis of NAFLD in older adults (age >65 years) and discuss the types of pharmacological interventions available for the management of non-alcoholic steatohepatitis (NASH) in the aging population.

CML/RAGE Signal Bridges a Common Pathogenesis Between Atherosclerosis and Non-alcoholic Fatty Liver

Non-alcoholic fatty liver disease (NAFLD) has become a common chronic disease in the world. NAFLD is not only a simple intrahepatic lesion, but also affects the occurrence of a variety of extrahepatic complications. In particular, cardiovascular complications are particularly serious, which is the main cause of death in patients with NAFLD. To study the relationship between NAFLD and AS may be a new way to improve the quality of life in patients with NAFLD. As we all known, inflammatory response plays an important role in the occurrence and development of NAFLD and AS. In this study, we found that the accumulation of Nε-carboxymethyllysine (CML) in the liver leads to hepatic steatosis. CML can induce the expression of interleukin (IL-1β), interleukin (IL-6), tumor necrosis factor (TNF-α), C-reactionprotein (CRP) by binding with advanced glycosylation end-product receptor (RAGE) and accelerate the development of AS. After silencing RAGE expression, the expression of pro-inflammatory cytokines was inhibited and liver and aorta pathological changes were relieved. In conclusion, CML/RAGE signal promotes the progression of non-alcoholic fatty liver disease and atherosclerosis. We hope to provide new ideas for the study of liver vascular dialogue in multi organ communication.

Association Between Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome with Gallstone Disease, South Iran: A Population-Based Study

AIM

Gallstone disease (GSD), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS) are common problems. The aim of this study was to investigate the association between NAFLD, MetS and its components with GSD.

MATERIALS AND METHODS

This cross-sectional study was conducted as a part of the Kavar Cohort Study (KCS) affiliated to Shiraz University of Medical Sciences, Shiraz, Iran between January 2012 and January 2018. A total of 2239 participants of the general population of the KCS were selected randomly. Ultrasonography for GSD and NAFLD diagnosis and clinical and laboratory assaying for MetS evaluation were performed for the participants. The National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP-III) and Criteria for Clinical Diagnosis of MetS in Iranian Adults (CCDMIA) were used for diagnosis of MetS.

RESULTS

Overall, 59 patients with GSD and 177 age- and sex- matched participants without gallstones as a comparison group were enrolled. According to GSD groups, NAFLD was observed in 42.4% and 22.6% of patients with and without GSD, respectively, and the difference between the two groups was statistically significant (P = 0.003). MetS was present in 33.9% and 39.0% of GSD subjects, compared with 32.8% and 33.3% of the non-GSD group, based on NCEP/ATPIII and CCDMIA, respectively. Although the mean of all components of MetS except HDL-cholesterol were higher in the GSD group than in the non-GSD group,  the difference was only significant in waist circumference (P = 0.041).

CONCLUSION

The present study found an obvious association between NAFLD and GSD. This study also showed a significant association between increasing waist circumference and risk of GSD. We recommend that patients with GSD should be evaluated for the likelihood of NAFLD and its treatment in addition to lifestyle changes to gain proper weight. However, further researches are needed to clarify the relationship between the nature of GSD, NAFLD, and obesity.

Prevalence and long-term outcomes of non-alcoholic fatty liver disease among elderly individuals from the United States

BACKGROUND

The prevalence and outcomes of non-alcoholic fatty liver disease (NAFLD) among elderly have not been well described. Our aim was to assess the prevalence, risk factors and mortality of NAFLD in individuals older than 60 years.

METHODS

The data from the Third National Health and Nutrition Examination Survey with linked mortality files were utilized. NAFLD was defined by United States Fatty Liver Index in the absence of other causes of liver disease. Cox proportional hazards models were used to assess all-cause and cardiovascular (CV) mortality. All analyses were performed using SAS software.

RESULTS

Three thousand two hundred seventy-one NHANES-III participants were included. The prevalence rates from NAFLD were 40.3% (95% CI: 37.2-43.5%) and 39.2% (95% CI: 34.4-44.0%) among 60-74 and > 74 years old. Among aged 60-74, the risks for 5-year and 10-year all-cause mortality were associated with presence of NAFLD [adjusted hazard ratios: 1.60 (95% CI: 1.24-1.96) for 5-year and 1.22 (95%CI: 1.01-1.49) for 10-year]. CV mortality were higher in this group were (aHR: 2.12 (95% CI: 1.20-3.75) for 5-year and 1.06 (95%CI: 0.73-1.52) for 10-year]. In contrast, in individuals > 74 years old, diagnosis of NAFLD was not associated with all-cause or CVD mortality.

CONCLUSIONS

NAFLD is common among elderly population. Although NAFLD is associated with increased risk of mortality for 60-74-year-old individuals, this risk was not increased in those older than 74 years.

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.

