Intra-pancreatic fat deposition: bringing hidden fat to the fore

Diabetes remission and nonalcoholic fatty pancreas disease

This editorial focuses on the relationship between nonalcoholic fatty pancreas disease (NAFPD) and the development and remission of type 2 diabetes (T2D). NAFPD is characterized by intrapancreatic fatty deposition associated with obesity and not associated with alcohol abuse, viral infections, and other factors. Ectopic fat deposition in the pancreas is associated with the development of T2D, and the underlying mechanism is lipotoxic β-cell dysfunction. However, the results on the relationship between intrapancreatic fat deposition (IPFD) and β-cell function are conflicting. Regardless of the therapeutic approach, weight loss improves IPFD, glycemia, and β-cell function. Pancreatic imaging is valuable for clinically monitoring and evaluating the management of T2D.

Exocrine Pancreas in Type 1 and Type 2 Diabetes: Different Patterns of Fibrosis, Metaplasia, Angiopathy, and Adiposity

The endocrine and exocrine compartments of the pancreas are spatially related but functionally distinct. Multiple diseases affect both compartments, including type 1 diabetes (T1D), pancreatitis, cystic fibrosis, and pancreatic cancer. To better understand how the exocrine pancreas changes with age, obesity, and diabetes, we performed a systematic analysis of well-preserved tissue sections from the pancreatic head, body, and tail of organ donors with T1D (n = 20) or type 2 diabetes (T2D) (n = 25) and donors with no diabetes (ND; n = 74). Among ND donors, we found that the incidence of acinar-to-ductal metaplasia (ADM), angiopathy, and pancreatic adiposity increased with age, and ADM and adiposity incidence also increased with BMI. Compared with age- and sex-matched ND organs, T1D pancreata had greater rates of acinar atrophy and angiopathy, with fewer intralobular adipocytes. T2D pancreata had greater rates of ADM and angiopathy and a higher total number of T lymphocytes, but no difference in adipocyte number, compared with ND organs. Although total pancreatic fibrosis was increased in both T1D and T2D, the patterns were different, with periductal and perivascular fibrosis occurring more frequently in T1D pancreata and lobular and parenchymal fibrosis occurring more frequently in T2D. Thus, the exocrine pancreas undergoes distinct changes as individuals age or develop T1D or T2D.

ARTICLE HIGHLIGHTS

Adipocyte-specific FAK deletion promotes pancreatic β-cell apoptosis via adipose inflammatory response to exacerbate diabetes mellitus

BACKGROUND

White adipose tissue (WAT) has a key role in maintaining energy balance throughout the body, and their dysfunction take part in the regulation of diabetes mellitus. However, the internal regulatory mechanisms underlying are still unknown.

METHODS AND RESULTS

We generated adipocyte-specific FAK KO (FAK-AKO) mice and investigated their phenotype. The cascade of adipocyte, macrophage in adipocyte tissues, and pancreatic β-cells were proposed in FAK-AKO mice and validated by cell line studies using 3T3-L1, Raw264.7 and Min6. The FAK-AKO mice exhibited glucose intolerance, reduced adipose tissue mass and increased apoptosis, lipolysis and inflammatory response in adipose tissue. We further demonstrate that adipocyte FAK deletion increases β cell apoptosis and inflammatory infiltrates into islets, which is potentiated if mice were treated with STZ. In the STZ-induced diabetes model, FAK AKO mice exhibit less serum insulin content and pancreatic β cell area. Moreover, serum pro-inflammatory factors increased and insulin levels decreased after glucose stimulation in FAK AKO mice. In a parallel vitro experiment, knockdown or inhibition of FAK during differentiation also increased apoptosis, lipolysis and inflammatory in 3T3-L1 adipocytes, whereas the opposite was observed upon overexpression of FAK. Moreover, coculturing LPS-treated RAW264.7 macrophages with knockdown FAK of 3T3-L1 adipocytes increased macrophage pro-inflammatory response. Furthermore, conditioned medium from above stimulated Min6 cells apoptosis (with or without STZ), whereas the opposite was observed upon overexpression of FAK. Mechanistically, FAK protein interact with TRAF6 in adipocytes and knockdown or inhibition of FAK activated TRAF6/TAK1/NF-κB signaling, which exacerbates inflammation of adipocytes themselves.

CONCLUSION

Adipocyte FAK deletion promotes both adipocyte apoptosis and adipose tissue inflammation. Pro-inflammatory factors released by the FAK-null adipose tissue further trigger apoptosis in pancreatic islets induced by the administration of STZ, thereby exacerbating the diabetes mellitus. This study reveals a link between FAK-mediated adipose inflammation and diabetes mellitus, a mechanism that has not been previously recognized.

The Potential Mechanism of Remission in Type 2 Diabetes Mellitus After Vertical Sleeve Gastrectomy

In recent years, there has been a gradual increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM), with bariatric surgery remaining the most effective treatment strategy for these conditions. Vertical sleeve gastrectomy (VSG) has emerged as the most popular surgical procedure for bariatric/metabolic surgeries, effectively promoting weight loss and improving or curing T2DM. The alterations in the gastrointestinal tract following VSG may improve insulin secretion and resistance by increasing incretin secretion (especially GLP-1), modifying the gut microbiota composition, and through mechanisms dependent on weight loss. This review focuses on the potential mechanisms through which the enhanced action of incretin and metabolic changes in the digestive system after VSG may contribute to the remission of T2DM.

Obesity management for the treatment of type 2 diabetes: emerging evidence and therapeutic approaches

Excess adiposity can contribute to metabolic complications, such as type 2 diabetes mellitus (T2DM), which poses a significant global health burden. Traditionally viewed as a chronic and irreversible condition, T2DM management has evolved and new approaches emphasizing reversal and remission are emerging. Bariatric surgery demonstrates significant improvements in body weight and glucose homeostasis. However, its complexity limits widespread implementation as a population-wide intervention. The identification of glucagon-like peptide 1 (GLP-1) and the development of GLP-1 receptor agonists (GLP-1RAs) have improved T2DM management and offer promising outcomes in terms of weight loss. Innovative treatment approaches combining GLP-1RA with other gut and pancreatic-derived hormone receptor agonists, such as glucose-dependant insulinotropic peptide (GIP) and glucagon (GCG) receptor agonists, or coadministered with amylin analogues, are demonstrating enhanced efficacy in both weight loss and glycemic control. This review aims to explore the benefits of bariatric surgery and emerging pharmacological therapies such as GLP-1RAs, and dual and triple agonists in managing obesity and T2DM while highlighting the caveats and evolving landscape of treatment options.

Intra-pancreatic fat is associated with continuous glucose monitoring metrics

AIM

To investigate the relationship of fat in the pancreas with time spent in different glycaemic ranges.

METHODS

Abdominal magnetic resonance imaging at 3.0 Tesla was used to quantify fat in the pancreas as both continuous [i.e. intra-pancreatic fat deposition (IPFD)] and binary (i.e. fatty change of the pancreas vs. normal pancreas) variables. Dexcom G6 devices were used to collect continuous glucose monitoring data every 5 min over a continuous 7-day period. Time above range (TAR), time in range (TIR) and time below range were computed. Statistical models were built to adjust for age, sex, body composition, and other covariates in linear regression analysis and analysis of covariance.

RESULTS

In total, 38 individuals were studied. IPFD was significantly associated with TAR (p = .036) and TIR (p = .042) after adjustment for covariates. For every 1% increase in IPFD, there was a 0.3 unit increase in TAR and a decrease in TIR. Individuals with fatty change of the pancreas, when compared with those with normal pancreas, had significantly higher TAR (p = .034) and lower TIR (p = .047) after adjustment for covariates. Neither IPFD (p = .805) nor fatty change of the pancreas (p = .555) was associated with time below range after adjustment for covariates.

CONCLUSION

Increased fat in the pancreas is associated with excessive glycaemic variability. Fatty change of the pancreas may contribute to heightening the risk of cardiovascular diseases.

Intra-pancreatic fat deposition and its relation to obesity: a magnetic resonance imaging study

OBJECTIVES

Intra-pancreatic fat deposition (IPFD) is suspected to be associated with various medical conditions. This study aimed to assess pancreatic fat content in lean and obese individuals, characterize obese individuals with and without IPFD, and explore the underlying mechanisms.

MATERIALS AND METHODS

Sixty-two obese individuals without diabetes and 35 lean controls underwent magnetic resonance imaging (MRI) using proton density fat fraction (PDFF) maps to evaluate pancreatic and hepatic fat content, and visceral adipose tissue (VAT) content. Pancreatic fibrosis was explored by T1 relaxation time and MR elastography (MRE) measurements. Associations between pancreatic fat, measures of obesity and metabolic syndrome were examined using uni- and multivariate regression analyses.

