The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD

Patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis are at the highest risk for progressing to end-stage liver disease. We constructed and validated a scoring system consisting of routinely measured and readily available clinical and laboratory data to separate NAFLD patients with and without advanced fibrosis. A total of 733 patients with NAFLD confirmed by liver biopsy were divided into 2 groups to construct (n = 480) and validate (n = 253) a scoring system. Routine demographic, clinical, and laboratory variables were analyzed by multivariate modeling to predict presence or absence of advanced fibrosis. Age, hyperglycemia, body mass index, platelet count, albumin, and AST/ALT ratio were independent indicators of advanced liver fibrosis. A scoring system with these 6 variables had an area under the receiver operating characteristic curve of 0.88 and 0.82 in the estimation and validation groups, respectively. By applying the low cutoff score (-1.455), advanced fibrosis could be excluded with high accuracy (negative predictive value of 93% and 88% in the estimation and validation groups, respectively). By applying the high cutoff score (0.676), the presence of advanced fibrosis could be diagnosed with high accuracy (positive predictive value of 90% and 82% in the estimation and validation groups, respectively). By applying this model, a liver biopsy would have been avoided in 549 (75%) of the 733 patients, with correct prediction in 496 (90%).

CONCLUSION

a simple scoring system accurately separates patients with NAFLD with and without advanced fibrosis, rendering liver biopsy for identification of advanced fibrosis unnecessary in a substantial proportion of patients.

Liver Fibrosis, but No Other Histologic Features, Is Associated With Long-term Outcomes of Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Histologic analysis of liver biopsy specimens allows for grading and staging of nonalcoholic fatty liver disease (NAFLD). We performed a longitudinal study to investigate the long-term prognostic relevance of histologic features for patients with NAFLD.

METHODS

We performed a retrospective analysis of 619 patients diagnosed with NAFLD from 1975 through 2005 at medical centers in the United States, Europe, and Thailand. Patients underwent laboratory and biopsy analyses, and were examined every 3-12 months after their diagnosis. Outcomes analyzed were overall mortality, liver transplantation, and liver-related events. Cumulative outcomes were compared by log-rank analysis. Cox proportional-hazards regression was used to estimate adjusted hazard ratios (HRs). Time at risk was determined from the date of liver biopsy to the date of outcome or last follow-up examination.

RESULTS

Over a median follow-up period of 12.6 years (range, 0.3-35.1 y), 193 of the patients (33.2%) died or underwent liver transplantation. Features of liver biopsies significantly associated with death or liver transplantation included fibrosis stage 1 (HR, 1.88; 95% confidence interval [CI], 1.28-2.77), stage 2 (HR, 2.89; 95% CI, 1.93-4.33), stage 3 (HR, 3.76; 95% CI, 2.40-5.89), and stage 4 (HR, 10.9; 95% CI, 6.06-19.62) compared with stage 0, as well as age (HR, 1.07; 95% CI, 1.05-1.08), diabetes (HR, 1.61; 95% CI, 1.13-2.30), current smoking (HR, 2.62; 95% CI, 1.67-4.10), and statin use (HR, 0.32; 95% CI, 0.14-0.70). Twenty-six patients (4.2%) developed liver-related events; fibrosis stage 3 (HR, 14.2; 95% CI, 3.38-59.68) and stage 4 (HR, 51.5; 95% CI, 9.87-269.2) compared with stage 0, were associated significantly with the events. Patients with fibrosis, regardless of steatohepatitis or NAFLD activity score, had shorter survival times than patients without fibrosis.

CONCLUSIONS

In a longitudinal study of patients with NAFLD, fibrosis stage, but no other histologic features of steatohepatitis, were associated independently with long-term overall mortality, liver transplantation, and liver-related events.

The natural history of nonalcoholic fatty liver disease: a population-based cohort study

BACKGROUND & AIMS

The natural history of nonalcoholic fatty liver disease (NAFLD) in the community remains unknown. We sought to determine survival and liver-related morbidity among community-based NAFLD patients.

METHODS

Four hundred twenty patients diagnosed with NAFLD in Olmsted County, Minnesota, between 1980 and 2000 were identified using the resources of the Rochester Epidemiology Project. Medical records were reviewed to confirm diagnosis and determine outcomes up to 2003. Overall survival was compared with the general Minnesota population of the same age and sex.

