Organizational and Implementation Factors Associated with Cirrhosis Care in the Veterans Health Administration.

BACKGROUND: The Veterans Health Administration provides care to more than 100,000 Veterans with cirrhosis. AIMS: This implementation evaluation aimed to understand organizational resources and barriers associated with cirrhosis care. METHODS: Clinicians across 145 Department of Veterans Affairs (VA) medical centers (VAMCs) were surveyed in 2022 about implementing guideline-concordant cirrhosis care. VA Corporate Data Warehouse data were used to assess VAMC performance on two national cirrhosis quality measures: HCC surveillance and esophageal variceal surveillance or treatment (EVST). Organizational factors associated with higher performance were identified using linear regression models. RESULTS: Responding VAMCs (n = 124, 86%) ranged in resource availability, perceived barriers, and care processes. In multivariable models, factors independently associated with HCC surveillance included on-site interventional radiology and identifying patients overdue for surveillance using a national cirrhosis population management tool ("dashboard"). EVST was significantly associated with dashboard use and on-site gastroenterology services. For larger VAMCs, the average HCC surveillance rate was similar between VAMCs using vs. not using the dashboard (47% vs. 41%), while for smaller and less resourced VAMCs, dashboard use resulted in a 13% rate difference (46% vs. 33%). Likewise, higher EVST rates were more strongly associated with dashboard use in smaller (55% vs. 50%) compared to larger (57% vs. 55%) VAMCs. CONCLUSIONS: Resources, barriers, and care processes varied across diverse VAMCs. Smaller VAMCs without specialty care achieved HCC and EVST surveillance rates nearly as high as more complex and resourced VAMCs if they used a population management tool to identify the patients due for cirrhosis care.

Metabolic Dysfunction-Associated Steatotic Liver Disease: From Pathogenesis to Current Therapeutic Options.

The epidemiological burden of liver steatosis associated with metabolic diseases is continuously growing worldwide and in all age classes. This condition generates possible progression of liver damage (i.e., inflammation, fibrosis, cirrhosis, hepatocellular carcinoma) but also independently increases the risk of cardio-metabolic diseases and cancer. In recent years, the terminological evolution from "nonalcoholic fatty liver disease" (NAFLD) to "metabolic dysfunction-associated fatty liver disease" (MAFLD) and, finally, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been paralleled by increased knowledge of mechanisms linking local (i.e., hepatic) and systemic pathogenic pathways. As a consequence, the need for an appropriate classification of individual phenotypes has been oriented to the investigation of innovative therapeutic tools. Besides the well-known role for lifestyle change, a number of pharmacological approaches have been explored, ranging from antidiabetic drugs to agonists acting on the gut-liver axis and at a systemic level (mainly farnesoid X receptor (FXR) agonists, PPAR agonists, thyroid hormone receptor agonists), anti-fibrotic and anti-inflammatory agents. The intrinsically complex pathophysiological history of MASLD makes the selection of a single effective treatment a major challenge, so far. In this evolving scenario, the cooperation between different stakeholders (including subjects at risk, health professionals, and pharmaceutical industries) could significantly improve the management of disease and the implementation of primary and secondary prevention measures. The high healthcare burden associated with MASLD makes the search for new, effective, and safe drugs a major pressing need, together with an accurate characterization of individual phenotypes. Recent and promising advances indicate that we may soon enter the era of precise and personalized therapy for MASLD/MASH.

Overlooked subclinical portal hypertension in non-cirrhotic NAFLD: Is it real and how to measure it?