RESULTS

Pancreatic PDFF was higher in obese than in lean controls (median 8.0%, interquartile range (6.1;13.3) % vs 2.6(1.7;3.9)%, p < 0.001). Obese individuals with IPFD (PDFF ≥6.2%) had higher waist circumference (114.0 ± 12.5 cm vs 105.2 ± 8.7 cm, p = 0.007) and VAT (224.9(142.1; 316.1) cm2 vs 168.2(103.4; 195.3) cm2, p < 0.001) than those without. In univariate analysis, pancreatic PDFF in obese individuals correlated with BMI (r = 0.27, p = 0.03), waist circumference (r = 0.44, p < 0.001), VAT (r = 0.37, p = 0.004), hepatic PDFF (r = 0.25, p = 0.046) and diastolic blood pressure (r = 0.32, p = 0.01). However, in multivariate analysis, only VAT was associated to pancreatic fat content. MRI measures of pancreatic fibrosis indicated no evident fibrosis in relation to increased pancreatic fat content.

CONCLUSIONS

Pancreatic fat content was increased in obese individuals compared with lean controls and predominantly correlated with the amount of visceral adipose tissue. Pancreatic fat content was not clearly linked to measures of pancreatic fibrosis.

Associations of Intrapancreatic Fat Deposition With Incident Diseases of the Exocrine and Endocrine Pancreas: A UK Biobank Prospective Cohort Study

INTRODUCTION

To investigate whether increased intrapancreatic fat deposition (IPFD) heightens the risk of diseases of the exocrine and endocrine pancreas.

METHODS

A prospective cohort study was conducted using data from the UK Biobank. IPFD was quantified using MRI and a deep learning-based framework called nnUNet. The prevalence of fatty change of the pancreas (FP) was determined using sex- and age-specific thresholds. Associations between IPFD and pancreatic diseases were assessed with multivariate Cox-proportional hazard model adjusted for age, sex, ethnicity, body mass index, smoking and drinking status, central obesity, hypertension, dyslipidemia, liver fat content, and spleen fat content.

RESULTS

Of the 42,599 participants included in the analysis, the prevalence of FP was 17.86%. Elevated IPFD levels were associated with an increased risk of acute pancreatitis (hazard ratio [HR] per 1 quintile change 1.513, 95% confidence interval [CI] 1.179-1.941), pancreatic cancer (HR per 1 quintile change 1.365, 95% CI 1.058-1.762) and diabetes mellitus (HR per 1 quintile change 1.221, 95% CI 1.132-1.318). FP was also associated with a higher risk of acute pancreatitis (HR 3.982, 95% CI 2.192-7.234), pancreatic cancer (HR 1.976, 95% CI 1.054-3.704), and diabetes mellitus (HR 1.337, 95% CI 1.122-1.593, P = 0.001).

DISCUSSION

FP is a common pancreatic disorder. Fat in the pancreas is an independent risk factor for diseases of both the exocrine pancreas and endocrine pancreas.

Screening for pancreatic cancer in high-risk individuals using MRI: optimization of scan techniques to detect small lesions

Pancreatic cancer has a dismal prognosis in the general population. However, early detection and treatment of disease in high-risk individuals can improve survival, as patients with localized disease and especially patients with lesions smaller than 10 mm show greatly improved 5-year survival rates. To achieve early detection through MRI surveillance programs, optimization of imaging is required. Advances in MRI technologies in both hardware and software over the years have enabled reliable detection of pancreatic cancer at a small size and early stage. Standardization of dedicated imaging protocols for the pancreas are still lacking. In this review we discuss state of the art scan techniques, sequences, reduction of artifacts and imaging strategies that enable early detection of lesions. Furthermore, we present the imaging features of small pancreatic cancers from a large cohort of high-risk individuals. Refinement of MRI techniques, increased scan quality and the use of artificial intelligence may further improve early detection and the prognosis of pancreatic cancer in a screening setting.

Relationship of Liver Blood Tests and T1 Relaxation Time With Intra-pancreatic Fat Deposition

Background

Liver is well recognised as a metabolically active organ. While intra-pancreatic fat deposition (IPFD) is emerging as an important player in the whole-body metabolism, the interplay between the liver and IPFD has been poorly investigated. This study aimed to investigate the associations of liver blood tests and non-invasive tests for hepatic fibrosis with IPFD.

Methods

Participants underwent a 3.0 Tesla magnetic resonance imaging to measure IPFD and map liver T1 (longitudinal relaxation time). Four liver tests were done on the same sample of blood. Hepatic fibrosis risk score (BARD) was calculated. Linear regression models were built, accounting for age, sex, visceral-to-subcutaneous fat ratio, and other covariates.

Results

A total of 143 individuals were studied. In the most adjusted model, alkaline phosphatase (P < 0.001), alanine aminotransferase (P < 0.001), and γ-glutamyl transferase (P = 0.042) were significantly positively associated with IPFD. The BARD score was not significantly associated with IPFD in the most adjusted model (P = 0.295). T1 relaxation time of the liver was not significantly associated with IPFD in the most adjusted model (P = 0.782).

Conclusions

Elevated alkaline phosphatase, alanine aminotransferase, and γ-glutamyl transferase are associated with increased IPFD. Hepatic fibrosis does not appear to be associated with IPFD.

The Pharmacological Landscape for Fatty Change of the Pancreas

The quest for medications to reduce intra-pancreatic fat deposition is now quarter a century old. While no specific medication has been approved for the treatment of fatty change of the pancreas, drug repurposing shows promise in reducing the burden of the most common disorder of the pancreas. This leading article outlines the 12 classes of medications that have been investigated to date with a view to reducing intra-pancreatic fat deposition. Information is presented hierarchically-from preclinical studies to retrospective findings in humans to prospective interventional studies to randomised controlled trials. This lays the grounds for shepherding the most propitious drugs into medical practice through well-designed basic science studies and adequately powered randomised controlled trials.

Intrapancreatic fat deposition is unrelated to liver steatosis in metabolic dysfunction-associated steatotic liver disease

Background & Aims

Individuals with obesity may develop intrapancreatic fat deposition (IPFD) and fatty pancreas disease (FPD). Whether this causes inflammation and fibrosis and leads to pancreatic dysfunction is less established than for liver damage in metabolic dysfunction-associated steatotic liver disease (MASLD). Moreover, the interrelations of FPD and MASLD are poorly understood. Therefore, we aimed to assess IPFD and fibro-inflammation in relation to pancreatic function and liver disease severity in individuals with MASLD.

Methods

Seventy-six participants from the Amsterdam MASLD-MASH cohort (ANCHOR) study underwent liver biopsy and multiparametric MRI of the liver and pancreas, consisting of proton-density fat fraction sequences, T1 mapping and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI).

Results

The prevalence of FPD was 37.3%. There was a clear correlation between pancreatic T1 relaxation time, which indicates fibro-inflammation, and parameters of glycemic dysregulation, namely HbA1c (R = 0.59; p <0.001), fasting glucose (R = 0.51; p <0.001) and the presence of type 2 diabetes (mean 802.0 ms vs. 733.6 ms; p <0.05). In contrast, there was no relation between IPFD and hepatic fat content (R = 0.03; p = 0.80). Pancreatic IVIM diffusion (IVIM-D) was lower in advanced liver fibrosis (p <0.05) and pancreatic perfusion (IVIM-f), reflecting vessel density, inversely correlated to histological MASLD activity (p <0.05).

Conclusions

Consistent relations exist between pancreatic fibro-inflammation on MRI and endocrine function in individuals with MASLD. However, despite shared dysmetabolic drivers, our study suggests IPFD is a separate pathophysiological process from MASLD.

Impact and implications

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide and 68% of people with type 2 diabetes have MASLD. However, fat infiltration and inflammation in the pancreas are understudied in individuals with MASLD. In this cross-sectional MRI study, we found no relationship between fat accumulation in the pancreas and liver in a cohort of patients with MASLD. However, our results show that inflammatory and fibrotic processes in the pancreas may be interrelated to features of type 2 diabetes and to the severity of liver disease in patients with MASLD. Overall, the results suggest that pancreatic endocrine dysfunction in individuals with MASLD may be more related to glucotoxicity than to lipotoxicity.

Clinical trial number

NTR7191 (Dutch Trial Register).

Fateful fat: Intra-pancreatic lipids cause pancreatic cancer

In a Mendelian randomization and prospective cohort study,1 intra-pancreatic fat increases the risk of pancreatic cancer. This provides persuasive human evidence of causal relation between lipids and cancer in the pancreas, which confirms a prediction of the PANDORA hypothesis.