RESULTS

Mean (SD) age at diagnosis was 49 (15) years; 231 (49%) were male. Mean follow-up was 7.6 (4.0) years (range, 0.1-23.5) culminating in 3192 person-years follow-up. Overall, 53 of 420 (12.6%) patients died. Survival was lower than the expected survival for the general population (standardized mortality ratio, 1.34; 95% CI, 1.003-1.76; P = .03). Higher mortality was associated with age (hazard ratio per decade, 2.2; 95% CI, 1.7-2.7), impaired fasting glucose (hazard ratio, 2.6; 95% CI, 1.3-5.2), and cirrhosis (hazard ratio, 3.1, 95% CI, 1.2-7.8). Liver disease was the third leading cause of death (as compared with the thirteenth leading cause of death in the general Minnesota population), occurring in 7 (1.7%) subjects. Twenty-one (5%) patients were diagnosed with cirrhosis, and 13 (3.1%) developed liver-related complications, including 1 requiring transplantation and 2 developing hepatocellular carcinoma.

CONCLUSIONS

Mortality among community-diagnosed NAFLD patients is higher than the general population and is associated with older age, impaired fasting glucose, and cirrhosis. Liver-related death is a leading cause of mortality, although the absolute risk is low.

Independent predictors of liver fibrosis in patients with nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) may present with increased hepatic fibrosis progressing to end-stage liver disease. No factors that determine increasing fibrosis and histologically advanced disease have been recognized, thus, liver biopsy is recommended in all patients for diagnosis and prognosis. Our aim was to identify independent predictors of severe hepatic fibrosis in patients with NASH. One hundred and forty-four patients were studied. All patients underwent liver biopsy. Clinical and biochemical variables were examined with univariate and multivariate analysis. Thirty-seven (26%) patients had no abnormal fibrosis, 53 (37%) had mild fibrosis, 15 (10%) had moderate fibrosis, 14 (10%) had bridging fibrosis, and 25 (17%) had cirrhosis. In multivariate analysis, older age (P =. 001), obesity (P =.002), diabetes mellitus (P =.009), and aspartate transaminase/alanine transaminase (AST/ALT) ratio greater than 1 (P =.03) were significant predictors of severe liver fibrosis (bridging/cirrhosis). Body mass index (P =.003) was the only independent predictor of the degree of fat infiltration. Increased transferrin saturation correlated positively with the severity of fibrosis (P =.02) in univariate analysis, and there was a trend for more female patients among those with more advanced fibrosis (P =. 09). However, iron studies or gender were not significant when controlled for age, obesity, diabetes, and AST/ALT ratio. In conclusion, older age, obesity, and presence of diabetes mellitus help identify those NASH patients who might have severe liver fibrosis. This is the subgroup of patients with NASH who would be expected to derive the most benefit from having a liver biopsy and considering investigational therapies.

Hepatocyte apoptosis and fas expression are prominent features of human nonalcoholic steatohepatitis

BACKGROUND & AIMS

The pathogenesis of nonalcoholic steatohepatitis (NASH) remains poorly understood. Although apoptosis is a common mechanism of liver injury, the extent and clinical significance of apoptosis in NASH has not been examined. Thus, the aims of this study were to quantify hepatocyte apoptosis in NASH, correlate it with disease severity, and identify possible mechanisms of apoptosis induction.

METHODS

Hepatocyte apoptosis was assessed in NASH, simple steatosis, alcoholic hepatitis, and controls without liver disease using the TUNEL assay and immunohistochemistry for activated caspases 3 and 7. Liver specimens were also graded according to the magnitude of inflammation and fibrosis.

RESULTS

TUNEL-positive cells were significantly increased in liver biopsy specimens from patients with NASH compared with simple steatosis and controls. Unexpectedly, TUNEL-positive cells were also greater in NASH vs. alcoholic hepatitis. Immunohistochemistry demonstrated active caspases 3 and 7 in NASH specimens, confirming the occurrence of apoptosis in this disease. A positive correlation was observed between hepatocyte apoptosis and hepatic fibrosis and inflammatory activity, respectively. The Fas receptor was strongly expressed in hepatocytes in liver specimens from NASH patients as compared with controls.