Nonalcoholic fatty liver disease: Evolving paradigms

In the last years new evidence has accumulated on nonalcoholic fatty liver disease (NAFLD) challenging the paradigms that had been holding the scene over the previous 30 years. NAFLD has such an epidemic prevalence as to make it impossible to screen general population looking for NAFLD cases. Conversely, focusing on those cohorts of individuals exposed to the highest risk of NAFLD could be a more rational approach. NAFLD, which can be diagnosed with either non-invasive strategies or through liver biopsy, is a pathogenically complex and clinically heterogeneous disease. The existence of metabolic as opposed to genetic-associated disease, notably including ”lean NAFLD” has recently been recognized. Moreover, NAFLD is a systemic condition, featuring metabolic, cardiovascular and (hepatic/extra-hepatic) cancer risk. Among the clinico-laboratory features of NAFLD we discuss hyperuricemia, insulin resistance, atherosclerosis, gallstones, psoriasis and selected endocrine derangements. NAFLD is a precursor of type 2 diabetes (T2D) and metabolic syndrome and progressive liver disease develops in T2D patients in whom the course of disease is worsened by NAFLD. Finally, lifestyle changes and drug treatment options to be implemented in the individual patient are also critically discussed. In conclusion, this review emphasizes the new concepts on clinical and pathogenic heterogeneity of NAFLD, a systemic disorder with a multifactorial pathogenesis and protean clinical manifestations. It is highly prevalent in certain cohorts of individuals who are thus potentially amenable to selective screening strategies, intensive follow-up schedules for early identification of liver-related and extrahepatic complications and in whom earlier and more aggressive treatment schedules should be carried out whenever possible.

Nonalcoholic fatty liver was associated with asymptomatic gallstones in a Chinese population

The aim of this study was to determine the association between nonalcoholic fatty liver disease (NAFLD) and asymptomatic gallstones in a Chinese population.The study had a cross-sectional design and enrolled 7583 subjects who visited the physical check-up center at Sir Run Run Shaw Hospital between 2009 and 2011. Colorimetric methods were used to measure the levels of cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), whereas fasting plasma glucose (FPG) level was measured using a dextrose-oxidizing enzyme method. Subjects who completed a questionnaire and underwent a medical and ultrasound examinations were included in the study.The prevalence of NAFLD was significantly higher in patients with asymptomatic gallstones than in those without asymptomatic gallstones (58.98% vs 46.58%, respectively; P < .0001). The age-adjusted odds ratio (OR) for NAFLD being accompanied by asymptomatic gallstones was 1.35 [95% confidence interval (CI), 1.13-1.61; P = .0009] in male and 1.92 (95% CI, 1.45-2.54; P < .0001) in female subjects. Asymptomatic gallstones were associated with NAFLD in subjects aged < 50 years (OR = 1.74, 95% CI, 1.44-2.12; P < .0001), but not in subjects aged > 50 years (OR = 1.17, 95% CI, 0.92-1.48; P = .2040). The OR of NAFLD for asymptomatic gallstones was 1.28 after multivariate logistic regression analysis (95% CI, 1.07-1.52; P = .006).Our results indicated that asymptomatic gallstones are strongly associated with NAFLD in the Chinese study population.

Clinical characteristics of patients with diabetes mellitus and fatty liver diagnosed by liver/spleen Hounsfield units on CT scan

Objective The leading cause of liver injuries in diabetes mellitus may be associated with fatty liver. We aimed to elucidate the relationship between fatty liver and diabetes characteristics. Methods Retrospectively, 970 patients with diabetes were analysed. Fatty liver was diagnosed when the liver/spleen Hounsfield unit ratio by computed tomography was below 0.9. Clinical diabetes characteristics were compared between patients with and without fatty liver. Results Of 970 patients (717 male and 253 female; mean age 64.4 years), 175 males (24.4%) and 60 females (23.7%) had fatty liver. None of the 28 patients with type 1 diabetes had fatty liver. In male patients with type 2 diabetes, age, visceral adipose tissue (VAT), albumin, alanine amino-transferase (ALT), and triglycerides were independently associated with fatty liver. In females, age and bilirubin were associated with fatty liver. Conclusions Fatty liver is associated with type 2 diabetes characteristics, including younger age and elevated VAT, albumin, ALT, and triglycerides in males and younger age and elevated bilirubin levels in females.

Metabolic concerns in aging HIV-infected persons: from serum lipid phenotype to fatty liver

: Among HIV-infected persons, the assessment of nonalcoholic fatty liver disease (NAFLD) provides a window through which overall metabolic health can be evaluated. In this review, we summarize clinical data that support the roles of aging and metabolic dysregulation as factors contributing to fatty liver/NAFLD among HIV-infected persons.Age-related metabolic alterations include hepatic anatomic and functional changes, altered homeostasis of gastrointestinal microbiota and anthropometric changes (such as a shift of body fat depots from the subcutaneous to the visceral compartment) that are often associated with the development of insulin resistance and increased cardiovascular risk.Fatty changes in the liver occur not only with metabolic disruption but also with virus-induced injury. Chronic hepatitis C virus infection is commonly associated with fatty liver, and can be related to both hepatitis C virus genotype and host metabolic features. Similarly, HIV infection is associated with fatty liver as a result of multiple viral and host factors. Clearly, lipodystrophy, dysregulation of the gut-liver axis and HIV infection itself may each contribute simultaneously to NAFLD pathogenesis. Although lifestyle changes are the mainstay of treatment, to date no drug has specifically been approved for use in persons with NAFLD. Moreover, current guidelines provide no specific therapeutic recommendations for persons with NAFLD older than 65 years.Well-designed studies characterizing the epidemiology, pathogenesis, clinical outcomes and potential therapeutic interventions for liver disease and associated metabolic comorbidities in older HIV-infected patients are urgently needed.

