Obesity and fat distribution imply a greater systemic inflammatory response and a worse prognosis in acute pancreatitis

Obesity and the risk and prognosis of gallstone disease and pancreatitis

Obesity is a risk factor for the formation of cholesterol gallstones and exposes patients to increased risk of gallstone-related complications and cholecystectomy. Rapid weight loss achieved by very low calorie diets or bariatric surgery is also a risk factor for cholelithiasis in obese patients, and therapy should take into account the higher prevalence of gallstones, the possibility of more frequent complications and the need for prophylactic treatment with oral ursodeoxycholic acid during weight loss. Obesity is also frequent in children and adolescents, and the burden of cholesterol cholelithiasis is increasing in this population. The chance to develop acute pancreatitis and the severity of the disease are higher in obese subjects because of specific pathogenic factors, including supersaturated bile and crystal formation, rapid weight loss, and visceral obesity. All health policies aimed at reducing the incidence of obesity worldwide will decrease the incidence of gallstones and gallstone-related complications. The pathophysiological scenarios and the therapeutic implications for obesity, gallstone disease, and pancreatitis are discussed.

Does the presence of obesity and/or metabolic syndrome affect the course of acute pancreatitis?: A prospective study

OBJECTIVE

The incidence of acute pancreatitis (AP) is rising with increased prevalence of obesity, which exacerbates pancreatic injury. Metabolic syndrome (MS) is defined as a cluster condition of cardiovascular risk factors, including hyperglycemia, dyslipidemia, hypertension, and central obesity. We analyze if the presence of obesity and/or MS affects the course of pancreatitis.

METHODS

Data were collected from 140 patients with AP between January 2010 and February 2013. Anthropometric data, including body mass index and waist circumference, were measured. Biochemical tests were used including fasting glucose, triglyceride, low- and high-density lipoprotein cholesterol levels, and total cholesterol level. Atlanta criteria, Acute Physiology and Chronic Health Evaluation II, and Ranson scoring system were used to define severe AP. Patients were classified as having MS based on the International Diabetic Federation criteria.

RESULTS

The mean body mass index was 30.15 kg/m(2). Sixteen (11.4%) patients had severe AP, whereas 124 (88.6%) patients had mild AP. We found that 62.8% of patients with AP fulfilled the criteria of MS (P = 0.000). Body weight can be used to predict clinical severity of AP with significant P value (P = 0.009).

CONCLUSIONS

The presence of MS in patients with pancreatitis is noticeable, but it does not affect the course of disease severity, whereas obesity correlates with pancreatitis severity.

Role of pancreatic fat in the outcomes of pancreatitis

The role of obesity in relation to various disease processes is being increasingly studied, with reports over the last several years increasingly mentioning its association with worse outcomes in acute disease. Obesity has also gained recognition as a risk factor for severe acute pancreatitis (SAP).The mortality in SAP may be as high as 30% and is usually attributable to multi system organ failure (MSOF) earlier in the disease, and complications of necrotizing pancreatitis later [9-11]. To date there is no specific treatment for acute pancreatitis (AP) and the management is largely expectant and supportive. Obesity in general has also been associated with poor outcomes in sepsis and other pathological states including trauma and burns. With the role of unsaturated fatty acids (UFA) as propagators in SAP having recently come to light and with the recognition of acute lipotoxicity, there is now an opportunity to explore different strategies to reduce the mortality and morbidity in SAP and potentially other disease states associated with such a pathophysiology. In this review we will discuss the role of fat and implications of the consequent acute lipotoxicity on the outcomes of acute pancreatitis in lean and obese states and during acute on chronic pancreatitis.

Clinical predictors of severe acute pancreatitis: value-adding the view from the end of the bed

BACKGROUND

Research into clinical determinants of severe acute pancreatitis remains important for therapeutic and preventive purposes. To contribute to prognostication, this study aimed to define clinical risk factors for the development of severe acute pancreatitis.

METHODS

Study design was a prospective cohort study, using multiple logistic regression. From March 2004 to July 2007, 153 cases of acute pancreatitis were recruited in a regional Australian hospital. Data were collected regarding demographic and clinical characteristics. The outcome measure was severe acute pancreatitis, as defined by composite consensus criteria.

RESULTS

After adjustment for potential confounders, there was a significant positive association with waist circumference and a negative association with current smoking status.

CONCLUSION

The study confirms other work suggesting central adiposity as a risk factor for severe acute pancreatitis. The finding of a possible protective effect for smoking may be physiologically plausible but merits further confirmatory research.