CONCLUSIONS

Hepatocyte apoptosis is significantly increased in patients with NASH and correlates with disease severity, suggesting that antiapoptotic therapy may be useful in this syndrome.

The histological course of nonalcoholic fatty liver disease: a longitudinal study of 103 patients with sequential liver biopsies

BACKGROUND/AIMS

The histological course of nonalcoholic fatty liver disease (NAFLD) remains undescribed. Therefore, we examined the liver histology of NAFLD patients who had undergone sequential liver biopsies.

METHODS

Data on 103 patients who underwent serial liver biopsies in the absence of effective treatment were reviewed, and biopsies scored in a blind fashion.

RESULTS

Mean interval between biopsies was 3.2+/-3.0 years (range 0.7-21.3). Fibrosis stage apparently progressed in 37%, remained stable in 34% and regressed in 29%. Severity of steatosis, inflammation, hepatocyte ballooning and Mallory's hyaline improved significantly. Aminotransferases decreased significantly between biopsies, paralleling improvement in steatosis and inflammatory features but not fibrosis stage. The rate of fibrosis change ranged from -2.05 to 1.7 stages/year. By multivariate analysis, diabetes (P = 0.007) and low initial fibrosis stage (P < 0.001) were associated with higher rate of fibrosis progression, as was higher body mass index (P = 0.008) when cirrhotics were excluded.

CONCLUSIONS

Fibrosis in NAFLD progresses slowly over time with considerable variability in the rate of changes among patients. Changes of aminotransferases do not parallel changes in fibrosis stage. Diabetic patients with elevated BMI and low fibrosis stage are at risk for higher rates of fibrosis progression.

The natural history of non-alcoholic fatty liver disease in children: a follow-up study for up to 20 years

OBJECTIVES

The long-term prognosis of non-alcoholic fatty liver disease (NAFLD) in children remains uncertain. We aimed at determining the long-term outcomes and survival of children with NAFLD.

DESIGN

Retrospective longitudinal hospital-based cohort study.

PATIENTS

Sixty-six children with NAFLD (mean age 13.9 (SD 3.9) years) were followed up for up to 20 years with a total of 409.6 person-years of follow-up.

RESULTS

The metabolic syndrome was present in 19 (29%) children at the time of NAFLD diagnosis with 55 (83%) presenting with at least one feature of the metabolic syndrome including obesity, hypertension, dyslipidaemia and/or hyperglycaemia. Four children with baseline normal fasting glucose developed type 2 diabetes 4-11 years after NAFLD diagnosis. A total of 13 liver biopsies were obtained from five patients over a mean of 41.4 (SD 28.8) months showing progression of fibrosis stage in four children. During follow-up, two children died and two underwent liver transplantation for decompensated cirrhosis. The observed survival free of liver transplantation was significantly shorter in the NAFLD cohort as compared to the expected survival in the general United States population of the same age and sex (log-rank test, p<0.00001), with a standardised mortality ratio of 13.6 (95% confidence interval, 3.8 to 34.8). NAFLD recurred in the allograft in the two cases transplanted, with one patient progressing to cirrhosis and requiring re-transplantation.

CONCLUSIONS

Children with NAFLD may develop end-stage liver disease with the consequent need for liver transplantation. NAFLD in children seen in a tertiary care centre may be associated with a significantly shorter survival as compared to the general population.

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.

Ursodeoxycholic acid for treatment of nonalcoholic steatohepatitis: results of a randomized trial

No effective medical therapy is available for all patients with nonalcoholic steatohepatitis (NASH). Ursodeoxycholic acid (UDCA) has been suggested to be of benefit based on open label clinical studies. We randomized 166 patients with liver biopsy-proven NASH to receive between 13 and 15 mg/kg/d of UDCA or placebo for 2 years. End points included changes in liver test results and liver histology at 2 years of therapy. The treatment groups were comparable at entry with regard to age, gender, risk factors for NASH, serum liver biochemistries, and baseline liver histology. A total of 126 patients completed 2 years of therapy. Pre- and posttreatment liver biopsies were available in 107 patients for review at the end of the study. UDCA was well tolerated and body weight was stable during the study duration. Serum liver biochemistries were stable or improved in both the UDCA and placebo-treated groups. Changes in the degree of steatosis, necroinflammation, or fibrosis that occurred with therapy were not significantly different between the UDCA and placebo groups. In conclusion, 2 years of therapy with UDCA at a dose of 13 to 15 mg/kg/d, although safe and well tolerated, is not better than placebo for patients with NASH.

