Peripheral insulin resistance predicts liver damage in nondiabetic subjects with nonalcoholic fatty liver disease.

UNLABELLED: Surrogate indexes of insulin resistance and insulin sensitivity are widely used in nonalcoholic fatty liver disease (NAFLD), although they have never been validated in this population. We aimed to validate the available indexes in NAFLD subjects and to test their ability to predict liver damage also in comparison with the NAFLD fibrosis score. Surrogate indexes were validated by the tracer technique (6,6-D2 -glucose and U-(13) C-glucose) in the basal state and during an oral glucose tolerance test. The best-performing indexes were used in an independent cohort of 145 nondiabetic NAFLD subjects to identify liver damage (fibrosis and nonalcoholic steatohepatitis). In the validation NAFLD cohort, homeostasis model assessment of insulin resistance, insulin to glucose ratio, and insulin sensitivity index Stumvoll had the best association with hepatic insulin resistance, while peripheral insulin sensitivity was most significantly related to oral glucose insulin sensitivity index (OGIS), insulin sensitivity index Stumvoll, and metabolic clearance rate estimation without demographic parameters. In the independent cohort, only oral glucose tolerance test-derived indexes were associated with liver damage and OGIS was the best predictor of significant (≥F2) fibrosis (odds ratio = 0.76, 95% confidence interval 0.61-0.96, P = 0.0233) and of nonalcoholic steatohepatitis (odds ratio = 0.75, 95% confidence interval 0.63-0.90, P = 0.0021). Both OGIS and NAFLD fibrosis score identified advanced (F3/F4) fibrosis, but OGIS predicted it better than NAFLD fibrosis score (odds ratio = 0.57, 95% confidence interval 0.45-0.72, P < 0.001) and was also able to discriminate F2 from F3/F4 (P < 0.003). CONCLUSION: OGIS is associated with peripheral insulin sensitivity in NAFLD and inversely associated with an increased risk of significant/advanced liver damage in nondiabetic subjects with NAFLD.

Different Serum Free Fatty Acid Profiles in NAFLD Subjects and Healthy Controls after Oral Fat Load.

BACKGROUND: Free fatty acid (FFA) metabolism can impact on metabolic conditions, such as obesity and nonalcoholic fatty liver disease (NAFLD). This work studied the increase in total FFA shown in NAFLD subjects to possibly characterize which fatty acids significantly accounted for the whole increase. METHODS: 21 patients with NAFLD were selected according to specified criteria. The control group consisted of nine healthy subjects. All subjects underwent an oral standard fat load. Triglycerides; cholesterol; FFA; glucose and insulin were measured every 2 h with the determination of fatty acid composition of FFA. RESULTS: higher serum FFA levels in NAFLD subjects are mainly due to levels of oleic, palmitic and linoleic acids at different times. Significant increases were shown for docosahexaenoic acid, linolenic acid, eicosatrienoic acid, and arachidonic acid, although this was just on one occasion. In the postprandial phase, homeostatic model assessment HOMA index positively correlated with the ω3/ω6 ratio in NAFLD patients. CONCLUSIONS: the higher serum levels of FFA in NAFLD subjects are mainly due to levels of oleic and palmitic acids which are the most abundant circulating free fatty acids. This is almost exactly corresponded with significant increases in linoleic acid. An imbalance in the n-3/n-6 fatty acids ratio could modulate postprandial responses with more pronounced effects in insulin-resistant subjects, such as NAFLD patients.

Systemic Complications of Nonalcoholic Fatty Liver Disease: When the Liver Is Not an Innocent Bystander.