Fibrosis reduces severity of acute-on-chronic pancreatitis in humans

BACKGROUND & AIMS

Acute pancreatitis (AP) and chronic pancreatitis (CP) share etiologies, but AP can be more severe and is associated with a higher rate of mortality. We investigated features of CP that protect against severe disease. The amount of intrapancreatic fat (IPF) is increased in obese patients and fibrosis is increased in patients with CP, so we studied whether fibrosis or fat regulate severity of AP attacks in patients with CP.

METHODS

We reviewed records from the University of Pittsburgh Medical Center/Presbyterian Hospital Autopsy Database (1998-2008) for patients with a diagnosis of AP (n = 23), CP (n = 35), or both (AP-on-CP; n = 15). Pancreatic histology samples from these patients and 50 randomly selected controls (no pancreatic disease) were analyzed, and IPF data were correlated with computed tomography data. An adipocyte and acinar cell Transwell coculture system, with or without collagen type I, was used to study the effects of fibrosis on acinar-adipocyte interactions. We studied the effects of nonesterified fatty acids (NEFAs) and adipokines on acinar cells in culture.

RESULTS

Levels of IPF were significantly higher in nonobese patients with CP than in nonobese controls. In patients with CP or AP-on-CP, areas of IPF were surrounded by significantly more fibrosis than in controls or patients with AP. Fat necrosis-associated peri-fat acinar necrosis (PFAN, indicated by NEFA spillage) contributed to most of the necrosis observed in samples from patients with AP; however, findings of peri-fat acinar necrosis and total necrosis were significantly lower in samples from patients with CP or AP-on-CP. Fibrosis appeared to wall off the fat necrosis and limit peri-fat acinar necrosis, reducing acinar necrosis. In vitro, collagen I limited the lipolytic flux between acinar cells and adipocytes and prevented increases in adipokines in the acinar compartment. This was associated with reduced acinar cell necrosis. However, NEFAs, but not adipokines, caused acinar cell necrosis.

CONCLUSIONS

Based on analysis of pancreatic samples from patients with CP, AP, or AP-on-CP and in vitro studies, fibrosis reduces the severity of acute exacerbations of CP by reducing lipolytic flux between adipocytes and acinar cells.

The epidemiology of pancreatitis and pancreatic cancer

Acute pancreatitis is one of the most frequent gastrointestinal causes of hospital admission in the United States. Chronic pancreatitis, although lower in incidence, significantly reduces patients' quality of life. Pancreatic cancer is associated with a high mortality rate and is one of the top 5 causes of death from cancer. The burden of pancreatic disorders is expected to increase over time. The risk and etiology of pancreatitis differ with age and sex, and all pancreatic disorders affect the black population more than any other race. Gallstones are the most common cause of acute pancreatitis, and early cholecystectomy eliminates the risk of future attacks. Alcohol continues to be the single most important risk factor for chronic pancreatitis. Smoking is an independent risk factor for acute and chronic pancreatitis, and its effects could synergize with those of alcohol. Significant risk factors for pancreatic cancer include smoking and non-O blood groups. Alcohol abstinence and smoking cessation can alter the progression of pancreatitis and reduce recurrence; smoking cessation is the most effective strategy to reduce the risk of pancreatic cancer.

Abdominal and total adiposity and the risk of acute pancreatitis: a population-based prospective cohort study

OBJECTIVES

Previous research has indicated that obesity may be linked to the severity of acute pancreatitis. However, the association between abdominal and total adiposity as risk factors in the development of acute pancreatitis in a general population has not been studied.

METHODS

A follow-up study was conducted, using the Swedish Mammography Cohort and the Cohort of Swedish Men, to examine the association between waist circumference and body mass index (BMI) and the risk of first-time acute pancreatitis. Severe acute pancreatitis was defined as hospital stay of >14 days, in-hospital death, or mortality within 30 days of discharge. Cox proportional hazards models were used to estimate rate ratios (RRs) with 95% confidence intervals (CIs), adjusted for confounders.

RESULTS

In total, 68,158 individuals, aged 46-84 years, were studied for a median of 12 years. During this time, 424 persons developed first-time acute pancreatitis. The risk of acute pancreatitis among those with a waist circumference of >105 cm was twofold increased (RR=2.37; 95% CI: 1.50-3.74) compared with individuals with a waist circumference of 75.1-85.0 cm, when adjusted for confounders. This association was seen in patients with non-gallstone-related and gallstone-related acute pancreatitis. The results remained unchanged when stratifying the analyses with regards to sex or the severity of acute pancreatitis. There was no association between BMI and the risk of acute pancreatitis.