Evidence for a causal link between intra-pancreatic fat deposition and pancreatic cancer: A prospective cohort and Mendelian randomization study

Prior observational studies suggest an association between intra-pancreatic fat deposition (IPFD) and pancreatic ductal adenocarcinoma (PDAC); however, the causal relationship is unclear. To elucidate causality, we conduct a prospective observational study using magnetic resonance imaging (MRI)-measured IPFD data and also perform a Mendelian randomization study using genetic instruments for IPFD. In the observational study, we use UK Biobank data (N = 29,463, median follow-up: 4.5 years) and find that high IPFD (>10%) is associated with PDAC risk (adjusted hazard ratio [HR]: 3.35, 95% confidence interval [95% CI]: 1.60-7.00). In the Mendelian randomization study, we leverage eight out of nine IPFD-associated genetic variants (p < 5 × 10-8) from a genome-wide association study in the UK Biobank (N = 25,617) and find that genetically determined IPFD is associated with PDAC (odds ratio [OR] per 1-standard deviation [SD] increase in IPFD: 2.46, 95% CI: 1.38-4.40) in the Pancreatic Cancer Cohort Consortium I, II, III (PanScan I-III)/Pancreatic Cancer Case-Control Consortium (PanC4) dataset (8,275 PDAC cases and 6,723 non-cases). This study provides evidence for a potential causal role of IPFD in the pathogenesis of PDAC. Thus, reducing IPFD may lower PDAC risk.

Dietary Fibre for the Prevention of Post-Pancreatitis Diabetes Mellitus: A Review of the Literature and Future Research Directions

Post-pancreatitis diabetes mellitus-the most common sequela of pancreatitis-leads to poorer glycaemic control compared with type 2 diabetes. Because post-pancreatitis diabetes mellitus is an exemplar of secondary diabetes (with a clear underlying cause), much post-pancreatitis diabetes mellitus is preventable or treatable early. Earlier literature established the important role of dietary fibre in reducing plasma glucose in individuals with type 2 diabetes. The present review benchmarks available evidence on the role of habitual dietary fibre intake in pancreatitis and post-pancreatitis diabetes mellitus. It also paves the way for future research on the use of dietary fibre in the post-pancreatitis setting.

Effects of liraglutide on intrapancreatic fat deposition in patients with type 2 diabetes

BACKGROUND & AIMS

Ectopic fat deposition is associated with worsening of glycemic control. This study was conducted to determine whether liraglutide reduces ectopic fat deposition, especially in pancreas, in patients with type 2 diabetes (T2D).

METHODS

We retrospectively recruited T2D patients who underwent abdominal unenhanced CT scans both before and after administration of liraglutide (N = 13) or glimepiride (N = 29). Using CT values of pancreas (P), liver (L) and spleen (S), we defined the indices of intrapancreatic and liver fat as P-S value and L-S value, respectively. Increase of each value suggests the reduction of each fat deposition.

RESULTS

The values of HbA1c (p = 0.0017) and body weight (p = 0.0081) decreased, and L-S (p = 0.0024) increased significantly after administration of liraglutide compared with those at baseline. Similarly, P-S tended to increase in the liraglutide group (p = 0.0547) and increased significantly in the liraglutide subgroup with fatty pancreas (p = 0.0303), defined as having baseline P-S less than -5. In the glimepiride group, P-S did not increase regardless of baseline P-S. Among patients with fatty pancreas, administration of liraglutide tended to be a significant factor for the change in P-S after adjustment for the change in HbA1c (p = 0.1090) and the change in visceral fat area (p = 0.1030).

CONCLUSIONS

Intrapancreatic fat deposition was decreased after treatment with liraglutide, but not glimepiride, in T2D patients with fatty pancreas. Liraglutide might reduce intrapancreatic fat deposition independently of decreases in HbA1c and visceral fat volume.

Association between type 2 diabetes mellitus and body composition based on MRI fat fraction mapping

Purpose

To explore the association between type 2 diabetes mellitus (T2DM) and body composition based on magnetic resonance fat fraction (FF) mapping.

Methods

A total of 341 subjects, who underwent abdominal MRI examination with FF mapping were enrolled in this study, including 68 T2DM patients and 273 non-T2DM patients. The FFs and areas of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and abdominal muscle (AM) were measured at the level of the L1-L2 vertebral. The FF of bone marrow adipose tissue (BMAT) was determined by the averaged FF values measured at the level of T12 and L1 vertebral, respectively. The whole hepatic fat fraction (HFF) and pancreatic fat fraction (PFF) were measured based on 3D semi-automatic segmentation on the FF mapping. All data were analyzed by GraphPad Prism and MedCalc.

Results

VAT area, VAT FF, HFF, PFF of T2DM group were higher than those of non-T2DM group after adjusting for age and sex (P < 0.05). However, there was no differences in SAT area, SAT FF, BMAT FF, AM area and AM FF between the two groups (P > 0.05). VAT area and PFF were independent risk factors of T2DM (all P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) for VAT area and PFF in differentiating between T2DM and non-T2DM were 0.685 and 0.787, respectively, and the AUC of PFF was higher than VAT area (P < 0.05). Additionally, in seemingly healthy individuals, the SAT area, VAT area, and AM area were found to be significantly associated with being overweight and/or obese (BMI ≥ 25) (all P < 0.05).

Conclusions

In this study, it was found that there were significant associations between T2DM and VAT area, VAT FF, HFF and PFF. In addition, VAT area and PFF were the independent risk factors of T2DM. Especially, PFF showed a high diagnostic performance in discrimination between T2DM and non-T2DM. These findings may highlight the crucial role of PFF in the pathophysiology of T2DM, and it might be served as a potential imaging biomarker of the prevention and treatment of T2DM. Additionally, in individuals without diabetes, focusing on SAT area, VAT area and AM area may help identify potential health risks and provide a basis for targeted weight management and prevention measures.

Pathophysiological Mechanisms and Clinical Associations of Non-Alcoholic Fatty Pancreas Disease

Non-Alcoholic Fatty Pancreas disease (NAFPD), characterized by fat accumulation in pancreatic tissue, is an emerging clinical entity. However, the clinical associations, the underlying molecular drivers, and the pathophysiological mechanisms of NAFPD have not yet been characterized in detail. The NAFPD spectrum not only includes infiltration and accumulation of fat within and between pancreatic cells but also involves several inflammatory processes, dysregulation of physiological metabolic pathways, and hormonal defects. A deeper understanding of the underlying molecular mechanisms is key to correlate NAFPD with clinical entities including non-alcoholic fatty liver disease, metabolic syndrome, diabetes mellitus, atherosclerosis, as well as pancreatic cancer and pancreatitis. The aim of this review is to examine the pathophysiological mechanisms of NAFPD and to assess the possible causative/predictive risk factors of NAFPD-related clinical syndromes.

Associations of pancreas fat content and size with markers of iron metabolism

OBJECTIVE

To comprehensively investigate the associations of pancreas fat content and size with circulating markers of iron metabolism.

METHODS

A total of 116 individuals underwent magnetic resonance imaging and spectroscopy on a 3.0 Tesla scanner, exclusively for the purpose of the COSMOS research programme. Intra-pancreatic fat deposition, total pancreas volume, liver fat content, visceral and subcutaneous fat volumes were quantified. Plasma levels of hepcidin and ferritin were measured. Multiple linear regression analysis was conducted, adjusting for body mass index, age, and sex.

RESULTS

Total intra-pancreatic fat deposition was inversely associated with hepcidin (β = -0.54, 95 % confidence interval -1.02 to -0.07) whereas total pancreas volume was not associated with hepcidin (β = 0.36, 95 % confidence interval -7.12 to 7.84) in the most adjusted model. Neither total intra-pancreatic fat deposition (β = -0.03, 95 % confidence interval -0.39 to 0.33) nor total pancreas volume (β = -1.02, 95 % confidence interval -6.67 to 4.63) was associated with ferritin in the most adjusted model. Subcutaneous fat, visceral fat, and liver fat were not associated with hepcidin. Subcutaneous fat was inversely associated with ferritin (β = -0.06, 95 % CI -0.11 to -0.01) whereas visceral fat (β = 0.05, 95 % CI -0.01 to 0.14) and liver fat (β = 0.09, 95 % CI -0.04 to 0.34) were not associated with ferritin in the most adjusted model.

CONCLUSIONS

Increased intra-pancreatic fat deposition, but not other fat depots, is associated with reduced circulating levels of hepcidin. Deranged iron metabolism may play a role in the pathogenesis of fatty change of the pancreas.

Intrapancreatic fat deposition and nutritional treatment: the role of various dietary approaches

Ectopic fat accumulation in various organs and tissues, such as the liver, muscle, kidney, heart, and pancreas, is related to impaired capacity of adipose tissue to accumulate triglycerides, as a consequence of overnutrition and an unhealthy lifestyle. Ectopic fat promotes organ dysfunction and is a key factor in the development and progression of cardiometabolic diseases. Interest in intrapancreatic fat deposition (IPFD) has developed in the last few years, particularly in relation to improvement in methodological techniques for detection of fat in the pancreas, and to growing evidence for the role that IPFD might have in glucose metabolism disorders and cardiometabolic disease. Body weight reduction represents the main option for reducing fat, and the evidence consistently shows that hypocaloric diets are effective in reducing IPFD. Changes in diet composition, independently of changes in energy intake, might offer a more feasible and safe alternative treatment to energy restriction. This current narrative review focused particularly on the possible beneficial role of the diet and its nutrient content, in hypocaloric and isocaloric conditions, in reducing IPFD in individuals with high cardiometabolic risk, highlighting the possible effects of differences in calorie quantity and calorie quality. This review also describes plausible mechanisms by which the various dietary approaches could modulate IPFD.

