Fatty Liver Disease in Morbid Obesity

Patient perception of obesity versus physician documentation of obesity: A quality improvement study

As the prevalence of obesity increases, the prevalence of associated comorbid diseases, obesity-related mortality rates and healthcare costs rise concordantly. Two main factors that hinder efforts to treat obesity include a lack of recognition by patients and documentation by physicians. This study evaluates the relationship between patient perception of obese weight and physician documentation of obesity. This quality improvement observational study surveyed patients of an academic internal medicine clinic on their perception of obesity. Responses were compared to longitudinal physician documentation of obesity and body mass index (BMI). A total of 59.9% of patients with obesity perceived their weight as obese. While 33.7% of patients with a BMI of 30 to 34.9 kg/m² perceived themselves as having obesity, 71.4% of patients with a BMI of 45 to 49.9 kg/m² perceived themselves as having obesity. A total of 42.4% of patients with obesity had physician documentation of obesity in the last year. While 25% of patients with a BMI of 30 to 34.9 kg/m² had physician documentation of obesity, 85.7% of patients with a BMI of 45 to 49.9 kg/m² had physician documentation of obesity. For patients with a BMI ≥50 kg/m² , 52.9% perceived their weight to be obese and 76.5% had physician documentation of obesity in the last year. Both patient perception and physician documentation of obesity were significantly less than the prevalence of obesity. Patient perception of obesity and provider documentation of obesity increased as BMI increased until a BMI ≥50 kg/m² . Both patients and providers must improve recognition of this disease.

Combined effects of Diospyros lotus leaf and grape stalk extract in high-fat-diet-induced obesity in mice

The aim of this study was to investigate the combined effects of Diospyros lotus leaves extracts (DLE) and Muscat Bailey A grape stalk extracts (MGSE) in obesity induced by high-fat diet (HFD) in mice. The mice were fed with HFD and orally administered daily with DLE, MGSE, a mixture of DLE and MGSE, and Garcinia cambogia extract over a period of 16 weeks. The results revealed that daily administration of DLE and MGSE mixtures markedly prevented HFD-induced weight gain, plasma lipid profile, hepatic steatosis, hepatic fibrosis, diabetic symptoms, and the risk of developing cardiovascular diseases. Also, DLE and MGSE mixtures administration greatly prevented oxidative stress and liver toxicity. The combined effects of DLE and MGSE mixtures were higher than effects of the single extracts and of G. cambogia, a plant known for its anti-obesity effects. In summary, these findings demonstrated that DLE and MGSE mixtures, exhibit anti-obesity activity in HFD-fed mice.

Muscat Bailey A grape stalk extract ameliorates high-fat diet‑induced obesity by downregulating PPARγ and C/EPBα in mice

Muscat Bailey A grape stalk is an organic waste produced in marked amounts during the vinification of grapes. Previous studies have indicated that grape stalk is rich in bioactive phenolic compounds, and exhibits antioxidant and UV‑protective activities. However, its effects on obesity and obesity‑associated disorders have not yet been investigated. The effects of grape stalk extract on improving metabolic features were examined using a high‑fat diet (HFD)‑induced obesity mouse model. Oral administration of 200 mg/kg/day grape stalk extract over 16 weeks markedly prevented HFD‑induced obesity, hepatic steatosis, diabetic symptoms and the risk of developing cardiovascular disease. Furthermore, grape stalk extract prevented oxidative stress and inflammation caused by HFD in mice. The beneficial effect may be associated with CCAAT/enhancer‑binding protein α and peroxisome‑proliferator‑activated receptor γ down-regulation in liver tissue. Collectively, the results of the present study indicated that grape stalk extract may be a potent functional food ingredient for preventing obesity, hepatic steatosis and type 2 diabetes.

Low-dose attenuation correction in diagnosis of non-alcoholic fatty liver disease

BACKGROUND

Non-enhanced computed tomography (CT) is a valuable modality in the diagnosis of non-alcoholic fatty liver disease (NAFLD). However, it is not clear if low-dose CT attenuation correction (CTAC) scans have the same accuracy to diagnose NAFLD. Our aim is to evaluate the diagnostic accuracy of low-dose CTAC in the diagnosis of NAFLD using non-enhanced CT as a gold standard.

METHODS

A total of 864 patients who underwent a clinically indicated hybrid nuclear imaging scanning between May 2011 and April 2014 were included in the study. Diagnosis of fatty liver was established if an absolute liver attenuation was <40 Hounsfield units and/or a liver-to-spleen ratio was <1.1. The diagnostic accuracy parameters were calculated to detect NAFLD by low-dose CTAC using unenhanced CT as a gold standard.

RESULTS

The prevalence of fatty liver by diagnostic CT and low-dose attenuation correction were 9.9 and 12.9% (using liver attenuation <40HU and liver-to-spleen ratio <1.1), respectively, with 32.9 and 34.9% (using absolute liver attenuation or ratio-to-spleen criteria), correspondingly. Low-dose CTAC had sensitivity (81.3%), specificity (94.0%), positive predictive value (60.2%), and negative predictive value (97.8%) using both diagnostic criteria. Using either of the diagnostic criteria resulted in sensitivity (76.8%), specificity (83.5%), PPV (66.3%), and NPV (89.5%).

CONCLUSION

Low-dose CT could be used as a tool to rule out the presence of fatty liver if neither liver attenuation of less than 40 HU nor liver-to-spleen below 1.1 is present.

Mesozeaxanthin protects the liver and reduces cardio-metabolic risk factors in an insulin resistant rodent model

Background: Mesozeaxanthin (MZ) is a macular carotenoid which has been reported to have a number of pharmacological properties, including the antioxidant, and anticarcinogenic property, and has been stated to decrease the hepatocyte lipid content.

Objective: In this study, we investigated the effect of MZ on cardio-metabolic health risk (CMHR) and its probable mechanisms of action in rats fed a high-fat diet (HFD).

Design: Rats were randomly divided into four groups consisting of (i) Control, (ii) MZ, (iii) HFD, and (iv) HFD+MZ.