Sarcopenic obesity and myosteatosis are associated with higher mortality in patients with cirrhosis

BACKGROUND AND AIMS

Obesity is frequently associated with cirrhosis, and cirrhotic patients may develop simultaneous loss of skeletal muscle and gain of adipose tissue, culminating in the condition of sarcopenic obesity. Additionally, muscle depletion is characterized by both a reduction in muscle size and increased proportion of muscular fat, termed myosteatosis. In this study, we aimed to establish the frequency and clinical significance of sarcopenia, sarcopenic obesity and myosteatosis in cirrhotic patients.

METHODS

We analysed 678 patients with cirrhosis. Sarcopenia, sarcopenic obesity and myosteatosis were analysed by CT scan using the third lumbar vertebrae skeletal muscle and attenuation indexes, using previously validated gender-and body mass index-specific cutoffs.

RESULTS

Patients were predominately men (n = 457, 67%), and cirrhosis aetiology was hepatitis C virus in 269 patients (40%), alcohol in 153 (23%), non-alcoholic steatohepatitis/cryptogenic in 96 (14%), autoimmune liver disease in 55 (8%), hepatitis B virus in 43 (6%), and others in 5 patients (1%). Sarcopenia was present in 292 (43%), 135 had sarcopenic obesity (20%) and 353 had myosteatosis (52%). Patients with sarcopenia (22 ± 3 vs. 95 ± 22 months, P < 0.001), sarcopenic obesity (22 ± 3 vs. 95 ± 22 months, P < 0.001), and myosteatosis (28 ± 5 vs. 95 ± 22 months, P < 0.001) had worse median survival than patients without muscular abnormalities. By multivariate Cox regression analysis, both sarcopenia [hazard ratio (HR) 2.00, 95% confidence interval (CI) 1.44-2.77, P < 0.001], and myosteatosis (HR 1.42, 95% CI 1.02-1.07, P = 0.04) were associated with mortality.

CONCLUSIONS

Sarcopenia, sarcopenic obesity and myosteatosis are often present in patients with cirrhosis, and sarcopenia and myosteatosis are independently associated with a higher long-term mortality in cirrhosis.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is emerging as the most common chronic liver condition in the Western world. It is associated with insulin resistance and frequently occurs with features of the metabolic syndrome. Disease presentation ranges from asymptomatic elevated liver enzyme levels to cirrhosis with complications of liver failure and hepatocellular carcinoma. Current treatment recommendations are limited to weight loss and exercise, although several promising medications are on the horizon. In this article we discuss the etiology, pathogenesis and diagnosis of nonalcoholic fatty liver disease as well as approaches to its management.

The natural history of nonalcoholic fatty liver disease with advanced fibrosis or cirrhosis: an international collaborative study

Information on the long-term prognosis of nonalcoholic fatty liver disease (NAFLD) is limited. We sought to describe the long-term morbidity and mortality of patients with NAFLD with advanced fibrosis or cirrhosis by prospectively studying 247 such patients from four international centers (in Australia, USA, UK and Italy). Their natural history was then compared with 264 patients with HCV infection who were either naïve or non-responders to treatment. Both cohorts were Child-Pugh class A and had advanced fibrosis (stage 3) or cirrhosis (stage 4) confirmed by liver biopsy at enrollment. In the NAFLD cohort, followed up for a mean of 85.6 months (range, 6-297), there were 48 (19.4%) liver-related complications and 33 (13.4%) deaths or liver transplants. In the HCV cohort, followed up for 74.9 months (mean; range, 6-238), there were 47 (16.7%) liver-related complications and 25 (9.4%) deaths or liver transplants. When adjusting for baseline differences in age and gender, the cumulative incidence of liver-related complications was lower in the NAFLD than the HCV cohort (P = 0.03), including incident hepatocellular cancer (6 versus 18; P = 0.03), but that of cardiovascular events (P = 0.17) and overall mortality (P = 0.6) were similar in both groups. In the NAFLD cohort, platelet count, stage 4 fibrosis, lowered platelet count, and lowered serum cholesterol and alanine aminotransferase (ALT) levels were associated with liver-related complications; an aspartate aminotransferase/ALT ratio >1 and older age were associated with overall mortality, and higher serum bilirubin levels and stage 4 fibrosis were associated with liver-related mortality.