Global research trends of diabetes remission: a bibliometric study

Background

Research on diabetes remission has garnered prominence in recent years. However, to date, no pertinent bibliometric study has been published. This study sought to elucidate the current landscape and pinpoint potential new research directions through a bibliometric analysis of diabetes remission.

Methods

We perused relevant articles on diabetes remission from January 1, 2000, to April 16, 2023, in the Web of Science. We utilized CiteSpace software and VOSviewer software to construct knowledge maps and undertake analysis of countries, institutional affiliations, author contributions, journals, and keywords. This analysis facilitated the identification of current research foci and forecasting future trends.

Results

A total of 970 English articles were procured, and the annual publication volume manifested a steady growth trend. Most of the articles originated from America (n=342, 35.26%), succeeded by China and England. Pertaining to institutions, the University of Newcastle in England proliferated the most articles (n=36, 3.71%). Taylor R authored the most articles (n=35, 3.61%), and his articles were also the most co-cited (n=1756 times). Obesity Surgery dominated in terms of published articles (n=81, 8.35%). "Bariatric surgery" was the most prevalently used keyword. The keyword-clustering map revealed that the research predominantly centered on diabetes remission, type 1 diabetes, bariatric surgery, and lifestyle interventions. The keyword emergence and keyword time-zone maps depicted hotspots and shifts in the domain of diabetes remission. Initially, the hotspots were primarily fundamental experiments probing the feasibilities and mechanisms of diabetes remission, such as transplantation. Over the course, the research trajectory transitioned from basic to clinical concerning diabetes remission through bariatric surgery, lifestyle interventions, and alternative strategies.

Conclusion

Over the preceding 20 years, the domain of diabetes remission has flourished globally. Bariatric surgery and lifestyle interventions bestow unique advantages for diabetes remission. Via the maps, the developmental milieu, research foci, and avant-garde trends in this domain are cogently portrayed, offering guidance for scholars.

Causal link between gut microbiota and four types of pancreatitis: a genetic association and bidirectional Mendelian randomization study

BACKGROUND

A number of recent observational studies have indicated a correlation between the constitution of gut microbiota and the incidence of pancreatitis. Notwithstanding, observational studies are unreliable for inferring causality because of their susceptibility to confounding, bias, and reverse causality, the causal relationship between specific gut microbiota and pancreatitis is still unclear. Therefore, our study aimed to investigate the causal relationship between gut microbiota and four types of pancreatitis.

METHODS

An investigative undertaking encompassing a genome-wide association study (GWAS) comprising 18,340 participants was undertaken with the aim of discerning genetic instrumental variables that exhibit associations with gut microbiota, The aggregated statistical data pertaining to acute pancreatitis (AP), alcohol-induced AP (AAP), chronic pancreatitis (CP), and alcohol-induced CP (ACP) were acquired from the FinnGen Consortium. The two-sample bidirectional Mendelian randomization (MR) approach was utilized. Utilizing the Inverse-Variance Weighted (IVW) technique as the cornerstone of our primary analysis. The Bonferroni analysis was used to correct for multiple testing, In addition, a number of sensitivity analysis methodologies, comprising the MR-Egger intercept test, the Cochran's Q test, MR polymorphism residual and outlier (MR-PRESSO) test, and the leave-one-out test, were performed to evaluate the robustness of our findings.

RESULTS

A total of 28 intestinal microflora were ascertained to exhibit significant associations with diverse outcomes of pancreatitis. Among them, Class Melainabacteria (OR = 1.801, 95% CI: 1.288-2.519, p = 0.008) has a strong causality with ACP after the Bonferroni-corrected test, in order to assess potential reverse causation effects, we used four types of pancreatitis as the exposure variable and scrutinized its impact on gut microbiota as the outcome variable, this analysis revealed associations between pancreatitis and 30 distinct types of gut microflora. The implementation of Cochran's Q test revealed a lack of substantial heterogeneity among the various single nucleotide polymorphisms (SNP).

CONCLUSION

Our first systematic Mendelian randomization analysis provides evidence that multiple gut microbiota taxa may be causally associated with four types of pancreatitis disease. This discovery may contribute significant biomarkers conducive to the preliminary, non-invasive identification of Pancreatitis. Additionally, it could present viable targets for potential therapeutic interventions in the disease's treatment.

Update on Adipose Tissue and Cancer

Adipose tissue is the largest endocrine organ and an accepted contributor to overall energy homeostasis. There is strong evidence linking increased adiposity to the development of 13 types of cancer. With increased adiposity comes metabolic dysfunction and insulin resistance, and increased systemic insulin and glucose support the growth of many cancers, including those of the colon and endometrium. There is also an important direct crosstalk between adipose tissue and various organs. For instance, the healthy development and function of the mammary gland, as well as the development, growth, and progression of breast cancer, are heavily impacted by the breast adipose tissue in which breast epithelial cells are embedded. Cells of the adipose tissue are responsive to external stimuli, including overfeeding, leading to remodeling and important changes in the secretion of factors known to drive the development and growth of cancers. Loss of factors like adiponectin and increased production of leptin, endotrophin, steroid hormones, and inflammatory mediators have been determined to be important mediators of the obesity-cancer link. Obesity is also associated with a structural remodeling of the adipose tissue, including increased localized fibrosis and disrupted angiogenesis that contribute to the development and progression of cancers. Furthermore, tumor cells feed off the adipose tissue, where increased lipolysis within adipocytes leads to the release of fatty acids and stromal cell aerobic glycolysis leading to the increased production of lactate. Both have been hypothesized to support the higher energetic demands of cancer cells. Here, we aim to provide an update on the state of the literature revolving around the role of the adipose tissue in cancer initiation and progression.

Metabolic Sequelae: The Pancreatitis Zeitgeist of the 21st Century

Holistic management of pancreatitis means that gastroenterologists in the 21st Century should think beyond improving in-hospital outcomes of pancreatitis alone. In particular, there is considerable room for optimizing the management of new-onset diabetes, exocrine pancreatic insufficiency, and other metabolic sequelae of pancreatitis. The present article provides state-of-the-art information on classification, terminology, and burden of the common sequelae of pancreatitis. A high-risk group of patients with pancreatitis is identified, which is positioned to benefit the most from the metabolic sequelae surveillance program introduced in this article. The program involves continuous follow-up after pancreatitis diagnosis, with the focus on early identification of new-onset diabetes after pancreatitis and exocrine pancreatic insufficiency. The metabolic sequelae surveillance program is scalable and has the potential to reduce the burden of pancreatitis through tertiary prevention in the decades to come.

Remnant cholesterol, but not low-density lipoprotein cholesterol, is associated with intra-pancreatic fat deposition

AIM

To investigate the associations of components of the lipid panel (and its derivatives) with intra-pancreatic fat deposition (IPFD).

METHODS

All participants underwent abdominal magnetic resonance imaging on the same 3.0-Tesla scanner and IPFD was quantified. Blood samples were collected in the fasted state for analysis of lipid panel components. A series of linear regression analyses was conducted, adjusting for age, sex, ethnicity, body mass index, fasting plasma glucose, homeostatic model assessment of insulin resistance, and liver fat deposition.

RESULTS

A total of 348 participants were included. Remnant cholesterol (P = 0.010) and triglyceride levels (P = 0.008) were positively, and high-density lipoprotein cholesterol level (P = 0.001) was negatively, associated with total IPFD in the most adjusted model. Low-density lipoprotein cholesterol and total cholesterol were not significantly associated with total IPFD. Of the lipid panel components investigated, remnant cholesterol explained the greatest proportion (9.9%) of the variance in total IPFD.

CONCLUSION

Components of the lipid panel have different associations with IPFD. This may open up new opportunities for improving outcomes in people at high risk for cardiovascular diseases (who have normal low-density lipoprotein cholesterol) by reducing IPFD.

Comprehensive analysis of dyslipidemia states associated with fat in the pancreas

BACKGROUND

The global burden of cardiovascular diseases continues to rise, and it is increasingly acknowledged that guidelines based on traditional risk factors fail to identify a substantial fraction of people who develop cardiovascular diseases. Fat in the pancreas could be one of the unappreciated risk factors. This study aimed to investigate the associations of dyslipidemia states with fat in the pancreas.

METHODS

All participants underwent magnetic resonance imaging on the same 3.0 T scanner for quantification of fat in the pancreas, analyzed as both binary (i.e., fatty change of the pancreas) and continuous (i.e., intra-pancreatic fat deposition) variables. Statistical analyses were adjusted for body mass index, glycated hemoglobin, fasting insulin, ethnicity, age, and sex.