Results: MZ treatment increased the antioxidant enzyme activities and helped improve the liver function. The treatment alleviated CMHR and decreased the level of nuclear factor kappa B (NF-κB p65) and tumor necrosis factor-alpha (TNF-α). The levels of hepatic peroxisome proliferator-activated receptor gamma (PPAR-γ), phosphorylated insulin receptor substrate 1 (p-IRS-1), β,β-carotene 9’,10’-oxygenase 2 (BCO2) and nuclear factor erythroid 2-related factor 2 (Nrf2), which decrease in HFD rats, were found to be significantly higher in MZ supplemented animals.

Conclusion: MZ has antioxidant and anti-inflammatory properties and can is reported in this study toprotect against fatty liver and cardio-metabolic syndrome, possibly through regulation of PPAR-γ, IRS-1, Nrf2 and NF-κB proteins, in an insulin-resistant rodent model.

Nonalcoholic Fatty Liver Disease: Lipids and Insulin Resistance

Obesity and its major comorbidities, including type 2 diabetes mellitus, nonalcoholic fatty liver disease (NAFLD), obesity cardiomyopathy, and certain cancers, have caused life expectancy in the United States to decline in recent years. Obesity is the increased accumulation of triglycerides (TG), which are synthesized from glycerol and long-chain fatty acids (LCFA) throughout the body. LCFA enter adipocytes, hepatocytes, and cardiomyocytes via specific, facilitated transport processes. Metabolism of increased cellular TG content in obesity may lead to comorbidities such as NAFLD and cardiomyopathy. Better understanding of LCFA transport processes may lead to successful treatment of obesity and NAFLD.

Lipidomic Profiling of Liver Tissue from Obesity-Prone and Obesity-Resistant Mice Fed a High Fat Diet

Obesity is a multifactorial health problem resulting from genetic, environmental, and behavioral factors. A particularly interesting aspect of obesity is the differences observed in response to the same high-fat diet (HFD). In this study, we performed lipidomic profiling on livers from HFD-fed C57BL/6J mice using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Mice were divided into three groups: normal diet (ND), HFD-obesity prone (HFD-OP), and HFD-obesity resistant (HFD-OR). Principal components analyses showed a difference between the HFD-OP and HFD-OR groups. Individuals in the HFD-OR group were closer to those in the ND group compared with those in the HFD-OP group. In particular, phosphocholine (PC) and triglyceride (TG) levels differed significantly depending on the length of the acyl chain and degree of unsaturation, respectively. PC species were either positively or negatively correlated with concentrations of glucose, insulin, leptin, and hepatic cholesterol according to the length of the acyl chain. Decreased expression of the scavenger receptor B1 and ATP-binding cassette A1 in HFD-OP mice indicated that the acyl chain length of PC species may be related to high-density lipoprotein cholesterol metabolism. This study demonstrates that lipidomic profiling is an effective approach to analyzing global lipid alterations as they pertain to obesity.

Intrahepatic triglyceride measurement and estimation of viability in rat fatty livers by near-infrared spectroscopy

AIM

This study investigated the features of fatty livers using near-infrared (NIR) spectroscopy and validated the usefulness of NIR spectroscopy for the measurement of intrahepatic triglyceride (TG) contents and evaluation of viability in fatty livers.

METHODS

In vitro, we examined specific spectra for each purified TG fraction by NIR. In vivo, the differences between the spectra obtained from normal and fatty livers before warm ischemia and the differences between the spectra obtained from each rat liver before and after warm ischemia were subjected to multicomponent analysis.

RESULTS

In vitro experiments revealed a specific peak at 925 nm in major TG fractions, and NIR spectroscopy precisely detected changes in TG volume. In vivo experiments revealed that NIR spectroscopy detected TG content changes in rat fatty livers induced by a choline-deficient diet following the addition of purified TG spectrum for NIR spectroscopic analysis in least square curve fitting. The TG level in the fatty livers measured by NIR spectroscopy significantly correlated with the morphometric measurement of lipid content in the livers. NIR spectroscopy also revealed decreased levels of total hemoglobin (Hb) and oxidized Hb and maintenance of homeostasis in cytochrome redox states in fatty livers under normal condition. However, NIR spectroscopy showed irreversible deterioration of hepatic microcirculation, Hb oxygenation and homeostasis of the cytochrome redox states in fatty livers after 60-min warm ischemia reperfusion.

CONCLUSION

These studies demonstrated that NIR spectroscopy can quantitatively measure the intrahepatic TG content in addition to simultaneously evaluating microcirculation and Hb oxygenation.

Computed tomography scans in the evaluation of fatty liver disease in a population based study: the multi-ethnic study of atherosclerosis

RATIONALE AND OBJECTIVES

Fatty liver disease is a common clinical entity in hepatology practice. This study evaluates the prevalence and reproducibility of computed tomography (CT) measures for diagnosis of fatty liver and compares commonly used CT criteria for the diagnosis of liver fat.

MATERIALS AND METHODS

The study includes 6814 asymptomatic participants from a population-based sample. The ratio of liver-to-spleen (L/S) Hounsfield units (HU) <1.0 and liver attenuation <40 HU were used for diagnosing and assessing the severity of liver fat content. Participants with heavy alcohol intake (>7 drinks/week for women and >14 drinks/week for men) were excluded. Final analysis was performed on participants where images of both liver and spleen were available on the scans.

RESULTS

The overall prevalence of fatty liver (4175 subjects included in final analysis) was 17.2% (using L/S ratio <1.0), with 6.3% (with <40 HU cutoff) of the population having moderate to severe steatosis (>30% liver fat content). The prevalence was high in participants with dyslipidemia (70.4%), hypertension (56.8%), and obesity (53%). Diabetic patients had 24.1% prevalence of fatty liver. The prevalence provided by L/S ratio <1.0 (17.2%) was comparable to prevalence provided by <51 HU (17.3%), whereas prevalence obtained by <40 HU (6.3%) cutoff corresponded to L/S ratio of <0.8 (6.5%). The measurements of liver and spleen HU attenuations were highly reproducible (0.96, 0.99 and 0.99, 0.99 for intra- and inter-reader variability, respectively) in a sample of 100 scans.

CONCLUSION

Fatty liver can be reliably diagnosed using nonenhanced CT scans.