CONCLUSIONS

Patients with NAFLD with advanced fibrosis or cirrhosis have lower rates of liver-related complications and hepatocellular cancer than corresponding patients with HCV infection, but similar overall mortality. Some clinical and laboratory features predict liver-related complications and other outcomes in patients with NAFLD.

Incidence and risk factors for cholangiocarcinoma in primary sclerosing cholangitis

Cholangiocarcinoma (CCA) is a dreaded complication of primary sclerosing cholangitis (PSC); however, marked variability in the incidence of CCA in PSC is reported. Furthermore, limited information exists on risk factors for the development of CCA in PSC. The aim of this study was to determine the incidence of CCA in patients with PSC and to evaluate baseline risk factors for the later development of CCA. From a previous study of the natural history of PSC, we identified 161 patients with PSC who did not have CCA at study entry. Patients were followed until a diagnosis of CCA was established, liver transplantation was performed, or death occurred. Patients were followed for a median of 11.5 yr (interquartile range 4.0-16.1 yr). Fifty-nine patients (36.6%) died, 50 patients (31.1%) underwent liver transplantation, and 11 patients (6.8%) developed CCA. The rate of CCA developing was approximately 0.6% per year. Compared to the incidence rates of CCA in the general population, the relative risk of CCA in PSC was significantly increased (RR = 1,560; 95%CI = 780, 2,793; p < 0.0001). On univariate analysis, a history of variceal bleeding (p < 0.001), proctocolectomy (p= 0.01), and lack of symptoms (p= 0.02) were significant risk factors for CCA with the Mayo Risk Score being marginally significant (p= 0.051). Multivariate analysis determined only variceal bleeding to be a significant risk factor for CCA (RR 24.2; 95%CI: 3.3-67.1). No association was found between the duration of PSC and the incidence of CCA. In conclusion, approximately 7% of PSC patients later developed CCA over a mean follow-up of 11.5 yr, which is dramatically higher than the rates in the general population. Variceal bleeding is a major risk factor for the later development of CCA.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects a high proportion of the world's population. Insulin resistance and oxidative stress play a critical role in the pathogenesis of NAFLD. Clinical, biochemical and imaging studies are of value in the diagnostic evaluation of patients with NAFLD, but liver biopsy remains the most sensitive and specific means of providing important diagnostic and prognostic information. Simple steatosis has the best prognosis within the spectrum of NAFLD, but NAFLD has the potential to progress to steatohepatitis, fibrosis and even cirrhosis. No effective medical therapy is currently available for all patients with NAFLD. In patients with diabetes mellitus and hyperlipidemia, appropriate metabolic control is always recommended, but rarely effective in resolving the liver disease. Weight reduction, when achieved and sustained, may improve the liver disease, although the results with weight loss have been inconsistent. Pharmacological therapy aimed at the underlying liver disease holds promise. Several medications with different mechanisms of action and potential benefit are currently being evaluated in clinical trials. Liver transplantation is a life-extending therapeutic alternative for patients with end-stage NAFLD, but NAFLD may recur after liver transplantation.

Lifestyle intervention and antioxidant therapy in children with nonalcoholic fatty liver disease: a randomized, controlled trial

No proven treatment exists for nonalcoholic fatty liver disease (NAFLD) in children and adolescents. We sought to determine the efficacy of lifestyle intervention with or without antioxidant therapy in pediatric NAFLD. A total of 53 patients (age 5.7-18.8 years, 37 boys) were included. Lifestyle intervention consisting of a diet tailored to the patient's calorie needs, and increased physical activity was prescribed in all. Patients were concomitantly randomized to alpha-tocopherol 600 IU/day plus ascorbic acid 500 mg/day (n = 25) or placebo (n = 28), and treated for 24 months. The study was an extension of a previous study aimed at evaluating the effect of 12-month lifestyle intervention and antioxidant therapy on serum levels of aminotransferases. The primary end point of the present study was change in liver histology on repeated biopsy at 24 months. Secondary end points were changes in body weight, liver enzymes, and insulin sensitivity indices on 2-hour oral glucose tolerance test. The amount of weight lost at 24 months was similar in the placebo and antioxidant groups (-4.75 [range, -16-4.0] versus -5.5 [range, -12.2-0.4] kg, respectively, P = 0.9). A significant improvement occurred in the grade of steatosis, lobular inflammation, and hepatocyte ballooning, and in the NAFLD activity score in both groups. Levels of aminotransferases, triglycerides, cholesterol, fasting glucose, and insulin, and insulin sensitivity indices improved significantly as well. The improvement in all these parameters was not significantly different between the two groups.

