Has natural selection in human populations produced two types of metabolic syndrome (with and without fatty liver)?

Analysis of clinical findings and serum micronutrients in pediatric patients with nonalcoholic fatty liver disease

Aim: Serum micronutrient levels play an important role in liver metabolism. This study examines risk factors and diagnostic methods for patients on follow-up due to nonalcoholic fatty liver disease (NAFLD). NAFLD and the control groups were compared for clinical findings, serum ferritin, B12, and vitamin D levels, and their relationship with NAFLD was examined. Material and Method: Included in the study were 60 NAFLD patients and 66 other children that formed the control group. The two groups were compared in serum lipid profile, aminotransferase, insulin, glucose, and HOMA-IR. Ultrasonography (USG) and Shear wave elastography (SWE) were performed on all patients. Both groups were then analyzed in terms of serum ferritin, B12, and vitamin D levels. Results: NAFLD and control groups were compared in terms of USG and SWE results. 35% (n=21)of the patients in the NAFLD group had grade 1, 55% (n=33) had grade 2 and 10% (n=6) had grade 3 adiposity. HOMA-IR and insulin levels were higher in the NAFLD group (p=0.02; p=0.001). While the serum ferritin level of the patients in the NAFLD group was higher than the control group (p=0.001); the B12 level was lower (p=0.006). In terms of vitamin D, there was no difference (p=0.368). Conclusion: It is essential to identify risk factors in children on follow-up due to NAFLD. USG and liver function tests remain the first option in the diagnosis and screening of NAFLD in children. Serum ferritin, B12, and vitamin D levels of children on follow-up due to NAFLD should be analyzed in consideration of liver fattening.

Epidemiologic, Genetic, Pathogenic, Metabolic, Epigenetic Aspects Involved in NASH-HCC: Current Therapeutic Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is the sixth most frequent cancer in the world, being the third cause of cancer-related deaths. Nonalcoholic steatohepatitis (NASH) is characterized by fatty infiltration, oxidative stress and necroinflammation of the liver, with or without fibrosis, which can progress to advanced liver fibrosis, cirrhosis and HCC. Obesity, metabolic syndrome, insulin resistance, and diabetes exacerbates the course of NASH, which elevate the risk of HCC. The growing prevalence of obesity are related with increasing incidence of NASH, which may play a growing role in HCC epidemiology worldwide. In addition, HCC initiation and progression is driven by reprogramming of metabolism, which indicates growing appreciation of metabolism in the pathogenesis of this disease. Although no specific preventive pharmacological treatments have recommended for NASH, dietary restriction and exercise are recommended. This review focuses on the molecular connections between HCC and NASH, including genetic and risk factors, highlighting the metabolic reprogramming and aberrant epigenetic alterations in the development of HCC in NASH. Current therapeutic aspects of NASH/HCC are also reviewed.

Association of elevated serum aminotransferase levels with chronic kidney disease measures: hispanic community health study/study of latinos

Background

Previous studies have shown an association between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD), but it is unclear whether the association is independent of metabolic syndrome.

Methods

Data from 13,006 participants aged 18 to 74 years in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) without viral hepatitis, excessive alcohol consumption, or high transferrin saturation levels were analyzed. Suspected NAFLD was defined as presence of sex-specific elevations in serum aminotransferase levels (aspartate aminotransferase (AST) > 37 U/L or alanine aminotransferase (ALT) > 40 U/L for men and AST or ALT > 31 U/L for women). Logistic regression was used to examine cross-sectional associations of elevated serum aminotransferase levels with low estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m² based on cystatin C), and with high urinary albumin-to-creatinine ratio (UACR) (> 17 mg/g in men and > 25 mg/ g in women) in separate models adjusting for demographic characteristics and metabolic syndrome.

Results

Mean (SD) age was 41 (0.27) years, and 45 % were male. Elevated serum aminotransferase levels were noted in 18.8 % of the population and were associated with greater odds of high UACR (OR = 1.31; 95 % CI = 1.10, 1.56) after adjusting for demographic characteristics; this association became non-significant after adjustment for metabolic syndrome (OR = 1.11, 95 % CI = 0.92, 1.33). In contrast, elevated serum aminotransferase levels were not associated with low eGFR (odds ratio (OR) = 0.73; 95 % confidence interval (CI) = 0.45, 1.18) after adjusting for covariates.