Provision of nutritional support to those experiencing complications following bariatric surgery

This review details the practicalities of providing nutrition support to obese patients who experience complications following bariatric surgery and highlights some of the nutritional challenges encountered by this group of patients. Bariatric surgery to treat morbid obesity has significantly increased internationally over the past decade with hospital admissions rising annually. The gastric bypass is currently the most commonly performed procedure. The complication rate can be up to 16%, with a considerable proportion having nutritional implications. The treatment can involve avoidance of oral diet and nutrition support, i.e. enteral or parenteral nutrition. Opposition to nutrition support can be encountered. It is useful to clarify the aims of nutrition support, these being: the avoidance of overfeeding and its consequences, preservation of lean body mass and promotion of healing. Evidence suggests that hypoenergic nutrition is not harmful and may actually be beneficial. There is a lack of consensus regarding the optimum method to predict the nutritional requirements in the obese acutely unwell patient. The literature suggests that the predicted equations are fairly accurate compared to measured energy expenditure in free living obese patients before and after bariatric surgery. However, these findings cannot be directly applied to those obese patients experiencing complications of bariatric surgery, who will be acutely unwell exhibiting inflammatory response. It is therefore necessary to refer to the literature on energy expenditure in hospitalized obese patients, to help guide practice. More research examining the energy and protein requirements of obese patients needing nutrition support following bariatric surgery is urgently required.

Effect of preoperative weight loss on laparoscopic gastric bypass outcomes

BACKGROUND

Requiring patients to lose weight before weight reduction surgery is controversial. The goal of this study was to determine whether preoperative weight loss affects laparoscopic Roux-en-Y gastric bypass surgery outcomes.

METHODS

The medical records of all laparoscopic Roux-en-Y gastric bypass patients from September 1, 2001 to March 31, 2005 were retrospectively reviewed in our prospective database. Depending on their habitus, patients were selectively required to lose >4.54 kg (10 lb) preoperatively (WL group). Their outcomes were compared with those of the patients not required to lose weight preoperatively (no-WL group). Statistical analysis was performed with the chi-square test and Student's t test for demographic data. Student's t test was used to assess the outcome data. P <.05 was considered significant.

RESULTS

Of the 353 patients, 74 (21%) were in the WL group. The operative times in the WL group averaged 10 minutes longer than in the no-WL group (P = .022). The mean length of stay was not significantly different between the 2 groups. Of the 353 patients, 262 (74%) completed 1 year of follow-up. The mean net postoperative weight loss was not significantly different between the 2 groups. The no-WL patients had a greater percentage of excess postoperative weight loss than the WL group (74% versus 66%; P = .01). Net complications occurred less frequently in the WL group (P = .035).

CONCLUSION

Preoperative weight loss did not decrease the operative times or the length of stay. Preoperative weight loss increased neither the mean net postoperative weight loss nor the percentage of excess postoperative weight loss at 1-year follow-up. However, the WL group had fewer net complications.

Physical activity in the treatment of obesity: beyond body weight reduction

The prevalence of obesity is high and continues to increase. Obesity is a leading risk factor for premature mortality and numerous chronic health conditions. The role of physical activity as a treatment and (or) preventive strategy for combating obesity has been the subject of substantial research. Most of this research has focused solely on reductions in total body weight and (or) fat mass as the indicator of treatment success. Because the deposition of fat in the abdomen and nonadipose tissues of the liver and muscle plays a major role in the development of obesity-related health risk, these depots have emerged as alternative targets for obesity treatment. Absent from previous reviews is a detailed consideration of the influence of physical activity on these treatment outcomes. The purpose of this review is to evaluate the independent role of physical activity in the treatment of obesity in a broader context; that is, through its effects on abdominal obesity and liver and muscle fat, in addition to its established effects on body weight and (or) total fat mass. Consideration is also given to the utility of physical activity with minimal or no weight loss in the treatment of obesity.

Laparoscopic bariatric surgery: what else are we uncovering? Liver pathology and preoperative indicators of advanced liver disease in morbidly obese patients

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the US, and obesity is the most common cause of NAFLD. Obesity and NAFLD are associated with hyperlipidemia, type 2 diabetes, and hypertension, all components of the metabolic syndrome. The purpose of this study was to examine the incidence of NAFLD among morbidly obese patients undergoing bariatric surgery and to determine if advanced liver disease can be predicted by demographics, comorbidities, and/or preoperative biochemical profiles. 135 nonconsecutive patients (109 female, average age 46) with mean body mass index (BMI) 50 (SD 7.6) who underwent liver biopsies during bariatric surgery were studied. Patient data including age, BMI, comorbidities, and preoperative liver function tests were analyzed against liver biopsy pathology. 86% of patients had abnormal liver biopsy results. 60% of patients had steatosis, and 27% had advanced liver disease (7% steatohepatitis, 16% fibrosis, and 4% cirrhosis). Patients were grouped according to liver biopsy pathology. Group A included patients with normal results and steatosis only. Group B included those patients with advanced liver disease:steatohepatitis, fibrosis, and cirrhosis. Of 37 patients in group B, 27% had abnormal preoperative liver function tests (LFTs) compared to 10% of patients in group A (p = 0.022). Patients in group B were more likely to have preoperative hyperlipidemia (p = 0.020) and were also found to have a significantly higher BMI (p = 0.042). Diabetes mellitus, male gender, and age were not predictive of advanced liver disease on liver biopsy, with p = 0.056, p = 0.074, p = 0.26, respectively. Liver disease is common in the morbidly obese. More than one quarter of morbidly obese patients undergoing bariatric surgery have advanced liver disease. Patients with increased preoperative LFTs, hyperlipidemia, and increased BMI are more likely to have non-alcoholic steatohepatitis, fibrosis, or cirrhosis on liver biopsy during weight loss surgery. Diabetes, male gender, and age did not predict advanced liver disease.

Hepatic complications of obesity

Obesity increases the risk and severity of liver disease. The most common form of liver disease that occurs in obesity is NAFLD. A better understanding of the basic disease mechanisms and natural histories ofNAFLD is needed to guide management and treatment of obese patients and others with this disorder. Large, prospective, randomized, controlled treatment trials also are needed. Ideally, such studies will focus on well-defined patient subsets and monitor the impact of therapy on clinically relevant endpoints, such as liver-related morbidity and mortality.

