Bile acids associate with specific gut microbiota, low-level alcohol consumption and liver fibrosis in patients with non-alcoholic fatty liver disease.

BACKGROUND: Bile acids (BAs) are synthesized by the liver and modified by gut bacteria, and may play an intermediary role between the gut microbiome and liver in promoting fibrosis in non-alcoholic fatty liver disease (NAFLD). We investigated the associations between serum and faecal BAs, gut microbiome and fibrosis in patients with and without NAFLD and examined the impact of diet and alcohol consumption on these relationships. METHODS: Adult patients (n = 122) underwent liver biopsy and BAs characterization by high-performance liquid chromatography/mass spectrometry. Gut microbiome composition was analysed using next-generation 16S rRNA sequencing. Diet and alcohol intake were determined by 3-day food diary. RESULTS: Serum and faecal BA concentrations increased progressively among non-NAFLD controls (n = 55), NAFLD patients with no/mild fibrosis (F0-2, n = 58) and NAFLD with advanced fibrosis (F3/4, n = 9). Progressive increases in serum BAs were driven by primary conjugated BAs including glycocholic acid [GCA] and secondary conjugated BAs. In contrast, faecal BA increase was driven by secondary unconjugated BAs (predominately deoxycholic acid [DCA]). Serum GCA levels and faecal DCA levels correlated with the abundance of Bacteroidaceae and Lachnospiraceae, and stool secondary BAs with an unclassifiable family of the order Bacteroidales (Bacteroidales;other). These bacterial taxa were also associated with advanced fibrosis. Modest alcohol consumption was positively correlated with faecal DCA levels and relative abundance of Lachnospiracaea and Bacteroidales;other. CONCLUSIONS: Higher serum and faecal BA levels are associated with advanced fibrosis in NAFLD. Specific gut bacteria link alterations in BA profiles and advanced fibrosis, and may be influenced by low-level alcohol consumption.

Ad Libitum Mediterranean and Low-Fat Diets Both Significantly Reduce Hepatic Steatosis: A Randomized Controlled Trial.

Although diet-induced weight loss is first-line treatment for patients with nonalcoholic fatty liver disease (NAFLD), long-term maintenance is difficult. The optimal diet for improvement in either NAFLD or associated cardiometabolic risk factors, regardless of weight loss, is unknown. We examined the effect of two ad libitum isocaloric diets (Mediterranean [MD] or low fat [LF]) on hepatic steatosis (HS) and cardiometabolic risk factors. Subjects with NAFLD were randomized to a 12-week blinded dietary intervention (MD vs. LF). HS was determined by magnetic resonance spectroscopy (MRS). From a total of 56 subjects enrolled, 49 completed the intervention and 48 were included for analysis. During the intervention, subjects on the MD had significantly higher total and monounsaturated fat, but lower carbohydrate and sodium, intakes compared to LF subjects (P < 0.01). At week 12, HS had reduced significantly in both groups (P < 0.01), and there was no difference in liver fat reduction between groups (P = 0.32), with mean (SD) relative reductions of 25.0% (±25.3%) in LF and 32.4% (±25.5%) in MD. Liver enzymes also improved significantly in both groups. Weight loss was minimal and not different between groups (-1.6 [±2.1] kg in LF vs -2.1 [±2.5] kg in MD; P = 0.52). Within-group improvements in Framingham Risk Score (FRS), total cholesterol, serum triglyceride (TG), and glycated hemoglobin (HbA1c) were observed in the MD (all P < 0.05), but not with the LF diet. Adherence was higher for the MD compared to LF (88% vs. 64%; P = 0.048). Conclusion: Ad libitum low-fat and Mediterranean diets both improve HS to a similar degree.

Type and Pattern of Alcohol Consumption is Associated With Liver Fibrosis in Patients With Non-alcoholic Fatty Liver Disease.