Conclusions

In this sample of diverse U.S. Hispanic Latino adults, elevated serum aminotransferase levels were not independently associated with measures of CKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02483-y.

Non-alcoholic fatty liver disease: An overview of risk factors, pathophysiological mechanisms, diagnostic procedures, and therapeutic interventions

Non-alcoholic fatty liver disease (NAFLD) is a disorder of excessive fat accumulation in the liver, known as steatosis, without alcohol overconsumption. NAFLD can either manifest as simple steatosis or steatohepatitis, known as non-alcoholic steatohepatitis (NASH), which is accompanied by inflammation and possibly fibrosis. Furthermore, NASH might progress to hepatocellular carcinoma. NAFLD and NASH prevalence is in a continuous state of growth, and by 2018, NAFLD became a devastating metabolic disease with a global pandemic prevalence. The pathophysiology of NAFLD and NASH is not fully elucidated, but is known to involve the complex interplay between different metabolic, environmental, and genetic factors. In addition, unhealthy dietary habits and pre-existing metabolic disturbances together with other risk factors predispose NAFLD development and progression from simple steatosis to steatohepatitis, and eventually to fibrosis. Despite their growing worldwide prevalence, to date, there is no FDA-approved treatment for NAFLD and NASH. Several off-label medications are used to target disease risk factors such as obesity and insulin resistance, and some medications are used for their hepatoprotective effects. Unfortunately, currently used medications are not sufficiently effective, and research is ongoing to investigate the beneficial effects of different drugs and phytochemicals in NASH. In this review article, we outline the different risk factors and pathophysiological mechanisms involved in NAFLD, diagnostic procedures, and currently used management techniques.

Therapeutic Landscape for NAFLD in 2020

Lifestyle modifications focused on healthy eating and regular exercise are the primary recommendations for patients with nonalcoholic steatohepatitis (NASH). However, for multiple societal, psychological, physical, genetic, and epigenetic reasons, the ability of people to adopt and sustain such changes is challenging and typically not successful. To end the epidemic of NASH and prevent its complications, including cirrhosis and hepatocellular carcinoma, pharmacological interventions are now being evaluated in clinical trials. Treatments include drugs targeting energy intake, energy disposal, lipotoxic liver injury, and the resulting inflammation and fibrogenesis that lead to cirrhosis. It is likely that patients develop the phenotype of NASH by multiple mechanisms, and thus the optimal treatments of NASH will likely evolve to personalized therapy once we understand the mechanistic underpinnings of NASH in each patient. Reviewed here is the treatment landscape in this rapidly evolving field with an emphasis on drugs in Phase 2 and Phase 3 trials.

Burden of hepatocellular carcinoma among hispanics in South Texas: a systematic review

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the fastest rising causes of cancer-related mortality in the United States (U.S.). Despite improved HCC screening and surveillance guidelines, significant race/ethnicity-specific disparities in hepatocellular carcinoma remain, disproportionately affecting at risk racial minorities in the U.S. The current review aims to provide an updated analysis on race/ethnicity-specific disparities in HCC epidemiology with a focus on predisposing risk factors.

CONCLUSION

Among different race/ethnicities in the U.S., Hispanics experienced the greatest burden of HCC, particularly those residing in South Texas. It is important to understand that the underlying etiologies for these disparities are complex and multi-factorial. Some of these risk factors for developing chronic liver disease include non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and alcohol use. In addition, population genetics, acculturation of ethnic minorities, and access to healthcare may be further contributing to the observed disparities in HCC. By increasing awareness, improved modalities for screening and surveillance for HCC are important in guiding future research for targeted preventive and therapeutic interventions.

Prevalence of chronic liver disease and cirrhosis by underlying cause in understudied ethnic groups: The multiethnic cohort