The top three leading causes of death in patients with nonalcoholic fatty liver disease (NAFLD) in descending order are cardiovascular disease, cancer, and liver disease. It is clear now that the increased risk of metabolic and macro- and microvascular complications in NAFLD stems from the associated features of metabolic syndrome. However, NAFLD itself may contribute to the spectrum of risk factors associated with insulin resistance. The primary focus of this review is to summarize the main systemic associations of NAFLD, as well as to discuss the mechanisms that link them to NAFLD. Hepatic lipid accumulation in NAFLD impairs hepatic glucose and lipid metabolism further increasing the risk of type 2 diabetes mellitus and of cardiovascular disease, independently of established risk factors. The incidence, prevalence, and severity of these complications are proportional to the histological severity of liver damage suggesting that NAFLD, but particularly nonalcoholic steatohepatitis, can also contribute to the low-grade inflammatory state through the systemic release of several markers of inflammation, oxidative stress, and of procoagulant factors. The clinical implication of these findings is that patients with NAFLD require a multidisciplinary evaluation, with a major focus on type 2 diabetes mellitus and cardiovascular disease complications and may benefit from more intensive surveillance and early treatment interventions to decrease the risk for cardiovascular and kidney complications.

The combination of liver stiffness measurement and NAFLD fibrosis score improves the noninvasive diagnostic accuracy for severe liver fibrosis in patients with nonalcoholic fatty liver disease.

BACKGROUND & AIMS: The accuracy of noninvasive tools for the diagnosis of severe fibrosis in patients with nonalcoholic fatty liver disease(NAFLD) in clinical practice is still limited. We aimed at assessing the diagnostic performance of combined noninvasive tools in two independent cohorts of Italian NAFLD patients. METHODS: We analysed data from 321 Italian patients(179 Sicilian-training cohort, and 142 northern Italy-validation cohort) with an histological diagnosis of NAFLD. Severe fibrosis was defined as fibrosis ≥ F3 according to Kleiner classification. The APRI, AST/ALT, BARD, FIB-4, and NFS scores were calculated according to published algorithms. Liver stiffness measurement(LSM) was performed by FibroScan. Cut-off points of LSM, NFS and FIB-4 for rule-in or rule-out F3-F4 fibrosis were calculated by the reported formulas. RESULTS: In the Sicilian cohort AUCs of LSM, NFS, FIB-4, LSM plus NFS, LSM plus FIB-4, and NFS plus FIB-4 were 0.857, 0.803, 0.790, 0.878, 0.888 and 0.807, respectively, while in the northern Italy cohort the corresponding AUCs were 0.848, 0.730, 0.703, 0.844, 0.850, and 0.733 respectively. In the training cohort, the combination of LSM plus NFS was the best performing strategy, providing false positive, false negative and uncertainty area rates of 0%,1.1% and 48% respectively. Similar results were obtained in the validation cohort with false positive, false negative and uncertainty area rates of 0%,7.3% and 40.8%. CONCLUSIONS: The combination of LSM with NFS, two complementary, easy-to-perform, and widely available tools, is able to accurately diagnose or exclude the presence of severe liver fibrosis, also reducing of about 50-60% the number of needed diagnostic liver biopsies.

Serum ferritin levels lack diagnostic accuracy for liver fibrosis in patients with nonalcoholic fatty liver disease.

BACKGROUND & AIMS: Series studies have associated increased serum levels of ferritin with liver fibrosis in patients with nonalcoholic fatty liver disease. We aimed to determine the accuracy with which measurements of serum ferritin determine the presence and severity of liver fibrosis, and whether combining noninvasive scoring systems with serum ferritin analysis increases the accuracy of diagnosis of advanced liver fibrosis. METHODS: We performed a retrospective analysis of data from 1014 patients with liver biopsy-confirmed nonalcoholic fatty liver disease. Three cut points of serum ferritin level, adjusted for sex, were established based on receiver operating characteristic curve analysis: 1.0-, 1.5-, and 2.0-fold the upper limit of normal. Three multiple logistic regression models were created to determine the association of these cutoff values with liver fibrosis, adjusting for age, sex, race, diabetes, body mass index, and level of alanine aminotransferase. RESULTS: A greater proportion of patients with increased serum levels of ferritin had definitive nonalcoholic steatohepatitis and more-advanced fibrosis than patients without increased levels. In all models, serum level of ferritin was significantly associated with the presence and severity of liver fibrosis. However, for all 3 cutoff values, area under the receiver operating characteristic curve values were low (less than 0.60) for the presence of fibrosis or any stage of liver fibrosis; ferritin level identified patients with fibrosis with 16%-41% sensitivity and 70%-92% specificity. The accuracy with which noninvasive scoring systems identified patients with advanced fibrosis did not change with inclusion of serum ferritin values. CONCLUSIONS: Although serum levels of ferritin correlate with more-severe liver fibrosis, based on adjusted multiple logistic regression analysis, serum ferritin levels alone have a low level of diagnostic accuracy for the presence or severity of liver fibrosis in patients with nonalcoholic fatty liver disease.