RESULTS

There were 346 participants studied. On most adjusted analyses, high-density lipoprotein cholesterol dyslipidemia was significantly associated with both fatty change of the pancreas (p = 0.010) and intra-pancreatic fat deposition (p = 0.008). Neither low-density lipoprotein cholesterol dyslipidemia nor triglyceride dyslipidemia were significantly associated with fatty change of the pancreas and intra-pancreatic fat deposition. The absence of any dyslipidemia was inversely associated with both fatty change of the pancreas (p = 0.016) and intra-pancreatic fat deposition (p < 0.001).

CONCLUSIONS

Dyslipidemias are uncoupled when it comes to the relationship with fat in the pancreas, with only high-density lipoprotein cholesterol dyslipidemia having a consistent and strong link with it. The residual cardiovascular diseases risk may be attributed to fatty change of the pancreas.

Dynamic changes in the transcriptome of tRNA-derived small RNAs related with fat metabolism

The prevalence of obesity and overweight is steadily rising, posing a significant global challenge for humanity. The fundamental cause of obesity and overweight lies in the abnormal accumulation of adipose tissue. While numerous regulatory factors related to fat deposition have been identified in previous studies, a considerable number of regulatory mechanisms remain unknown. tRNA-derived small RNAs (tsRNAs), a novel class of non-coding RNAs, have emerged as significant regulators in various biological processes. In this study, we obtained small RNA sequencing data from subcutaneous white adipose tissue and omental white adipose tissue of lean and obese pigs. In addition, we similarly obtained tsRNAs profiles from scapular brown adipose tissue (BAT), inguinal white adipose tissue (iWAT) and epigonadal white adipose tissue (eWAT) of normal mice. Finally, we successfully identified a large number of expressed tsRNAs in each tissue type and identified tsRNAs conserved in different adipose tissues of pigs and mice. These datasets will be a valuable resource for elucidating the epigenetic mechanisms of fat deposition.

Effect of laparoscopic sleeve gastrectomy on mobilization of site-specific body adipose depots: a prospective cohort study

BACKGROUND

Effect of bariatric surgery on mobilization of site-specific body adipose depots is not well investigated. Herein, the authors conducted a prospective cohort study to assess whether bariatric surgery can differentially affect specific fat storage pools and to further investigate correlations between site-specific fat mobilization and clinical outcomes.

MATERIALS AND METHODS

In this single-centre prospective cohort study, 49 participants underwent laparoscopic sleeve gastrectomy (LSG) from 24 May 2022 to 20 October 2022 and underwent MRI to estimate subcutaneous fat area, visceral fat area (VFA), hepatic and pancreatic proton density fat fraction (PDFF) at baseline and 3 months after surgery. The protocol for this study was registered on clinicaltrials.gov.

RESULTS

Among 49 patients who met all inclusion criteria, the median [interquartile range (IQR)] age was 31.0 (23.0-37.0) years, the median (IQR) BMI was 38.1 (33.7-42.2) kg/m 2 and 36.7% were male. Median (IQR) percentage hepatic PDFF loss was the greatest after bariatric surgery at 68.8% (47.3-79.7%), followed by percentage pancreatic PDFF loss at 51.2% (37.0-62.1%), percentage VFA loss at 36.0% (30.0-42.4%), and percentage subcutaneous fat area loss at 22.7% (17.2-32.4%) ( P <0.001). By calculating Pearson correlation coefficient and partial correlation coefficient, the positive correlations were confirmed between change in VFA and change in glycated haemoglobin ( r =0.394, P =0.028; partial r =0.428, P =0.042) and between change in hepatic PDFF and change in homoeostatic model assessment of insulin resistance ( r =0.385, P =0.025; partial r =0.403, P =0.046).

CONCLUSIONS

LSG preferentially mobilized hepatic fat, followed by pancreatic fat and visceral adipose tissue, while subcutaneous adipose tissue was mobilized to the least extent. Reduction in visceral adipose tissue and hepatic fat is independently associated with the improvement of glucose metabolism after LSG.

Fatty infiltration of the pancreas: a systematic concept analysis

Fatty infiltration of the pancreas (FIP) has been recognized for nearly a century, yet many aspects of this condition remain unclear. Regular literature reviews on the diagnosis, consequences, and management of FIP are crucial. This review article highlights the various disorders for which FIP has been established as a risk factor, including type 2 diabetes mellitus (T2DM), pancreatitis, pancreatic fistula (PF), metabolic syndrome (MS), polycystic ovary syndrome (PCOS), and pancreatic duct adenocarcinoma (PDAC), as well as the new investigation tools. Given the interdisciplinary nature of FIP research, a broad range of healthcare specialists are involved. This review article covers key aspects of FIP, including nomenclature and definition of pancreatic fat infiltration, history and epidemiology, etiology and pathophysiology, clinical presentation and diagnosis, clinical consequences, and treatment. This review is presented in a detailed narrative format for accessibility to clinicians and medical students.

Relationship of Serum Bile Acids with Fat Deposition in the Pancreas, Liver, and Skeletal Muscle

Introduction

Ectopic fat deposition is well appreciated as a key contributor to digestive and liver diseases. Bile acids have emerged as pleiotropic signalling molecules involved in numerous metabolic pathways. The aim was to study the associations of bile acids with ectopic fat deposition and lipid panel.

Methods

A single 3.0 Tesla magnetic resonance imaging scanner was employed to measure fat deposition in the pancreas, liver, and skeletal muscle in 76 adults. Blood samples were drawn to determine total bile acids and lipid panel. Linear regression analyses were run, taking into account age, sex, body mass index, and other covariates.

Results

The studied ectopic fat depots were not significantly associated with levels of total bile acids in serum. Total bile acids were significantly associated high-density lipoprotein cholesterol - consistently in both the unadjusted (p = 0.018) and all adjusted models (p = 0.012 in the most adjusted model). Low-density lipoprotein cholesterol, total cholesterol, and triglycerides were not significantly associated with total bile acids in both the unadjusted and all adjusted models.

Conclusion

Fat deposition in the pancreas, liver, and skeletal muscle is not associated with circulating levels of total bile acids. High-density lipoprotein cholesterol is the only component of lipid panel that is associated with total bile acids.

Pancreatic steatosis and iron overload increases cardiovascular risk in non-alcoholic fatty liver disease

Objective

To assess the prevalence of pancreatic steatosis and iron overload in non-alcoholic fatty liver disease (NAFLD) and their correlation with liver histology severity and the risk of cardiometabolic diseases.

Method

A prospective, multicenter study including NAFLD patients with biopsy and paired Magnetic Resonance Imaging (MRI) was performed. Liver biopsies were evaluated according to NASH Clinical Research Network, hepatic iron storages were scored, and digital pathology quantified the tissue proportionate areas of fat and iron. MRI-biomarkers of fat fraction (PDFF) and iron accumulation (R2*) were obtained from the liver and pancreas. Different metabolic traits were evaluated, cardiovascular disease (CVD) risk was estimated with the atherosclerotic CVD score, and the severity of iron metabolism alteration was determined by grading metabolic hiperferritinemia (MHF). Associations between CVD, histology and MRI were investigated.

Results

In total, 324 patients were included. MRI-determined pancreatic iron overload and moderate-to severe steatosis were present in 45% and 25%, respectively. Liver and pancreatic MRI-biomarkers showed a weak correlation (r=0.32 for PDFF, r=0.17 for R2*). Pancreatic PDFF increased with hepatic histologic steatosis grades and NASH diagnosis (p<0.001). Prevalence of pancreatic steatosis and iron overload increased with the number of metabolic traits (p<0.001). Liver R2* significantly correlated with MHF (AUC=0.77 [0.72-0.82]). MRI-determined pancreatic steatosis (OR=3.15 [1.63-6.09]), and iron overload (OR=2.39 [1.32-4.37]) were independently associated with high-risk CVD. Histologic diagnosis of NASH and advanced fibrosis were also associated with high-risk CVD.

Conclusion

Pancreatic steatosis and iron overload could be of utility in clinical decision-making and prognostication of NAFLD.

Intra-pancreatic fat deposition across the pancreatitis spectrum and the influence of gut hormones

BACKGROUND AND AIMS

Acute pancreatitis (AP) and chronic pancreatitis (CP) often represent parts of the spectrum of disease. While growing evidence indicates that intra-pancreatic fat deposition (IPFD) plays an important role in the pathogenesis of pancreatitis, no study of living individuals has investigated IPFD in both AP and CP. Further, the associations between IPFD and gut hormones remain to be elucidated. The aims were to investigate the associations of IPFD with AP, CP, and health; and to study whether gut hormones affect these associations.

METHODS

Magnetic resonance imaging on the same 3.0 Tesla scanner was used to determine IPFD in 201 study participants. These participants were arranged into the health, AP, and CP groups. Gut hormones (ghrelin, glucagon-like peptide-1, gastric inhibitory peptide, peptide YY, and oxyntomodulin) were measured in blood, both after an 8-hour overnight fasting and after ingestion of a standardised mixed meal. A series of linear regression analyses was run, accounting for age, sex, ethnicity, body mass index, glycated haemoglobin, and triglycerides.