Chronic liver disease (CLD) and cirrhosis are major sources of morbidity and mortality in the United States. Little is known about the epidemiology of these two diseases in ethnic minority populations in the United States. We examined the prevalence of CLD and cirrhosis by underlying etiologies among African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites in the Multiethnic Cohort. CLD and cirrhosis cases were identified using Medicare claims between 1999 and 2012 among the fee-for-service participants (n = 106,458). We used International Classification of Diseases Ninth Revision codes, body mass index, history of diabetes mellitus, and alcohol consumption from questionnaires to identify underlying etiologies. A total of 5,783 CLD (3,575 CLD without cirrhosis and 2,208 cirrhosis) cases were identified. The prevalence of CLD ranged from 3.9% in African Americans and Native Hawaiians to 4.1% in whites, 6.7% in Latinos, and 6.9% in Japanese. Nonalcoholic fatty liver disease (NAFLD) was the most common cause of CLD in all ethnic groups combined (52%), followed by alcoholic liver disease (21%). NAFLD was the most common cause of cirrhosis in the entire cohort. By ethnicity, NAFLD was the most common cause of cirrhosis in Japanese Americans, Native Hawaiians, and Latinos, accounting for 32% of cases. Alcoholic liver disease was the most common cause of cirrhosis in whites (38.2%), while hepatitis C virus was the most common cause in African Americans (29.8%).

CONCLUSIONS

We showed racial/ethnic variations in the prevalence of CLD and cirrhosis by underlying etiology; NAFLD was the most common cause of CLD and cirrhosis in the entire cohort, and the high prevalence of NAFLD among Japanese Americans and Native Hawaiians is a novel finding, warranting further studies to elucidate the causes. (Hepatology 2016;64:1969-1977).

Treatment of nonalcoholic steatohepatitis in adults: present and future. Gastroenterol Res Pract. 2015;2015:732870. [PMID: 25866507 DOI: 10.1155/2015/732870]

Nonalcoholic steatohepatitis has become one of the most common liver-related health problems. This condition has been linked to an unhealthy diet and weight gain, but it can also be observed in nonobese people. The standard of care is represented by the lifestyle intervention. However, because this approach has several limitations, such as a lack of compliance, the use of many drugs has been proposed. The first-line pharmacological choices are vitamin E and pioglitazone, both showing a positive effect on transaminases, fat accumulation, and inflammation. Nevertheless, vitamin E has no proven effect on fibrosis and on long-term morbidity and mortality and pioglitazone has a negative impact on weight. Other drugs have been studied such as metformin, ursodeoxycholic acid, statins, pentoxiphylline, and orlistat with only partially positive results. Among the emerging treatments, telmisartan is particularly interesting as it seems to have an impact on insulin resistance, liver steatosis, inflammation, and fibrosis. However, the pathogenesis of steatohepatitis is highly complex and is determined by different parallel hits; indeed, the association of different drugs that act on various levels has been suggested. In conclusion, lifestyle intervention should be optimised and the associations of different drugs should be tested in large studies with long-term outcomes.

Nonalcoholic fatty liver disease: a precursor of the metabolic syndrome

The conventional paradigm of nonalcoholic fatty liver disease representing the "hepatic manifestation of the metabolic syndrome" is outdated. We identified and summarized longitudinal studies that, supporting the association of nonalcoholic fatty liver disease with either type 2 diabetes mellitus or metabolic syndrome, suggest that nonalcoholic fatty liver disease precedes the development of both conditions. Online Medical databases were searched, relevant articles were identified, their references were further assessed and tabulated data were checked. Although several cross-sectional studies linked nonalcoholic fatty liver disease to either diabetes and other components of the metabolic syndrome, we focused on 28 longitudinal studies which provided evidence for nonalcoholic fatty liver disease as a risk factor for the future development of diabetes. Moreover, additional 19 longitudinal reported that nonalcoholic fatty liver disease precedes and is a risk factor for the future development of the metabolic syndrome. Finally, molecular and genetic studies are discussed supporting the view that aetiology of steatosis and lipid intra-hepatocytic compartmentation are a major determinant of whether fatty liver is/is not associated with insulin resistance and metabolic syndrome. Data support the novel paradigm of nonalcoholic fatty liver disease as a strong determinant for the development of the metabolic syndrome, which has potentially relevant clinical implications for diagnosing, preventing and treating metabolic syndrome.

Translational approaches: From fatty liver to non-alcoholic steatohepatitis

Over the past few decades, non-alcoholic fatty liver disease (NAFLD) has become one, if not the most common, cause of chronic liver disease affecting both adults and children. The increasing number of cases at an early age is the most worrying aspect of this pathology, since it provides more time for its evolution. The spectrum of this disease ranges from liver steatosis to steatohepatitis, fibrosis and in some cases, hepatocellular carcinoma. NAFLD may not always be considered a benign disease and hepatologists must be cautious in the presence of fatty liver. This should prompt the use of the available experimental models to understand better the pathogenesis and to develop a rational treatment of a disease that is dangerously increasing. In spite of the growing efforts, the pathogenesis of NAFLD is still poorly understood. In the present article we review the most relevant hypotheses and evidence that account for the progression of NAFLD to non-alcoholic steatohepatitis (NASH) and fibrosis. The available in vitro and in vivo experimental models of NASH are discussed and revised in terms of their validity in translational studies. These studies must be aimed at the discovery of the still unknown triggers or mediators that induce the progression of hepatic inflammation, apoptosis and fibrosis.