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.

Cannabis use is associated with reduced prevalence of non-alcoholic fatty liver disease: A cross-sectional study

Cannabis use is associated with reduced prevalence of obesity and diabetes mellitus (DM) in humans and mouse disease models. Obesity and DM are a well-established independent risk factor for non-alcoholic fatty liver disease (NAFLD), the most prevalent liver disease globally. The effects of cannabis use on NAFLD prevalence in humans remains ill-defined. Our objective is to determine the relationship between cannabis use and the prevalence of NAFLD in humans. We conducted a population-based case-control study of 5,950,391 patients using the 2014 Healthcare Cost and Utilization Project (HCUP), Nationwide Inpatient Survey (NIS) discharge records of patients 18 years and older. After identifying patients with NAFLD (1% of all patients), we next identified three exposure groups: non-cannabis users (98.04%), non-dependent cannabis users (1.74%), and dependent cannabis users (0.22%). We adjusted for potential demographics and patient related confounders and used multivariate logistic regression (SAS 9.4) to determine the odds of developing NAFLD with respects to cannabis use. Our findings revealed that cannabis users (dependent and non-dependent) showed significantly lower NAFLD prevalence compared to non-users (AOR: 0.82[0.76-0.88]; p<0.0001). The prevalence of NAFLD was 15% lower in non-dependent users (AOR: 0.85[0.79-0.92]; p<0.0001) and 52% lower in dependent users (AOR: 0.49[0.36-0.65]; p<0.0001). Among cannabis users, dependent patients had 43% significantly lower prevalence of NAFLD compared to non-dependent patients (AOR: 0.57[0.42-0.77]; p<0.0001). Our observations suggest that cannabis use is associated with lower prevalence of NAFLD in patients. These novel findings suggest additional molecular mechanistic studies to explore the potential role of cannabis use in NAFLD 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.

Evidence that non-alcoholic fatty liver disease and polycystic ovary syndrome are associated by necessity rather than chance: a novel hepato-ovarian axis?

Increasing evidence suggests that non-alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) are associated with obesity, insulin resistance, metabolic syndrome, cardiovascular disease, cirrhosis, and liver tumors. On these grounds, we have hypothesized that NAFLD and PCOS occur more frequently than expected by chance alone. We have tested this hypothesis by reviewing the clinical and biological evidence that supports a significant association between NAFLD and PCOS. PubMed was extensively searched for articles published through March 2015 using the keywords "nonalcoholic fatty liver disease" or "fatty liver" combined with "PCOS." Several cross-sectional and case-control studies have consistently demonstrated that the prevalence of NAFLD is remarkably increased in young women with PCOS, independent of overweight/obesity and other coexisting metabolic syndrome features, and that these women are more likely to have the more severe forms of NAFLD (non-alcoholic steatohepatitis, advanced fibrosis, and cirrhosis). Accumulating evidence suggests that NAFLD, especially its necro-inflammatory form, may exacerbate hepatic and systemic insulin resistance and releases multiple pro-inflammatory, pro-coagulant, and pro-fibrogenic mediators that may play important roles in the pathophysiology of PCOS. These findings call for more active and systematic search for NAFLD among women with PCOS. Conversely, gastroenterologists/hepatologists need to be aware of the presence of PCOS among female patients with NAFLD and compatible clinical features. Finally, all these patients should undergo regular follow-up not only for liver-related complications but also for cardio-metabolic diseases.

Nonalcoholic Fatty Liver Disease for Identification of Preclinical Carotid Atherosclerosis

Nonalcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease, yet whether identification of NAFLD in asymptomatic individuals is helpful over established risk factors remains unknown. A total of 37,799 asymptomatic adults aged 20 years or older who underwent comprehensive health check-up examination, including abdominal and carotid artery duplex ultrasonography (US) were included in the analysis. Nonalcoholic fatty liver disease was diagnosed with US and exclusion of secondary causes of fat accumulation or other causes of chronic liver disease, and graded as mild or moderate to severe fatty liver. Individuals with carotid plaque identified on carotid artery US were considered at risk for cardiovascular disease. Metabolic syndrome (MetS) was defined by the adult treatment panel III criteria. Nonalcoholic fatty liver disease was an independent factor associated with carotid plaque in a dose-dependent manner (odds ratio [OR]; 95% confidence interval [CI]: 1.09 [1.03-1.16] and 1.13 [1.06-1.21] for mild and ≥ moderate degree of NAFLD). Among clinically-relevant subgroups, NAFLD was more closely associated with carotid plaque in young adults (aged < 60 years) without MetS (OR [95% CI]: 1.13 [1.03-1.19] and 1.16 [1.06-1.27] for mild and ≥ moderate degree of NAFLD) than old adults (aged ≥ 60 years) or with MetS (OR [95% CI]: 1.06 [0.97-1.17] and 1.07 [0.97-1.19] for mild and ≥ moderate degree NAFLD). In young adults without MetS, the prevalence of carotid plaques was 32.8% and the sensitivity and specificity of NAFLD for carotid plaque was 0.38 and 0.67, respectively. In conclusion, NAFLD is associated with carotid plaque independent of traditional risk factors, especially in young adults without MetS. Nonalcoholic fatty liver disease could help identify additional individuals with preclinical atherosclerosis in asymptomatic young adults without MetS, yet, showed suboptimal performance as a screening tool.