INTRODUCTION: It is unclear whether low levels of alcohol are harmful in patients with non-alcoholic fatty liver disease (NAFLD). We aimed to determine whether quantity, binge pattern consumption, or type of alcohol was associated with liver fibrosis in patients with NAFLD. METHODS: Previous and current alcohol consumption was assessed in NAFLD patients undergoing liver biopsy. All subjects currently consumed <210 g per week (male) or <140 g per week (female). Binge consumption was defined as ≥4 standard drinks (female) or ≥5 standard drinks (male) in one sitting. Liver biopsies were scored according to the NASH CRN system with F3/4 fibrosis defined as advanced. RESULTS: Among 187 patients (24% with advanced fibrosis), the median weekly alcohol consumption was 20 (2.3-60) g over an average of 18 years. Modest consumption (1-70 g per week) was associated with lower mean fibrosis stage compared to lifetime abstainers (p < 0.05) and a decreased risk of advanced fibrosis (OR 0.33, 95% CI 0.14-0.78, p = 0.01). The association with reduced fibrosis was not seen in subjects drinking in a binge-type fashion. Exclusive wine drinkers but not exclusive beer drinkers, had lower mean fibrosis stage and lower odds of advanced fibrosis (OR 0.20, 95% CI 0.06-0.69, p = 0.01), compared to lifetime abstinent subjects. No interaction between gender and alcohol quantity, type, or binge consumption on fibrosis was observed. DISCUSSION: Modest (1-70 g per week) alcohol consumption, particularly wine in a non-binge pattern, is associated with lower fibrosis in patients with NAFLD. Prospective longitudinal studies into fibrosis progression, cardiovascular outcomes, and mortality are required before clinical recommendations can be made.

The impact of phlebotomy in nonalcoholic fatty liver disease: A prospective, randomized, controlled trial.

UNLABELLED: Iron is implicated in the pathogenesis of liver injury and insulin resistance (IR) and thus phlebotomy has been proposed as a treatment for nonalcoholic fatty liver disease (NAFLD). We performed a prospective 6-month randomized, controlled trial examining the impact of phlebotomy on the background of lifestyle advice in patients with NAFLD. Primary endpoints were hepatic steatosis (HS; quantified by magnetic resonance imaging) and liver injury (determined by alanine aminotransaminase [ALT] and cytokeratin-18 [CK-18]). Secondary endpoints included insulin resistance measured by the insulin sensitivity index (ISI) and homeostasis model of assessment (HOMA), and systemic lipid peroxidation determined by plasma F2-isoprostane levels. A total of 74 subjects were randomized (33 phlebotomy and 41 control). The phlebotomy group underwent a median (range) of 7 (1-19) venesection sessions and had a significantly greater reduction in ferritin levels over 6 months, compared to controls (-148 ± 114 vs. -38 ± 89 ng/mL; P < 0.001). At 6 months, there was no difference between phlebotomy and control groups in HS (17.7% vs. 15.5%; P = 0.4), serum ALT (36 vs. 46 IU/L; P = 0.4), or CK-18 levels (175 vs. 196 U/L; P = 0.9). Similarly, there was no difference in end-of-study ISI (2.5 vs. 2.7; P = 0.9), HOMA (3.2 vs. 3.2; P = 0.6), or F2-isoprostane levels (1,332 vs. 1,190 pmmol/L; P = 0.6) between phlebotomy and control groups. No differences in any endpoint were noted in patients with hyperferritinemia at baseline. Among patients undergoing phlebotomy, there was no correlation between number of phlebotomy sessions and change in HS, liver injury, or IR from baseline to end of study. CONCLUSION: Reduction in ferritin by phlebotomy does not improve liver enzymes, hepatic fat, or IR in subjects with NAFLD.

High biological variation of serum hyaluronic acid and Hepascore, a biochemical marker model for the prediction of liver fibrosis.

BACKGROUND: Serum hyaluronic acid and biochemical models which require hyaluronic acid analysis are commonly used as predictors of liver fibrosis in patients with chronic liver disease, however biological variation data for hyaluronic acid are deficient. METHODS: Four serial serum samples were obtained at weekly intervals from healthy volunteers and patients with chronic hepatitis B, chronic hepatitis C and non- alcoholic fatty liver disease (NAFLD; 20 in each group). The within-individual week-to-week variation (CVI) and reference change values for hyaluronic acid, α2-macroglobulin and Hepascore were obtained. Hepascore is calculated from hyaluronic acid, α2-macroglobulin, bilirubin and γ-glutamyltransferase activity. RESULTS: Hyaluronic acid displayed large within-individual variation, the CVI values were 62% in healthy subjects, 38% in hepatitis C, 37% in hepatitis B and 36% in NAFLD patients. Hepascore CVIs were 43% in healthy subjects, 24% in hepatitis C, 28% in hepatitis B and 39% in NAFLD patients. α2-Macroglobulin was much less variable with CVIs ranging from 4.4% to 7.6%. Bland-Altman plots of week-to-week variations showed rates of significant disagreement for samples collected in any 2 successive weeks varied from 5% in NAFLD patients to 8.3% in healthy subjects. CONCLUSIONS: When using non-fasting serum samples, hyaluronic acid and to a lesser extent, the Hepascore model display large within-individual variations in both health and chronic liver disease. This information is critical for interpreting the significance of both single measurements and changes in serial measurements.