CONCLUSION

Lifestyle intervention with diet and increased physical activity induces weight loss and is associated with a significant improvement in liver histology and laboratory abnormalities in pediatric NAFLD. Alpha-tocopherol plus ascorbic acid does not seem to increase the efficacy of lifestyle intervention alone.

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.

GI epidemiology: nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common diagnosis in clinical practice. Insulin resistance and oxidative stress play an important role in NAFLD development and progression.

AIM

To review the data available on the epidemiology and natural history of NAFLD as well as the risk factors for its development and the areas where future research is necessary. RESULTS /CONCLUSIONS: NAFLD may affect individuals of any age range and race/ethnicity. NAFLD affects one in three adults and one in ten children/adolescents in the United States. Mortality in patients with NAFLD is significantly higher than in the general population of same age and gender with liver-related complications being a common cause of death. Liver-related morbidity and mortality in NAFLD occurs when the disease has progressed to advanced fibrosis and cirrhosis. Further studies are necessary to determine the impact of NAFLD on health-related quality of life and resources utilization, and to the extent to which preventing the development of the metabolic syndrome would prevent NAFLD development and reduce liver-related morbidity and mortality. Lifestyle intervention may improve NAFLD, but medications that increase insulin sensitivity and the antioxidant defenses in the liver deserve evaluation in carefully controlled trials.

Suspected nonalcoholic fatty liver disease and mortality risk in a population-based cohort study

OBJECTIVE

Case series suggest that nonalcoholic fatty liver disease (NAFLD) is associated with increased all-cause and cardiovascular mortality. The current study compared the survival of subjects with and without suspected NAFLD in a population-based cohort, and placed the finding in the context of previously published case series.

METHODS

Primary analysis assessed mortality for NHANES-III participants with and without suspected NAFLD using the National Death Index. Suspected NAFLD was based upon unexplained ALT elevation. The Olmsted County and Cleveland Clinic case series were also used for comparison. Survivals were compared using Proportional Hazards Model and direct age standardization.

RESULTS

The NHANES cohort included 980 with and 6,594 subjects without suspected NAFLD. Over a mean of 8.7 yr, suspected NAFLD had a hazards ratio of 1.37 (95% CI 0.98-1.91) for all-cause mortality. In the 45-54 age group, suspected NAFLD had significantly higher all-cause (4.40 95% CI 1.27-13.23) and cardiovascular mortality (8.15, 95% CI 2.00-33.20) after adjusting for conventional cardiovascular risk factors. The age-standardized rate per 10,000 per year was 129 (95% CI 118-140) for the NHANES non-NAFLD cohort, 154 (95% CI 116-198) for the NHANES suspected NAFLD cohort, 214 (95% CI 157-279) for the Olmsted County series, and 426 (95% CI 298-573) for the Cleveland Clinic series.

CONCLUSION

The magnitude of mortality risk in NAFLD depends on the setting and method of ascertainment. Suspected NAFLD in the 45-54 age group is a strong independent risk factor for cardiovascular death and warrants further cardiovascular risk management guidelines.