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.

Association between non-alcoholic fatty liver disease and arterial stiffness in the non-obese, non-hypertensive, and non-diabetic young and middle-aged Chinese population

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is associated with arterial stiffness in the general population. Age, obesity, hypertension, and diabetics are risk factors for arterial stiffness. In this study, we aimed to investigate the association between NAFLD and arterial stiffness as measured by brachial-ankle pulse wave velocity (baPWV) in the non-obese, non-hypertensive, and non-diabetic young and middle-aged Chinese population.

METHODS

A cross-sectional study with 1296 non-obese, non-hypertensive, and non-diabetic young and middle-aged (20-65 years) subjects undergoing routine medical check-ups in the International Health Care Center of the Second Affiliated Hospital of School of Medicine of Zhejiang University was carried out. Fatty liver was diagnosed by ultrasonography, and baPWV was measured using an automatic waveform analyzer. The subjects were classified into two groups according to the presence of NAFLD, and divided into a further two groups according to their baPWV.

RESULTS

The overall incidence of NAFLD was 19.0%, and NAFLD patients had a significantly higher level of baPWV than the controls ((1321±158) cm/s vs. (1244±154) cm/s; P<0.001). The incidence of NAFLD was clearly higher in the increased baPWV group than in the normal baPWV group (29.3% vs. 16.9%; P<0.001), and the incidence increased in line with the increase of baPWV quartiles in the normal range as well as with the severity of arterial stiffness (both P for trend <0.001). Multiple linear logistic regression analysis showed that the presence of NAFLD was positively and independently associated with baPWV.

CONCLUSIONS

Our results suggest that the presence of NAFLD is associated with arterial stiffness as measured by baPWV in the non-obese, non-hypertensive, and non-diabetic young and middle-aged Chinese population.

Nonalcoholic fatty liver disease and carotid artery atherosclerosis in children and adults: a meta-analysis

Observational studies suggest that nonalcoholic fatty liver disease (NAFLD) is associated with increased carotid intimal medial thickness (C-IMT) and carotid plaques in both children and adults. We carried out a meta-analysis to evaluate the relationship between NAFLD and carotid atherosclerosis measured as C-IMT and carotid plaque prevalence. Medline (Ovid), PubMed, Web of Science, and CINAHL databases were searched from 1946 to September 2014, complemented with a manual review of references of the published articles for studies that compared C-IMT or carotid plaque prevalence in adults and children. Results were pooled using both fixed and random effects models. Of the studies identified, 20 were suitable for testing the effect of NAFLD on C-IMT in adults, 13 for testing the effect of NAFLD on carotid plaque prevalence in adults, and five for testing the effect of NAFLD on C-IMT in the pediatric population. The pooled data from 20 studies (19,274 adult participants: NAFLD=8652, controls=10,622) showed significantly increased C-IMT in patients with NAFLD, compared with controls without NAFLD, according to both fixed [standardized mean difference (SMD)=0.251, 95% confidence interval (CI): 0.220-0.282, P<0.001] and random effects models (SMD=0.944, 95% CI: 0.728-1.160, P<0.001). NAFLD was also found to be associated with a higher carotid artery plaque prevalence when compared with controls, according to both fixed (OR=1.273, 95% CI=1.162-1.394, P<0.001) and random effects models (OR=1.769, 95% CI: 1.213-2.581, P=0.003), on pooling of 13 studies (14,445 adult participants: NAFLD=5399 and controls=9046). Analysis of pooled data from five studies in the pediatric population (1121 pediatric participants: NAFLD=312 and controls=809) also found NAFLD to be associated with significantly increased C-IMT according to fixed (SMD=0.995, 95% CI: 0.840-1.150, P<0.001) and random effects models (1.083, 95% CI: 0.457-1.709, P=0.001). NAFLD is associated with increased C-IMT in both children and adults, and with increased carotid plaque prevalence in adults. Individuals identified with carotid disease should be evaluated for NAFLD and vice versa.