Race and the insulin resistance syndrome

Type 2 diabetes remains an important cause of morbidity and mortality. The metabolic syndrome affects 25% of the adult US population based on the Third Report of the Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults from the National Cholesterol Education Program. Knowledge on the impact of obesity on metabolic health parameters has increased greatly over the past decade. This review discusses the limitations of the National Cholesterol Education Program metabolic syndrome definition and the racial disparities in the clinical presentation of the insulin resistance syndrome. We also examine the current literature with particular emphasis on albuminuria, nonalcoholic fatty liver disease, and intramyocellular lipid content. This review explores potential environmental and genetic reasons for differences in the manifestation of insulin resistance across racial/ethnic groups and highlights several promising areas for further study.

Racial differences in nonalcoholic fatty liver disease in the U.S. population

OBJECTIVE

To characterize the prevalence of nonalcoholic fatty liver disease (NAFLD) by race in a nationally representative sample of the U.S. population and to investigate potential explanatory factors for racial disparities.

DESIGN AND METHODS

Cross-sectional study of 4,037 non-Hispanic white, 2,746 non-Hispanic black, and 2,892 Mexican-American adults in the Third National Health and Nutrition Examination Survey. NAFLD was defined using ultrasound and with elevated aminotransferases.

RESULTS

Age-adjusted prevalence of NAFLD was highest in Mexican-Americans (21.2%), followed by non-Hispanic whites (12.5%), and was lowest in non-Hispanic blacks (11.6%). Even after adjustment for demographic, lifestyle, adiposity, and metabolic factors, compared to non-Hispanic whites, Mexican-Americans were more likely to have NAFLD (OR: 1.67, 95% CI: 1.26, 2.22). Non-Hispanic blacks were significantly less likely to have NAFLD with elevated aminotransferases (OR: 0.51, 95% CI: 0.27, 0.97). Racial differences were attenuated among those with normal BMI and among "never drinkers."

CONCLUSION

In this representative sample of the U.S. population, we found significant racial differences in the prevalence of ultrasound-defined NAFLD (with and without elevated liver enzymes). The racial differences were not fully explained by lifestyle, adiposity, and metabolic factors. More works is needed to identify potential contributors.

Liver enzymes, race, gender and diabetes risk: the Atherosclerosis Risk in Communities (ARIC) Study

AIMS

To examine the associations of the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase(AST), and gamma-glutamyl transferase (GGT) with diabetes risk and to determine whether associations differ by race and/or gender. We hypothesized that all liver enzymes would be associated with diabetes risk and that associations would differ by race and gender.

METHODS

Prospective cohort of 7495 white and 1842 black participants without diabetes in the Atherosclerosis Risk in Communities Study. Poisson and Cox models adjusted for demographic, socio-behavioural, and metabolic and health-related factors were used.

RESULTS

During a median of 12 years of follow-up, 2182 incident cases of diabetes occurred. Higher liver enzyme levels were independently associated with diabetes risk: adjusted hazard ratios (95% confidence intervals) were 1.68 (1.49-1.89), 1.16 (1.02-1.31) and 1.95 (1.70-2.24) comparing the highest with the lowest quartiles of ALT, AST, and GGT, respectively. Gamma-Glutamyl transferase was most strongly related to diabetes risk, even at levels considered within the normal range (≤ 60 U/l) in clinical practice. Adjusted incidence rates by quartiles of liver enzymes were similar by gender but higher in black versus white participants. Nonetheless, relative associations of ALT, AST, and GGT with diabetes were similar by race (P for interactions > 0.05).

CONCLUSIONS

Compared with ALT and AST, GGT was more strongly associated with diabetes risk. Our findings suggest that abnormalities in liver enzymes precede the diagnosis of diabetes by many years and that individuals with elevated liver enzymes, even within the normal range as defined in clinical practice, are at high risk for diabetes.