RESULTS

Both the AP group and CP group had significantly higher IPFD in comparison with the health group, consistently across all models (p for trend 0.027 in the most adjusted model). Ghrelin in the fasted state had a significant positive association with IPFD in the AP group (but not the CP or health group), consistently across all models (p = 0.019 in the most adjusted model). None of the studied gut hormones in the postprandial state was significantly associated with IPFD.

CONCLUSION

Fat deposition in the pancreas is similarly high in individuals with AP and those with CP. The gut-brain axis, and more specifically overexpression of ghrelin, may contribute to increased IPFD in individuals with AP.

Artificial intelligence assisted whole organ pancreatic fat estimation on magnetic resonance imaging and correlation with pancreas attenuation on computed tomography

BACKGROUND

Fatty pancreas is associated with inflammatory and neoplastic pancreatic diseases. Magnetic resonance imaging (MRI) is the diagnostic modality of choice for measuring pancreatic fat. Measurements typically use regions of interest limited by sampling and variability. We have previously described an artificial intelligence (AI)-aided approach for whole pancreas fat estimation on computed tomography (CT). In this study, we aimed to assess the correlation between whole pancreas MRI proton-density fat fraction (MR-PDFF) and CT attenuation.

METHODS

We identified patients without pancreatic disease who underwent both MRI and CT between January 1, 2015 and June 1, 2020. 158 paired MRI and CT scans were available for pancreas segmentation using an iteratively trained convolutional neural network (CNN) with manual correction. Boxplots were generated to visualize slice-by-slice variability in 2D-axial slice MR-PDFF. Correlation between whole pancreas MR-PDFF and age, BMI, hepatic fat and pancreas CT-Hounsfield Unit (CT-HU) was assessed.

RESULTS

Mean pancreatic MR-PDFF showed a strong inverse correlation (Spearman -0.755) with mean CT-HU. MR-PDFF was higher in males (25.22 vs 20.87; p = 0.0015) and in subjects with diabetes mellitus (25.95 vs 22.17; p = 0.0324), and was positively correlated with age and BMI. The pancreatic 2D-axial slice-to-slice MR-PDFF variability increased with increasing mean whole pancreas MR-PDFF (Spearman 0.51; p < 0.0001).

CONCLUSION

Our study demonstrates a strong inverse correlation between whole pancreas MR-PDFF and CT-HU, indicating that both imaging modalities can be used to assess pancreatic fat. 2D-axial pancreas MR-PDFF is variable across slices, underscoring the need for AI-aided whole-organ measurements for objective and reproducible estimation of pancreatic fat.

Relationships between intra-pancreatic fat deposition and lifestyle factors: a cross-sectional study

Aims

The excess deposition of intra-pancreatic fat deposition (IPFD) has been reported to be associated with type 2 diabetes, chronic pancreatitis, and pancreatic ductal adenocarcinoma. In the current study, we aimed to identify a relationship between lifestyle factors and IPFD.

Materials and methods

99 patients admitted to the Osaka University Hospital who had undergone abdominal computed tomography were selected. We evaluated the mean computed tomography values of the pancreas and spleen and then calculated IPFD score. Multiple regression analyses were used to assess the associations between IPFD score and lifestyle factors.

Results

Fast eating speed, late-night eating, and early morning awakening were significantly associated with a high IPFD score after adjusting for age, sex, diabetes status and Body Mass Index (p=0.04, 0.01, 0.01, respectively).

Conclusion

The current study has elucidated the significant associations of fast eating speed, late-night eating, and early morning awakening with IPFD.

Heparanase 2 (Hpa2)- a new player essential for pancreatic acinar cell differentiation

Heparanase 2 (Hpa2, HPSE2) is a close homolog of heparanase. Hpa2, however, lacks intrinsic heparan sulfate (HS)-degrading activity, the hallmark of heparanase enzymatic activity. Mutations of HPSE2 were identified in patients diagnosed with urofacial syndrome (UFS), a rare genetic disorder that exhibits abnormal facial expression and bladder voiding dysfunction, leading to renal damage and eventually renal failure. In order to reveal the role of HPSE2 in tissue homeostasis, we established a conditional Hpa2-KO mouse. Interestingly, the lack of Hpa2 was associated with a marked decrease in the expression of key pancreatic transcription factors such as PTF1, GATA6, and Mist1. This was associated with a two-fold decrease in pancreas weight, increased pancreatic inflammation, and profound morphological alterations of the pancreas. These include massive accumulation of fat cells, possibly a result of acinar-to-adipocyte transdifferentiation (AAT), as well as acinar-to-ductal metaplasia (ADM), both considered to be pro-tumorigenic. Furthermore, exposing Hpa2-KO but not wild-type mice to a carcinogen (AOM) and pancreatic inflammation (cerulein) resulted in the formation of pancreatic intraepithelial neoplasia (PanIN), lesions that are considered to be precursors of invasive ductal adenocarcinoma of the pancreas (PDAC). These results strongly support the notion that Hpa2 functions as a tumor suppressor. Moreover, Hpa2 is shown here for the first time to play a critical role in the exocrine aspect of the pancreas.

Intrapancreatic fat, pancreatitis, and pancreatic cancer

Pancreatic cancer is typically detected at an advanced stage, and is refractory to most forms of treatment, contributing to poor survival outcomes. The incidence of pancreatic cancer is gradually increasing, linked to an aging population and increasing rates of obesity and pancreatitis, which are risk factors for this cancer. Sources of risk include adipokine signaling from fat cells throughout the body, elevated levels of intrapancreatic intrapancreatic adipocytes (IPAs), inflammatory signals arising from pancreas-infiltrating immune cells and a fibrotic environment induced by recurring cycles of pancreatic obstruction and acinar cell lysis. Once cancers become established, reorganization of pancreatic tissue typically excludes IPAs from the tumor microenvironment, which instead consists of cancer cells embedded in a specialized microenvironment derived from cancer-associated fibroblasts (CAFs). While cancer cell interactions with CAFs and immune cells have been the topic of much investigation, mechanistic studies of the source and function of IPAs in the pre-cancerous niche are much less developed. Intriguingly, an extensive review of studies addressing the accumulation and activity of IPAs in the pancreas reveals that unexpectedly diverse group of factors cause replacement of acinar tissue with IPAs, particularly in the mouse models that are essential tools for research into pancreatic cancer. Genes implicated in regulation of IPA accumulation include KRAS, MYC, TGF-β, periostin, HNF1, and regulators of ductal ciliation and ER stress, among others. These findings emphasize the importance of studying pancreas-damaging factors in the pre-cancerous environment, and have significant implications for the interpretation of data from mouse models for pancreatic cancer.

Quantitative imaging predicts pancreatic fatty infiltration on routine CT examination

PURPOSE

The purpose of this study was to assess the performance of quantitative computed tomography (CT) imaging for detecting pancreatic fatty infiltration, using the results of histopathological analysis as reference.

MATERIALS AND METHODS

Sixty patients who underwent pancreatic surgery for a pancreatic tumor between 2016 and 2019 were retrospectively included. There were 33 women and 27 men with a mean age of 56 ± 12 (SD) years (age range: 18-79 years). Patients with dilatation of the main pancreatic duct, chronic pancreatitis, or preoperative treatment were excluded to prevent any bias in the radiological-pathological correlation. Pancreatic fatty infiltration was recorded at pathology. Pancreatic surface lobularity, pancreatic attenuation, visceral fat area, and subcutaneous fat area were derived from preoperative CT images. The performance for the prediction of fatty infiltration was assessed using area under receiver operating characteristic curve (AUC) and backward binary logistic regression analysis. Results were validated in a separate cohort of 34 patients (17 women; mean age, 50 ± 14 [SD] years; age range: 18-73).

RESULTS

A total of 28/60 (47%) and 17/34 (50%) patients had pancreatic fatty infiltration in the derivation and validation cohorts, respectively. In the derivation cohort, patients with pancreatic fatty infiltration had a significantly higher PSL (P < 0.001) and a lower pancreatic attenuation on both precontrast and portal venous phase images (P = 0.011 and 0.003, respectively), and higher subcutaneous fat area and visceral fat area (P = 0.010 and 0.007, respectively). Multivariable analysis identified pancreatic surface lobularity > 7.6 and pancreatic attenuation on portal venous phase images < 83.5 Hounsfield units as independently associated with fatty infiltration. The combination of these variables resulted in an AUC of 0.85 (95% CI: 0.74-0.95) and 0.83 (95% CI: 0.67-0.99) in the derivation and validation cohorts, respectively.

CONCLUSION

CT-based quantitative imaging accurately predicts pancreatic fatty infiltration.

Non-alcoholic fatty pancreas disease and pancreatic exocrine insufficiency: pilot study and systematic review

INTRODUCTION

The prevalence of non-alcoholic fatty pancreas disease (NAFPD) is estimated as 2-46% among patients without known pancreatic diseases. An association between NAFPD and non-alcoholic fatty liver disease (NAFLD) has been proposed, as well as an association between NAFPD and pancreatic exocrine insufficiency (PEI).

