Ectopic fat storage in the pancreas, liver, and abdominal fat depots: impact on β-cell function in individuals with impaired glucose metabolism

Human Peripancreatic Adipose Tissue Paracrine Signaling Impacts Insulin Secretion, Blood Flow, and Gene Transcription

CONTEXT

Adipose tissue accumulation around nonadipose tissues is associated with obesity and metabolic disease. One relatively unstudied depot is peripancreatic adipose tissue (PAT) that accumulates in obesity and insulin resistance and may impact β-cell function. Pancreatic lipid accumulation and PAT content are negatively related to metabolic outcomes in humans, but these studies are limited by the inability to pursue mechanisms.

OBJECTIVE

We obtained PAT from human donors through the Human Pancreas Analysis Program to evaluate differences in paracrine signaling compared to subcutaneous adipose tissue (SAT), as well as effects of the PAT secretome on aortic vasodilation, human islet insulin secretion, and gene transcription using RNA sequencing.

RESULTS

PAT had greater secretion of interferon-γ and most inflammatory eicosanoids compared to SAT. Secretion of adipokines negatively related to metabolic health were also increased in PAT compared to SAT. We found no overall effects of PAT compared to SAT on human islet insulin secretion; however, insulin secretion was suppressed after PAT exposure from men compared to women. Vasodilation was significantly dampened by PAT conditioned media, an effect explained almost completely by PAT from men and not women. Islets treated with PAT showed selective changes in lipid metabolism pathways while SAT altered cellular signaling and growth. RNA sequencing analysis showed changes in islet gene transcription impacted by PAT compared to SAT, with the biggest changes found between PAT based on sex.

CONCLUSION

The PAT secretome is metabolically negative compared to SAT, and impacts islet insulin secretion, blood flow, and gene transcription in a sex-dependent manner.

Pancreatic volume, fat content and T1 relaxation time using magnetic resonance imaging in patients with prior gestational diabetes mellitus

PURPOSE

To compare the volume, fat content, and T1 relaxation time of the pancreas in participants with and without prior gestational diabetes mellitus (GDM).

METHODS

In this prospective case-control study, we enrolled 29 women with prior GDM, and divided them into three groups (normoglycemic, prediabetic, and diabetic) based on their glycaemic status in the postpartum period; and a group of 13 participants as controls who had normoglycemia during pregnancy. Participants underwent MR examination including an axial multi-echo DIXON-based sequence and an axial-oblique T1 mapping sequence. The average proton density fat fraction (PDFF) and T1 value of the pancreas were measured by drawing multiple circular regions of interest (ROIs). Average hepatic PDFF was similarly calculated. Pancreatic volume was computed by summating cleaned freehand ROIs outlining pancreatic parenchyma.

RESULTS

Women were evaluated at a mean age of 32.9 ± 4.0 years and with a mean BMI of 25.2 ± 2.9 kg/m2. The median (IQR) duration of follow-up after childbirth was 24 (34-44) months. In controls, the pancreatic PDFF, T1 value, and volume were 5.4 ± 2.3%, 850.6 ± 101.6 ms, and 69.3 ± 16.2 cm³, respectively, while in subjects with a history of GDM, these values were 4.7 ± 2.0%, 844.6 ± 91.8 ms, and 69.8 ± 16.6 cm³, respectively. No statistical differences were observed (all p > 0.05). Mean hepatic PDFF was significantly higher in the diabetic and prediabetic groups (12.2 ± 6.4% and 11.0 ± 7.6% respectively) than in the control and normoglycemic groups (7.9 ± 7.3 and 4.7 ± 1.6% respectively; p -0.01).

CONCLUSION

We did not find any significant changes in pancreatic volume, fat content, or fibrosis in women with prior GDM and with different glycaemic categories when evaluated in the early postpartum period, compared to the control group. These findings may be a consequence of the transient state of insulin resistance in GDM and the finite duration of the disease course in new-onset prediabetes and diabetes patients.

Liver Fat Accumulation Is Associated With Increased Insulin Secretion Independent of Total, Visceral, and Pancreatic Fat

CONTEXT

Studies in heterogeneous groups of people with respect to sex, body mass index (BMI), and glycemic status (normoglycemia, impaired glucose tolerance, diabetes), indicate no relationship between liver fat accumulation and pancreatic insulin secretion.

OBJECTIVE

This work aimed to better understand the association of liver fat with insulin secretion.

METHODS

A cross-sectional analysis was conducted of 61 men with abdominal obesity who had high liver fat (HLF, ≥ 5.6% by magnetic resonance spectroscopy, n = 28) or low liver fat (LLF, n = 33), but were balanced on BMI, total body fat, visceral adipose tissue (VAT), and pancreatic fat. A frequently sampled 5-hour oral glucose tolerance test with 11 samples, in conjunction with mathematical modeling, was used to compute indices of insulin sensitivity and insulin secretion (oral minimal model).

RESULTS

Compared to individuals with LLF, those with HLF had significantly greater fasting glucose, insulin, C-peptide, and triglycerides; lower high-density lipoprotein cholesterol; but similar glycated hemoglobin A1c. Areas under the 5-hour curve for glucose, insulin, and C-peptide were greater in the HLF group than the LLF group (by ∼10%, ∼38%, and ∼28%, respectively); fasting and total postprandial insulin secretion rates were approximately 37% and approximately 50% greater, respectively (all P < .05); whereas the insulinogenic index was not different. HLF participants had lower whole-body and hepatic insulin sensitivity, disposition index, and total insulin clearance than LLF participants (all P < .05).

CONCLUSION

Accumulation of liver fat is associated with increased insulin secretion independently of total adiposity, abdominal fat distribution, and pancreatic fat. Thereby, hyperinsulinemia in fatty liver disease is partly because of insulin hypersecretion and partly because of impaired insulin clearance.

The Impact of Exercise Training Plus Dietary Interventions on Ectopic Fat in Population with Overweight/Obesity with and without Chronic Disease: A Systematic Review, Meta-analysis, and Metaregression of Randomized Clinical Trials

Background

The growing prevalence of obesity and related chronic diseases has led to increased interest in interventions targeting ectopic fat reduction to which its accumulation is linked to metabolic dysfunction.

Objectives

This study aimed to evaluate the effects of combined exercise training combined with dietary interventions compared with dietary interventions alone on ectopic fat [visceral fat area (VFA), liver fat, intramuscular fat (IMF), pancreatic fat, renal sinus fat, and pericardial and epicardial fats] in adults with overweight and obesity, both with and without chronic diseases.

Methods

Web of Science, Scopus, and PubMed were searched for original articles up to 1 March, 2024, that included exercise compared with control interventions on body weight and ectopic fat in adults with overweight or obesity. Weighted mean differences (WMD) for body weight, liver fat, pancreatic fat, and renal sinus fat and standardized mean differences (SMD) for VFA, IMF, pericardial and epicardial fats, and 95% confidence intervals were determined using random-effects models.

Results

Thirty-two studies, including 1488 participants and 38 intervention groups, met the inclusion criteria. The combined intervention of exercise and diet did not reduce body weight (WMD = -0.23 kg, P = 0.180), liver fat (WMD = 0.05%, P = 0.730), IMF (SMD = -0.08, P = 0.640), pericardial and epicardial fats (SMD = -0.12, P = 0.280), pancreatic fat (WMD = -0.24%, P = 0.370), and renal sinus fat (WMD = 0.01 cm2, P = 0.170) when compared with a diet-only group. Interestingly, exercise combined with diet significantly reduced VFA in participants with obesity (SMD = -0.12, P = 0.040) and healthy males (SMD = -0.33, P = 0.001) when compared with a diet-only group.

Conclusions

The findings suggest that combined exercise and dietary interventions did not lead to significant reductions in most ectopic fat depots when compared with diet alone. However, a modest reduction in VFA was observed in participants with obesity and healthy males. These results highlight the nuanced impact of exercise in combination with dietary interventions and the need to consider specific fat depots and participant characteristics in obesity management strategies.The trial was registered at PROSPERO as CRD42024546770.