Clinical and experimental advances related to the detection, magnitude and pathobiology of subclinical portal hypertension in non-alcoholic fatty liver disease (NAFLD), primarily observed in the presence of non-alcoholic steatohepatitis (NASH), prompt us to revisit current disease paradigms. Hepatic venous pressure gradient (HVPG) has been reported to underestimate portal pressure in NASH-related cirrhosis, while inaccuracy is more likely in non-cirrhotic livers, indicating a potential need for new and preferably non-invasive methods of measurement. Although clinically significant portal hypertension (HVPG ≥10 mmHg) retains its prognostic significance in NASH, subclinical portal hypertension (HVPG 6.0-9.5 mmHg) has been repeatedly detected in patients with NAFLD in the absence of cirrhosis or even significant fibrosis whereas the impact of these findings on disease outcomes remains unclear. Mechanocrine signalling pathways in various types of liver cell reveal a molecular basis for the adverse effects of subclinical portal hypertension and suggest a bidirectional relationship between portal pressure and fibrosis. These findings may guide efforts to improve risk assessment and identify novel therapeutic targets in NAFLD.

Mechanotransduction in the pathogenesis of non-alcoholic fatty liver disease.

Mechanobiology is a domain of interdisciplinary research that aims to explore the impact of physical force, applied externally or internally, on cell and tissue function, including development, growth, and differentiation. Mechanotransduction is a term that describes how cells sense physical forces (such as compression, stretch, and shear stress), convert them into biochemical signals, and mount adaptive responses integrated by the nucleus. There is accumulating evidence that mechanical forces extensively inform the biological behaviour of liver cells in health and disease. Recent research has elucidated many cellular and molecular mechanisms involved in this process including the pleiotropic control and diverse effects of the paralogous transcription co-activators YAP/TAZ, which play a prominent role in mechanotransduction. The liver sinusoids represent a unique microenvironment in which cells are exposed to mechanical cues originating in the cytoskeleton and at interfaces with adjacent cells, the extracellular matrix, and vascular or interstitial fluids. In non-alcoholic fatty liver disease (NAFLD), hepatocellular lipid accumulation and ballooning, activation of inflammatory responses, dysfunction of liver sinusoidal endothelial cells, and transdifferentiation of hepatic stellate cells into a pro-contractile and pro-fibrotic phenotype have been associated with aberrant cycles of mechanosensing and mechanoresponses. The downstream consequences of disrupted mechanical homeostasis likely contribute to the progression of NAFLD and promote the development of portal hypertension, cirrhosis, and hepatocellular carcinoma. Identification of molecular targets involved in pathogenic mechanotransduction will allow for the development of novel strategies to prevent the progression of liver disease in NAFLD.

Microbiota transplantation in portal hypertension: promises and pitfalls.

In this commentary, we discuss new findings indicating that microbiota transplantation has favorable impact on portal hypertension (PH) in the experimental model of cirrhosis induced by bile duct ligation (BDL) (Huang et al.; Clin Sci (Lond) (2021) 135(24): 2709-2728, doi: 10.1042/CS20210602). Sinusoidal PH is an ominous outcome of advanced chronic liver disease, characterized by increased intrahepatic vascular resistance (IHVR), splanchnic hyperemia, and the development of portosystemic collaterals. In the work of Huang et al., microbiota transplantation not only alleviated splanchnic hyperdynamic circulation by improving vascular responsiveness and decreasing mesenteric angiogenesis, but also reduced blood flow in portosystemic collaterals. Surprisingly, however, microbiota transplantation had no effect on intrahepatic vasoconstriction in this experimental model. We discuss these observations in the context of recent literature showing that manipulation of the gut microbiota (either by transplantation or through the use of probiotics) may improve IHVR, which is one of the earliest abnormalities in the pathogenesis of sinusoidal PH. Further research is needed to explore the specific molecular and cellular targets associated with the correction of dysbiosis in liver disease.

Artificial Intelligence-Based Assessment of Colorectal Polyp Histology by Elastic-Scattering Spectroscopy.