PATIENTS AND METHODS

Patients with histologically confirmed NAFLD were included in the study. The control group consisted of individuals included in a surveillance screening program. Magnetic resonance imaging (MRI) of the pancreas was performed in all patients and fat measurement was made using 2-point Dixon imaging. Fecal elastase-1 (FE-1) was performed to evaluate pancreatic exocrine function. Additionally, a 13C-mixed triglyceride breath test (13 C-MTG-BT) was performed in patients with FE-1 < 200 μg/g.

RESULTS

Imaging signs of NAFPD were present in 17 (71%) patients; 11 (85%) from the NAFLD group and 6 (55%) from the control group. FE-1 < 200 μg/g was found in six (25%) patients (four in the NAFLD group and two in the control group); however, none of them had clinical symptoms of PEI. Therefore, in five out of six patients with low FE-1, a 13C-MTG-BT was performed, showing normal results (>20.9%) in all tested patients. Furthermore, the serum nutritional panel was normal in all patients with low FE-1. A systematic review identified five studies relevant to the topic.

CONCLUSION

NAFPD was found in 85% of patients with NAFLD and in 55% of control patients. We did not diagnose PEI in either group. A literature review showed PEI in 9-56% of patients with NAFPD.

Acinar cells and the development of pancreatic fibrosis

Pancreatic fibrosis is caused by excessive deposition of extracellular matrixes of collagen and fibronectin in the pancreatic tissue as a result of repeated injury often seen in patients with chronic pancreatic diseases. The most common causative conditions include inborn errors of metabolism, chemical toxicity and autoimmune disorders. Its pathophysiology is highly complex, including acinar cell injury, acinar stress response, duct dysfunction, pancreatic stellate cell activation, and persistent inflammatory response. However, the specific mechanism remains to be fully clarified. Although the current therapeutic strategies targeting pancreatic stellate cells show good efficacy in cell culture and animal models, they are not satisfactory in the clinic. Without effective intervention, pancreatic fibrosis can promote the transformation from pancreatitis to pancreatic cancer, one of the most lethal malignancies. In the normal pancreas, the acinar component accounts for 82% of the exocrine tissue. Abnormal acinar cells may activate pancreatic stellate cells directly as cellular source of fibrosis or indirectly via releasing various substances and initiate pancreatic fibrosis. A comprehensive understanding of the role of acinar cells in pancreatic fibrosis is critical for designing effective intervention strategies. In this review, we focus on the role of and mechanisms underlying pancreatic acinar injury in pancreatic fibrosis and their potential clinical significance.

Lipid droplet biogenesis and functions in health and disease

Ubiquitous yet unique, lipid droplets are intracellular organelles that are increasingly being recognized for their versatility beyond energy storage. Advances uncovering the intricacies of their biogenesis and the diversity of their physiological and pathological roles have yielded new insights into lipid droplet biology. Despite these insights, the mechanisms governing the biogenesis and functions of lipid droplets remain incompletely understood. Moreover, the causal relationship between the biogenesis and function of lipid droplets and human diseases is poorly resolved. Here, we provide an update on the current understanding of the biogenesis and functions of lipid droplets in health and disease, highlighting a key role for lipid droplet biogenesis in alleviating cellular stresses. We also discuss therapeutic strategies of targeting lipid droplet biogenesis, growth or degradation that could be applied in the future to common diseases, such as cancer, hepatic steatosis and viral infection.

Genetic Evidence Causally Linking Pancreas Fat to Pancreatic Cancer: A Mendelian Randomization Study

Background & Aims

Pancreatic ductal adenocarcinoma (PDAC) is highly lethal, and any clues to understanding its elusive etiology could lead to breakthroughs in prevention, early detection, or treatment. Observational studies have shown a relationship between pancreas fat accumulation and PDAC, but the causality of this link is unclear. We therefore investigated whether pancreas fat is causally associated with PDAC using two-sample Mendelian randomization.

Methods

We leveraged eight genetic variants associated with pancreas fat (P<5×10 ^-8 ) from a genome-wide association study (GWAS) in the UK Biobank (25,617 individuals), and assessed their association with PDAC in the Pancreatic Cancer Cohort Consortium I-III and the Pancreatic Cancer Case-Control Consortium dataset (8,275 PDAC cases and 6,723 non-cases). Causality was assessed using the inverse-variance weighted method. Although none of these genetic variants were associated with body mass index (BMI) at genome-wide significance, we further conducted a sensitivity analysis excluding genetic variants with a nominal BMI association in GWAS summary statistics from the UK Biobank and the Genetic Investigation of Anthropometric Traits consortium dataset (806,834 individuals).

Results

Genetically determined higher levels of pancreas fat using the eight genetic variants was associated with increased risk of PDAC. For one standard deviation increase in pancreas fat levels (i.e., 7.9% increase in pancreas fat fraction), the odds ratio of PDAC was 2.46 (95%CI:1.38-4.40, P=0.002). Similar results were obtained after excluding genetic variants nominally linked to BMI (odds ratio:3.79, 95%CI:1.66-8.65, P=0.002).

Conclusions

This study provides genetic evidence for a causal role of pancreas fat in the pathogenesis of PDAC. Thus, reducing pancreas fat could lower the risk of PDAC.

Fatty change of the pancreas: the Pandora's box of pancreatology

Prevention of common diseases of the pancreas or interception of their progression is as attractive in theory as it is elusive in practice. The fundamental challenge has been an incomplete understanding of targets coupled with a multitude of intertwined factors that are associated with the development of pancreatic diseases. Evidence over the past decade has shown unique morphological features, distinctive biomarkers, and complex relationships of intrapancreatic fat deposition. Fatty change of the pancreas has also been shown to affect at least 16% of the global population. This knowledge has solidified the pivotal role of fatty change of the pancreas in acute pancreatitis, chronic pancreatitis, pancreatic cancer, and diabetes. The pancreatic diseases originating from intrapancreatic fat (PANDORA) hypothesis advanced in this Personal View cuts across traditional disciplinary boundaries with a view to tackling these diseases. New holistic understanding of pancreatic diseases is well positioned to propel pancreatology through lasting research breakthroughs and clinical advances.

Sex differences in type 2 diabetes

The prevalence of type 2 diabetes mellitus is increasing in both sexes, but men are usually diagnosed at a younger age and lower body fat mass than women. Worldwide, an estimated 17.7 million more men than women have diabetes mellitus. Women appear to bear a greater risk factor burden at the time of their type 2 diabetes diagnosis, especially obesity. Moreover, psychosocial stress might play a more prominent role in diabetes risk in women. Across their lifespan, women experience greater hormone fluctuations and body changes due to reproductive factors than men. Pregnancies can unmask pre-existing metabolic abnormalities, resulting in the diagnosis of gestational diabetes, which appears to be the most prominent risk factor for progression to type 2 diabetes in women. Additionally, menopause increases women's cardiometabolic risk profile. Due to the progressive rise in obesity, there is a global increase in women with pregestational type 2 diabetes, often with inadequate preconceptual care. There are differences between men and women regarding type 2 diabetes and other cardiovascular risk factors with respect to comorbidities, the manifestation of complications and the initiation of and adherence to therapy. Women with type 2 diabetes show greater relative risk of CVD and mortality than men. Moreover, young women with type 2 diabetes are currently less likely than men to receive the treatment and CVD risk reduction recommended by guidelines. Current medical recommendations do not provide information on sex-specific or gender-sensitive prevention strategies and management. Thus, more research on sex differences, including the underlying mechanisms, is necessary to increase the evidence in the future. Nonetheless, intensified efforts to screen for glucose metabolism disorders and other cardiovascular risk factors, as well as the early establishment of prophylactic measures and aggressive risk management strategies, are still required for both men and women at increased risk of type 2 diabetes. In this narrative review we aim to summarise sex-specific clinical features and differences between women and men with type 2 diabetes into risk factors, screening, diagnosis, complications and treatment.

Pancreatic changes with lifestyle and age: What is normal and what is concerning?

During the aging process, typical morphological changes occur in the pancreas, which leads to a specific "patchy lobular fibrosis in the elderly." The aging process in the pancreas is associated with changes in volume, dimensions, contour, and increasing intrapancreatic fat deposition. Typical changes are seen in ultrasonography, computed tomography, endosonography, and magnetic resonance imaging. Typical age-related changes must be distinguished from lifestyle-related changes. Obesity, high body mass index, and metabolic syndrome also lead to fatty infiltration of the pancreas. In the present article, age-related changes in morphology and imaging are discussed. Particular attention is given to the sonographic verification of fatty infiltration of the pancreas. Ultrasonography is a widely used screening examination method. It is important to acknowledge the features of the normal aging processes and not to interpret them as pathological findings. Reference is made to the uneven fatty infiltration of the pancreas. The differential diagnostic and the differentiation from other processes and diseases leading to fatty infiltration of the pancreas are discussed.