Unexplained common bile duct dilatation with normal serum liver enzymes: diagnostic yield of endoscopic ultrasound and follow-up of this condition.

BACKGROUND: There is scant literature about common bile duct (CBD) dilatation with normal liver function tests (LFTs). AIMS: The aims of this study were to assess the diagnostic yield of endoscopic ultrasound (EUS) in patients with CBD dilatation, normal LFTs, and prior inconclusive imaging tests, and to assess the natural history of these subjects. METHODS: We retrospectively reviewed our EUS database for patients referred for evaluation of CBD dilatation, normal LFTs, and prior inconclusive imaging. We excluded patients with a prior endoscopic retrograde cholangiopancreatography or a history of biliary obstruction, pancreatitis, or jaundice. Follow-up data were retrieved from medical records or by calling the general practitioners, referring specialists, patients, or their closest relatives. RESULTS: A total of 57 patients were enrolled. The mean CBD diameter was 12.5±3.6 mm. The majority of patients (50.8%) were asymptomatic. Abnormal EUS findings were recorded in 12 (21%) subjects: 6 patients had a periampullary diverticulum, 2 had ampullary adenoma, 2 had signs of chronic pancreatitis, 1 had a cancer of the pancreatic head, and 1 had a 7 mm CBD stone. Neither age, sex, prior cholecystectomy, clinical presentation, CBD diameter, nor a dilated main pancreatic duct were predictors of abnormal EUS findings. None of the patients complained of biliary symptoms or showed abnormal LFTs on long-term follow-up. CONCLUSIONS: CBD dilatation with normal liver chemistry is not always a benign condition. Even when prior imaging tests are negative, EUS may allow to diagnose conditions overlooked by standard diagnostic imaging.

Preliminary experience with a new cytology brush in EUS-guided FNA.

BACKGROUND: Despite the high diagnostic yield of EUS-guided FNA, room for technical improvements remains. Recently, the EchoBrush (Cook Endoscopy, Winston-Salem, NC), a disposable cytologic brush, was introduced to the market. To date, only 1 study, limited to 10 pancreatic cyst cases, using this device has been published. OBJECTIVE: To assess the diagnostic yield of the EchoBrush in a cohort of consecutive patients, irrespective of the target lesion. DESIGN: Case series. SETTING: Tertiary care university hospital (Molinette Hospital, Turin, Italy). PATIENTS: Thirty-nine consecutive patients (12 with solid pancreatic masses, 12 with pancreatic cysts, 7 with enlarged lymph nodes, and 8 with submucosal masses) were enrolled. INTERVENTIONS: The material collected with the EchoBrush and with a standard FNA needle was double-blind evaluated by 2 cytopathologists. MAIN OUTCOME MEASUREMENTS: Adequacy of the sample and sensitivity and specificity of the EchoBrush method. RESULTS: Adequate material for cytologic analysis was collected in 17 of 39 patients (43.6%) with a single pass of the EchoBrush. Results were better for pancreatic lesions (for solid and cystic lesions, the adequacy was 58.3% and 50%, respectively); adequacy was low (28.6% and 25%, respectively) for lymph nodes and submucosal masses. The overall sensitivity and specificity were 57.9% and 31.2%, respectively. There were no adverse events with the procedure. LIMITATION: Preliminary study. CONCLUSIONS: This report suggests that the EchoBrush may provide adequate cellularity to diagnose solid and cystic pancreatic lesions. More extensive studies are needed to compare the EchoBrush and standard needles.