BACKGROUND: Colonoscopic screening and surveillance for colorectal cancer could be made safer and more efficient if endoscopists could predict histology without the need to biopsy and perform histopathology on every polyp. Elastic-scattering spectroscopy (ESS), using fiberoptic probes integrated into standard biopsy tools, can assess, both in vivo and in real time, the scattering and absorption properties of tissue related to its underlying pathology. AIMS: The objective of this study was to evaluate prospectively the potential of ESS to predict polyp pathology accurately. METHODS: We obtained ESS measurements from patients undergoing screening/surveillance colonoscopy using an ESS fiberoptic probe integrated into biopsy forceps. The integrated forceps were used for tissue acquisition, following current standards of care, and optical measurement. All measurements were correlated to the index pathology. A machine learning model was then applied to measurements from 367 polyps in 169 patients to prospectively evaluate its predictive performance. RESULTS: The model achieved sensitivity of 0.92, specificity of 0.87, negative predictive value (NPV) of 0.87, and high-confidence rate (HCR) of 0.84 for distinguishing 220 neoplastic polyps from 147 non-neoplastic polyps of all sizes. Among 138 neoplastic and 131 non-neoplastic polyps ≤ 5 mm, the model achieved sensitivity of 0.91, specificity of 0.88, NPV of 0.89, and HCR of 0.83. CONCLUSIONS: Results show that ESS is a viable endoscopic platform for real-time polyp histology, particularly for polyps ≤ 5 mm. ESS is a simple, low-cost, clinically friendly, optical biopsy modality that, when interfaced with minimally obtrusive endoscopic tools, offers an attractive platform for in situ polyp assessment.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: Epidemiology, Pathogenesis, and Clinical and Research Implications.

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide, affecting up to ~30% of adult populations. NAFLD defines a spectrum of progressive liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma, which often occur in close and bidirectional associations with metabolic disorders. Chronic kidney disease (CKD) is characterized by anatomic and/or functional renal damage, ultimately resulting in a reduced glomerular filtration rate. The physiological axis linking the liver and kidneys often passes unnoticed until clinically significant portal hypertension, as a major complication of cirrhosis, becomes apparent in the form of ascites, refractory ascites, or hepatorenal syndrome. However, the extensive evidence accumulated since 2008 indicates that noncirrhotic NAFLD is associated with a higher risk of incident CKD, independent of obesity, type 2 diabetes, and other common renal risk factors. In addition, subclinical portal hypertension has been demonstrated to occur in noncirrhotic NAFLD, with a potential adverse impact on renal vasoregulation. However, the mechanisms underlying this association remain unexplored to a substantial extent. With this background, in this review we discuss the current evidence showing a strong association between NAFLD and the risk of CKD, and the putative biological mechanisms underpinning this association. We also discuss in depth the potential pathogenic role of the hepatorenal reflex, which may be triggered by subclinical portal hypertension and is a poorly investigated but promising research topic. Finally, we address emerging pharmacotherapies for NAFLD that may also beneficially affect the risk of developing CKD in individuals with NAFLD.

Real-time artificial intelligence-based histologic classification of colorectal polyps with augmented visualization.

BACKGROUND AND AIMS: Artificial intelligence (AI)-based computer-aided diagnostic (CADx) algorithms are a promising approach for real-time histology (RTH) of colonic polyps. Our aim is to present a novel in situ CADx approach that seeks to increase transparency and interpretability of results by generating an intuitive augmented visualization of the model's predicted histology over the polyp surface. METHODS: We developed a deep learning model using semantic segmentation to delineate polyp boundaries and a deep learning model to classify subregions within the segmented polyp. These subregions were classified independently and were subsequently aggregated to generate a histology map of the polyp's surface. We used 740 high-magnification narrow-band images from 607 polyps in 286 patients and over 65,000 subregions to train and validate the model. RESULTS: The model achieved a sensitivity of .96, specificity of .84, negative predictive value (NPV) of .91, and high-confidence rate (HCR) of .88, distinguishing 171 neoplastic polyps from 83 non-neoplastic polyps of all sizes. Among 93 neoplastic and 75 non-neoplastic polyps ≤5 mm, the model achieved a sensitivity of .95, specificity of .84, NPV of .91, and HCR of .86. CONCLUSIONS: The CADx model is capable of accurately distinguishing neoplastic from non-neoplastic polyps and provides a histology map of the spatial distribution of localized histologic predictions along the delineated polyp surface. This capability may improve interpretability and transparency of AI-based RTH and offer intuitive, accurate, and user-friendly guidance in real time for the clinical management and documentation of optical histology results.