CONCLUSIONS

Abdominal adiposity, but not total adiposity, is an independent risk factor for the development of acute pancreatitis.

Editorial: abdominal fat: a key player in metabolic acute pancreatitis

Excess body fat is widely considered one of the factors that is linked to acute pancreatitis (AP), but its specific role is far from being fully understood. This Editorial offers an insight into the recent research in this field with particular emphasis on findings of the latest prospective population-based studies. It discusses whether body fat distribution influences the risk of developing first-time AP, whether excess body fat affects clinically meaningful outcomes in patients with developed AP, and whether a case can be made for biological interaction between several metabolic components in this disease.

Effects of abdominal fat distribution parameters on severity of acute pancreatitis

BACKGROUND

Obesity is a well-established risk factor for acute pancreatitis. Increased visceral fat has been shown to exacerbate the pro-inflammatory milieu experienced by patients. This study aimed to investigate the relationship between the severity of acute pancreatitis and abdominal fat distribution parameters measured on computed tomography (CT) scan.

METHODS

Consecutive patients admitted to Cork University Hospital with acute pancreatitis between January 2005 and December 2010 were evaluated for inclusion in the study. An open source image analysis software (Osirix, v 3.9) was used to calculate individual abdominal fat distribution parameters from CT scans by segmentation of abdominal tissues.

RESULTS

A total of 214 patients were admitted with pancreatitis between January 2005 and December 2010. Sixty-two of these patients underwent a CT scan and were thus eligible for inclusion. Visceral fat volume was the volumetric fat parameter that had the most significant association with severe acute pancreatitis (P = 0.003). There was a significant association between visceral fat volume and subsequent development of systemic complications of severe acute pancreatitis (P = 0.003). There was a strong association between mortality and visceral fat volume (P = 0.019). Multivariate regression analysis, adjusted for gender, did not identify any individual abdominal fat distribution index as an independent risk factor for severe acute pancreatitis.

CONCLUSIONS

Overall, estimation of abdominal fat distribution parameters from CT scans performed on patients with acute pancreatitis indicates a strong association between visceral fat, severe acute pancreatitis, and the subsequent development of systemic complications. These data suggest that visceral fat volume should be incorporated into future predictive scoring systems.

Obese rats exhibit high levels of fat necrosis and isoprostanes in taurocholate-induced acute pancreatitis

BACKGROUND

Obesity is a prognostic factor for severity in acute pancreatitis in humans. Our aim was to assess the role of oxidative stress and abdominal fat in the increased severity of acute pancreatitis in obese rats.

METHODOLOGY

Taurocholate-induced acute pancreatitis was performed in lean and obese Zucker rats. Levels of reduced glutathione, oxidized glutathione, L-cysteine, cystine, and S-adenosylmethionine were measured in pancreas as well as the activities of serine/threonine protein phosphatases PP1 and PP2A and tyrosin phosphatases. Isoprostane, malondialdehyde, triglyceride, and free fatty acid levels and lipase activity were measured in plasma and ascites. Lipase activity was measured in white adipose tissue with and without necrosis and confirmed by western blotting.

FINDINGS

Under basal conditions obese rats exhibited lower reduced glutathione levels in pancreas and higher triglyceride and free fatty acid levels in plasma than lean rats. S-adenosyl methionine levels were markedly increased in pancreas of obese rats. Acute pancreatitis in obese rats led to glutathione oxidation and lower reduced glutathione levels in pancreas together with decreased activities of redox-sensitive phosphatases PP1, and PP2A. S-adenosyl methionine levels decreased but cystine levels increased markedly in pancreas upon pancreatitis. Acute pancreatitis triggered an increase in isoprostane levels in plasma and ascites in obese rats. Free fatty acid levels were extremely high in pancreatitis-associated ascitic fluid from obese rats and lipase was bound with great affinity to white adipose tissue, especially to areas of necrosis.

CONCLUSIONS

Our results show that oxidative stress occurs locally and systemically in obese rats with pancreatitis favouring inactivation of protein phosphatases in pancreas, which would promote up-regulation of pro-inflammatory cytokines, and the increase of isoprostanes which might cause powerful pulmonary and renal vasoconstriction. Future studies are needed to confirm the translational relevance of the present findings obtained in a rat model of taurocholate-induced pancreatic damage and necrosis.