The natural history of gastrointestinal subepithelial tumors arising from muscularis propria: an endoscopic ultrasound survey.

AIM: The majority of lesions originating from muscularis propria of stomach, duodenum, and colon are gastrointestinal stromal tumors (GISTs). Surgery is indicated when endosonographic criteria of malignancy are met, but little is known about the natural history of lesions with benign endosonographic features. Aim of this study was to evaluate the natural course of benign-appearing lesions originating from muscularis propria in organs where GISTs significantly overcome leiomyomas. MATERIALS AND METHODS: A total of 49 asymptomatic patients with hypoechoic lesions originating from the fourth layer of the gastrointestinal tract entered a follow-up program by means of endoscopic ultrasonography. All lesions were nonulcerated, <3 cm in maximal diameter, with regular margins, and cystic spaces of <3 mm. RESULTS: After a mean follow-up of 31+/-20.8 months and a median of 2 (range, 1 to 5) endosonographies/patient, no change in echostructure or dimensions was seen in 44 subjects whereas in 5, an increase of at least 25% in 1 diameter occurred. Surgical removal was proposed to all: 1 patient refused (she is still alive and symptom-free after 4 y), 3 of the 4 lesions removed proved to be GISTs with very low or low risk of malignancy and 1 lesion was classified as a glomus tumor with no malignant appearance. CONCLUSIONS: Even small and benign-appearing lesions from muscularis propria may increase in size over time but this increase cannot be considered as an index of malignancy. As most of these lesions are GISTs, a policy of surveillance is advisable.

Pancreatic cancer imaging: the new role of endoscopic ultrasound.

Pancreatic cancer is the most deadly of all gastrointestinal malignancies and has a very poor prognosis. Unfortunately, most patients present late in the course of their disease and, at the time of diagnosis, only 10 to 25% of patients will be eligible for potentially curative resection. Efforts must be oriented towards an early diagnosis and towards reliably identifying patients who can really benefit from major surgery. A suspected pancreatic tumor can be a difficult challenge for the clinician. In the last ten years, we have witnessed notable technological improvements in radiological and nuclear imaging. Taking this into account, we will try to delineate the new role of endoscopic ultrasound (EUS) in pancreatic tumor imaging and to place EUS in a shareable diagnostic and staging algorithm. To date, the most accurate imaging techniques for pancreatic neoplasms remain contrast-enhanced computed tomography and EUS. EUS has the highest accuracy in detecting small lesions, in assessing tumor size and lymph node involvement, but helical CT must still be the first choice in patients with a suspected pancreatic tumor. However, after this first step, there is a place for EUS as a second diagnostic level in several cases: negative results on CT scan and persistent strong clinical suspicion of pancreatic cancer, doubtful results on CT scans or the need for cytohistological confirmation. In the near future, there will be great opportunities for the development of diagnostic and therapeutic EUS and pancreatic cancer could be the best testing ground.

Cytokeratin 18-Aspartate396 apoptotic fragment for fibrosis detection in patients with non-alcoholic fatty liver disease and chronic viral hepatitis.