Fresh frozen plasma transfusion in acute variceal haemorrhage: Results from a multicentre cohort study.

BACKGROUND: Fresh frozen plasma (FFP) transfusion is often used in the management of acute variceal haemorrhage (AVH) despite best practice advice suggesting otherwise. OBJECTIVE: We investigated if FFP transfusion affects clinical outcomes in AVH. DESIGN, SETTING AND PATIENTS: We performed a retrospective cohort study of 244 consecutive, eligible patients admitted to five tertiary health care centres between 2013 and 2018 with AVH. MAIN OUTCOME MEASUREMENTS: Multivariable regression analyses were used to study the association of FFP transfusion with mortality at 42 days (primary outcome) and failure to control bleeding at 5 days and length of stay (secondary outcomes). RESULTS: Patients who received FFP transfusion (n = 100) had higher mean Model for End Stage Liver Disease (MELD) score and more severe variceal bleeding than those who did not received FFP transfusion (n = 144). Multivariable analysis showed that FFP transfusion was associated with increased odds of mortality at 42 days (odds ratio [OR] 9.41, 95% confidence interval [CI] 3.71-23.90). FFP transfusion was also associated with failure to control bleeding at 5 days (OR 3.87, 95% CI 1.28-11.70) and length of stay >7 days (adjusted OR 1.88, 95% CI 1.03-3.42). The independent association of FFP transfusion with mortality at 42 days persisted when the cohort was restricted to high-risk patients and in patients without active bleeding. LIMITATIONS AND CONCLUSIONS: Fresh frozen plasma transfusion in AVH is independently associated with poor clinical outcomes. As this an observational study, there may be residual bias due to confounding; however, we demonstrate no benefit and potential harm with FFP transfusions in AVH.

Prevalence of Advanced Colorectal Neoplasia in Veterans: Effects of Age, Sex, and Race/Ethnicity.

GOAL: We sought to quantify the independent effects of age, sex, and race/ethnicity on risk of colorectal cancer (CRC) and advanced neoplasia (AN) in Veterans. STUDY: We conducted a retrospective, cross-sectional study of Veterans aged 40 to 80 years who had diagnostic or screening colonoscopy between 2002 and 2009 from 1 of 14 Veterans Affairs Medical Centers. Natural language processing identified the most advanced finding and location (proximal, distal). Logistic regression was used to examine the adjusted, independent effects of age, sex, and race, both overall and in screening and diagnostic subgroups. RESULTS: Among 90,598 Veterans [mean (SD) age 61.7 (9.4) y, 5.2% (n=4673) were women], CRC and AN prevalence was 1.3% (n=1171) and 8.9% (n=8081), respectively. Adjusted CRC risk was higher for diagnostic versus screening colonoscopy [odds ratio (OR)=3.79; 95% confidence interval (CI), 3.19-4.50], increased with age, was numerically (but not statistically) higher for men overall (OR=1.53; 95% CI, 0.97-2.39) and in the screening subgroup (OR=2.24; 95% CI, 0.71-7.05), and was higher overall for Blacks and Hispanics, but not in screening. AN prevalence increased with age, and was present in 9.2% of men and 3.9% of women [adjusted OR=1.90; 95% CI, 1.60-2.25]. AN risk was 11% higher in Blacks than in Whites overall (OR=1.11; 95% CI, 1.04-1.20), was no different in screening, and was lower in Hispanics (OR=0.74; 95% CI, 0.55-0.98). Women had more proximal CRC (63% vs. 39% for men; P=0.03), but there was no difference in proximal AN (38.3% for both genders). CONCLUSIONS: Age and race were associated with AN and CRC prevalence. Blacks had a higher overall prevalence of both CRC and AN, but not among screenings. Men had increased risk for AN, while women had a higher proportion of proximal CRC. These findings may be used to tailor when and how Veterans are screened for CRC.