Differences in the inflammatory response induced by acute pancreatitis in different white adipose tissue sites in the rat

BACKGROUND

There is increasing evidence of the role of adipose tissue on the systemic effects of acute pancreatitis. Patients with higher body mass index have increased risk of local and systemic complications and patients with android fat distribution and higher waist circumference are at greater risk for developing the severe form of the disease. Here we evaluated the changes on different areas of adipose tissue and its involvement on the inflammatory response in an experimental model of acute pancreatitis.

METHODS

Pancreatitis was induced in male Wistar rats by intraductal administration of sodium taurocholate. Orlistat was administered to inhibit lipase activity. Activation of peritoneal macrophages was evaluated by measuring IL1β and TNFα expression. Inflammation was evaluated by measuring myeloperoxidase activity in mesenteric, epididymal and retroperitoneal areas of adipose tissue. Changes in the expression of inflammatory mediator in these areas of adipose tissue were also evaluated by RT-PCR.

RESULTS

Pancreatitis induces the activation of peritoneal macrophages and a strong inflammatory response in mesenteric and epididymal sites of adipose tissue. By contrast, no changes were found in retroperitoneal adipose tissue. Inhibition of lipase prevented the activation of macrophages and the local inflammation in adipose tissue.

CONCLUSIONS

Our results confirm the involvement of adipose tissue on the progression of systemic inflammatory response during acute pancreatitis. However, there is a considerable diversity in different adipose tissue sites. These differences need to be taken into account in order to understand the progression from local pancreatic damage to systemic inflammation during acute pancreatitis.

Obesity and the risk and outcome of infection

The interactions between obesity and infectious diseases have recently received increasing recognition as emerging data have indicated an association between obesity and poor outcome in pandemic H1N1 influenza infection. Obesity is an established risk factor for surgical-site infections, nosocomial infections, periodontitis and skin infections. Several studies indicate that acute pancreatitis is more severe in the obese. Data are controversial and limited as regards the association between obesity and the risk and outcome of community-acquired infections such as pneumonia, bacteremia and sepsis and obesity and the course of HIV infection. As the cause-effect relationship between obesity and infection remains obscure in many infectious diseases, further studies are warranted. The consequences of obesity may have substantial effects on the global burden of infectious diseases.

Is obesity an indicator of complications and mortality in acute pancreatitis? An updated meta-analysis

OBJECTIVE

To provide a meta-analyisis on whether obesity could be a prognostic indicator on the severity, development of complications and mortality of acute pancreatitis (AP).

METHODS

Eligible articles were retrieved using electronic databases. Clinical studies evaluating the association between obesity and disease course of patients with AP were included. Weighted mean difference (WMD) and 95% confidence interval (CI) were estimated and pooled using RevMan 4.2.8.

RESULTS

In all, 12 clinical studies with a total of 1483 patients were included in the analysis. Obese patients had a significantly increased risk of severe acute pancreatitis (SAP; RR=2.20, 95% CI 1.82-2.66, P<0.05), local complication (RR=2.68, 95% CI 2.09-3.43, P<0.05), systemic complication (RR=2.14, 95% CI 1.42-3.21, P<0.05) and in-hospital mortality (RR=2.59, 95% CI 1.66-4.03, P<0.05) compared with non-obese patients.

CONCLUSIONS

Obesity is a definite risk factor of morbidity and in-hospital mortality for AP and may serve as a prognostic indicator.

Acute pancreatitis due to diabetes: the role of hyperglycaemia and insulin resistance

BACKGROUND

The co-existence of diabetes mellitus (DM) in patients with acute pancreatitis (AP) is linked to poor outcomes. Four large epidemiological studies have suggested an aetiological role for DM in AP. The exact nature of this role is poorly understood.

OBJECTIVE

To analyse the available clinical and experimental literature to determine if DM may play a causative role in AP.

METHODS

A systematic search of the scientific literature was carried out using EMBASE, PubMed/MEDLINE, and the Cochrane Central Register of Controlled Trials for the years 1965-2011 to obtain access to all publications, especially randomized controlled trials, systematic reviews, and meta-analyses exploring the mechanisms of pathogenesis of AP in patients with DM.

RESULTS

No clinical studies could be identified directly providing pathogenetic mechanisms of DM in the causation of AP. The available data on DM and its associated metabolic changes and therapy indicate that hyperglycaemia coupled with the factors influencing insulin resistance (tumour necrosis-α, NFκB, amylin) cause an increase in reactive oxygen species generation in acinar cells.