Role of ultrasound in the diagnosis and treatment of nonalcoholic fatty liver disease and its complications

We review the role of liver ultrasonography (US) and related techniques as non-invasive tools in predicting metabolic derangements, liver histology, portal hypertension and cardiovascular risk as well as allowing early diagnosis and management of hepatocellular carcinoma in patients with nonalcoholic fatty liver disease. In this setting, US detects fatty changes as low as ≥20% and hepatic steatosis identified ultrasonographically, in its turn, closely mirrors coronary and carotid atherosclerosis burden. Semi-quantitative US indices (to exclude nonalcoholic steatohepatitis) and sonoelastography (to quantify fibrosis) help in predicting liver histology and selecting patients to submit to liver biopsy. Surveillance for hepatocellular carcinoma conducted through biannual US is mandatory and US has a role in guiding locoregional treatment and in evaluating the efficacy of treatment. High-intensity focused ultrasound can be delivered with precision resulting in coagulative necrosis of hepatocellular carcinoma without puncturing the liver. Costs and inconveniences have so far hampered its diffusion.

Gallstone disease does not predict liver histology in nonalcoholic fatty liver disease

Background/Aims

We sought to examine whether the presence of gallstone disease (GD) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) is associated with liver fibrosis and histological nonalcoholic steatohepatitis (NASH) score.

Methods

We included 441 Turkish patients with biopsy-proven NAFLD. GD was diagnosed in the presence of sonographic evidence of gallstones, echogenic material within the gallbladder with constant shadowing and little or no visualization of the gallbladder or absence of gallbladder at ultrasonography, coupled with a history of cholecystectomy.

Results

Fifty-four patients (12.2%) had GD (GD+ subjects). Compared with the GD- subjects, GD+ patients were older, had a higher body mass index and were more likely to be female and have metabolic syndrome. However, GD+ patients did not have a higher risk of advanced fibrosis or definite NASH on histology. After adjustment for potential confounding variables, the prevalence of GD in NAFLD patients was not associated with significant fibrosis (≥2) (odds ratio [OR], 1.06; 95% confidence interval [CI], 0.53 to 2.21; p=0.68) or definite NASH (OR, 1.03; 95% CI, 0.495 to 2.12; p=0.84).

Conclusions

The presence of GD is not independently associated with advanced fibrosis and definite NASH in adult Turkish patients with biopsy-proven NAFLD.

Gallstone disease and the risk of stroke: a nationwide population-based study

BACKGROUND

Gallstone disease (GD) and stroke share a number of risk factors including diabetes and hyperlipidemia. This nationwide population-based study was designed to estimate the risk of stroke after a diagnosis of GD.

METHODS

Data were obtained from the Taiwan National Health Insurance Research Database. A total of 135,512 patients with a diagnosis of GD and 271,024 age- and gender-matched non-GD control patients were included to assess the risk of stroke using Cox proportional hazard regression.

RESULTS

During the study period (2000-2003), 12,234 (153.67/10,000 person-years) strokes occurred among the GD patients, and 20,680 (114.83/10,000 person-years) among the controls. The diagnosis of GD carried a higher risk of developing ischemic and hemorrhagic stroke, with a hazard ratio (HR) of 1.28 and 1.33 (95% confidence interval [CI], 1.25-1.31 and 1.25-1.41, both P < .0001), respectively. Stroke risk was increased in both genders but at a higher rate in younger age. The GD group had significantly higher prevalence rate of comorbidities that are known stroke risk factors, including hypertension, diabetes, and coronary artery disease. Stroke risk was higher in the GD group with or without any of these comorbidities.

CONCLUSIONS

In this population-based longitudinal follow-up study, GD carried a significantly higher stroke risk, particularly for younger age with or without stroke risk factors. Stroke preventive measures maybe needed for patients with GD, especially those of younger age and with stroke risk factor(s).

Nonalcoholic fatty liver disease and cholesterol gallstones: which comes first?

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are both highly prevalent in the general population and are associated with obesity, insulin resistance, dyslipidemia, and high dietary cholesterol intake. Insulin resistance is a key feature of both NAFLD and GD. Hepatic insulin resistance provides a crucial link between the metabolic syndrome, NAFLD, and increased cholesterol gallstone susceptibility. Hepatic insulin resistance is not only associated with accumulation of hepatic fat but also has a crucial role in supersaturation and excessive production of bile salts. It is not yet clear whether NAFLD is a precursor of GD or whether the presence of GD possibly indicates the presence of long-standing features of metabolic syndrome that accelerates the progression of NAFLD. Recent reports suggested the association between gallstones and nonalcoholic steatohepatitis and liver fibrosis. Importantly, both NAFLD and GD are both associated with high incidence of cardiovascular disease (CVD) and mortality. Emerging evidence suggests a potential benefit of statin therapy in NAFLD and GD. Further research is needed to determine (i) how the presence of NAFLD and GD is associated with CVD (ii) and whether the presence of GD in association with NAFLD increases the risk of liver fibrosis, and (iii) the impact of therapy of NAFLD in the incidence of GD.