Mitochondria Matter: Systemic Aspects of Nonalcoholic Fatty Liver Disease (NAFLD) and Diagnostic Assessment of Liver Function by Stable Isotope Dynamic Breath Tests.

The liver plays a key role in systemic metabolic processes, which include detoxification, synthesis, storage, and export of carbohydrates, lipids, and proteins. The raising trends of obesity and metabolic disorders worldwide is often associated with the nonalcoholic fatty liver disease (NAFLD), which has become the most frequent type of chronic liver disorder with risk of progression to cirrhosis and hepatocellular carcinoma. Liver mitochondria play a key role in degrading the pathways of carbohydrates, proteins, lipids, and xenobiotics, and to provide energy for the body cells. The morphological and functional integrity of mitochondria guarantee the proper functioning of ß-oxidation of free fatty acids and of the tricarboxylic acid cycle. Evaluation of the liver in clinical medicine needs to be accurate in NAFLD patients and includes history, physical exam, imaging, and laboratory assays. Evaluation of mitochondrial function in chronic liver disease and NAFLD is now possible by novel diagnostic tools. "Dynamic" liver function tests include the breath test (BT) based on the use of substrates marked with the non-radioactive, naturally occurring stable isotope 13C. Hepatocellular metabolization of the substrate will generate 13CO2, which is excreted in breath and measured by mass spectrometry or infrared spectroscopy. Breath levels of 13CO2 are biomarkers of specific metabolic processes occurring in the hepatocyte cytosol, microsomes, and mitochondria. 13C-BTs explore distinct chronic liver diseases including simple liver steatosis, non-alcoholic steatohepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug, and alcohol effects. In NAFLD, 13C-BT use substrates such as α-ketoisocaproic acid, methionine, and octanoic acid to assess mitochondrial oxidation capacity which can be impaired at an early stage of disease. 13C-BTs represent an indirect, cost-effective, and easy method to evaluate dynamic liver function. Further applications are expected in clinical medicine. In this review, we discuss the involvement of liver mitochondria in the progression of NAFLD, together with the role of 13C-BT in assessing mitochondrial function and its potential use in the prevention and management of NAFLD.

Gut Microbiota and Cancer of the Host: Colliding Interests.

Cancer develops in multicellular organisms from cells that ignore the rules of cooperation and escape the mechanisms of anti-cancer surveillance. Tumorigenesis is jointly encountered by the host and microbiota, a vast collection of microorganisms that live on the external and internal epithelial surfaces of the body. The largest community of human microbiota resides in the gastrointestinal tract where commensal, symbiotic and pathogenic microorganisms interact with the intestinal barrier and gut mucosal lymphoid tissue, creating a tumor microenvironment in which cancer cells thrive or perish. Aberrant composition and function of the gut microbiota (dysbiosis) has been associated with tumorigenesis by inducing inflammation, promoting cell growth and proliferation, weakening immunosurveillance, and altering food and drug metabolism or other biochemical functions of the host. However, recent research has also identified several mechanisms through which gut microbiota support the host in the fight against cancer. These mechanisms include the use of antigenic mimicry, biotransformation of chemotherapeutic agents, and other mechanisms to boost anti-cancer immune responses and improve the efficacy of cancer immunotherapy. Further research in this rapidly advancing field is expected to identify additional microbial metabolites with tumor suppressing properties, map the complex interactions of host-microbe 'transkingdom network' with cancer cells, and elucidate cellular and molecular pathways underlying the impact of specific intestinal microbial configurations on immune checkpoint inhibitor therapy.

Potential mechanisms linking gut microbiota and portal hypertension.