Association of dietary glycemic index and glycemic load with pancreatic steatosis: a case control study

BACKGROUND

Carbohydrate intake, its type and characteristics including glycemic index (GI) and glycemic load (GL) may be associated with the risk of pancreatic steatosis (PS), but there is no conclusive evidence. The aim of the present study was to investigate whether the intake of carbohydrates, GI and GL were associated with an increased risk of PS.

METHODS

To conduct this study, 278 patients with common bile duct stones (CBD) underwent endoscopic ultrasound, including 89 patients with PS (case group) and 189 healthy individuals (control group). In addition to demographic and anthropometric information, a 168-item questionnaire of food frequency was completed to calculate GL and GI.

RESULTS

With the increase of GI and GL, the number of patients with PS increased significantly (P = 0.013, P < 0.001, respectively) and the risk of PS increased significantly. A similar increase in risk of PS was found with increased risk of carbohydrate, simple sugar and fructose intake. After adjusting all the confounders, the risk of PS with increasing simple sugar and fructose intake was 4.3 times (OR T3 vs. T1 = 4.3, 95% CI: 1.7-10.6, P trend < 0.001) and 5.3 times (OR T3 vs. T1 = 5.3, 95% CI: 2.2-12.9, P trend < 0.001), respectively, compared to the first tertile. Conversely, increased fiber intake showed a reverse association with the PS, so that those in the second and third tertiles of fiber intake were 84% (OR = 0.16, 95% CI: 0.05-0.45) and 87% (OR = 0.13, 95% CI: 0.04-0.39) less at risk of developing PS, respectively (P trend = 0.001).

CONCLUSIONS

These findings support the hypothesis of direct associations between GI and GL increased risk of PS.

Gamma-glutamyl transferase: A potential biomarker for pancreas steatosis in patients with concurrent obesity, insulin resistance and metabolic dysfunction-associated steatotic liver disease

To evaluate the relationship between serum gamma-glutamyl transferase (GGT) levels and fatty pancreas in subjects with concurrent obesity, insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD) without a history of pancreatitis. From March 2019 to September 2021, 31 adult subjects with concurrent obesity and MASLD were recruited as part of the study investigating the biological impact of bariatric surgery and lifestyle modification on obesity. Chemical shift encoded MRI of the abdomen, LiverMultiScan, anthropometric, clinical and blood biochemistry analyses were performed prior to any intervention at baseline. GGT (p <.001) was significantly different between those 'with fatty pancreas' and 'without fatty pancreas' groups. GGT (p <.001) was significantly different between those 'with both metabolic syndrome and fatty pancreas' and those 'with metabolic syndrome but without fatty pancreas.' GGT (p <.001) was also significantly different between those 'with both diabetes and fatty pancreas' and those 'with diabetes but without fatty pancreas'. Logistic regression analysis showed that abnormal GGT levels (p = .010) and Hypertension (p = .045) were significant independent predictors of fatty pancreas. GGT was associated with fatty pancreas by an odds ratio 7.333 (95% [CI]: 1.467-36.664), while the AUROC of GGT in determining fatty pancreas was 0.849. Elevation in serum GGT might be a potential marker to identify fatty pancreas.

Incretin-responsive human pancreatic adipose tissue organoids: A functional model for fatty pancreas research

OBJECTIVE

Infiltration of adipocytes into the pancreatic parenchyma has been linked to impaired insulin secretion in individuals with increased genetic risk of T2D and prediabetic conditions. However, the study of this ectopic fat depot has been limited by the lack of suitable in vitro models.

METHODS

Here, we developed a novel 3D model of functionally mature human pancreatic adipose tissue organoids by aggregating human pancreatic adipose tissue-derived stromal vascular fraction (SVF) cells into organoids and differentiating them over 19 days.

RESULTS

These organoids carry biological properties of the in situ pancreatic fat, presenting levels of adipogenic markers comparable to native pancreatic adipocytes and improved lipolytic and anti-lipolytic response compared to conventional 2D cultures. The organoids harbour a small population of immune cells, mimicking in vivo adipose environment. Furthermore, they express GIPR, allowing investigation of incretin effects in pancreatic fat. In accordance, GIP and the dual GLP1R/GIPR agonist tirzepatide stimulate lipolysis but had distinct effects on the expression of proinflammatory cytokines.

CONCLUSIONS

This novel adipose organoid model is a valuable tool to study the metabolic impact of incretin signalling in pancreatic adipose tissue, revealing potential therapeutic targets of incretins beyond islets. The donor-specific metabolic memory of these organoids enables examination of the pancreatic fat-islet crosstalk in a donor-related metabolic context.

Changes in pancreatic steatosis by computed tomography 24 months after sleeve gastrectomy in youth with severe obesity

BACKGROUND

Pancreatic steatosis has been associated with obesity and the metabolic syndrome. Studies in adults have demonstrated improvement in pancreatic steatosis following sleeve gastrectomy (SG) with concomitant improvement in glucose homeostasis.

OBJECTIVES

To examine changes in pancreatic steatosis in youth with severe obesity 24 months following SG.

SETTING

Academic hospital system.

METHODS

Forty-seven youth (13-24 years) with severe obesity (37 females) were followed for 24 months; 23 had SG and 24 were nonsurgical (NS) controls. Attenuations of the pancreas and spleen were measured using computed tomography (CT) at baseline, 12- and 24-month follow-up. Subjects underwent magnetic resonance imaging (MRI) for subcutaneous and visceral adipose tissue (SAT, VAT), dual energy x-ray absorptiometry (DXA) for body composition, blood sampling for glycated hemoglobin (A1C), and fasting and postprandial insulin and glucose. Linear mixed effects (LMEs) models were used to compare within- and between-group changes over 24 months.

RESULTS

At baseline, SG had higher body mass index (BMI) versus NS (P = .033). Over 24 months, significant reductions were noted in weight, BMI, VAT, SAT, fat mass (FM), and lean mass (LM) in the SG versus NS groups (P ≤ .0001). There was a significant 24-month decrease in pancreatic steatosis in the SG group (P = .006). In the whole group, 24-month reductions in pancreatic steatosis correlated with BMI and FM decreases. No associations were found between pancreatic steatosis and glucose homeostasis parameters.

CONCLUSIONS

Pancreatic steatosis measured by CT improved after SG in youth. Further studies are needed to understand the relationship between pancreatic steatosis and glucose homeostasis.

Relationship between imaging changes of the pancreas and islet beta-cell function

Imaging changes in the pancreas can provide valuable information about the status of islet beta-cell function in different pancreatic diseases, such as diabetes, pancreatitis, pancreatic cancer, fatty pancreas, and insulinoma. While imaging cannot directly measure beta-cell function; it can be used as a marker of disease progression and a tool to guide therapeutic interventions. As imaging technologies continue to advance, they will likely play an increasingly important role in diagnosing, monitoring, and managing diabetes.

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.

Association of visceral adipose tissue with gout: Observational and Mendelian randomization analyses

BACKGROUND

The causal relationship between visceral adipose tissue (VAT) and gout is still unclear. We aimed to examine the potential association between them using observational and Mendelian randomization (MR) analyses.

METHODS

In the observational analyses, a total of 11,967 participants (aged 39.5 ± 11.5 years) were included from the National Health and Nutrition Examination Survey. Logistic regression models were used to investigate the association between VAT mass and the risk of gout. In two-sample MR analyses, 211 VAT mass-related independent genetic variants (derived from genome-wide association studies in 325,153 UK biobank participants) were used as instrumental variables. The random-effects inverse-variance weighted (IVW) method was used as the primary analysis. Additional sensitivity analyses were also performed to validate our results.

RESULTS

Observational analyses found that an increase in VAT mass (per standard deviation) was associated with a higher risk of gout after controlling for confounding factors (odds ratio [OR] = 1.27, 95% confidence intervals [CI] = 1.11-1.45). The two-sample MR analyses demonstrated a causal relationship between increased VAT mass and the risk of gout in primary analyses (OR = 1.78, 95% CI = 1.57-2.03). Sensitivity analyses also showed similar findings, including MR-Egger, weighted median, simple mode, weighted mode, and leave-one-out analyses.

CONCLUSIONS

Observational analyses showed a robust association of VAT mass with the risk of gout. Meanwhile, MR analyses also provided evidence of a causal relationship between them. In summary, our findings suggested that targeted interventions for VAT mass may be beneficial to prevent gout.