Clinical and histological determinants of nonalcoholic steatohepatitis and advanced fibrosis in elderly patients

The characteristics of nonalcoholic fatty liver disease (NAFLD) in elderly patients are unknown. Therefore, we aimed to examine the differences between elderly and nonelderly patients with NAFLD and to identify determinants of nonalcoholic steatohepatitis (NASH) and advanced fibrosis (bridging fibrosis or cirrhosis) in elderly patients. This is a cross-sectional analysis of adult participants who were prospectively enrolled in the NASH Clinical Research Network studies. Participants were included based on availability of the centrally reviewed liver histology data within 1 year of enrollment, resulting in 61 elderly (age ≥65 years) and 735 nonelderly (18-64 years) participants. The main outcomes were the presence of NASH and advanced fibrosis. Compared to nonelderly patients with NAFLD, elderly patients had a higher prevalence of NASH (56% versus 72%, P = 0.02), and advanced fibrosis (25% versus 44%, P = 0.002). Compared to nonelderly patients with NASH, elderly patients with NASH had higher rates of advanced fibrosis (35% versus 52%, P = 0.03), as well as other features of severe liver disease including the presence of ballooning degeneration, acidophil bodies, megamitochondria, and Mallory-Denk bodies (P ≤ 0.05 for each). In multiple logistic regression analyses, independent determinants of NASH in elderly patients included higher aspartate aminotransferase (AST) (odds ratio [OR] = 1.12, P = 0.007) and lower platelets (OR = 0.98, P = 0.02); and independent determinants of advanced fibrosis included higher AST (OR = 1.08, P = 0.007), lower alanine aminotransferase value (OR = 0.91, P = 0.002), and an increased odds of having low high-density lipoprotein (OR = 8.35, P = 0.02).

CONCLUSION

Elderly patients are more likely to have NASH and advanced fibrosis than nonelderly patients with NAFLD. Liver biopsy may be considered in elderly patients and treatment should be initiated in those with NASH and advanced fibrosis.

Relationship of non-alcoholic fatty liver disease with cholecystectomy in the US population

OBJECTIVES

Other than weight-related conditions, risk factors for non-alcoholic fatty liver disease (NAFLD) are not well defined. We investigated the association of gallstones and cholecystectomy with NAFLD in a large, national, population-based study.

METHODS

Among adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, ultrasonography for gallstone disease was performed, and videotapes were subsequently evaluated for NAFLD. Odds ratios (ORs) for the association of gallstone disease with NAFLD were calculated using logistic regression analysis to adjust for common associated factors.

RESULTS

Among 12,232 participants without viral hepatitis or significant alcohol intake, the prevalence of gallstones was 7.4%, cholecystectomy 5.6%, and NAFLD 20.0%. Participants with cholecystectomy had higher age-sex-adjusted prevalence of NAFLD (48.4%) than those with gallstones (34.4%) or without gallstone disease (17.9%) (P<0.01 for all comparisons). Controlling for numerous factors associated with both NAFLD and gallstone disease, multivariate-adjusted analysis confirmed the association of NAFLD with cholecystectomy (OR=2.4; 95% confidence interval (CI): 1.8-3.3), but not with gallstones (OR=1.1; 95% CI: 0.84-1.4).

CONCLUSIONS

The association of NAFLD with cholecystectomy, but not with gallstones, indicates that cholecystectomy may itself be a risk factor for NAFLD.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world. It is closely associated with metabolic syndrome. The alarming epidemics of diabetes and obesity have fueled an increasing prevalence of NAFLD, particularly among these high-risk groups. Histologically, NAFLD encompasses a disease spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which is characterized by hepatocyte injury, inflammation, and variable degrees of fibrosis on liver biopsy. Non-alcoholic steatohepatitis can progress to cirrhosis in a fraction of patients. There is currently little understanding of risk factors for disease progression and the disease pathogenesis has not been fully defined. Liver biopsy remains the gold standard for diagnosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. There are no well-established pharmacological agents for treatment of NASH, although this is a subject of ongoing research.

Ezetimibe improves glucose metabolism by ameliorating hepatic function in Japanese patients with type 2 diabetes

Aims/Introduction:  Several experimental studies have shown that ezetimibe improves steatosis and insulin resistance in the liver. This suggests that ezetimibe may improve glucose metabolism, as well as lipid metabolism, by inhibiting hepatic lipid accumulation. Therefore, we compared HbA1c levels after 3 months ezetimibe treatment with baseline levels in patients with type 2 diabetes and examined the factors associated with reductions in HbA1c following ezetimibe administration.

MATERIALS AND METHODS

  Lipid profiles, hepatic function, and HbA1c were assessed before and after 3 months treatment with 10 mg/day ezetimibe in 96 patients with type 2 diabetes and hypercholesterolemia. Regression analysis was used to investigate associations between metabolite levels and the percentage change in HbA1c.

RESULTS

  Low-density lipoprotein-cholesterol was significantly lower after 3 months treatment compared with baseline, and HbA1c decreased in approximately 50% of patients. Univariate linear regression analyses showed that changes in HbA1c were significantly associated with serum alanine aminotransferase (ALT), the aspartate aminotransferase (AST)/ALT ratio, and age. Two-tailed chi-square tests revealed that serum ALT ≥35 IU/L and an AST/ALT ratio <1.0 were significantly associated with decreases in HbA1c following ezetimibe administration.

CONCLUSIONS

  The results of the present study indicate that ezetimibe may improve glucose metabolism. Serum ALT levels and the AST/ALT ratio were useful predictors of a glucose metabolism response to ezetimibe. This trial was registered with UMIN (no. UMIN000005307). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00147.x, 2011).