Gut microbiota is the largest collection of commensal micro-organisms in the human body, engaged in reciprocal cellular and molecular interactions with the liver. This mutually beneficial relationship may break down and result in dysbiosis, associated with disease phenotypes. Altered composition and function of gut microbiota has been implicated in the pathobiology of nonalcoholic fatty liver disease (NAFLD), a prevalent condition linked to obesity, insulin resistance and endothelial dysfunction. NAFLD may progress to cirrhosis and portal hypertension, which is the result of increased intrahepatic vascular resistance and altered splanchnic circulation. Gut microbiota may contribute to rising portal pressure from the earliest stages of NAFLD, although the significance of these changes remains unclear. NAFLD has been linked to lower microbial diversity and weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defence and inflammation. Moreover, disrupted host-microbial metabolic interplay alters bile acid signalling and the release of vasoregulatory gasotransmitters. These perturbations become prominent in cirrhosis, increasing the risk of clinically significant portal hypertension and leading to bacterial translocation, sepsis and acute-on-chronic liver failure. Better understanding of the gut-liver axis and identification of novel microbial molecular targets may yield specific strategies in the prevention and management of portal hypertension.

Whose patient is it? The path to multidisciplinary management of achalasia.

In the past decade, the introduction of high-resolution manometry and the classification of achalasia into subtypes has made possible to accurately diagnose the disease and predict the response to treatment for its different subtypes. However, even to date, in an era of exponential medical progress and increased insight in disease mechanisms, treatment of patients with achalasia is still rather simplistic and mostly confined to mechanical disruption of the lower esophageal sphincter by different means. In addition, there is partial consensus on what is the best form of available treatments for patients with achalasia. Herein, we provide a comprehensive outlook to a general approach to the patient with suspected achalasia by: 1) defining the modern evaluation process; 2) describing the diagnostic value of high-resolution manometry and the Chicago Classification in predicting treatment outcomes and 3) discussing the available treatment options, considering the patient conditions, alternatives available to both the surgeon and the gastroenterologist, and the burden to the health care system. It is our hope that such discussion will contribute to value-based management of achalasia through promoting a leaner clinical flow of patients at all points of care.

Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.

Hepatocellular Carcinoma in Obesity: Finding a Needle in the Haystack?

Obesity has been implicated in the development of hepatocellular carcinoma (HCC), one of the most common malignancies worldwide with an increasing incidence in the United States. Obesity and associated metabolic disorders such as type II diabetes and the metabolic syndrome are key factors in the development of nonalcoholic fatty liver disease (NAFLD) and promote several molecular mechanisms that may contribute to hepatocarcinogenesis. The vast majority of HCC occur in cirrhotic livers, but a subgroup of patients may develop HCC in non-advanced NAFLD. While the incidence rate for noncirrhotic HCC is low, the population-attributable fraction is still significant due to the extraordinary prevalence of obesity-associated liver disease. This is a challenge since HCC surveillance cannot be provided to the large population of non-advanced NAFLD in a cost-efficient way and requires enhanced risk stratification strategies. Recent advances may offer new clinical, laboratory, and genetic biomarkers and help us meet this important public health need.

Mitochondrial uncoupling in cancer cells: Liabilities and opportunities.

Acquisition of the endosymbiotic ancestor of mitochondria was a critical event in eukaryote evolution. Mitochondria offered an unparalleled source of metabolic energy through oxidative phosphorylation and allowed the development of multicellular life. However, as molecular oxygen had become the terminal electron acceptor in most eukaryotic cells, the electron transport chain proved to be the largest intracellular source of superoxide, contributing to macromolecular injury, aging, and cancer. Hence, the 'contract of endosymbiosis' represents a compromise between the possibilities and perils of multicellular life. Uncoupling proteins (UCPs), a group of the solute carrier family of transporters, may remove some of the physiologic constraints that link mitochondrial respiration and ATP synthesis by mediating inducible proton leak and limiting oxidative cell injury. This important property makes UCPs an ancient partner in the metabolic adaptation of cancer cells. Efforts are underway to explore the therapeutic opportunities stemming from the intriguing relationship of UCPs and cancer. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux.