Non-alcoholic fatty liver disease: a brief review

The term 'non-alcoholic fatty liver disease' (NAFLD) includes cases with steatosis alone and those with non-alcoholic steatohepatitis (NASH). Usually there are no signs or symptoms, sometimes fatigue or pain, and apart from hepatomegaly the condition is revealed by abnormal liver biochemistry or by abdominal ultrasound. Most cases are associated with overweight or diabetes. Liver enzymes are usually elevated, especially GGT, ASAT and ALAT. Other conditions, including alcohol abuse and autoimmune hepatitis, have to be excluded. The diagnosis of steatosis can be made with ultrasound or CT scan. A liver biopsy is often needed to exclude other disease and to assess inflammation and fibrosis. Cirrhosis can develop. NAFLD is usually caused by two 'hits': the 'first hit' is peripheral insulin resistance, causing steatosis. The 'second hit' is caused by reactive oxygen species, inducing vicious cycles leading to inflammation. Weight loss, metformin or thiazolidinediones can improve NAFLD by increasing insulin sensitivity. Radical scavengers such as vitamin E, betaine and perhaps also urodeoxycholic acid may improve the hepatitis component. Further studies on treatment are needed.

Increased NAD(P)H fluorescence with decreased blood flow in the steatotic liver of the obese Zucker rat

The steatotic liver is characterized by deranged intrahepatic microvasculature that is believed to predispose it to ischemia-reperfusion injury. The aim of this study was to investigate the distorted hepatic hemodynamics and its impact on the redox status of the steatotic liver. Hepatic hemodynamic parameters, hepatic microcirculatory perfusion (HMP), and in vivo reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] autofluorescence, which reflects the mitochondrial redox status and tissue oxygen levels, were measured in obese (n = 7) and lean Zucker rats (n = 7). Portal venous and total hepatic blood flow per unit of liver weight were found to exhibit a 37.9% and 35.9% reduction, respectively, in the steatotic liver compared to the nonsteatotic liver of the lean group (P < 0.0001) as was HMP (obese, 96.1 +/- 18.1 PU; lean, 143.8 +/- 12.0 PU, P < 0.05) that showed a 33.2% decrease in the former. Hepatic arterial resistance, however, was 38.7% lower in the obese rat (83.1 +/- 9.1 mmHg. ml(-1). min) than in the lean rat (135.5 +/- 15.8 mmHg. ml(-1). min) (P < 0.05). NAD(P)H fluorescence intensity was significantly elevated in the steatotic liver (0.16 +/- 0.001 aU) compared with the lean one (0.14 +/- 0.007 aU) (P = 0.014). Our results suggest that, in response to a reduced portal venous blood flow, there is a significant decrease in hepatic arterial resistance that, nevertheless, cannot completely compensate for the drop in overall hepatic perfusion and oxygenation of the microvascular bed in the steatotic liver of the obese Zucker rat.

Risk of cancer in patients hospitalized with fatty liver: a Danish cohort study

GOALS

To examine the risk of cancer in patients with fatty liver.

BACKGROUND

The relation between liver disease, including fatty liver, and cancer risk is poorly understood.

STUDY

Using the population-based National Registry of Patients, we examined the incidence of cancer in 7,326 patients discharged with a diagnosis of fatty liver from a Danish hospital during 1977-1993. Patients with a prior diagnosis of liver cirrhosis were excluded. We identified cancers through the Danish Cancer Registry. The expected number of cancers was estimated from national age-, sex-, and site-specific incidence rates.

RESULTS

Overall, 523 cancers were diagnosed during 47,594 person-years of follow-up, yielding a 1.7-fold increased risk (95% confidence interval, 1.6-1.9) compared with the Danish general population. The risk of primary liver cancer was markedly elevated in patients with alcoholic as well as nonalcoholic fatty liver with a standardized incidence ratio of 9.5 (95% confidence interval, 5.7-14.8) and 4.4 (95% confidence interval, 1.2-11.4), respectively. Patients with alcoholic fatty liver also had substantially increased risks of several types of cancer associated with alcohol and tobacco use (cancers of the lung, pharynx, larynx, esophagus, and stomach) and a moderately increased risk for cancers of the colon and breast. Among patients with nonalcoholic fatty liver, an increased risk of some alcohol- and tobacco-related cancers was seen, and there was also an increased risk of colon and pancreas cancer.

CONCLUSIONS

Patients discharged with a diagnosis of fatty liver have an increased risk of cancer, in particular liver cancer, most prominently among patients with alcoholic fatty liver.

The metabolic and microcirculatory impact of orthotopic liver transplantation on the obese Zucker rat

BACKGROUND

The purpose of this study was to investigate the metabolic alterations in the recipient and microcirculatory changes to the graft in the first 3 months after orthotopic liver transplantation (OLT) of nonsteatotic liver grafts from lean rats into obese Zucker rats.

METHODS

Body weight and plasma lipids were measured for 3 months post-OLT. Graft perfusion (hepatic microcirculatory perfusion [HMP]) and vascular structure were measured in vivo at 3 months. Liver biopsy specimens were obtained throughout for morphologic analysis. Sham-operation obese and lean Zucker rats acted as controls.

RESULTS

Plasma cholesterol levels were elevated from 2 months after OLT, whereas plasma triglyceride levels were reduced (P<0.05). Plasma high-density lipoprotein cholesterol concentrations increased from the first month after OLT (P<0.05). HMP in OLT animals (137+/-3 perfusion units [PU]) (P<0.05) was intermediate between lean (221+/-11 PU) and obese controls (113+/-5 PU). Hepatic cord width in the OLT group was similar to that in lean controls. Mean liver-to-body weight ratios in OLT animals (4.12%+/-0.39%) were significantly higher than in lean controls (3.25%+/-0.1%). The number of viable hepatocytes per high-power field in the OLT animals was lower than in the lean animals but higher than in obese controls (P<0.05). The transplanted livers showed moderate to marked microvesicular fatty change (MIFC) and glycogen deposition at 3 months after OLT.

CONCLUSIONS

Transplantation of a nonsteatotic liver into an obese Zucker rat initially has a positive effect on lipid metabolism. However, 3 months after OLT, the donor liver became steatotic with MIFC changes and reduced perfusion. The authors' results emphasize the importance of the recipient's metabolic status in the maintenance of liver graft function after OLT.