NAFLD in children: a prospective clinical-pathological study and effect of lifestyle advice

Nonalcoholic fatty liver disease (NAFLD), a common cause of chronic liver disease in adults, is incompletely characterized in children. We conducted a prospective study to better characterize the clinical presentation of NAFLD in children and to determine the effect of lifestyle advice in the management of pediatric NAFLD. From June 2001 to April 2003, 84 children (age 3-18.8 yr) who had elevated aminotransferases and the diagnosis of NAFLD confirmed via liver biopsy underwent a 2-hour oral glucose tolerance test and a 12-month program of lifestyle advice consisting of diet and physical exercise. Thirty-four (40.5%) patients were obese (body mass index [BMI] >97th percentile), and 43 (51.2%) were overweight (BMI 85th-97th percentile). Ten (12%) had abnormal glucose tolerance; 10 (12%) had elevated triglycerides, cholesterol, or both; and all had normal blood pressure. Most children (67/84, 80%) were insulin-resistant, including the 7 children with normal BMI (<85th percentile). Increased liver fibrosis was present in 49 (58.1%) patients and was independently associated with obesity (OR 2.7, 95% CI 1.2-6.2) and age (1-year increase; OR 1.2, 95% CI 1.04-1.5). A 12-month program with diet and physical exercise resulted in a significant decrease in BMI, and levels of fasting glucose, insulin, lipids, and liver enzymes, as well as liver echogenicity on ultrasonography. In conclusion, children with NAFLD are almost always insulin-resistant regardless of BMI. Obesity and older age are independently associated with increased liver fibrosis. A simple lifestyle advice program significantly improves insulin resistance, and the liver disease in pediatric NAFLD.

The value of serum CA 19-9 in predicting cholangiocarcinomas in patients with primary sclerosing cholangitis

CA 19-9 has been used with questionable accuracy to aid diagnosis of cholangiocarcinoma complicating primary sclerosing cholangitis. We aimed to characterize the test properties of CA 19-9 and of a change in CA 19-9 over time in predicting cholangiocarcinoma. Charts of 208 patients were reviewed. Fourteen patients had cholangiocarcinoma. Median CA 19-9 was higher with cholangiocarcinoma (15 vs. 290 U/ml, p < 0.0001). A cutoff of 129 U/ml provided: sensitivity 78.6%, specificity 98.5%, adjusted positive predictive value 56.6% and negative predictive value 99.4%. The median change over time was 664 U/ml in cholangiocarcinoma compared to 6.7 U/ml in primary sclerosing cholangitis alone (p < 0.0001). A cutoff of 63.2 U/ml for change in CA 19-9 provided: sensitivity 90%, specificity 98% and positive predictive value 42%. Only 2 patients with cholangiocarcinoma were the candidates for curative therapy. In conclusion, the positive predictive value of an elevated CA 19-9 was 56.6%; only advanced cases were detected by this method.

Effect of changes on body weight and lifestyle in nonalcoholic fatty liver disease

BACKGROUND/AIMS

The effects of lifestyle modifications in nonalcoholic fatty liver disease (NAFLD) are incompletely defined. We aimed at determining the association of changes in body weight and lifestyle with changes in serum ALT levels.

METHODS

We analyzed annual health checkup data from 1546 employees. Of 469 subjects with elevated ALT, we selected 348 male subjects by excluding those who had other causes of liver disease. They were followed for one year to assess the association of change in lifestyle with change in serum ALT. The 136 subjects who had ALT normalization were followed for two years to assess the association between lifestyle management and persistently normal ALT.

RESULTS

In adjusted analysis, weight loss and regular exercise were significantly associated with improvement in serum ALT and increased the odds of ALT normalization, while starting smoking was significantly associated with deterioration in serum ALT. Subjects achieving > or = 5% weight reduction showed improvement in serum ALT. Reduction in alcohol consumption was not associated with changes in serum ALT. Maintaining reduced weight (<5% gain) was significantly associated with persistently normal ALT.

CONCLUSIONS

Reducing weight by at least 5% with subsequent weight control and exercising regularly may be beneficial in treating NAFLD.

Recent concepts in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is present in up to one-third of the general population and in the majority of patients with metabolic risk factors such as obesity and diabetes. Insulin resistance is a key pathogenic factor resulting in hepatic fat accumulation. Recent evidence demonstrates NAFLD in turn exacerbates hepatic insulin resistance and often precedes glucose intolerance. Once hepatic steatosis is established, other factors, including oxidative stress, mitochondrial dysfunction, gut-derived lipopolysaccharide and adipocytokines, may promote hepatocellular damage, inflammation and progressive liver disease. Confirmation of the diagnosis of NAFLD can usually be achieved by imaging studies, however, staging the disease requires a liver biopsy. NAFLD is associated with an increased risk of all-cause death, probably because of complications of insulin resistance such as vascular disease, as well as cirrhosis and hepatocellular carcinoma, which occur in a minority of patients. NAFLD is also now recognized to account for a substantial proportion of patients previously diagnosed with 'cryptogenic cirrhosis'. Diabetes, obesity and the necroinflammatory form of NAFLD known as non-alcoholic steatohepatitis, are risk factors for progressive liver disease. Current treatment relies on weight loss and exercise, although various insulin-sensitizing medications appear promising. Further research is needed to identify which patients will achieve the most benefit from therapy.