Systematic review: the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease, and its worldwide prevalence continues to increase with the growing obesity epidemic. This study assesses the epidemiology of NAFLD in adults based on clinical literature published over the past 30 years.

AIM

To review epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults based on clinical literature published over the past 30 years.

METHODS

An in-depth search of PubMed (1980-2010) was based on five search terms: 'non-alcoholic fatty liver disease' OR 'non-alcoholic steatohepatitis' OR 'fatty liver' OR 'steatosis' AND 'incidence' [MeSH Terms] OR 'prevalence' [MeSH Terms] OR 'natural history'. Studies of paediatric cohorts were excluded. Articles were categorised by topic and summarised, noting generalisations concerning their content.

RESULTS

Four study categories included NAFLD incidence, prevalence, risk factors and natural history. Studies related to NAFLD prevalence and incidence indicate that the diagnosis is heterogeneous and relies on a variety of assessment tools, including liver biopsy, radiological tests such as ultrasonography, and blood testing such as liver enzymes. The prevalence of NAFLD is highest in populations with pre-existing metabolic conditions such as obesity and type II diabetes. Many studies investigating the natural history of NAFLD verify the progression from NASH to advanced fibrosis and hepatocellular carcinoma.

CONCLUSIONS

Non-alcoholic fatty liver disease is the most common cause of elevated liver enzymes. Within the NAFLD spectrum, only NASH progresses to cirrhosis and hepatocellular carcinoma. With the growing epidemic of obesity, the prevalence and impact of NAFLD continues to increase, making NASH potentially the most common cause of advanced liver disease in coming decades.

Increased arterial stiffness and impaired endothelial function in nonalcoholic Fatty liver disease: a pilot study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease both in the general and pediatric population and has been associated with increased cardiovascular risk. Arterial function and early atherosclerotic changes are markers of cardiovascular disease and independent predictors of the corresponding risk. Through a global approach, we investigated the relationships between NAFLD and functional arterial changes and early atherosclerosis.

METHODS

A total of 23 consecutive patients (mean age 55 ± 14 years, 11 males) with biopsy evidence of NAFLD and 28 control subjects matched for age, gender, body mass index, and other cardiovascular risk factors participated in the study.

RESULTS

Compared to controls, NAFLD subjects had significantly higher carotid-femoral pulse wave velocity (PWV; 8.2 ± 1.3 m/s vs. 6.9 ± 1.3 m/s, P = 0.001), higher carotid intima-media thickness (IMT; 0.79 ± 0.18 mm vs. 0.67 ± 0.13 mm, P = 0.01), and reduced flow-mediated dilatation (FMD; 1.92 ± 2.11% vs. 4.8 ± 2.43%, P < 0.001). In multivariable analysis, presence of NAFLD was an independent determinant of both PWV and FMD, whereas leptin was an independent determinant of PWV (B = 0.036, P < 0.05), and adiponectin was independently associated with FMD (B = 0.104, P < 0.05). In addition, histological activity of liver disease expressed by the global Brunt Grade was associated independently with FMD (B = -1.054, P < 0.05).

CONCLUSIONS

NAFLD is associated with arterial stiffness and endothelial dysfunction. Given the important independent prognostic role of these arterial indexes, these findings have important implications for increased cardiovascular risk in patients with NAFLD.

Is liver fat detrimental to vessels?: intersections in the pathogenesis of NAFLD and atherosclerosis

NAFLD (non-alcoholic fatty liver disease) encompasses the spectrum of fatty liver disease in insulin-resistant individuals who often display T2DM (Type 2 diabetes mellitus) and obesity. The present review highlights the pathophysiological basis and clinical evidence for a possible causal linkage between NAFLD and CVD (cardiovascular disease). The role of traditional and non-traditional CVD risk factors in the pathophysiology of NAFLD is considered in the first part of the review, with the basic science shared by atherogenesis and hepatic steatogenesis discussed in depth in the second part. In conclusion, NAFLD is not an innocent bystander, but a major player in the development and progression of CVD. NAFLD and CVD also share similar molecular mechanisms and targeted treatment strategies. On the research side, studies should focus on interventions aimed at restoring energy homoeostasis in lipotoxic tissues and at improving hepatic (micro)vascular blood supply.

Hepatic steatosis and subclinical cardiovascular disease in a cohort enriched for type 2 diabetes: the Diabetes Heart Study

OBJECTIVES

To explore mechanisms whereby hepatic steatosis may be associated with cardiovascular risk, we investigated cross-sectional relationships between hepatic steatosis, regional fat accumulation, inflammatory biomarkers, and subclinical measures of atherosclerosis in the Diabetes Heart Study.

METHODS

The Diabetes Heart Study is a family study of sibling pairs concordant for type 2 diabetes. A subset of 623 randomly selected participants was evaluated for hepatic steatosis, defined as a liver:spleen attenuation ratio of <1.0 by computed tomography. We quantified visceral fat, subcutaneous fat, coronary, aortic, and carotid artery calcium by computed tomography; and carotid atherosclerosis by ultrasound. Associations between the liver:spleen attenuation ratio and these factors were expressed as Spearman correlations.