CONCLUSIONS

Complex pathogenetic connections exist between AP and factors involved in the development and therapy of DM. Insulin resistance and hyperglycaemia, hallmarks of DM, are important factors linked to the susceptibility of diabetics to AP. Given the high morbidity associated with an attack of AP in a diabetic patient, targeting these two aspects by therapy may help not only to reduce the risk of development of AP, but may also help reduce the severity of an established attack in a diabetic patient.

Immune function and HPA axis activity in free-ranging rhesus macaques

In mammals, the hypothalamic-pituitary-adrenal (HPA) axis and immune system play an important role in the maintenance of homeostasis. Dysregulation of either system resulting, for example, from psychosocial or reproductive stress increases susceptibility to disease and mortality risk, especially in aging individuals. In a study of free-ranging rhesus macaques, we examined how female age, reproductive state, social rank, and body condition influence (i) aspects of cytokine biology (plasma concentrations of interleukin-1 receptor antagonist (IL-1ra), IL-6 and IL-8), and (ii) HPA axis activity (plasma and fecal glucocorticoid levels). We also assessed individual differences in cytokine and hormone concentrations over time to determine their consistency and to investigate relations between these two indicators of physiological regulation and demand. Female monkeys showed marked increases in HPA axis activity during pregnancy and lactation, and increased circulating levels of IL-1ra with advancing age. Inter-individual differences in IL-1ra and IL-8 were consistent over successive years, suggesting that both are stable, trait-like characteristics. Furthermore, the concentrations of fecal glucocorticoid hormones in non-pregnant, non-lactating females were correlated with their plasma cortisol and IL-8 concentrations. Some individuals showed permanently elevated cytokine levels or HPA axis activity, or a combination of the two, suggesting chronic stress or disease. Our results enhance our understanding of within- and between-individual variation in cytokine levels and their relationship with glucocorticoid hormones in free-ranging primates. These findings can provide the basis for future research on stress and allostatic load in primates.

Overweight is an additional prognostic factor in acute pancreatitis: a meta-analysis

BACKGROUND/AIMS

It is generally accepted that there is a correlation between obesity and poor outcome in acute pancreatitis (AP); however, the relationship between overweight and the prognosis of AP is unknown. The aim of this study was to determine the correlation between overweight and the prognosis of AP.

METHODS

MEDLINE and PubMed were searched using the terms 'acute pancreatitis', 'obesity', 'overweight', and 'body mass index' ('BMI'). All prospective clinical studies correlating BMI and AP were included. Obesity and overweight were defined as BMI ≥30 and from 25 to 30, respectively. A meta-analysis was performed with the endpoints severe AP (SAP), local complications, systemic complications, and mortality.

RESULTS

Eight studies including 939 patients were found. The incidence rates of SAP (OR 2.48, 95% CI 1.34-4.60), local complications (OR 2.58, 95% CI 1.20-5.57), and mortality (OR 3.81, 95% CI 1.22-11.83) were increased in overweight patients with AP. No difference was detected in the incidence of systemic complications between the normal-weight and overweight patients (OR 1.62, 95% CI 0.76-3.43). In addition, the correlation between obesity and poor prognosis was again confirmed.

CONCLUSION

Overweight is an additional prognostic factor of severity, local complications, and mortality in AP. and IAP.

A novel model of severe gallstone pancreatitis: murine pancreatic duct ligation results in systemic inflammation and substantial mortality

BACKGROUND

Suitable experimental models of gallstone pancreatitis with systemic inflammation and mortality are limited. We developed a novel murine model of duct-ligation-induced acute pancreatitis associated with multiorgan dysfunction and severe mortality.

METHODS

Laparotomy was done on C57/BL6 mice followed by pancreatic duct (PD) ligation, bile duct (BD) ligation without PD ligation, or sham operation.

RESULTS

Only mice with PD ligation developed acute pancreatitis and had 100% mortality. Pulmonary compliance was significantly reduced after PD ligation but not BD ligation. Bronchoalveolar lavage fluid neutrophil count and interleukin-1β concentration, and the plasma creatinine level, were significantly elevated with PD ligation but not BD ligation. Pancreatic nuclear factor κB (p65) and activator protein 1 (c-Jun) were activated within 1 h of PD ligation.

CONCLUSION

PD-ligation-induced acute pancreatitis in mice is associated with systemic inflammation, acute lung injury, multiorgan dysfunction and death. The development of this novel model is an exciting and notable advance in the field.

Circulating levels of visfatin, resistin and pro-inflammatory cytokine interleukin-8 in acute pancreatitis

BACKGROUND

Resistin and visfatin, hormones produced by adipose tissue, have pro-inflammatory potential; however, their role in acute pancreatitis (AP) has been investigated only rarely.