Obesity and liver disease

Non-alcoholic steatohepatitis (NASH) is a disease of emerging identity and importance. It is frequently associated with obesity, especially visceral fat, and is intimately related to fatty liver and markers of the insulin resistance syndrome. Both the prevalence and the severity of liver steatosis are related to body mass index, waist circumference, hyperinsulinaemia, hypertriglyceridaemia and impaired glucose tolerance or type 2 diabetes. The identification of obese patients who may progress from steatosis to NASH and from NASH to fibrosis/cirrhosis is an important clinical challenge. Substantial weight loss is accompanied by a marked attenuation of insulin resistance and related metabolic syndrome and, concomitantly, by a remarkable regression of liver steatosis in most patients, although increased inflammation may be detected in some subjects. Thus, NASH may be considered as another disease of affluence, as is the insulin resistance syndrome, and perhaps being part of it, especially in obese patients.

The extent of the problem of obesity

The prevalence of obesity is increasing worldwide. In the United States, in 1999, 27% of adults had a body mass index >30 kg/m(2), almost double the prevalence of 20 years earlier. The estimated mortality from obesity-related diseases in the United States is approximately 300,000 annually and growing. In the future, mortality related to obesity is expected to exceed that of smoking. Numerous diseases are caused or made worse by obesity. These include type 2 diabetes; hypertension; dyslipidemia; ischemic heart disease; stroke; obstructive sleep apnea; asthma; nonalcoholic steatohepatitis; gastroesophageal reflux disease; degenerative joint disease of the back, hips, knees, and feet; infertility and polycystic ovary syndrome; various malignancies; and depression. Type 2 diabetes is perhaps the most visible obesity-related problem. Present in at least 14 million Americans, it leads to serious complications and premature death. It is largely caused by obesity, and is generally cured by weight loss. The quality of life of the obese is markedly reduced, and the costs to health care systems are great. Preventive programs have yet to affect the rising prevalence. An effective solution is needed.

The liver in obesity and type 2 diabetes mellitus

Obesity and type 2 diabetes are associated strongly with NAFLD. It is not clear if one of these conditions causes the others, or if all are consequences of another process. Although NAFLD is known to occur in overly lean individuals, which indicates that excessive adiposity is not required for the development of NAFLD, the severities of insulin resistance and NAFLD tend to parallel each other, and the greatest prevalence of type 2 diabetes occurs in patients with NAFLD and cirrhosis. This observation suggests that insulin resistance and NAFLD may be related pathogenically. Experiments in mice demonstrate that insulin resistance and NAFLD result from a chronic inflammatory state that is characterized by increased levels of TNF alpha. The mechanisms that drive this chronic inflammation are unknown but might involve the oxidative stress that develops during fatty acid metabolism or when products from intestinal bacteria escape into the mesenteric blood to trigger a sustained hepatic inflammatory cytokine response in genetically susceptible individuals, promoting a positive feedback loop that reinforces insulin resistance and inflammation. This hypothesis is supported by some animal and human studies; however, more research is needed to evaluate this theory. Additional studies also are required to determine the benefits of treatments that interrupt this pathogenic cascade at various points. Preliminary work in animal and human studies suggests that diverse strategies that inhibit production of TNF alpha and improve insulin resistance also ameliorate NAFLD.

The utility of radiological imaging in nonalcoholic fatty liver disease

BACKGROUND & AIMS

This prospective study evaluates the role of radiological modalities in establishing the diagnosis of nonalcoholic steatohepatitis (NASH).

METHODS

Consecutive patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) were enrolled (2000-2001). Patients with other liver diseases and significant alcohol consumption (>20 g/day) were excluded. Clinicodemographic data were gathered at the time of liver biopsy. Each biopsy specimen was assessed by a hepatopathologist. Each patient underwent a limited abdominal ultrasonography (US), computerized tomography (CT), and magnetic resonance imaging (MRI). Films were interpreted by a radiologist who used a predetermined radiological protocol. Each radiological study was reread by the same radiologist and a second radiologist.

RESULTS

Patients with NASH had greater aspartate aminotransferase levels (P = 0.03), greater ferritin levels (P = 0.05), more hepatocyte ballooning (P < 0.0001), and more fibrosis (P = 0.002). None of the radiological features distinguished between NASH and other types of NAFLD. No radiological modality detected the presence of hepatocyte ballooning, Mallory's hyaline, or fibrosis, which are important features in the diagnosis of NASH. The presence of >33% fat on liver biopsy was optimal for detecting steatosis on radiological imaging.

CONCLUSIONS

Differences between NASH and nonprogressive NAFLD were not apparent with any radiological modality. Of the pathologic features important for establishing the diagnosis of NASH, only the severity of steatosis was reflected in these radiological modalities. Good intraobserver agreement was evident for each modality (US, CT, and MRI) that was superior to interobserver agreement.

Activities of overt and latent diacylglycerol acyltransferases (DGATs I and II) in liver microsomes of ob/ob mice

The effect of the ob/ob mutation on microsomal overt and latent acyl CoA:diacylglycerol acyl transferase activities (DGATs I and II) in liver microsomes of mice was investigated. Overt and latent hepatic DGAT activities for 16-week-old lean Ob/? mice were 0.42+/-0.14 and 1.57+/-0.04 micromol/mg/min, respectively. For ob/ob mice DGAT I and II activities were 1.17+/-0.28 and 3.09+/-0.78 micromol/mg/min, respectively. The hepatic triacylglycerol (TAG) concentration of 16-week-old mice was increased three-fold in ob/ob mice relative to those in lean controls. The data suggest that the increased rate of hepatic TAG secretion and intracellular accumulation in ob/ob mice is accompanied by parallel increases in the activities of both DGATs.