RESULTS

After adjustment for age, race, gender, body mass index, and diabetes status, the liver:spleen attenuation ratio correlated with visceral fat (r =-0.22, P < 0.0001) and subcutaneous fat (r =-0.13, P= 0.031). Hepatic steatosis was associated with lower high-density lipoprotein (r = 0.21, P < 0.0001), higher triglycerides (r =-0.25, P < 0.0001), higher C-reactive protein (r =-0.095, P= 0.004), and lower serum adiponectin (r = 0.34, P < 0.0001). There were no significant associations between the liver:spleen attenuation ratio and coronary, aortic, or carotid calcium, or carotid intimal thickness.

CONCLUSIONS

This suggests that hepatic steatosis is less likely a direct mediator of cardiovascular disease and may best be described as an epiphenomenon. The strong correlations between pro-atherogenic biomarkers, visceral fat, and elements of the metabolic syndrome suggest that hepatic steatosis reflects more than general adiposity, but represents a systemic, inflammatory, pro-atherogenic adipose state.

Non-alcoholic fatty liver disease is strongly associated with carotid atherosclerosis: a systematic review

BACKGROUND/AIMS

To perform a systematic review of the studies addressing the association between non-alcoholic fatty liver disease (NAFLD) and carotid intima-media thickness (IMT).

METHODS

Literature searches identified seven studies that met inclusion criteria: population-based or hospital-based case-control studies about the relation between NAFLD and carotid IMT, in which information on number of subjects in controls and NAFLD patients, and data to evaluate carotid IMT and carotid plaques (measured by carotid ultrasound) could be extracted.

RESULTS

From a total of 3497 subjects (1427 patients and 2070 controls), we found a significant association between NAFLD and carotid IMT either in fixed (D: 0.51, 95% CI: 0.44-0.58, p<1 x 10(-8)) or random models (D: 1.44, CI: 95% 0.63-2.24, p<0.0006). Meta-regression analysis showed that mean differences in alanine aminotransferase and gamma-GT were strongly correlated with those in IMT (p<0.00006 and 0.004, respectively). In addition, 5 reports including 3212 subjects showed that carotid plaques were more frequently observed in NAFLD patients in comparison with controls, fixed model (p<1 x 10(-10)), OR: 1.97 95% CI: 1.67-2.32 and random model p<0.0002, OR: 3.13, 95% CI: 1.75-5.58.

CONCLUSIONS

Routine measurement of carotid IMT might be implemented in NAFLD patients, as they carry an increase of 13% of carotid IMT.

Fasting in healthy subjects is associated with intrahepatic accumulation of lipids as assessed by 1H-magnetic resonance spectroscopy

The impact of fasting on IHL (intrahepatic lipid) content in human subjects has not been investigated previously, but results indicate that it may change rapidly in response to metabolic cues. The aim of the present study was to measure IHL content after fasting and to correlate this with circulating lipid intermediates. A total of eight healthy non-obese young males were studied before and after 12 or 36 h of fasting. IHL content was assessed by 1H-magnetic resonance spectroscopy, and blood samples were drawn after the fasting period. IHL content increased significantly after the 36 h fasting period [median increase 156% (range, 4–252%); P<0.05]. Furthermore, a significant positive correlation between this increase and 3-hydroxybutyrate concentration was detected (P=0.03). No significant change in IHL content was demonstrated after the 12 h fasting period. The baseline median inter-individual variation in IHLs was 0.51% (range, 0.25–0.72%). The coefficient of variation of IHL measurements was 11.6%; 25–30% of the variation was of analytical origin and the remaining 70–75% was attributed to repositioning. In conclusion, IHL content increases in healthy male subjects during fasting, which demonstrates that nutritional status should be accounted for when assessing IHLs in clinical studies. Moreover, the increase in IHLs was positively correlated with the concentration of 3-hydroxybutyrate.

The blind men ‘see’ the elephant-the many faces of fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a group of diseases with excess fat in liver in the absence of a poorly defined limit of alcohol consumption. Most common variety, a universal public health problem, is associated with insulin resistance caused by a host of genetic and epigenetic defects modulated by life style and environmental factors. In fact the term NAFLD is loose to incorporate so many etiologies except alcoholism and few other etiologies, presenting as fat in liver. However as a sign fatty liver is very important in predicting the risk of diabetes, cardiovascular disease, stroke, cirrhosis and cancer. Abnormal fat accumulation can result from several defects in nuclear receptors associated with lipid sensing, synthesis and oxidation like LXR, FXR, SREBP, ChREBP and PPAR; defects in the lipid influx-efflux channels, insulin signaling, proteins involved in fatty acid catabolism, defects in adipose tissue development and function, inappropriate nutrition and finally defects in neural regulatory mechanisms. The progress of the disease is determined by the basic defects which results in fat accumulation, an individual’s immunological response to the accumulated fat and its derivatives and the oxidant stress response. Congregation of unrelated genetic defects under same diagnosis ‘NAFLD’ can result in inefficient patient management. Further studies are required to understand the molecular basis of fatty liver to enable a personalized management of diseases presenting as fatty liver in the absence of alcohol abuse.