METHODS

The study group comprised 32 patients with alcoholic AP and 30 controls. In all cases AP was classified as C according to Balthazar's CT score and as severe according to Ranson's criteria. The serum level of visfatin, resistin, and interleukin(IL)-8 immunoassays were measured by ELISA on admission and on the third and fifth day of hospitalization.

RESULTS

On the admission day serum resistin and IL-8 concentrations in AP patients were significantly higher than in controls and they further increased on the third and fifth day of hospitalization. On the admission day serum visfatin levels in AP patients were significantly higher than in controls and further increased on the third day of hospitalization. On the fifth day the levels decreased; however, they were still higher than on admission. The correlation between visfatin and resistin as well as between C-reactive protein and visfatin, resistin and IL-8 levels has been found.

CONCLUSION

In the course of AP, visfatin and resistin levels increase in parallel with C-reactive protein. We speculate that those parameters may provide an additional tool for the prognosis and monitoring of AP. and IAP.

Release of inflammatory mediators by adipose tissue during acute pancreatitis

Obesity and lipid metabolism are associated with the severity of acute pancreatitis. Fat necrosis appears in the severe acute pancreatitis as a consequence of the release of lipolytic enzymes, but its potential role on the progression of the disease is unclear. In this study, we have examined the role of white adipose tissue as a source of inflammatory mediators that can promote systemic inflammation during experimental taurocholate-induced acute pancreatitis in rats. The inflammatory status and the expression of TNFalpha, iNOS, adiponectin and IL-10 were determined in necrotic and non-necrotic areas of adipose tissue. Samples of adipose tissue were also used to induce the activation of macrophages in vitro. Finally, the release of TNFalpha to mesenterial vessels surrounded by necrotic or non-necrotic fat was evaluated in ex vivo perfused mesenterium. A strong inflammatory infiltrate was observed in the border between necrotic and non-necrotic areas of adipose tissue. In these areas, high expression of TNFalpha and iNOS and a reduced expression of IL-10 were observed, while adiponectin showed only a moderate increase. Necrotic fat strongly activates peritoneal macrophages in vitro. Mesenterial areas with fat necrosis release to the vascular vessels significantly increased amounts of TNFalpha when compared to vessels without necrosis. Altogether, these results indicate that adipose tissue inflammation is a process secondary to acute pancreatitis but also contributes to the generation of mediators potentially involved in the induction of the systemic inflammatory response. In particular, the areas of fat necrosis are important sources of inflammatory mediators.

Methods for measuring abdominal obesity in the prediction of severe acute pancreatitis, and their correlation with abdominal fat areas assessed by computed tomography

BACKGROUND

Obesity increases the risk for severe acute pancreatitis, although abdominal obesity may be a better prognostic marker.

AIM

To determine if a single anthropometric parameter best predicts severe acute pancreatitis and correlates with intra-abdominal fat.

METHODS

Ninety-nine patients with acute pancreatitis were studied prospectively. Anthropometry included body mass index (BMI) and girths (umbilical/minimum waist, iliac/trochanter hip, thigh). Several waist-to-hip/waist-to-thigh ratios (WHR/WTR) were constructed. A CT-scan with calculation of cross-sectional abdominal fat areas was obtained in 37 cases.

RESULTS

Severe acute pancreatitis occurred in 25 patients. Waist circumference (WC), WHR and WTR - all using the umbilical reference - most accurately predicted severe acute pancreatitis. Only umbilical WC was retained in multivariate analysis: the risk for severe acute pancreatitis increased 16% with every 1 cm (OR 1.16, 95%CI: 1.1-1.3). Abdominal obesity caused a 6-fold increase in risk. Umbilical WC correlated best with subcutaneous fat area (r = 0.791, P < 0.001), whereas WHR with intra-abdominal (r = 0.594, P < 0.001).

CONCLUSIONS

Abdominal obesity according to umbilical WC is a better predictor for development of severe acute pancreatitis than BMI, minimum WC, WHR and WTR. The protocol for anthropometry must be standardized as it may affect results. Both subcutaneous and intra-abdominal fat appears to affect the likelihood of a severe outcome.

Advances in understanding the role of inflammatory and antiinflammatory factors in the pathogenesis of acute pancreatitis

Acute pancreatitis (AP) is a common clinical disorder presenting as acute abdomen. As AP is often complicated with many other serious diseases, the overall mortality rate is high in AP patients. At present, the research on the pathogenesis of AP has attracted wide attention though it has not been fully clarified yet. Many theories, such as "self-digestion of the pancreas", "inflammatory response" and "intestinal bacterial translocation", have been proposed to explain the pathogenesis of AP. Extensive research is being conducted to investigate the relationship of inflammatory and antiinflammatory factors with AP. In this article, we will review the recent advances in understanding the role of inflammatory and antiinflammatory factors in the pathogenesis of AP.