Non-alcoholic steatohepatitis: clinical significance and pathogenesis

Non-alcoholic steatohepatitis (NASH) is a form of liver disease resembling alcoholic liver disease in a patient who does not consume significant amounts of alcohol. Since its first description in 1980 it has been recognized with increasing frequency. The natural course is relatively benign, but liver cirrhosis. together with all its sequelae, may develop; sometimes liver transplantation is indicated. NASH should probably be regarded as a two-stage acquired metabolic disorder consisting of the development of the insulin resistance syndrome in a patient with pre-existing metabolic abnormalities. The insulin resistance syndrome may well be the most important metabolic abnormality giving rise to hepatic steatosis. The preexisting metabolic abnormalities can be diverse, and may well be multifactorial and/or polymorphogenetic. A steatotic liver may be more susceptible to the deleterious effects of the pre-existing metabolic abnormalities. Pre-existing metabolic abnormalities of particular interest are increased hepatic iron storage and derangements of lipoprotein metabolism. While awaiting the complete resolution of the pathogenesis, current treatment is largely conservative. Every patient should be encouraged to lose weight and to avoid alcohol and other hepatotoxins. In addition, diabetes, lipid abnormalities and increased iron stores should be looked for.

Test validity of periodic liver function tests in a population of Japanese male bank employees

The validity (sensitivity and specificity) of annual liver function tests, determined by assaying blood levels of aspartate aminotransferase, alanine aminotransferase and gammaglutamyl transpeptidase, was evaluated using the results of health checkups of male bank workers. The specificity of each liver function test to detect persons with fatty liver, excess alcohol users, and hepatic virus carriers, diagnosed respectively by ultrasound, detailed inquiry, and virus marker tests, was always higher than 80%, except for alanine aminotransferase in excess alcohol users (63.5%). However, the highest sensitivity to detect virus carriers was alanine aminotransferase to detect HCV antibody-positive workers, but it was only 45.5%. The highest sensitivity of the liver function tests to detect excess alcohol users in obese subjects was only 33.3%. The highest sensitivity by liver function tests to detect fatty liver was 35.7% which was inferior to that of the body mass index. These results indicate that the liver function tests mandated in the workplace periodic health checkups in Japan exhibit very low sensitivity for the detection of any of the proposed target clinical conditions.

Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study

OBJECTIVES

No effective therapy currently exists for patients with nonalcoholic steatohepatitis (NASH). Betaine, a naturally occurring metabolite of choline, has been shown to raise S-adenosylmethionine (SAM) levels that may in turn play a role in decreasing hepatic steatosis. Our aim was to determine the safety and effects of betaine on liver biochemistries and histological markers of disease activity in patients with NASH.

METHODS

Ten adult patients with NASH were enrolled. Patients received betaine anhydrous for oral solution (Cystadane) in two divided doses daily for 12 months. Seven out of 10 patients completed 1 yr of treatment with betaine.

RESULTS

A significant improvement in serum levels of aspartate aminotransferase (p = 0.02) and ALAT (p = 0.007) occurred during treatment. Aminotransferases normalized in three of seven patients, decreased by >50% in three of seven patients, and remained unchanged in one patient when compared to baseline values. A marked improvement in serum levels of aminotransferases (ALT -39%; AST -38%) also occurred during treatment in those patients who did not complete 1 yr of treatment. Similarly, a marked improvement in the degree of steatosis, necroinflammatory grade, and stage of fibrosis was noted at 1 yr of treatment with betaine. Transitory GI adverse events that did not require any dose reduction or discontinuation of betaine occurred in four patients.

CONCLUSIONS

Betaine is a safe and well tolerated drug that leads to a significant biochemical and histological improvement in patients with NASH. This novel agent deserves further evaluation in a randomized, placebo-controlled trial.

[The evaluation of the efficacy of a multidisciplinary treatment in a group of obese patients with a BMI > or = 35 and a change in lung function]

OBJECTIVE

To assess the efficacy of an interdisciplinary protocol for treating obesity in a group of patients with BMI > or = 35 and with altered respiratory function that was not necessarily related to obesity or not.

PATIENTS AND METHOD

Forty obese individuals between 18 and 60 years of age with altered respiratory function were enrolled. Spirometric values, plethysmograph volumes, arterial blood gases, and nighttime respiratory polygraphs were recorded. Following psychological and nutritional evaluation, the patients commenced year-long treatment for obesity involving a personalized diet and psychological counseling. Follow-up was weekly and individualized at first; in later sessions, patients were grouped. Lung function tests were repeated after loss of 5 kg. Sleep polygraphy was repeated after loss of 10 kg.

RESULTS

Weight loss over 15 kg was achieved by 48.6% of the patients. Respiratory function variables: FVC, FEV1, RV, ERV, PaO2 and SatO2 after treatment changed significantly from initial levels. Significant differences were also seen in the severity of sleep apnea and pressures needed for continuous positive airway pressure. Uric acid, glucose and triglyceride blood levels became normal in 89%, 61% and 50% of the patients, respectively, after weight loss. No characteristic psychological profile was identified for severe obesity, although levels of anxiety, eating behavior, marital adjustment and perception of body image were aspects that were fundamentally altered.

CONCLUSIONS

In the difficult group of obese patients with BMI > or = 35, interdisciplinary treatment has proven effective for achieving substantial weight loss, while improving respiratory function and severity of sleep disorder. This therapy, which is at present viable for few centers, deserves consideration in the interest of benefiting the increasing number of obese patients.

Nutritional hepatic steatosis and mortality after burn injury in rats

AIMS

To investigate the effects of diet composition and starvation on hepatic steatosis and mortality after severe burn injury in rats.

METHODS

Experiment 1: rats received either normal chow (55 cent of energy carbohydrates, 14 cent fat, 31 cent protein), a high-fat (40 cent carbohydrates, 40 cent fat, 20 cent protein), or a high-carbohydrate diet (81 cent carbohydrates, 4 cent fat, 15 cent protein) ad libitum for 6 days. Another three groups received these diets ad libitum for 6 days after 48|h starvation. Experiment 2: mortality after 60 cent total body surface area scald burn was determined in a control group of rats and a group with nutritionally induced hepatic steatosis. Hepatic steatosis was induced by feeding the rats a high-fat diet (40 cent carbohydrates, 4 cent fat, 15 cent protein) ad libitum for 6 days.