Non-alcoholic fatty pancreas disease: an updated review

Ectopic accumulation of fat can cause a variety of metabolic diseases, and the emerging non-alcoholic fatty pancreas disease (NAFPD) is increasingly being recognized by clinicians as a cause for concern. NAFPD is a disease caused by abnormal accumulation of adipose tissue in the pancreas, which is related to obesity. The main feature of NAFPD is death of acinar cells, which are then replaced by adipose cells. However, the underlying molecular mechanisms have not been fully explored. Obesity, aging, and metabolic syndrome are independent risk factors for the occurrence and development of NAFPD. Studies have shown that NAFPD leads to insulin resistance and pancreatic dysfunction, increases the risk of diabetes mellitus, worsens the severity of pancreatitis, and is significantly correlated with pancreatic cancer and postoperative pancreatic fistula. There is no standard treatment for NAFPD; exercise, a balanced diet, and lifestyle can help reduce pancreatic fat; however, other treatment modalities such as drugs and bariatric surgery are still being explored. The specific pathological mechanism of NAFPD remains unclear, and its potential association with various clinical diseases requires further study. This review summarizes the etiology, diagnosis, clinical consequences, and potential therapeutic strategies of NAFPD.

Correlation between type 2 diabetes mellitus remission and intrapancreatic fat deposition

BACKGROUND

Intrapancreatic fat deposition (IPFD) exerts a significant negative impact on patients with type 2 diabetes mellitus (T2DM), accelerates disease deterioration, and may lead to impaired β-cell quality and function.

AIM

To investigate the correlation between T2DM remission and IPFD.

METHODS

We enrolled 80 abdominally obese patients with T2DM admitted to our institution from January 2019 to October 2023, including 40 patients with weight loss-induced T2DM remission (research group) and 40 patients with short-term intensive insulin therapy-induced T2DM remission (control group). We comparatively analyzed improvements in IPFD [differential computed tomography (CT) values of the spleen and pancreas and average CT value of the pancreas]; levels of fasting blood glucose (FBG), 2-h postprandial blood glucose (2hPBG), and insulin; and homeostasis model assessment of insulin resistance (HOMA-IR) scores. Correlation analysis was performed to explore the association between T2DM remission and IPFD.

RESULTS

After treatment, the differential CT values of the spleen and pancreas, FBG, 2hPBG, and HOMA-IR in the research group were significantly lower than those before treatment and in the control group, and the average CT value of the pancreas and insulin levels were significantly higher. Correlation analysis revealed that the greater the T2DM remission, the lower the amount of IPFD.

CONCLUSION

T2DM remission and IPFD are inversely correlated.

What Not to Overlook in the Management of Patients with Type 2 Diabetes Mellitus: The Nephrological and Hepatological Perspectives

Diabetes mellitus (DM) significantly impacts renal and hepatic function, necessitating comprehensive understanding and management strategies. Renal involvement, namely diabetic kidney disease (DKD), presents a global challenge, with increasing prevalence paralleling DM rates. Lifestyle modifications and pharmacotherapy targeting hypertension and glycemic control have pivotal roles in DKD management. Concurrently, hepatic involvement in DM, characterized by metabolic dysfunction-associated steatotic liver disease (MASLD), presents a bidirectional relationship. DM exacerbates MASLD progression, while MASLD predisposes to DM development and worsens glycemic control. Screening for MASLD in DM patients is of high importance, utilizing non-invasive methods like ultrasound and fibrosis scores. Lifestyle modifications, such as weight loss and a Mediterranean diet, mitigate MASLD progression. Promising pharmacotherapies, like SGLT2 inhibitors and GLP-1 agonists, demonstrate efficacy in both DM and MASLD management. Special populations, such as diabetic individuals undergoing hemodialysis or kidney transplant recipients, demand special care due to unique clinical features. Similarly, DM exacerbates complications in MASLD patients, elevating the risks of hepatic decompensation and hepatocellular carcinoma. Recognizing the interconnectedness of DM, renal, and hepatic diseases underscores the need for multidisciplinary approaches for optimal patient outcomes. The present review aims to present the main characteristics and crucial points not to be overlooked regarding the renal and hepatic involvement in DM patients focusing on the inter-relationships between the renal and the hepatic involvements.

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.

Pancreatosteatosis in patients with adrenal incidentaloma: A risk factor for impaired glucose metabolism

AIMS

Patients with adrenal incidentaloma (AI) are at increased risk of impaired glucose metabolism, which is known to be associated with pancreatosteatosis (PS). We aimed to investigate the risk of developing dysglycemia for patients with non-functioning AI (NFAI) versus those without, and whether the presence of PS predicts future dysglycemia in patients with NFAI.

METHOD

In 80 patients with NFAI and 127 controls matched for age, sex, and body mass index, changes in fasting plasma glucose (FPG) and hemoglobin A1c(HbA1c) were evaluated at 2 years. PS was evaluated with data obtained from non-contrast abdominal computed tomography (CT) performed at the initial evaluation.

RESULTS

Mean FPG levels increased significantly after 2 years in both groups (P < 0.001, for both), albeit significantly higher among patients than the controls (P = 0.002). The increases in HbA1c and FPG levels were significantly higher among patients with PS than without PS, in the adenoma group (p < 0.001, P = 0.00, respectively). The change in Hba1c levels was associated with the presence of PS in patients with NFAI (p < 0.001).

CONCLUSIONS

Our findings suggest that the presence of PS may provide significant information in predicting newly developed dysglycemia in patients with NFAI.

Clinical impact of pancreatic steatosis measured by CT on the risk of post-ERCP pancreatitis: a multicenter prospective trial

BACKGROUND AND AIMS

Pancreatic steatosis (PS) may be a risk factor for acute pancreatitis. Whether it is also a risk factor for post-ERCP pancreatitis (PEP) has not been evaluated. This study aimed to determine the impact of PS on PEP development.

METHODS

This multicenter prospective trial enrolled 786 consecutive patients who underwent contrast-enhanced abdominal CT and subsequent first-time ERCP. PS was evaluated based on pancreatic attenuation on unenhanced CT images. The risk of PS for the development of PEP was evaluated using a logistic regression model.

RESULTS

Of 527 patients included in the study, 157 (29.8%) had PS and 370 (70.2%) did not. At 24 hours after ERCP, there was a significant difference in the PEP identified in 22 patients (14.0%) in the PS group and 23 patients (6.2%) in the "no PS" (NPS) group (P = .017). Diabetes and hypertension were more common in the PS group than in the NPS group; no differences in dyslipidemia were found. Patients with PS had a higher risk for the development of PEP than those with NPS (odds ratio, 2.09; 95% confidence interval, 1.08-4.03). No other variables were identified as risk factors for PEP.

CONCLUSIONS

PS is a significant risk factor for PEP for which preventive measures should be considered. Standardized measurement protocols to assess PS by CT are needed. (Clinical trial registration number: KCT0006068.).

Quantification of ectopic fat storage in the liver and pancreas using six-point Dixon MRI and its association with insulin sensitivity and β-cell function in patients with central obesity

OBJECTIVES

To assess the association of ectopic fat deposition in the liver and pancreas quantified by Dixon magnetic resonance imaging (MRI) with insulin sensitivity and β-cell function in patients with central obesity.

MATERIALS AND METHODS

A cross-sectional study of 143 patients with central obesity with normal glucose tolerance (NGT), prediabetes (PreD), and untreated type 2 diabetes mellitus (T2DM) was conducted between December 2019 and March 2022. All participants underwent routine medical history taking, anthropometric measurements, and laboratory tests, including a standard glucose tolerance test to quantify insulin sensitivity and β-cell function. The fat content in the liver and pancreas was measured with MRI using the six-point Dixon technique.

RESULTS

Patients with T2DM and PreD had a higher liver fat fraction (LFF) than those with NGT, while those with T2DM had a higher pancreatic fat fraction (PFF) than those with PreD and NGT. LFF was positively correlated with homeostatic model assessment of insulin resistance (HOMA-IR), while PFF was negatively correlated with homeostatic model assessment of insulin secretion (HOMA-β). Furthermore, using a structured equation model, we found LFF and PFF to be positively associated with glycosylated hemoglobin via HOMA-IR and HOMA-β, respectively.