Dominant negative p38 mitogen-activated protein kinase expression inhibits NF-kappaB activation in AR42J cells

BACKGROUND

The role of the p38 mitogen-activated protein (MAP) kinase in acute pancreatitis pathogenesis is controversial. We hypothesize that p38 plays a role in regulating NF-kappaB activation in exocrine pancreatic cells.

METHODS

AR42J cells incorporating an NF-kappaB-responsive luciferase reporter, with and without adenoviral transduction of DNp38, were stimulated with cholecystokinin (CCK) or tumor necrosis factor-alpha (TNF-alpha) prior to measuring NF-kappaB activation.

RESULTS

CCK- or TNF-alpha-stimulated NF-kappaB-dependent gene transcription (luciferase assay) was substantially subdued by DNp38 expression. These findings were confirmed by electrophoretic mobility shift assay. Nuclear translocation of the p65 NF-kappaB subunit following agonist stimulation was evident (supershift). Characterization studies showed excellent adenoviral infection efficiency and cell viability in our AR42J cell model. Agonist-stimulated dose- and time-dependent p38 activation, with inhibition by DNp38 expression, was also confirmed.

CONCLUSION

The p38 MAP kinase regulates NF-kappaB pathway activation in exocrine pancreatic cells, and thus potentially plays a role in the mechanism of acute pancreatitis pathogenesis..

Is obesity an additional risk factor for alcoholic chronic pancreatitis?

BACKGROUND/AIMS

Obesity is a known risk factor for severe acute pancreatitis (AP). Since alcoholic chronic pancreatitis (ACP) is closely linked to alcoholic AP, overweight before disease onset might impact on incidence and outcome of ACP, and represent an additional risk factor for ACP. This issue has not been investigated, despite discussions on the 'hypercaloric-high-fat' hypothesis as an additional risk factor for ACP for many years.

METHODS

The study is part of our prospective long-term study of a large, mixed, medical/surgical series of ACP patients. All cooperative patients were studied according to a protocol regarding clinical symptoms, physical status, routine laboratory tests, pancreatic function and pancreatic morphology (e.g. calcification) at yearly follow-ups. Our study includes 227 ACP patients with recorded body mass index (BMI) before disease onset followed up on average for 18 years from chronic pancreatitis (CP) onset.

RESULTS

Males predominated (89.9%), age at onset averaged at 36 years, and exocrine insufficiency (97.4%) and calcification (88.1%) developed in virtually all patients. Surgery for B-type pain was performed in 57.7%, and death occurred in 62.8%. Overweight before disease onset was found in 54.2% (obesity in 15.0%) compared to 37.7% (3.1%) from a contemporary male control population. The highest BMI before disease onset did not impact on some major variables of ACP such as gender, age, progression of exocrine insufficiency, diabetes and calcification, and mortality from CP, except for a delayed progression rate of ACP indices in the surgical series.

CONCLUSION

Overweight before disease onset appears to be another risk factor for ACP, supporting the 'hypercaloric-high-fat' hypothesis. and IAP.

Assessment of severity of acute pancreatitis according to new prognostic factors and CT grading

The assessment of severity at the initial medical examination plays an important role in introducing adequate early treatment and the transfer of patients to a medical facility that can cope with severe acute pancreatitis. Under these circumstances, "criteria for severity assessment" have been prepared in various countries, including Japan, and these criteria are now being evaluated. The criteria for severity assessment of acute pancreatitis in Japan were determined in 1990 (of which a partial revision was made in 1999). In 2008, an overall revision was made and the new Japanese criteria for severity assessment of acute pancreatitis were prepared. In the new criteria for severity assessment, the diagnosis of severe acute pancreatitis can be made according to 9 prognostic factors and/or the computed tomography (CT) grades based on contrast-enhanced CT. Patients with severe acute pancreatitis are expected to be transferred to a specialist medical center or to an intensive care unit to receive adequate treatment there. In Japan, severe acute pancreatitis is recognized as being a specified intractable disease on the basis of these criteria, so medical expenses associated with severe acute pancreatitis are covered by Government payment.