Obesity paradox in advanced liver disease: obesity is associated with lower mortality in hospitalized patients with cirrhosis.

BACKGROUND & AIMS: To investigate how obesity impacts inpatient mortality, length of stay (LOS) and costs in patients with cirrhosis. Obesity is a growing epidemic associated with multiple co-morbidities, increased morbidity, and a significant economic burden on healthcare. Despite the overall harmful impact of obesity, the 'obesity paradox' has been described as decreased mortality among obese vs non-obese patients in various chronic medical conditions. METHODS: Analysis of the Nationwide Inpatient Sample (NIS) for 2012, which contains data from 44 states and 4378 hospitals. Data from all cases with primary, secondary or tertiary discharge diagnosis of cirrhosis identified by International Classification of Diseases-9 code 571.2, 571.5 571.6 were included. Primary outcomes included inpatient mortality, LOS, and hospital charges. Obesity as a predictor of mortality was defined by a predetermined obesity co-morbidity variable. RESULTS: A total of 32,605 patients were included. Crude mortality was lower for obese cirrhotic patients (2.7% vs 3.5%, P = 0.02) than for non-obese cirrhotic patients. In contrast, median LOS was longer (4 vs 3 days, P < 0.001) and median hospital charges were higher for obese cirrhotic patients ($26 803 vs $23 447, P < 0.001) In multivariate logistic regression, obesity was associated with a lower risk of inpatient mortality (OR=0.73, 95%CI: 0.55-0.95, P = 0.02). CONCLUSIONS: In the acute care setting, obese patients with cirrhosis have lower mortality than non-obese patients with cirrhosis, longer hospitalizations and higher healthcare cost, providing new evidence for the obesity paradox in cirrhosis. Obese cirrhotic patients are more likely to have enhanced nutritional reserve which may play a role in survival during acute illness.

Probe-based confocal laser endomicroscopy quantitative morphometric markers associated with portal hypertension in duodenal mucosa.

BACKGROUND & AIMS: Early detection of portal hypertension (PH) may help to prevent the morbidity of late-stage cirrhosis by stratifying disease severity and enabling disease-modifying interventions in potentially reversible conditions like non-alcoholic fatty liver disease and alcoholic hepatitis. This study seeks to correlate morphometric features by confocal endomicroscopy with established surrogate clinical markers of PH. METHODS: Patients with and without PH scheduled for upper endoscopy at VA Boston participated in this IRB-approved study. Real-time probe-based confocal endomicroscopy (pCLE) was performed in the duodenum. Vascular and epithelial morphometry was performed off-line, in a blinded manner, using image-processing software. RESULTS: Morphometric analysis of pCLE images from 16 patients with PH and 15 control patients was performed. Statistically significant differences were observed among control and PH patients for average vessel diameter (AVD: 11.7 µm vs. 17.1 µm), average vessel branching (AVB: 0.11 vs. 0.31 bifurcations per image frame), and average columnar cell height (ACCH: 40.0 µm vs. 52.0 µm). Spearman correlations comparing AVD, AVB and ACCH to portal gastropathy scores (0.86, 0.44 and 0.70) and to grade of oesophageal varices (0.88, 0.41 and 0.66) were statistically significant. Similarly, Pearson correlations of AVD and ACCH to spleen size (0.72 and 0.57), platelet count (-0.69 and -0.40) and the platelet count/spleen size ratio (-0.69 and -0.41) were also found to be statistically significant. CONCLUSIONS: Duodenal pCLE reveals microvascular dilatation and altered epithelial cell volume/morphology in PH. These morphometric pCLE markers correlate with surrogate markers of PH. Additional studies will define the correlation between microscopic vascular patterns, epithelial cell volume and the hepatic venous pressure gradient.