CONCLUSIONS

In patients with central obesity, the effects of LFF and PFF on glucose metabolism. were associated with HOMA-IR and HOMA-β, respectively. Ectopic fat storage in the liver and pancreas quantified by MR Dixon imaging potentially plays a notable role in the onset ofT2DM.

CLINICAL RELEVANCE STATEMENT

We highlight the potential role of ectopic fat deposition in the liver and pancreas in the development of type 2 diabetes in patients with central obesity, providing valuable insights into the pathogenesis of the disease and potential targets for intervention.

KEY POINTS

• Ectopic fat deposition in the liver and pancreas is associated with T2DM. • T2DM and prediabetes patients had higher liver and pancreatic fat fractions than normal individuals. • The results provide valuable insights into pathogenesis of T2DM and potential targets for intervention.

Pancreatic steatosis and metabolic pancreatic disease: a new entity?

Overweight and obesity are some of the most important health challenges. Many diseases are related to these metabolic disorders, and, among them, the pancreatic fat accumulation, also called "pancreatic steatosis" or "nonalcoholic fatty pancreas", seems to have an emerging role in different conditions. There are different method to evaluate the fat content in the pancreas, such as histology, different imaging techniques and endoscopic ultrasound, but there is no gold standard for the correct diagnosis and for the identification of "inter/intralobular" and "intra-acinar" pancreatic fat. However, the fat storage in the pancreas is linked to chronic inflammation and to several conditions, such as acute and chronic pancreatitis, type 2 diabetes mellitus and pancreatic cancer. In addition, pancreatic fat accumulation has also been demonstrated to play a role in surgical outcome after pancreatectomy, in particular for the development of postoperative pancreatic fistula. Different possible therapeutic approaches have been proposed, but there is still a lack of evidence. The aim of this review is to report the current evidence about the relationship between the obesity, the pancreatic fat accumulation and its potential role in pancreatic diseases.

Metabolic Impact of Frailty Changes Diabetes Trajectory

Diabetes mellitus prevalence increases with increasing age. In older people with diabetes, frailty is a newly emerging and significant complication. Frailty induces body composition changes that influence the metabolic state and affect diabetes trajectory. Frailty appears to have a wide metabolic spectrum, which can present with an anorexic malnourished phenotype and a sarcopenic obese phenotype. The sarcopenic obese phenotype individuals have significant loss of muscle mass and increased visceral fat. This phenotype is characterised by increased insulin resistance and a synergistic increase in the cardiovascular risk more than that induced by obesity or sarcopenia alone. Therefore, in this phenotype, the trajectory of diabetes is accelerated, which needs further intensification of hypoglycaemic therapy and a focus on cardiovascular risk reduction. Anorexic malnourished individuals have significant weight loss and reduced insulin resistance. In this phenotype, the trajectory of diabetes is decelerated, which needs deintensification of hypoglycaemic therapy and a focus on symptom control and quality of life. In the sarcopenic obese phenotype, the early use of sodium-glucose transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists is reasonable due to their weight loss and cardio-renal protection properties. In the malnourished anorexic phenotype, the early use of long-acting insulin analogues is reasonable due to their weight gain and anabolic properties, regimen simplicity and the convenience of once-daily administration.

Exploring the relationship between pancreatic fat and insulin secretion in overweight or obese women without type 2 diabetes mellitus: A preliminary investigation of the TOFI_Asia cohort

OBJECTIVE

While there is an emerging role of pancreatic fat in the aetiology of type 2 diabetes mellitus (T2DM), its impact on the associated decrease in insulin secretion remains controversial. We aimed to determine whether pancreatic fat negatively affects β-cell function and insulin secretion in women with overweight or obesity but without T2DM.

METHODS

20 women, with normo- or dysglycaemia based on fasting plasma glucose levels, and low (< 4.5%) vs high (≥ 4.5%) magnetic resonance (MR) quantified pancreatic fat, completed a 1-hr intravenous glucose tolerance test (ivGTT) which included two consecutive 30-min square-wave steps of hyperglycaemia generated by using 25% dextrose. Plasma glucose, insulin and C-peptide were measured, and insulin secretion rate (ISR) calculated using regularisation deconvolution method from C-peptide kinetics. Repeated measures linear mixed models, adjusted for ethnicity and baseline analyte concentrations, were used to compare changes during the ivGTT between high and low percentage pancreatic fat (PPF) groups.

RESULTS

No ethnic differences in anthropomorphic variables, body composition, visceral adipose tissue (MR-VAT) or PPF were measured and hence data were combined. Nine women (47%) were identified as having high PPF values. PPF was significantly associated with baseline C-peptide (p = 0.04) and ISR (p = 0.04) in all. During the 1-hr ivGTT, plasma glucose (p<0.0001), insulin (p<0.0001) and ISR (p = 0.02) increased significantly from baseline in both high and low PPF groups but did not differ between the two groups at any given time during the test (PPF x time, p > 0.05). Notably, the incremental areas under the curves for both first and second phase ISR were 0.04 units lower in the high than low PPF groups, but this was not significant (p > 0.05).

CONCLUSION

In women with overweight or obesity but without T2DM, PPF did not modify β-cell function as determined by ivGTT-assessed ISR. However, the salient feature in biphasic insulin secretion in those with ≥4.5% PPF may be of clinical importance, particularly in early stages of dysglycaemia may warrant further investigation.

Fatty Pancreas: Linking Pancreas Pathophysiology to Nonalcoholic Fatty Liver Disease

Currently, scientific interest has focused on fat accumulation outside of subcutaneous adipose tissue. As various imaging modalities are available to quantify fat accumulation in particular organs, fatty pancreas has become an important area of research over the last decade. The pancreas has an essential role in regulating glucose metabolism and insulin secretion by responding to changes in nutrients under various metabolic circumstances. Mounting evidence has revealed that fatty pancreas is linked to impaired β-cell function and affects insulin secretion with metabolic consequences of impaired glucose metabolism, type 2 diabetes, and metabolic syndrome. It has been shown that there is a connection between fatty pancreas and the presence and severity of nonalcoholic fatty liver disease (NAFLD), which has become the predominant cause of chronic liver disease worldwide. Therefore, it is necessary to better understand the pathogenic mechanisms of fat accumulation in the pancreas and its relationship with NAFLD. This review summarizes the epidemiology, diagnosis, risk factors, and metabolic consequences of fatty pancreas and discusses its pathophysiology links to NAFLD.

Fatty Pancreas and Cardiometabolic Risk: Response of Ectopic Fat to Lifestyle and Surgical Interventions

Ectopic fat accumulation in non-adipose organs, such as the pancreas and liver, is associated with an increased risk of cardiometabolic disease. While clinical trials have focused on interventions to decrease body weight and liver fat, ameliorating pancreatic fat can be crucial but successful intervention strategies are not yet defined. We identified twenty-two published studies which quantified pancreatic fat during dietary, physical activity, and/or bariatric surgery interventions targeted at body weight and adipose mass loss alongside their subsequent effect on metabolic outcomes. Thirteen studies reported a significant decrease in body weight, utilising weight-loss diets (n = 2), very low-energy diets (VLED) (n = 2), isocaloric diets (n = 1), a combination of diet and physical activity (n = 2), and bariatric surgery (n = 5) including a comparison with VLED (n = 1). Surgical intervention achieved the largest decrease in pancreatic fat (range: -18.2% to -67.2%) vs. a combination of weight-loss diets, isocaloric diets, and/or VLED (range: -10.2% to -42.3%) vs. diet and physical activity combined (range: -0.6% to -3.9%), with a concurrent decrease in metabolic outcomes. While surgical intervention purportedly is the most effective strategy to decrease pancreas fat content and improve cardiometabolic health, the procedure is invasive and may not be accessible to most individuals. Given that dietary intervention is the cornerstone for the prevention of adverse metabolic health, the alternative approaches appear to be the use of weight-loss diets or VLED meal replacements, which are shown to decrease pancreatic fat and associated cardiometabolic risk.