BACKGROUND: The combination of non-invasive markers for the detection of fibrosis in patients with chronic liver diseases is still a matter of debate. AIMS: To test the performance of cytokeratin18-Aspartate396 alone or in combination with transient elastography as a marker of fibrosis, compared to liver biopsy as gold standard. METHODS: In 259 prospectively enrolled patients with chronic liver diseases, clinical, biochemical, and histological features were assessed. Serum cytokeratin18-Aspartate396 and Fibroscan were performed within 6 months prior to liver biopsy. RESULTS: Cytokeratin18-Aspartate396 levels predicted both significant and advanced fibrosis in non-alcoholic fatty liver disease group, correctly identifying 83.7% and 80.8% of cases, respectively. Liver stiffness performed best in predicting severe fibrosis in patients with chronic viral infection, correctly identifying 78.7% of chronic hepatitis B and 88.6% of chronic hepatitis C subjects. The combination of cytokeratin18-Aspartate396 and liver stiffness improved their diagnostic performance for the detection of significant and advanced fibrosis in non-alcoholic fatty liver disease group, only (sensitivity=78.3%, specificity=90.7%; sensitivity=91.7%, specificity=71.6%, respectively). CONCLUSION: Cytokeratin18-Aspartate396 and liver stiffness can improve the non-invasive prediction of significant and advanced fibrosis in patients with non-alcoholic fatty liver disease, while in hepatitis B and C virus infected patients their combined use had no advantage over the diagnostic accuracy of transient elastography alone.

Adrenal function and microbial DNA in noninfected cirrhotic patients with ascites: Relationship and effect on survival.

BACKGROUND: There are few data on clinical relevance of adrenal dysfunction and its relationship with occult microbial DNA in noninfected haemodynamically stable cirrhotic patients with ascites. AIMS: The aim of this study was to evaluate prognostic role of adrenal dysfunction, microbial DNA, and their relationship. METHODS: Adrenal function was assessed in 93 consecutive patients following a corticotropin stimulation test. Adrenal dysfunction was defined as: basal cortisol <10 µg/dl, delta cortisol <9 µg/dl, or peak cortisol <18 µg/dl. Microbial DNA was assessed in blood and ascites of 54 consecutive patients. Patients were followed up until liver transplantation or death. RESULTS: Adrenal dysfunction was not significantly associated with mortality, while the risk of death rose significantly with an increase in basal cortisol values (HR 1.13 per 1-µl/dl increase; 95% CI 1.01-1.26). Microbial DNA was independently associated with reduced survival (HR 8.05, 95% CI 1.57-41.2). In microbial DNA-positive patients a significant correlation was found between Model for End-Stage Liver Disease (MELD) score and basal cortisol values (Pearson's r=0.5107; p=0.018). CONCLUSIONS: Microbial DNA and MELD score, but not adrenal function, were the best independent predictors of mortality in noninfected cirrhotic patients with ascites. High serum cortisol levels may be a systemic reaction to microbial translocation, increasing in parallel with deterioration of liver function.

Prevention of paracentesis-induced circulatory dysfunction in cirrhosis: standard vs half albumin doses. A prospective, randomized, unblinded pilot study.

BACKGROUND: Paracentesis-induced circulatory dysfunction is a well-known complication of large volume paracentesis. Albumin infusion (8g of albumin/L of ascites removed) is effective in preventing it, but high costs and scant availability limit its use. AIM: To compare standard vs half albumin doses. METHODS: Seventy cirrhotic patients treated with large volume paracentesis were randomized to receive intravenous albumin as prevention of paracentesis-induced circulatory dysfunction: group 1 (35 patients) received 4g/L of ascites removed, group 2 (35 patients) received 8g/L of ascites removed. RESULTS: The incidence of paracentesis-induced circulatory dysfunction (14% vs 20% in group 1 and group 2, respectively; p=ns), hyponatremia (9% vs 6%, p=ns) and renal impairment (0% in both groups) on the 6th day from paracentesis was similar between the two groups. After 6 months of follow-up, rates of survival and of recurrence of ascites requiring large volume paracentesis were not different between the two groups. CONCLUSIONS: This unblinded, randomized, pilot study suggests that treatment with half doses of albumin is effective in the prevention of paracentesis-induced circulatory dysfunction and its related clinical complications in cirrhotic patients with tense ascites treated by large volume paracentesis. If confirmed, these results could support a significant costs reduction in the management of ascites in cirrhotic patients.