Nonalcoholic fatty liver disease increases risk of death among patients with diabetes: a community-based cohort study

OBJECTIVES

The significance of nonalcoholic fatty liver disease (NAFLD) among patients with diabetes is unknown. We sought to determine whether a diagnosis of NAFLD influenced mortality among a community-based cohort of patients with type II diabetes mellitus.

METHODS

A total of 337 residents of Olmsted County, Minnesota with diabetes mellitus diagnosed between 1980 and 2000 were identified using the Rochester Epidemiology Project and the Mayo Laboratory Information System, and followed for 10.9 + or - 5.2 years (range 0.1-25). Survival was analyzed using Cox proportional hazards modeling, with NAFLD treated as a time-dependent covariate.

RESULTS

Among the 337 residents, 116 were diagnosed with NAFLD 0.9 + or - 4.6 years after diabetes diagnosis. Patients with NAFLD were younger, and more likely to be female and obese. Overall, 99/337 (29%) patients died. In multivariate analysis to adjust for confounders, overall mortality was significantly associated with a diagnosis of NAFLD (hazard ratio (HR) 2.2; 95% confidence interval (CI) 1.1, 4.2; P=0.03), presence of ischemic heart disease (HR 2.3; 95% CI 1.2, 4.4), and duration of diabetes (HR per 1 year, 1.1; 95% CI 1.03, 1.2). The most common causes of death in the NAFLD cohort were malignancy (33% of deaths), liver-related complications (19% of deaths), and ischemic heart disease (19% of deaths). In adjusted multivariate models, NAFLD was borderline associated with an increased risk of dying from malignancy (HR 2.3; 95% CI 0.9, 5.9; P=0.09) and not from cardiovascular disease (HR 0.9; 95% CI 0.3, 2.4; P=0.81).

CONCLUSIONS

The diagnosis of NAFLD is associated with an increased risk of overall death among patients with diabetes mellitus.

Nonalcoholic fatty liver disease among patients with hypothalamic and pituitary dysfunction

Patients with hypopituitarism develop a phenotype similar to metabolic syndrome with central obesity and diabetes. Similarly, patients with hypothalamic damage may develop central obesity, insulin resistance, and hyperphagia. We sought to examine the clinical associations between hypopituitarism, hypothalamic dysfunction, and nonalcoholic fatty liver disease (NAFLD). A case series of patients seen at our institution with diagnoses of hypopituitarism, hypothalamic obesity, or craniopharyngioma and NAFLD was undertaken. Clinical, laboratory, and liver biopsy features were reviewed. Twenty-one patients were identified. NAFLD was diagnosed 6.4 +/- 7.5 years (median 3 years) after the diagnosis of hypothalamic/pituitary dysfunction. Mean gain in body mass index (BMI) between diagnoses of hypothalamic/pituitary disease and NAFLD was 11.3 +/- 8.9 kg/m(2) at an average yearly rate of 2.2 +/- 2.2 kg/m(2). The majority of patients developed elevated glucose levels and dyslipidemia by time of diagnosis of NAFLD. Of the 10 patients biopsied, six were cirrhotic, two had nonalcoholic steatohepatitis (NASH) with fibrosis, and two had simple steatosis. Long-term follow-up of 66 +/- 33 months (range 12-120) was available for 18 patients. Two required liver transplantation. Six patients died, two from liver related causes. In conclusion, patients with hypothalamic and/or pituitary disease are at risk of excessive weight gain, impaired glucose tolerance, and dyslipidemia with subsequent development of NAFLD. This group has a high prevalence of cirrhosis placing them at risk for liver-related death. The novel evidence that hypothalamic/pituitary dysfunction may be accompanied by progressive NAFLD has important implications for the work-up and management of patients with hypothalamic/pituitary disease.