Galectin-1 in Obesity and Type 2 Diabetes

Galectin-1 is a carbohydrate-binding protein expressed in many tissues. In recent years, increasing evidence has emerged for the role of galectin-1 in obesity, insulin resistance and type 2 diabetes. Galectin-1 has been highly conserved through evolution and is involved in key cellular functions such as tissue maturation and homeostasis. It has been shown that galectin-1 increases in obesity, both in the circulation and in the adipose tissue of human and animal models. Several proteomic studies have independently identified an increased galectin-1 expression in the adipose tissue in obesity and in insulin resistance. Large population-based cohorts have demonstrated associations for circulating galectin-1 and markers of insulin resistance and incident type 2 diabetes. Furthermore, galectin-1 is associated with key metabolic pathways including glucose and lipid metabolism, as well as insulin signalling and inflammation. Intervention studies in animal models alter animal weight and metabolic profile. Several studies have also linked galectin-1 to the progression of complications in diabetes, including kidney disease and retinopathy. Here, we review the current knowledge on the clinical potential of galectin-1 in obesity and type 2 diabetes.

Fatty Pancreas Is Independently Associated With Subsequent Diabetes Mellitus Development: A 10-Year Prospective Cohort Study

BACKGROUND & AIMS

Although the association between fatty pancreas and metabolic syndrome has been suggested in retrospective studies, long-term prospective data on the effect of fatty pancreas on various metabolic outcomes are lacking. We aimed to prospectively investigate the association between fatty pancreas and the development of major metabolic outcomes.

METHODS

A total of 631 subjects from a population study using fat-water magnetic resonance imaging to quantify pancreatic and liver fat content during 2008 to 2010 were followed up prospectively until December 2020 (mean follow-up time, 11.1 ± 1.1 y). Subjects with significant alcohol intake and diabetes mellitus (DM) at baseline were excluded. Incidence of newly diagnosed DM, hypertension, dyslipidemia, ischemic heart disease, cardiovascular accidents, pancreatic cancer, and mortality were evaluated.

RESULTS

Among the 631 subjects (mean age, 48 ± 11 y), 93 (14.7%) had fatty pancreas. The fatty pancreas group had a higher incidence of DM (33.3% vs 10.4%; P < .001), hypertension (37.7% vs 22.7%; P = .003), and dyslipidemia (37.7% vs 14.6%; P < .001) during long-term follow-up evaluation. Individuals with both fatty liver and pancreas had the highest DM incidence, followed by fatty liver only and fatty pancreas only groups (P < .001). Fatty pancreas was associated independently with DM (adjusted hazard ratio, 1.81; 95% CI, 1.10-3.00; P = .020), but not hypertension or dyslipidemia on multivariate analysis. Each percentage increase of pancreatic fat increased the risk of incident DM by 7% (adjusted hazard ratio, 1.07; 95% CI, 1.01-1.13; P = .016). No participants developed pancreatic cancer during the follow-up period.

CONCLUSIONS

Fatty pancreas is associated independently with subsequent DM development, but not hypertension or dyslipidemia.

The Association Between Pancreatic Steatosis and Metabolic Syndrome: A 5-Year Follow-up Study Among a General Chinese Population

OBJECTIVES

To date, the complete natural history of pancreatic steatosis is unknown. This study aimed to investigate the association of fatty pancreas (FP) in the incidence of metabolic syndrome and its components among Chinese patients with a 5-year follow-up.

METHODS

Three independent cross-sectional surveys were carried out in 2013, 2015, and 2018. Fatty pancreas was diagnosed via transabdominal sonography. Logistic regression analysis was used to estimate the correlation between FP and metabolic syndrome. New cases of metabolic syndrome and its components were estimated by Cox proportional hazards models.

RESULTS

At baseline, 12,551 individuals classified into FP (n = 1010) and non-FP (n = 11,541) groups were finally enrolled. In cross-sectional analyses, odds ratio of FP was 2.378 (95% confidence interval [CI], 2.085-2.713; P < 0.001). In longitudinal analyses, FP was associated with the occurrence of metabolic syndrome (hazard ratio [HR], 3.179; 95% CI, 2.197-4.6; P < 0.001), type 2 diabetes mellitus (HR, 13.99; 95% CI, 7.865-24.883; P < 0.001), nonalcoholic fatty liver disease (HR, 31.843; 95% CI, 7.73-131.171; P < 0.001), and hypertension (HR, 12.801; 95% CI, 7.323-22.38; P < 0.001).

CONCLUSIONS

Pancreatic steatosis is strongly associated with the occurrence of metabolic syndrome and its components such as hypertension and diabetes.

Abdominal Visceral Adipose Tissue and All-Cause Mortality: A Systematic Review

Introduction

Increased abdominal visceral adipose tissue (VAT) implies an adverse cardio-metabolic profile. We examined the association of abdominal VAT parameters and all-cause mortality risk.

Methods

We systematically searched four databases. We performed citations/articles screening, data abstraction, and quality assessment in duplicate and independently (CRD42020205021).

Results

We included 12 cohorts, the majority used computed tomography to assess abdominal VAT area. Six cohorts with a mean age ≤ 65 years, examining all-cause mortality risk per increment in VAT area (cm2) or volume (cm3), showed a 11-98% relative risk increase with higher VAT parameters. However, the association lost significance after adjusting for glycemic indices, body mass index, or other fat parameters. In 4 cohorts with a mean age >65 years, the findings on mortality were inconsistent. Conversely, in two cohorts (mean age 73-77 years), a higher VAT density, was inversely proportional to VAT area, and implied a higher mortality risk.

Conclusion

A high abdominal VAT area seems to be associated with increased all-cause mortality in individuals ≤ 65 years, possibly mediated by metabolic complications, and not through an independent effect. This relationship is weaker and may reverse in older individuals, most likely secondary to confounding bias and reverse causality. An individual participant data meta-analysis is needed to confirm our findings, and to define an abdominal VAT area cutoff implying increased mortality risk.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=205021, identifier CRD42020205021.

Combined effect of pancreatic lipid content and gene variants (TCF7L2, WFS1 and 11BHSD1) on B-cell function in Middle Aged Women in a Post Hoc Analysis

BACKGROUND

TCF7L2 rs7903146 and PNPLA3 rs738409 gene variants confer the strongest risk for type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD), respectively. Pancreatic triacylglycerol content (PTGC) was reported to have a role in T2DM development. We aimed to assess the correlation between PTGC and hepatic triacylglycerol content (HTGC) stratified by PNPLA3 rs738409 genotype and subsequently interactions between PTGC and gene variants associated with β-cell dysfunction (TCF7L2, WFS1) and visceral adiposity (11ΒHSD1) on β-cell function were also tested.

METHODS

PTGC and HTGC were assessed using MR in a post-hoc analysis of a genotype-based (PNPLA3 rs738409) recall study of 39 (lipid- and glucose lowering) drug-naïve women. Oral glucose tolerance test, HbA1c, insulin indices, anthropometric data were evaluated. The effect of minor allele carrying of TCF7L2 (rs7903146); WFS1 (rs1801214) and 11ΒHSD1 (rs4844880) variants in combination with PTGC was studied on surrogate markers of β-cell function. We used Spearman's rank-order, Mann-Whitney-U tests, and linear regression models.

RESULTS

PTGC and HTGC values were correlated after stratification by the rs738409 variant (only in CC genotype group R = 0.67, p = 10- 4). PTGC and HbA1c values correlated in the entire study population (R = 0.58, p = 10- 4). Insulin resistance, sensitivity and disposition indices were correlated with PTGC (HOMA2-IR: R = 0.42, p = 0.008; TyG: R = 0.38, p = 0.018; Matsuda: R= - 0.48, p = 0.002; DIbasal: R=-0.33, p = 0.039; ISSI-2: R=-0.35, p = 0.028). Surrogate markers of β-cell function (HOMA2-B, AUCinsulin/AUCglucose) correlated significantly with PTGC in subjects with the following genotypes rs7903146: CC R = 0.51, p = 0.022; rs18001214: CT + CC R = 0.55, p = 0.013; rs4844880: TA + AA R = 0.56, p = 0.016. The strongest interactions were found between PTGC and TCF7L2 rs7903146 effect on HOMA2-B (p = 0.001) and AUCinsulin/AUCglucose (p = 0.013).