Glucose metabolism after bariatric surgery: implications for T2DM remission and hypoglycaemia

Although promising therapeutics are in the pipeline, bariatric surgery (also known as metabolic surgery) remains our most effective strategy for the treatment of obesity and type 2 diabetes mellitus (T2DM). Of the many available options, Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are currently the most widely used procedures. RYGB and VSG have very different anatomical restructuring but both surgeries are effective, to varying degrees, at inducing weight loss and T2DM remission. Both weight loss-dependent and weight loss-independent alterations in multiple tissues (such as the intestine, liver, pancreas, adipose tissue and skeletal muscle) yield net improvements in insulin resistance, insulin secretion and insulin-independent glucose metabolism. In a subset of patients, post-bariatric hypoglycaemia can develop months to years after surgery, potentially reflecting the extreme effects of potent glucose reduction after surgery. This Review addresses the effects of bariatric surgery on glucose regulation and the potential mechanisms responsible for both the resolution of T2DM and the induction of hypoglycaemia.

Pancreatic fat fraction in dual-energy computed tomography as a potential quantitative parameter in the detection of type 2 diabetes mellitus

PURPOSE

To investigate the clinical value of measuring pancreatic fat fraction using dual-energy computed tomography (DECT) in association with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This retrospective study included patients who underwent abdominal DECT between September 2021 and July 2022. The fat fractions in the head, body, and tail of the pancreas were calculated using fat maps generated from unenhanced DECT images, and CT values were measured at the same locations. The intraclass correlation coefficient (ICC) was used to analyze the reproducibility of measurements from two observers. Diagnostic performance was assessed using receiver operating characteristic curves.

RESULTS

Seventy-eight patients, including 45 T2DM patients and 33 controls, were enrolled. The fat fractions of the pancreas were significantly higher in the T2DM group than in the control group (pancreatic head: 8.4 ± 6.3 % vs 5.1 ± 3.9 %; pancreatic body: 4.8 ± 4.0 % vs 2.7 ± 3.9 %; and pancreatic tail: 5.3 ± 3.2 % vs 2.7 ± 2.9 %, all p < 0.05). And the CT values of the pancreas were significantly lower in the T2DM group than in the control group (pancreatic head: 41.1 ± 8.5 HU vs 45.7 ± 4.6 HU; pancreatic body: 44.4 ± 5.0 HU vs 47.4 ± 3.7 HU; and pancreatic tail: 44.5 ± 5.0 HU vs 47.6 ± 3.2 HU, all p < 0.05). The fat fraction of the pancreatic tail was the best indicator for distinguishing T2DM patients from the controls (area under the curve: 0.716 (95 % CI: 0.601, 0.832), sensitivity: 64.4 % (95 % CI: 48.7 %, 77.7 %), and specificity: 78.8 % (95 % CI: 60.6 %, 90.4 %)).

CONCLUSION

The DECT fat fractions of the pancreas could be a valuable additional parameter in the detection of T2DM.

Effect of D-β-hydroxybutyrate-(R)-1,3 butanediol on plasma levels of asprosin and leptin: results from a randomised controlled trial

Background: D-β-Hydroxybutyrate-(R)-1,3 butanediol - a non-racemic ketone monoester for ingestion - has emerged as an effective way to achieve acute nutritional ketosis. Whether white adipose tissue plays a role in effects of acute nutritional ketosis is largely unknown. Objective: To investigate the effects of acute nutritional ketosis on plasma levels of asprosin and leptin and if they are affected by abdominal fat phenotypes. Methods: The design was a randomised crossover trial. Participants received either the D-β-hydroxybutyrate-(R)-1,3 butanediol monoester (KEβHB) drink or placebo drink. Blood samples were collected at baseline, 30, 60, 90, 120, and 150 minutes. 3.0 Tesla magnetic resonance imaging was used to measure visceral and subcutaneous fat volumes (VFV and SFV, respectively), intra-hepatic fat deposition (IHFD), and intra-pancreatic fat deposition (IPFD). Results: A total of 18 adults were randomised, with no drop-outs. There were no significant differences in plasma levels of asprosin and leptin (p = 0.808 and p = 0.907, respectively) between the KEβHB and placebo drinks. There was no effect of time, treatment, or interaction between time and treatment on asprosin and leptin. After stratification by the VFV/SFV ratio, IHFD, and IPFD, there were no differences in asprosin and leptin between the KEβHB and placebo drinks. Conclusion: Plasma levels of asprosin and leptin were not significantly affected by acute nutritional ketosis. Abdominal fat phenotypes did not significantly affect circulating levels of the two hormones. White adipose tissue does not appear to play a role in altering hormone levels during acute nutritional ketosis. The clinical trial registry number is NCT03889210 (https://clinicaltrials.gov).

Current Status of the Diagnosis of Early-Stage Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) can be treated with surgery, chemotherapy, and radiotherapy. Despite medical progress in each field in recent years, it is still insufficient for managing PDAC, and at present, the only curative treatment is surgery. A typical pancreatic cancer is relatively easy to diagnose with imaging. However, it is often not recommended for surgical treatment at the time of diagnosis due to metastatic spread beyond the pancreas. Even if it is operable, it often recurs during postoperative follow-up. In the case of PDAC with a diameter of 10 mm or less, the 5-year survival rate is as good as 80% or more, and the best index for curative treatment is tumor size. The early detection of pancreatic cancer with a diameter of less than 10 mm or carcinoma in situ is critical. Here, we provide an overview of the current status of diagnostic imaging features and genetic tests for the accurate diagnosis of early-stage PDAC.

Association between Intrapancreatic Fat Deposition and Lower High-Density Lipoprotein Cholesterol in Individuals with Newly Diagnosed T2DM

BACKGROUND

Intrapancreatic fat deposition (IPFD) usually occurs in individuals with type 2 diabetes mellitus (T2DM), but its physiopathological influence remains controversial. The present study aimed to investigate IPFD and its associations with various aspects of glucose and lipid metabolism in individuals with newly diagnosed T2DM.

METHODS

A total of 100 individuals were included, consisting of 80 patients with newly diagnosed T2DM and 20 age- and sex-matched healthy controls. Then, we assessed IPFD using magnetic resonance imaging (MRI) and various parameters of glucose and lipid metabolism.

RESULTS

Individuals with newly diagnosed T2DM had a significantly higher IPFD (median: 12.34%; IQR, 9.19-16.60%) compared with healthy controls (median: 6.35%; IQR, 5.12-8.96%) (p < 0.001). In individuals with newly diagnosed T2DM, IPFD was significantly associated with FINS and HOMA-IR in unadjusted model (β = 0.239, p=0.022; β = 0.578, p=0.007, respectively) and adjusted model for age and sex (β = 0.241, p=0.022; β = 0.535, p=0.014, respectively), but these associations vanished after adjustment for age, sex, and BMI. The OR of lower HDL-C for the prevalence of high IPFD was 4.22 (95% CI, 1.41 to 12.69; p=0.010) after adjustment for age, sex, BMI, and HbA1c.

CONCLUSIONS

Lower HDL-C was an independent predictor for a high degree of IPFD.

Metabolic traits affecting the relationship between liver fat and intrapancreatic fat: a mediation analysis

AIMS/HYPOTHESIS

The clinical importance of fat deposition in the liver and pancreas is increasingly recognised. However, to what extent deposition of fat in these two depots is affected by intermediate variables is unknown. The aim of this work was to conduct a mediation analysis with a view to uncovering the metabolic traits that underlie the relationship between liver fat and intrapancreatic fat deposition (IPFD) and quantifying their effect.

METHODS

All participants underwent MRI/magnetic resonance spectroscopy on the same 3.0 T scanner to determine liver fat and IPFD. IPFD of all participants was quantified manually by two independent raters in duplicate. A total of 16 metabolic traits (representing markers of glucose metabolism, incretins, lipid panel, liver enzymes, pancreatic hormones and their derivatives) were measured in blood. Mediation analysis was conducted, taking into account age, sex, ethnicity and BMI. Significance of mediation was tested by computing bias-corrected bootstrap CIs with 5000 repetitions.

RESULTS

A total of 353 individuals were studied. Plasma glucose, HDL-cholesterol and triacylglycerol mediated 6.8%, 17.9% and 24.3%, respectively, of the association between liver fat and IPFD. Total cholesterol, LDL-cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, insulin, glucagon, amylin, C-peptide, HbA_1c, glucagon-like peptide-1 and gastric inhibitory peptide did not mediate the association between liver fat and IPFD.

CONCLUSIONS/INTERPRETATION

At least one-quarter of the association between liver fat and IPFD is mediated by specific blood biomarkers (triacylglycerol, HDL-cholesterol and glucose), after accounting for potential confounding by age, sex, ethnicity and BMI. This unveils the complexity of the association between the two fat depots and presents specific targets for intervention.