Complex non-invasive fibrosis models are more accurate than simple models in non-alcoholic fatty liver disease.

BACKGROUND AND AIM: Significant hepatic fibrosis is prognostic of liver morbidity and mortality in non-alcoholic fatty liver disease (NAFLD); however, it remains unclear whether non-invasive fibrosis models can determine this end-point. We therefore compared the accuracy of simple bedside versus complex fibrosis models across a range of fibrosis in a multi-centre NAFLD cohort. METHODS: Simple (APRI, BARD) and complex (Hepascore, Fibrotest, FIB4) fibrosis models were calculated in 242 NAFLD subjects undergoing liver biopsy. Significant (F2-4) and advanced fibrosis (F3,4) were defined using Kleiner criteria. Models were compared using area under the receiver operator characteristic curves (AUC). Cut-offs were determined by Youden Index or 90% predictive values. RESULTS: For significant fibrosis, non-invasive fibrosis models had modest accuracy (AUC 0.707-0.743) with BARD being least accurate (AUC 0.609, P < 0.05 vs others). Using single cut-offs, sensitivities and predictive values were < 80%; using two cut-offs, > 75% of subjects fell within indeterminate ranges. Simple models had significantly more subjects within indeterminate ranges than complex models (99.1-100% vs 82.1-84.4% respectively, P < 0.05 for all). For advanced fibrosis, complex models were more accurate than BARD (AUC 0.802-0.858 vs 0.701, P < 0.05). Using two cut-offs, complex models had fewer individuals within indeterminate ranges than BARD (11.1-32.3% vs 70.7%, P < 0.01 for all). For cirrhosis, complex models had higher AUC values than simple models. CONCLUSIONS: In NAFLD subjects, non-invasive models have modest accuracy for determining significant fibrosis and have predictive values less than 90% in the majority of subjects. Complex models are more accurate than simple bedside models across a range of fibrosis.

Hepatic iron concentration correlates with insulin sensitivity in nonalcoholic fatty liver disease.

Rodent and cell-culture models support a role for iron-related adipokine dysregulation and insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD); however, substantial human data are lacking. We examined the relationship between measures of iron status, adipokines, and insulin resistance in patients with NAFLD in the presence and absence of venesection. This study forms part of the Impact of Iron on Insulin Resistance and Liver Histology in Nonalcoholic Steatohepatitis (IIRON2) study, a prospective randomized controlled trial of venesection for adults with NAFLD. Paired serum samples at baseline and 6 months (end of treatment) in controls (n = 28) and patients who had venesection (n = 23) were assayed for adiponectin, leptin, resistin, retinol binding protein-4, tumor necrosis factor α, and interleukin-6, using a Quantibody, customized, multiplexed enzyme-linked immunosorbent assay array. Hepatic iron concentration (HIC) was determined using MR FerriScan. Unexpectedly, analysis revealed a significant positive correlation between baseline serum adiponectin concentration and HIC, which strengthened after correction for age, sex, and body mass index (rho = 0.36; P = 0.007). In addition, there were significant inverse correlations between HIC and measures of insulin resistance (adipose tissue insulin resistance (Adipo-IR), serum insulin, serum glucose, homeostasis model assessment of insulin resistance, hemoglobin A1c, and hepatic steatosis), whereas a positive correlation was noted with the insulin sensitivity index. Changes in serum adipokines over 6 months did not differ between the control and venesection groups. Conclusion: HIC positively correlates with serum adiponectin and insulin sensitivity in patients with NAFLD. Further study is required to establish causality and mechanistic explanations for these associations and their relevance in the pathogenesis of insulin resistance and NAFLD. (Hepatology Communications 2018;2:644-653).

Nonalcoholic fatty liver disease-related cirrhosis is commonly unrecognized and associated with hepatocellular carcinoma.