Association between markers of fatty liver disease and impaired glucose regulation in men and women from the general population: the KORA-F4-study

OBJECTIVE

To investigate whether the elevated liver enzymes gamma-glutamyltransferase (GGT), glutamate-pyruvate transaminase (GPT), glutamate-oxalacetate transaminase (GOT) and alkaline phosphatase (AP) and non-alcoholic fatty liver disease (NAFLD) respectively are independently associated with pre-diabetic states, namely impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) or known and newly diagnosed diabetes (NDD), in men and women from the general German population.

METHODS

The study was based on 3009 subjects (1556 females, 1453 males) aged 32 to 81 years who participated in the KORA-F4-Study in 2006/2008 in Augsburg, Southern Germany. All non-diabetic participants underwent an oral glucose tolerance test to assess disturbances in glucose metabolism. NAFLD was estimated by liver enzyme concentrations and the Bedogni Fatty Liver Index (FLI).

RESULTS

229 participants (7.6%) reported known diabetes, 106 had NDD (3.5%), 107 (3.6%) had IFG, 309 (10.3%) had IGT, 69 (2.3%) were affected with both metabolic disorders (IFG/IGT) and 74 (2.5%) could not be classified. GGT and GPT were significantly elevated in persons with pre-diabetes and diabetes (GGT in diabetic persons OR = 1.76, [1.47-2.09], in IFG OR = 1.79 [1.50-2.13], GPT in diabetic persons OR = 1.51, [1.30-1.74], in NDD OR = 1.77 [1.52-2.06]), GOT and AP only inconsistently in some pre-diabetes groups. The effects were sharpened in models using an increase of two or three out of three enzymes as an estimate of fatty liver and especially in models using the FLI. Overall frequency of NAFLD applying the index was 39.8% (women: 27.3% and men: 53.2%). In participants with fatty liver disease, the OR for NDD adjusted for sex and age was 8.48 [5.13-14.00], 6.70 [3.74-12.01] for combined IFG and IGT and 4.78 [3.47-6.59] for known diabetes respectively.

CONCLUSIONS

Elevated GGT and GPT-values as well as estimates of fatty liver disease are significantly associated with pre-diabetes and diabetes and thus very useful first indicators of a disturbed glucose metabolism.

Inflammatory modulation of exercise salience: using hormesis to return to a healthy lifestyle

Most of the human population in the western world has access to unlimited calories and leads an increasingly sedentary lifestyle. The propensity to undertake voluntary exercise or indulge in spontaneous physical exercise, which might be termed "exercise salience", is drawing increased scientific attention. Despite its genetic aspects, this complex behaviour is clearly modulated by the environment and influenced by physiological states. Inflammation is often overlooked as one of these conditions even though it is known to induce a state of reduced mobility. Chronic subclinical inflammation is associated with the metabolic syndrome; a largely lifestyle-induced disease which can lead to decreased exercise salience. The result is a vicious cycle that increases oxidative stress and reduces metabolic flexibility and perpetuates the disease state. In contrast, hormetic stimuli can induce an anti-inflammatory phenotype, thereby enhancing exercise salience, leading to greater biological fitness and improved functional longevity. One general consequence of hormesis is upregulation of mitochondrial function and resistance to oxidative stress. Examples of hormetic factors include calorie restriction, extreme environmental temperatures, physical activity and polyphenols. The hormetic modulation of inflammation, and thus, exercise salience, may help to explain the highly heterogeneous expression of voluntary exercise behaviour and therefore body composition phenotypes of humans living in similar obesogenic environments.

Increased arterial stiffness in nonalcoholic fatty liver disease: the Cardio-GOOSE study. J Hypertens. 2010;28:1699-1707. [PMID: 20467324 DOI: 10.1097/hjh.0b013e32833a7de6]

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a very frequent disease in Western countries. NAFLD shares with metabolic syndrome the same etiologic factors, such as obesity, diabetes, and dyslipidemia, which are also major cardiovascular risk factors. Cardio-GOOSE (Cardio-Gambettola ObservatOry liver Steatosis Estimation) is a population-based cohort study finalized to evaluate the relationship between NAFLD, subclinical vascular damage, and arterial stiffness.

METHODS

The study population consisted of 220 participants (123 women), aged between 30 and 70 years, who participated in the GOOSE study. Arterial stiffness was determined by measuring the carotid-femoral pulse wave velocity (PWV) by means of the PulsePen device. Preclinical atherosclerosis was detected by carotid intima-media thickness (IMT) measurement.