RESULTS

Without starvation, liver triglyceride content (mg/g liver) increased in response to the high-fat diet (25.6'6.9) compared to normal chow (9.4'3.8; P < 0. 05); the high-carbohydrate diet had no influence on liver triglyceride content (12.4'3.7). Refeeding after starvation resulted in elevated (P < 0.05) liver triglyceride content in the high-fat (18.8'8.3) and the high-carbohydrate group (28.7'14.4 vs control 6. 7'3.7). Liver triglyceride content correlated (R2=0.72; P < 0.05) to non-protein energy intake but not to total energy intake. Burn caused 33 cent mortality in the hepatic steatosis group and no deaths in the control group (P < 0.05).

CONCLUSIONS

Diet composition and preceding starvation independently manipulate hepatic fat content in rats. Hepatic steatosis increases mortality after burn injury. Thus, nutritional interventions to reduce hepatic fat accumulation may be beneficial.

Magnetic resonance imaging of focal and diffuse hepatic disease

MRI is a powerful tool in the detection and characterization of both focal and diffuse liver pathology. Because of superior soft tissue characterization, direct multi-planar capabilities and lack of ionizing radiation, current state of the art MRI is useful when contrast CT is relatively contraindicated or not definitive. This article reviews the MRI findings of the most common focal and diffuse liver diseases encountered in clinical practice. Reviews of current MR techniques and MR contrast agents used in liver imaging have been recently published. For this article, discussion of specific techniques and use of contrast is addressed for each pathological entity discussed.

Nonalcoholic steatohepatitis

NASH is an important form of chronic liver disease that is increasingly recognized. The diagnosis is secured by biopsy findings with similarities to alcoholic hepatitis in a patient with a confirmed history of abstinence. Obesity is a major risk factor, but the disease also occurs in the nonobese. In 20% to 40% of patients the disease can progress to various stages of fibrosis and ultimately cause cirrhosis and death from end-stage liver disease. For this reason, recognition of NASH is important, and establishing the diagnosis provides a further impetus for performing a liver biopsy as part of the evaluation of unexplained liver abnormalities. The mainstay of treatment is weight reduction in the obese. For those individuals who are not obese, continued observation is the only option currently available. Patients who develop decompensated cirrhosis should be considered for liver transplantation unless advanced age or other underlying medical illnesses are a problem. With the increasing knowledge about the pathophysiology of hepatic steatosis, it is hoped that better diagnostic tests for specific causes of NASH will be available and lead to efficacious therapy.

Use of fatty donor liver is associated with diminished early patient and graft survival

It is well known that implantation of donor livers with severe fatty infiltration (>60%) is frequently associated with early hepatic dysfunction and an increased incidence of primary nonfunction after liver transplantation. The outcome of donor livers with less fatty infiltration has not been well defined. We, therefore, studied the outcome of 59 liver transplantations in which donor livers with up to 30% fat were used. Patient outcome was compared to a time-matched control group of 57 patients. The two groups were similar in terms of age, gender, preservation time, primary diagnosis, and UNOS status. We compared both groups with regard to 4-month and 2-year patient and graft survival. We also assessed the incidence of ischemic type biliary strictures and hepatic artery thrombosis, and evaluated the causes of graft loss in both groups. We found that use of donor livers with up to 30% fatty infiltration was associated with a significant decrease in 4-month graft survival (76% vs. 89%, P<0.05) and in 2-year patient survival (77% vs. 91%, P<0.05). Primary nonfunction and primary dysfunction formed the main cause of graft loss and mortality. Multivariate analysis showed that fatty infiltration is an independent predictive factor for outcome after transplantation. We conclude that liver allografts with up to 30% fat lead to diminished outcome after liver transplantation. However, this diminished outcome should be viewed with respect to the increasing mortality on the national waiting list.

Nonalcoholic steatohepatitis

NASH is a form of chronic liver disease that is defined by biopsy findings and has the appearance of alcoholic hepatitis. Although this disease was once thought to be a problem of women, diabetics, and the obese, more recent studies have identified a significant proportion of patients who do not fit these risk factors. In a fraction of patients, the disease can progress to various stages of fibrosis leading ultimately to cirrhosis and death from end-stage liver disease. For this reason, recognition of NASH is important and provides a further impetus for performing a liver biopsy as part of the evaluation of unexplained liver biochemical abnormalities. The mainstay of treatment is weight reduction in the obese. For those individuals who are not obese, continued observation is the only available option at this point. With increasing knowledge about the pathophysiology of hepatic steatosis, perhaps more specific diagnostic tests for the cause of the disease in specific patients will be available and will guide appropriate therapy.

Nonalcoholic steatohepatitis: an expanded clinical entity

BACKGROUND/AIMS

In the past, nonalcoholic steatohepatitis has been described mostly in obese women with diabetes. The aim of this study was to describe a series of patients with nonalcoholic steatohepatitis with a different clinical profile.

METHODS

The clinical, biochemical, and histological features of 33 patients with nonalcoholic steatohepatitis seen from July 1990 to June 1993 were analyzed.

RESULTS

The mean age was 47 years. All patients were antibody to hepatitis C virus-negative. Nineteen of 33 (58%) were men, 20 of 33 (61%) were nonobese, 26 of 33 (79%) had normal glucose levels, and 26 of 33 (79%) had normal lipid levels. Fourteen of 33 (42%) had normal glucose and lipid levels and were not obese. Thirteen of 33 (39%) had pathological increases in fibrosis, 5 of whom had micronodular cirrhosis. Of these 13 with severe, progressive disease, 8 (62%) were women, 8 (62%) were obese, 4 (31%) were diabetic or had an elevated glucose level, and 3 (23%) had hyperlipidemia. Although serum iron studies (transferrin saturation and ferritin) were abnormal in 18 of 31 (58%), no patient had hemochromatosis.

CONCLUSIONS

Nonalcoholic steatohepatitis can be a severe, progressive liver disease leading to the development of cirrhosis. It should no longer be considered a disease predominantly seen in obese women with diabetes.