Experimental evidence of obesity as a risk factor for severe acute pancreatitis

The incidence of acute pancreatitis, an inflammation of the pancreas, is increasing worldwide. Pancreatic injury is mild in 80%-90% of patients who recover without complications. The remaining patients may develop a severe disease with local complications such as acinar cell necrosis, abscess and remote organ injury including lung injury. The early prediction of the severity of the disease is an important goal for physicians in management of patients with acute pancreatitis in order to optimize the therapy and to prevent organ dysfunction and local complications. For that purpose, multiple clinical scale scores have been applied to patients with acute pancreatitis. Recently, a new problem has emerged: the increased severity of the disease in obese patients. However, the mechanisms by which obesity increases the severity of acute pancreatitis are unclear. Several hypotheses have been suggested: (1) obese patients have an increased inflammation within the pancreas; (2) obese patients have an increased accumulation of fat within and around the pancreas where necrosis is often located; (3) increase in both peri- and intra-pancreatic fat and inflammatory cells explain the high incidence of pancreatic inflammation and necrosis in obese patients; (4) hepatic dysfunction associated with obesity might enhance the systemic inflammatory response by altering the detoxification of inflammatory mediators; and (5) ventilation/perfusion mismatch leading to hypoxia associated with a low pancreatic flow might reduce the pancreatic oxygenation and further enhance pancreatic injury. Recent experimental investigations also show an increased mortality and morbidity in obese rodents with acute pancreatitis and the implication of the adipokines leptin and adiponectin. Such models are important to investigate whether the inflammatory response of the disease is enhanced by obesity. It is exciting to speculate that manipulation of the adipokine milieu has the potential to influence the severity of acute pancreatitis.

Advances in the pathogenesis of acute pancreatitis

Acute pancreatitis (AP), especially acute necrotizing pancreatitis, is a common clinical disorder presenting as an acute abdomen. As AP is often complicated with systemic inflammatory response syndrome and multiple organ failure, the overall mortality rate in AP patients is high. At present, the research on the pathogenesis of AP has attracted wide attention though it has not been fully clarified yet. Of many theories to explain the pathogenesis of AP, "the theory of self-digestion of the pancreas" is the dominant hypothesis. In recent years, concerns have also been raised over "the theory of inflammatory mediators", "the theory of intestinal bacterial translocation", "the theory of apoptosis" and "the theory of calcium overload of pancreatic acinar cells". In addition, extensive research on the relationship between hyperlipidemia, especially high triglycerides (TG), and AP has also been conducted. In this article, we will review the recent advances in the pathogenesis of AP.

The changing character of acute pancreatitis: epidemiology, etiology, and prognosis

Acute pancreatitis continues to be a diagnostic and therapeutic challenge for physicians and surgeons. It ranks third in the list of hospital discharges for gastro-intestinal diseases. In most patients the cause is either gallstones or alcoholism. The overall mortality is less than 5%, but severe acute pancreatitis leads to prolonged hospitalization and much higher mortality. There are important differences in disease susceptibility and case fatality rates: the incidence is higher in blacks than in whites, and mortality is higher in older patients than in younger patients. Reports from various countries reveal that the frequency of acute pancreatitis is increasing, perhaps in relation to rising obesity rates, which would increase the likelihood of gallstone pancreatitis. Conversely, mortality rates for acute pancreatitis are declining in many, but not all, reports.

Involvement of a Stat3 binding site in inflammation-induced enteric apelin expression

Apelin is the endogenous ligand for the APJ receptor; both are expressed in the gastrointestinal tract. Experimental colitis in rodents and inflammatory bowel disease in humans are associated with increased intestinal apelin production. Our aim was to use LPS and proinflammatory cytokine-treated (IL-6 and IFN-gamma) rodents or enteric cells to identify signaling mechanisms underlying inflammation-induced enteric apelin expression. LPS, IL-6, or IFN-gamma treatment of rodents increased enteric apelin expression. Pharmacological blockade of Jak/Stat signaling or IL-6 antibody administration inhibited elevations in enteric apelin expression. Transient transfection experiments showed that LPS, IL-6, or IFN-gamma increased apelin expression by stimulation of apelin promoter activity, and blockade of Jak/Stat signaling abolished elevations in apelin promoter activity. A chromatin immunoprecipitation assay showed that IL-6 induced binding of phospho-Stat3 to a putative Stat3 site in the apelin promoter; mutation of this site abrogated the LPS-induced elevation in apelin promoter activity. Together, our findings indicate that binding of phospho-Stat3 to the apelin promoter is the final step underlying proinflammatory cytokine-induced enteric apelin expression during intestinal inflammation.