CONCLUSIONS

The PNPLA3 rs738409 genotype has a major effect on the correlation between PTGC and HTGC. Furthermore we first report the combined effect of PTGC and individual risk gene variants of TCF7L2, WFS1 and 11ΒHSD1 on β-cell dysfunction. The correlation between pancreatic lipid accumulation and HbA1c also indicates an important role for the latter pathology.

Effects of body fat components on early renal functions of individuals following kidney donation

Objective:

Obesity stands as a risk factor for the chronic kidney disease. The objective of this study was to investigate the relationship between early renal function following kidney donation and the measurements of body fat components.

Methods:

In total, 86 donors followed up for at least 6 months postoperatively were included. Height and weight measurements and results of laboratory analysis of all donors were recorded retrospectively. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), hepatic fat (HF), pancreatic fat (PF) and splenic fat (SF) measurements were performed, and pancreatic splenic fat fraction difference (P−S) and pancreatic splenic fat fraction ratio (P/S) were calculated by a radiologist using the records of preoperative computed tomography scans of donors.

Results:

The estimated glomerular filtration rate (eGFR), serum creatinine and spot urinary microalbumin/creatinine ratio values of the donors at the sixth month postoperatively were statistically different from those of the preoperative values ( p < 0.001). In addition, the individuals were divided into two categories based on the postoperative eGFR: ⩾ 60 mL/min/1.73 m2 and < 60 mL/min/1.73 m2. Age, low-density lipoprotein (LDL) level and VAT/SAT ratio were lower in group eGFR: ⩾ 60 ( p < 0.001, p = 0.03, p = 0.007, respectively). Age and VAT/SAT ratio were the parameters found to be affecting the eGFR significantly, and VAT/SAT ratio (0.729, 95% CI: 0.602–0.856, p = 0.007) had higher predictive value in receiver operating characteristic curve (ROC).

Conclusion:

Preoperative measurements of body fat components may provide significant information to predict postoperative renal functions of kidney donor candidates.

Level of evidence:

Not applicable.

Changes in circulating microRNAs-99/100 and reductions of visceral and ectopic fat depots in response to lifestyle interventions: the CENTRAL trial

BACKGROUND

MicroRNAs (miRNAs) are short noncoding RNAs and important posttranscriptional regulators of gene expression. Adipose tissue is a major source of circulating miRNAs; adipose-related circulating miRNAs may regulate body fat distribution and glucose metabolism.

OBJECTIVES

We investigated how changes in adipose-related circulating microRNAs-99/100 (miR-99/100) in response to lifestyle interventions were associated with improved body fat distribution and reductions of diabetogenic ectopic fat depots among adults with abdominal obesity.

METHODS

This study included adults with abdominal obesity from an 18-mo diet and physical activity intervention trial. Circulating miR-99a-5p, miR-99b-5p, and miR-100-5p were measured at baseline and 18 mo; changes in these miRNAs in response to the interventions were evaluated. The primary outcomes were changes in abdominal adipose tissue [visceral (VAT), deep subcutaneous (DSAT), and superficial subcutaneous (SSAT) adipose tissue; cm2] (n = 144). The secondary outcomes were changes in ectopic fat accumulation in the liver (n = 141) and pancreas (n = 143).

RESULTS

Greater decreases in miR-100-5p were associated with more reductions of VAT (β ± SE per 1-SD decrease: -9.63 ± 3.13 cm2; P = 0.0025), DSAT (β ± SE: -5.48 ± 2.36 cm2; P = 0.0218), SSAT (β ± SE: -4.64 ± 1.68 cm2; P = 0.0067), and intrahepatic fat percentage (β ± SE: -1.54% ± 0.49%; P = 0.0023) after the interventions. Similarly, participants with greater decrease in miR-99a-5p had larger 18-mo reductions of VAT (β ± SE: -10.12 ± 3.31 cm2 per 1-SD decrease; P = 0.0027) and intrahepatic fat percentage (β ± SE: -1.28% ± 0.52%; P = 0.015). Further, decreases in circulating miR-99b-5p (β ± SE: per 1-SD decrease: -0.44% ± 0.21%; P = 0.038) and miR-100-5p (β ± SE: -0.50% ± 0.23%; P = 0.033) were associated with a decrease in pancreatic fat percentage, as well as improved glucose metabolism and insulin secretion at 18 mo.

CONCLUSIONS

Decreases in circulating miR-99-5p/100-5p expression induced by lifestyle interventions were related to improved body fat distribution and ectopic fat accumulation. Our study suggests that changes in circulating adipose-related miR-99-5p/100-5p may be linked to reducing diabetogenic fat depots in patients with abdominal obesity.This trial was registered at clinicaltrials.gov as NCT01530724.

Improvement of Pancreatic Steatosis and Indices of Insulin Resistance After Metabolic Surgery

PURPOSE

Obesity is associated with fat accumulation in ectopic sites such as the pancreas, the so-called pancreatic steatosis (PS). Bariatric surgery has been shown to be associated with reducing pancreatic fat. This study investigated the effect of laparoscopic sleeve gastrectomy (LSG) on pancreatic volume and its fat content and glucose homeostasis.

METHODS

The study enrolled 54 patients subjected to LSG. Metabolic variables and pancreatic exocrine function were assessed immediately before surgery and 12 months after. MRI of the abdomen was performed to measure pancreatic fat content and its total volume and visceral adipose tissue (VAT).

RESULTS

Surgery resulted in a significant reduction in body weight and BMI. HbA1c, fasting insulin, C-peptide levels, HOMA-IR, and Hs-CRP levels decreased significantly. Surgery resulted in significant improvement in lipid profile except for HDL-cholesterol and liver function tests. Total VAT volume decreased significantly. Total pancreas volume decreased by a mean of 9.0 cm3 (95% CI: 6.6-11.3). The median change of pancreatic fat was -26.1% (range: -55.6 to 58.3%). Pancreatic lipase decreased significantly (P < 0.001). There was a positive correlation between the percentage of total weight loss and decrease in pancreatic fat volume (r = 0.295, P = 0.030).

CONCLUSION

Weight loss after LSG is associated with a reduction of total VAT volume, total pancreatic volume, and pancreatic fat content. These changes are associated with improved glucose homeostasis, reduced systemic inflammation, and decreased pancreatic lipase secretion.

Pancreatic fat infiltration, β-cell function and insulin resistance: A study of the young patients with obesity

OBJECTIVE

This study aimed to investigate the relationship between pancreatic fat infiltration (PFI) and glucose metabolism disorder, β-cell function and insulin resistance in patients with obesity.

METHODS

Pancreatic fat fraction (PFF) was quantified by MRI IDEAL-IQ technique. PFF greater than 6.2 % was defined as PFI, and 34 obese patients were divided into PFI and non-PFI groups. The 5-point plasma glucose and insulin values during oral glucose tolerance test (OGTT) were recorded. OGTT-derived indices of insulin resistance and β-cell function were calculated.

RESULTS

Glucose values levels at 0-120 min during OGTT were significantly higher and β-cell function variables were lower in PFI group than non-PFI group. While indices of insulin resistance were not significantly different between two groups. Correlation analysis showed that PFF was positively correlated with glucose levels at 0, 30 and 60 min, negatively correlated with β-cell function variables and not significantly correlated with indices of insulin resistance. However, these associations of PFF with β-cell function and glucose levels were only present in type 2 diabetes mellitus (T2DM) group but not in non-T2DM group.

CONCLUSION

There is an association between PFI and impaired β-cell function, and increased pancreatic fat may be a potential risk factor for the development of T2DM.

Keeping It Local in Metabolic Disease: Adipose Tissue Paracrine Signaling and Insulin Resistance

Alterations in adipose tissue composition and function are associated with obesity and contribute to the development of type 2 diabetes. While the significance of this relationship has been cemented, our understanding of the multifaceted role of adipose tissue in metabolic heath and disease continues to evolve and expand. Heterogenous populations of cells that make up adipose tissue throughout the body generate diverse secretomes containing a mosaic of bioactive compounds with vast structural and signaling capabilities. While there are many reports highlighting the important role of adipose tissue endocrine signaling in insulin resistance and type 2 diabetes, the direct, local, paracrine effect of adipose tissue has received less attention. Recent studies have begun to underscore the importance of considering anatomically discrete adipose depots for their specific impact on local microenvironments and metabolic function in neighboring tissues as well as regulation of whole-body physiology. This article highlights the important role of adipose tissue paracrine signaling on metabolic function and insulin sensitivity in nearby tissues and organs, specifically focusing on visceral, pancreatic, subcutaneous, intermuscular, and perivascular adipose tissue depots.