RESULTS

NAFLD was associated with metabolic syndrome in 48% of cases. IMT values were strongly related to metabolic syndrome factors. No significant differences in IMT were found between controls and patients with isolated NAFLD (0.77 +/- 0.15 mm versus 0.76 +/- 0.14 mm). Conversely, in patients with NAFLD associated with metabolic syndrome, IMT values were significantly higher than in patients with NAFLD alone (0.85 +/- 0.16 mm, P < 0.005). PWV values were significantly lower in controls compared to patients with isolated NAFLD (7.40 +/- 1.47 versus 7.98 +/- 1.51 m/s, P < 0.05) as well as patients with both NAFLD and metabolic syndrome (8.29 +/- 2.2 m/s, P < 0.001). The prevalence in NAFLD was increased in patients with the highest PWV values, and persisted after adjustment for factors determining metabolic syndrome (P < 0.05).

CONCLUSIONS

This study has shown a possible independent role of NAFLD in determining arterial stiffness.

Prevalence of diabetes mellitus and impaired glucose tolerance in patients with decompensated cirrhosis being evaluated for liver transplantation: the utility of oral glucose tolerance test

CONTEXT: Cirrhosis, diabetes mellitus, impaired glucose tolerance, insulin resistance, and protein calorie malnutrition are important issues in cirrhotic patients because they can increase the progression of liver disease and worsen its prognosis. OBJECTIVE:To determine the prevalence of diabetes mellitus, impaired glucose tolerance and insulin resistance in cirrhotic patients being evaluated for liver transplantation and their impacts on a 3-month follow-up, and to compare fasting glycemia and oral glucose tolerance test. METHODS: A cross-sectional study was performed in consecutively included adult patients. Diabetes mellitus was established through fasting glycemia and oral glucose tolerance test in diagnosing diabetes mellitus in this population. HOMA-IR and HOMA-β indexes were calculated, and nutritional assessment was performed by subjective global assessment, anthropometry and handgrip strength through dynamometry. RESULTS: Diabetes mellitus was found in 40 patients (64.5%), 9 (22.5%) of them by fasting glycemia and 31 (77.5%) of them by oral glucose tolerance test. Insulin resistance was found in 40 (69%) of the patients. There was no relationship between diabetes mellitus and the etiology of cirrhosis. Protein calorie malnutrition was diagnosed in a range from 3.22% to 45.2% by anthropometry, 58.1% by subjective global assessment and 88.7% by handgrip strength. Diabetes mellitus identified by oral glucose tolerance test was related significantly to a higher prevalence of infectious complications and deaths in a 3-month period (P = 0.017). CONCLUSION: The prevalence of diabetes mellitus, impaired glucose tolerance, insulin resistance and protein calorie malnutrition is high in cirrhotic patients on the waiting list for liver transplantation. There were more infectious complications and/or deaths in a 3-month follow-up period in patients with diabetes mellitus diagnosed by oral glucose tolerance test. Oral glucose tolerance test seems to be indicated as a routine practice in this population.

Epidemiology and natural history of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in many parts of the world. This article describes the epidemiology and natural history of this disorder. It also describes current diagnostic and treatment methods and describes future implications NAFLD may have.

Differential pattern of lipid droplet-associated proteins and de novo perilipin expression in hepatocyte steatogenesis

Fatty change (steatosis) is the most frequent liver pathology in western countries and is caused by a broad range of disorders such as alcohol abuse and metabolic syndrome. The surface layer of lipid droplets (LDs) contains members of a protein family that share homologous sequences and domains, the so-called PAT proteins, named after their constituents, perilipin, adipophilin, and TIP47. We characterized the LD-associated proteins in normal and diseased liver connected with LD accumulation. Adipophilin and TIP47 are expressed in LDs of vitamin A-storing hepatic stellate cells and additionally in LDs of steatotic hepatocytes. Perilipin, which was thought to be characteristic for LDs of adipocytes and steroidogenic cells, becomes de novo expressed in hepatocytes of human steatotic liver. Perilipin splice variant A was found in human steatotic hepatocytes by biochemical, molecular biological, and immunohistochemical methods. Its association with LDs is different from TIP47 and adipophilin, and depends on size and localization of the LDs, suggesting that the different PAT proteins play specific roles during maturation of LDs.