Determination of cirrhosis in nonalcoholic fatty liver disease (NAFLD) is important as it alters prognosis and management. We aimed to examine whether cirrhosis was diagnosed incidentally or intentionally in patients with NAFLD. We reviewed 100 patients with NAFLD cirrhosis to determine mode of cirrhosis diagnosis (incidental or by intent), severity of liver disease at diagnosis, diagnostician, and previous clinical imaging or laboratory evidence of unrecognized cirrhosis. The majority (66/100) of patients with NAFLD cirrhosis were diagnosed incidentally, with the majority of these (74%) diagnosed with NAFLD simultaneously. Those with incidental cirrhosis diagnoses had more deranged platelet and international normalized ratio levels (P < 0.05) and were more likely to have concomitant hepatocellular carcinoma (HCC) (12% versus 0%, P < 0.05). Incidental cirrhosis was diagnosed following imaging (32%) or liver tests (26%) performed for reasons unrelated to liver disease, following unexpected endoscopic finding of varices (21%) or an unexpected surgical finding (14%). Diagnoses by intent were predominantly made by gastroenterologists/hepatologists, whereas general practitioners, surgeons, and physicians tended to diagnose cirrhosis incidentally (P < 0.001). The majority of patients diagnosed incidentally (n = 48/66, 73%) had previous thrombocytopenia, splenomegaly, or high noninvasive fibrosis scores. Following diagnosis, patients diagnosed incidentally were less likely to undergo HCC screening. Conclusion: The majority of patients with NAFLD cirrhosis are diagnosed incidentally. These patients are more likely to have advanced liver disease and HCC. Increased awareness of screening for cirrhosis is needed in patients with NAFLD. (Hepatology Communications 2017;1:53-60).

Interleukin-12 is associated with arterial stiffness in healthy individuals.

BACKGROUND: Atherosclerotic cardiovascular disease (CVD) is a chronic inflammatory disease mediated by the proinflammatory cytokines interleukin-12 (IL-12) and interleukin-18 (IL-18). Evidence suggests that IL-12 is dominant in early atherosclerosis, while IL-18 is critical in advanced atherosclerosis. In this study, we explore the association between IL-12 and IL-18 and arterial stiffness in healthy individuals. METHODS: We performed a cross-sectional study examining pulse wave velocity (PWV), augmentation index (AIx), IL-12, and IL-18 in healthy individuals (N = 53) without CVD risk factors. RESULTS: In multivariate regression, age (P < 0.01), systolic blood pressure (P = 0.05), and IL-12 (P < 0.01) were positively associated with PWV, and high-density lipoprotein (P = 0.04) was negatively associated with PWV (model R (2) = 0.476, P < 0.01). CONCLUSIONS: IL-12, but not IL-18, is associated with PWV in healthy individuals without clinical CVD, supporting a role for IL-12 in early atherosclerosis as suggested by animal studies.

Erectile dysfunction predicts generalised cardiovascular disease: evidence from a case-control study.

AIMS: To determine whether idiopathic erectile dysfunction, in the absence of overt cardiovascular disease or cardiovascular risk factors, is associated with vascular or autonomic dysfunction. METHODS: We studied 49 men with ED (without known cardiovascular risk factors or disease) and 50 age-matched controls, aged 40-70 years. Macrovascular endothelial function was examined by brachial artery ultrasonography and microvascular function by venous occlusion plethysmography. Blood pressure measurement and electrocardiography were performed lying and standing, and the 30:15 RR ratio calculated. RESULTS: Body mass index, testosterone, fasting lipids and glucose did not differ significantly between groups. Standing pulse pressure was higher (50+/-1mm Hg versus 43+/-2mm Hg, p<0.004) and 30:15 RR ratio lower (0.97+/-0.01 versus 1.01+/-0.01, p<0.02) in the ED group. Flow-mediated dilatation of the brachial artery was not significantly different between groups. Flow debt repayment during forearm reactive hyperaemia was lower in the ED group (7.2+/-0.7 ml versus 9.5+/-0.8 ml per 100ml, p<0.02) than in controls. CONCLUSIONS: Men with idiopathic ED have evidence of endothelial dysfunction in forearm resistance vessels, increased pulse pressure and impaired heart rate variability. This supports the concept that erectile dysfunction is a predictor of cardiovascular dysfunction and a precursor of clinical cardiovascular disease.