Pancreas Fat, an Early Marker of Metabolic Risk? A Magnetic Resonance Study of Chinese and Caucasian Women: TOFI_Asia Study

Objective

Prevalence of type 2 diabetes (T2D) is disproportionately higher in younger outwardly lean Asian Chinese compared to matched Caucasians. Susceptibility to T2D is hypothesised due to dysfunctional adipose tissue expansion resulting in adverse abdominal visceral and organ fat accumulation. Impact on early risk, particularly in individuals characterised by the thin-on-the-outside-fat-on-the-inside (TOFI) phenotype, is undetermined.

Methods

Sixty-eight women [34 Chinese, 34 Caucasian; 18–70 years; body mass index (BMI), 20–45 kg/m2] from the TOFI_Asia study underwent magnetic resonance imaging and spectroscopy to quantify visceral, pancreas, and liver fat. Total body fat was (TBF) assessed by dual-energy x-ray absorptiometry, and fasting blood biomarkers were measured. Ethnic comparisons, conducted using two-sample tests and multivariate regressions adjusted for age, % TBF and ethnicity, identified relationships between abdominal ectopic fat depots with fasting plasma glucose (FPG), insulin resistance (HOMA2-IR), and related metabolic clinical risk markers in all, and within ethnic groups.

Results

Despite being younger and of lower bodyweight, Chinese women in the cohort had similar BMI and % TBF compared to their Caucasian counterparts. Protective high-density lipoprotein cholesterol, total- and high-molecular weight adiponectin were significantly lower, while glucoregulatory glucagon-like peptide-1 and glucagon significantly higher, in Chinese. There were no ethnic differences between % pancreas fat and % liver fat. However, at low BMI, % pancreas and % liver fat were ∼1 and ∼2% higher in Chinese compared to Caucasian women. In all women, % pancreas and visceral adipose tissue had the strongest correlation with FPG, independent of age and % TBF. Percentage (%) pancreas fat and age positively contributed to variance in FPG, whereas % TBF, amylin and C-peptide contributed to IR which was 0.3 units higher in Chinese.

Conclusion

Pancreas fat accumulation may be an early adverse event, in TOFI individuals, with peptides highlighting pancreatic dysfunction as drivers of T2D susceptibility. Follow-up is warranted to explore causality.

Fatty Pancreas-Centered Metabolic Basis of Pancreatic Adenocarcinoma: From Obesity, Diabetes and Pancreatitis to Oncogenesis

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest types of cancer, and it is currently the third most common cause of cancer death in the U.S.A. Progress in the fight against PDAC has been hampered by an inability to detect it early in the overwhelming majority of patients, and also by the reduced oxygen levels and nutrient perfusion caused by new matrix formation through the activation of stromal cells in the context of desmoplasia. One harbinger of PDAC is excess intrapancreatic fat deposition, namely, fatty pancreas, which specifically affects the tumor macro- and microenvironment in the organ. Over half of PDAC patients have diabetes mellitus (DM) at the time of diagnosis, and fatty pancreas is associated with subsequent DM development. Moreover, there is a strong association between fatty pancreas and fatty liver through obesity, and a higher intrapancreatic fat percentage has been noted in acute pancreatitis patients with DM than in those without DM. All these findings suggest that the link between fatty pancreas and PDAC might occur through metabolic alterations, either DM-related or non-DM-related. Based on clinical, in vivo and in vitro evidence, the current review highlights the etiologies of fatty pancreas (including fatty infiltration and replacement) and the fatty pancreas-associated metabolic alterations involved in oncogenesis to provide crucial targets to prevent, detect, and/or effectively treat PDAC.

Imaging evaluation of the pancreas in diabetic patients

Diabetes mellitus (DM) is becoming a global epidemic and its diagnosis and monitoring are based on laboratory testing which sometimes have limitations. The pancreas plays a key role in metabolism and is involved in the pathogenesis of DM. It has long been known through cadaver biopsies that pancreas volume is decreased in patients with DM. With the development of different imaging modalities over the last two decades, many studies have attempted to determine whether there other changes occurred in the pancreas of diabetic patients. This review summarizes current knowledge about the use of different imaging approaches (such as CT, MR, and US) and radiomics for exploring pancreatic changes in diabetic patients. Imaging studies are expected to produce reliable information regarding DM, and radiomics could provide increasingly valuable information to identify some undetectable features and help diagnose and predict the occurrence of diabetes through pancreas imaging.

Morphological alteration of the pancreatic islet in ovariectomized rats fed a high-fat high-fructose diet

Diabetes and its complications are major causes of mortality worldwide. Type 2 diabetes coexists with insulin resistance and β-cell dysfunction, which are aggravated by overconsumption and estrogen-deprived conditions. However, the morphology of pancreatic islets in a combined condition of excessive caloric intake and estrogen deficiency has never been described. Herein, we examined morphological changes in the pancreatic islets of ovariectomized (OVX) rats fed a high-fat high-fructose diet (HFFD) for 12 weeks. The histological changes in the size and number of pancreatic islets were assessed by hematoxylin-eosin and immunohistochemical staining. Enlarged pancreatic islets with fat deposition in OVX rats were accompanied by whole-body insulin resistance and hyperglycemia. The addition of a HFFD to OVX rats (OVX + HFFD) further aggravated insulin resistance, with a substantial increase in the density of enlarged pancreatic islets and fat accumulation. The augmented number of enlarged islets was correlated with elevated plasma glucose and insulin levels. Intriguingly, unlike the HFFD and OVX alone, the OVX + HFFD markedly expanded the area of insulin-producing β-cells and glucagon-producing α-cells. Importantly, enlarged islets, pancreatic fat deposits, and diabetic states developing in OVX + HFFD conditions were resolved by estrogen replacement. Collectively, the morphological characteristics of pancreatic islets were influenced in an insulin-resistant state caused by estrogen deficiency and HFFD consumption and were distinct from each factor alone. A combination of estrogen deficiency with HFFD consumption worsened the integrity of pancreatic islets, ultimately resulting in disease progression. These findings expand our understanding of the causal relationship between pancreatic morphology and diabetes development and suggest therapeutic strategies.

Role of Distinct Fat Depots in Metabolic Regulation and Pathological Implications

People suffering from obesity and associated metabolic disorders including diabetes are increasing exponentially around the world. Adipose tissue (AT) distribution and alteration in their biochemical properties play a major role in the pathogenesis of these diseases. Emerging evidence suggests that AT heterogeneity and depot-specific physiological changes are vital in the development of insulin resistance in peripheral tissues like muscle and liver. Classically, AT depots are classified into white adipose tissue (WAT) and brown adipose tissue (BAT); WAT is the site of fatty acid storage, while BAT is a dedicated organ of metabolic heat production. The discovery of beige adipocyte clusters in WAT depots indicates AT heterogeneity has a more central role than hither to ascribed. Therefore, we have discussed in detail the current state of understanding on cellular and molecular origin of different AT depots and their relevance toward physiological metabolic homeostasis. A major focus is to highlight the correlation between altered WAT distribution in the body and metabolic pathogenesis in animal models and humans. We have also underscored the disparity in the molecular (including signaling) changes in various WAT tissues during diabetic pathogenesis. Exercise-mediated beneficial alteration in WAT physiology/distribution that protects against metabolic disorders is evolving. Here we have discussed the depot-specific biochemical adjustments induced by different forms of exercise. A detailed understanding of the molecular details of inter-organ crosstalk via substrate utilization/storage and signaling through chemokines provide strategies to target selected WAT depots to pharmacologically mimic the benefits of exercise countering metabolic diseases including diabetes.