Gastrointestinal disturbances with obesity

Steatosis and steatohepatitis are associated with obesity. Despite florid histological changes, patients with non-alcoholic steatohepatitis generally remain asymptomatic, and it usually runs a relatively benign course. An elevated insulin level may be important in the pathogenesis. There is a marked regression of fatty changes after weight reduction. In obese subjects the risk of developing gallstones is increased due to an increased saturation of gallbladder bile with cholesterol and possible gallbladder stasis. During weight reduction with very low calorie diets the incidence in gallstones increases probably because of an increased saturation of bile during the loss of weight. Ursodeoxycholic acid appears to be a promising prophylactic agent. Chenodeoxycholic acid is not useful for these subjects. There is controversy over whether obesity contributes to gastroesophageal reflux and gastric emptying disturbances. There are changes in gastrointestinal peptide plasma levels in obesity but it is not clear if this contributes to its development. The risk for high-risk colorectal adenomas and carcinomas is reported to be increased in obese males. Vertical banded gastroplasty and gastric bypass procedures are nowadays the surgical options for the treatment of obesity. Nutritional deficiencies, particularly of vitamin B12, folate and iron are common after gastric bypass and must be sought and treated. Dumping is another potential complication of this operation. If stenosis and gastric outlet obstruction develop endoscopic dilatation is a good therapeutic option.

Hepatitis C virus does not cause nonalcoholic steatohepatitis

The pathogenesis of nonalcoholic steatohepatitis (NASH) remains poorly understood. Since inflammation and fatty changes are associated with hepatitis C (HCV) infection, we have tested the role of HCV in the genesis of NASH. Five consecutive cases of classic NASH were tested by Abbott anti-c100-3 EIA and polymerase chain reaction (PCR) to detect HCV-RNA. All serum specimens were negative for anti-c100-3 (or anti-HCV EIA) and HCV PCR. Based on this study, we conclude that HCV does not play a causative or contributing role in the pathogenesis of NASH.

Clinicopathologic study of alcohol-like liver disease in non-alcoholics; non-alcoholic steatohepatitis and fibrosis

Alcohol-like liver injury (ALLI) in non-alcoholics has not been elucidated in Japan. The present study attempted to characterize the clinicopathologic features of ALLI in routine liver biopsies. ALLI was found in 1% of 561 biopsy cases obtained from 1988 to May, 1991 at Kanazawa University Hospital. Laboratory data characteristically showed only a mild to moderate degree of dysfunction, and none of the cases exhibited jaundice. Hepatic histology showed a mild to moderate degree of perivenular, pericellular and/or portal stellate fibrosis with a varying degree of fatty change and inflammatory cell infiltration. Portal stellate fibrosis with a varying degree of cell infiltration was more severe than the centrilobular or pericellular fibrosis in all cases. Intralobular inflammatory cell infiltration was associated with spotty or single hepatocyte necrosis, but extensive hepatocyte necrosis was not observed. Neutrophil infiltration was absent or minimal, and lymphocytes predominated in all cases. Mallory bodies were rare and were found in a few hepatocytes of only one of the 7 cases. The above histologic findings in ALLI were very similar to those seen in liver disease in Japanese alcoholics, and were somewhat different from ALLI reported in Western countries. In cases in which hepatic fibrosis, characterized by pericellular, perivenular or portal stellate fibrosis dominated without apparent hepatic necrosis and inflammation, the term "non-alcoholic steatofibrosis" is more suitable to depict its liver histology, being very similar to the alcoholic fibrosis frequently seen in Japanese alcoholics.

Effect of weight reduction on hepatic abnormalities in overweight patients

The effects of weight reduction on hepatic test results and physical findings related to the liver were retrospectively evaluated in 39 overweight patients screened to exclude other factors affecting the liver. An additional 11 overweight patients with primary liver disease were retrospectively evaluated to compare the effect of weight reduction in patients with liver disease with its effect in those without primary liver disease. This study showed that in overweight adults without primary liver disease, a weight reduction of greater than or equal to 10% corrected abnormal hepatic test results, decreased hepatosplenomegaly, and resolved some stigmata of liver disease. In similarly studied overweight patients with primary liver disease, some findings improved, but the changes did not correlate with a greater than or equal to 10% weight loss. Increased alanine aminotransferase activity was the most frequent hepatic enzyme abnormality in this population. For every 1% reduction in body weight, alanine aminotransferase activity improved by 8.1%. After other causes of liver disease are eliminated by clinical and biochemical parameters, weight reduction should be tried for overweight patients with abnormal hepatic test results in the absence of obvious primary liver disease as judged by clinical and biochemical parameters before extensive and expensive studies are undertaken.

The natural history of nonalcoholic steatohepatitis: a follow-up study of forty-two patients for up to 21 years

Forty-two patients with nonalcoholic steatohepatitis were followed for a median of 4.5 yr (range = 1.5 to 21.5 yr). Except for two patients with lipodystrophy, all were obese; 35 of 42 were women, 26 of 32 were hyperlipidemic and 15 were hyperglycemic. Upper abdominal pain was the most common reason for presentation. Initial liver biopsy specimens showed the presence of macrovesicular fatty infiltration, lobular (acinar) inflammation, apoptosis, Mallory bodies (in four cases) and fibrosis (in 18 cases). Cirrhosis was present at initial diagnosis in one subject and in another two subjects liver biopsy showed marked fibrosis with disturbed architecture. Serial liver biopsy specimens revealed minimal or no apparent progression of the disorder in most of the patients, in keeping with their benign clinical course. However, one patient showed progression from fibrosis to cirrhosis during the 5-yr observation period, and in the patients with extensive fibrosis the liver disease evolved from one of active inflammation to one of inactive cirrhosis without fat or inflammation. The patient with cirrhosis later died of hepatocellular carcinoma. The severity or type of hepatic change did not correlate with the degree of obesity, hyperlipidemia or hyperglycemia. However, in individual patients, poorly controlled diabetes and rapid weight loss preceded the onset of steatohepatitis. We conclude that nonalcoholic steatohepatitis is a cause of hepatic inflammation histologically resembling that of alcohol-induced liver disease but usually slowly progressive and of low-grade severity. However, the disorder may ultimately result in cirrhosis. Nonalcoholic steatohepatitis should be distinguished from alcoholic steatohepatitis and recognized as a further cause of "cryptogenic cirrhosis."

Steatohepatitis associated with limb lipodystrophy

Two patients who presented with steatohepatitis had acquired partial lipodystrophy. This association has not previously been well documented. A common pathophysiological mechanism in lipodystrophy, obesity-associated nonalcoholic steatohepatitis, and alcoholic liver disease is possible.