Pancreatic Steatosis Is Associated with Both Metabolic Syndrome and Pancreatic Stiffness Detected by Ultrasound Elastography

INTRODUCTION

There is increasing evidence that pancreatic steatosis (PS) is associated with metabolic syndrome (MS). However, it is not known whether it is associated with PS grade and pancreatic stiffness, or not. We aimed to evaluate the relationship between PS and its grade detected by transabdominal ultrasound, and pancreatic stiffness determined by two-dimensional shearwave elastography (2D-SWE), whether it has clinical significance and its relationship with MS.

METHODS

Patients with and without PS were evaluated prospectively.

RESULTS

Patients with PS had higher odds ratio for MS (OR 5.49). Also, ultrasonographic grade of PS was associated with MS parameters and hepatosteatosis. Pancreatic SWE value was significantly higher in PS group and positively correlated with PS grade, liver fat, MS, number of MS criteria.

DISCUSSION/CONCLUSION

PS and its grade were associated with MS. In this first comprehensive PS-SWE study, we found that pancreas stiffness increased in the presence of PS, in correlation with PS grade and MS.

Metabolic implications of pancreatic fat accumulation

Fat accumulation outside subcutaneous adipose tissue often has unfavourable effects on systemic metabolism. In addition to non-alcoholic fatty liver disease, which has received considerable attention, pancreatic fat has become an important area of research throughout the past 10 years. While a number of diagnostic approaches are available to quantify pancreatic fat, multi-echo Dixon MRI is currently the most developed method. Initial studies have shown associations between pancreatic fat and the metabolic syndrome, impaired glucose metabolism and type 2 diabetes mellitus. Pancreatic fat is linked to reduced insulin secretion, at least under specific circumstances such as prediabetes, low BMI and increased genetic risk of type 2 diabetes mellitus. This Review summarizes the possible causes and metabolic consequences of pancreatic fat accumulation. In addition, potential therapeutic approaches for addressing pancreatic fat accumulation are discussed.

Nonalcoholic Fatty Pancreas Disease: Role in Metabolic Syndrome, "Prediabetes," Diabetes and Atherosclerosis

Fat accumulation in the pancreas associated with obesity and the metabolic syndrome (MetS) has been defined as "non-alcoholic fatty pancreas disease" (NAFPD). The aim of this review is to describe the association of NAFPD with obesity, MetS, type 2 diabetes mellitus (T2DM) and atherosclerosis and also increase awareness regarding NAFPD. Various methods are used for the detection and quantification of pancreatic fat accumulation that may play a significant role in the differences that have been observed in the prevalence of NAFPD. Endoscopic ultrasound provides detailed images of the pancreas and its use is expected to increase in the future. Obesity and MetS have been recognized as NAFPD risk factors. NAFPD is strongly associated with non-alcoholic fatty liver disease (NAFLD) and it seems that the presence of both may be related with aggravation of NAFLD. A role of NAFPD in the development of "prediabetes" and T2DM has also been suggested by most human studies. Accumulation of fat in pancreatic tissue possibly initiates a vicious cycle of beta-cell deterioration and further pancreatic fat accumulation. Additionally, some evidence indicates a correlation between NAFPD and atherosclerotic markers (e.g., carotid intima-media thickness). Weight loss and bariatric surgery decreases pancreatic triglyceride content but pharmacologic treatments for NAFPD have not been evaluated in specifically designed studies. Hence, NAFPD is a marker of local fat accumulation possibly associated with beta-cell function impairment, carbohydrate metabolism disorders and atherosclerosis.

Why We Eat Too Much, Have an Easier Time Gaining Than Losing Weight, and Expend Too Little Energy: Suggestions for Counteracting or Mitigating These Problems

The intent of this review is to survey physiological, psychological, and societal obstacles to the control of eating and body weight maintenance and offer some evidence-based solutions. Physiological obstacles are genetic and therefore not amenable to direct abatement. They include an absence of feedback control against gaining weight; a non-homeostatic relationship between motivations to be physically active and weight gain; dependence of hunger and satiation on the volume of food ingested by mouth and processed by the gastrointestinal tract and not on circulating metabolites and putative hunger or satiation hormones. Further, stomach size increases from overeating and binging, and there is difficulty in maintaining weight reductions due to a decline in resting metabolism, increased hunger, and enhanced efficiency of energy storage. Finally, we bear the evolutionary burden of extraordinary human capacity to store body fat. Of the psychological barriers, human craving for palatable food, tendency to overeat in company of others, and gullibility to overeat when offered large portions, can be overcome consciously. The tendency to eat an unnecessary number of meals during the wakeful period can be mitigated by time-restricted feeding to a 6-10 hour period. Social barriers of replacing individual physical work by labor-saving appliances, designing built environments more suitable for car than active transportation; government food macronutrient advice that increases insulin resistance; overabundance of inexpensive food; and profit-driven efforts by the food industry to market energy-dense and nutritionally compromised food are best overcome by informed individual macronutrient choices and appropriate timing of exercise with respect to meals, both of which can decrease insulin resistance. The best defense against overeating, weight gain, and inactivity is the understanding of factors eliciting them and of strategies that can avoid and mitigate them.

Pancretic Fat Accummulation is Associated with Subclinical Atherosclerosis

We investigated the relationship between pancreatic fat accumulation and markers of atherosclerosis among patients with nonalcoholic fatty liver disease (NAFLD). Patients with NAFLD have been reported to be at an increased risk of vascular events. We grouped 183 patients in whom we detected and graded hepatosteatosis (HS) on transabdominal ultrasonography into 2 groups based on the presence/absence of pancreatic fat. There were 85 participants (50 female; mean age: 53.6 ± 9.7 years) who were nonalcoholic fatty pancreas disease (NAFPD) positive and 98 participants (56 female; mean age: 51.4 ± 9.3 years) who were NAFPD negative. Carotid intima media thickness (cIMT) was significantly greater in the group where HS was accompanied by NAFPD (0.51 [0.40-0.62] vs 0.45 [0.35-0.55] mm; P < .001). Multivariable analyses showed that the independent predictors of increased cIMT were age (odds ratio [OR]: 1.108; 95% CI: 1.059-1.158, P = .001), hypertension (OR: 2.244; 95% CI: 1.099-4.579, P = .026), and the presence of NAFPD (OR: 3.078; CI 95% CI: 1.531-6.190, P = .0002). In the present study we demonstrated that, in patients with NAFLD, pancreatic fat accumulation was significantly associated with cIMT, a marker of early atherosclerosis. NAFPD may increase the risk of vascular events associated with NAFLD.

Association between ectopic pancreatic and hepatic fat and metabolic risk factors in children with non-alcoholic fatty liver disease

BACKGROUND

Few studies have reported an association between ectopic pancreatic and hepatic fat and metabolic factors in children with non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

We investigated this association and also the factors associated with pancreatic and hepatic fat deposition in children with NAFLD.

METHODS

This cross-sectional study investigated 65 children with NAFLD (49 boys, 13.0 ± 3.2 years, mean body mass index z-score 2.5 ± 1.2), who underwent liver biopsy and magnetic resonance imaging-based proton density fat fraction, as well as anthropometry, laboratory tests, body composition analysis, and hepatic fat fraction (HFF) and pancreatic fat fraction (PFF) measurements.

RESULTS

HFF and PFF were 4.2%-49.9% (median 24.3) and 0.4%-26.9% (median 3.8), respectively. HFF was not significantly correlated with PFF. HFF was correlated with total body fat% (r = 0.329, p = 0.010) and γ-glutamyl transpeptidase (GGT) (r = 0.260, p = 0.040), while PFF was correlated with the diastolic blood pressure (r = 0.253, p = 0.045), GGT (r = 0.335, p = 0.007) and fasting plasma glucose (r = 0.417, p = 0.001). Multiple linear regression analysis showed that HFF was significantly associated with sex, age, body fat% and GGT, whereas PFF was associated with hypertension and fasting plasma glucose levels but not insulin resistance.

CONCLUSIONS

HFF was associated with sex, age and body fat in children with NAFLD, while PFF was associated with hypertension and increased fasting plasma glucose, which suggests that the pathophysiology of ectopic fat accumulation varies across organs in children with NAFLD.

Determinants of Pancreatic Steatosis: A Retrospective Observational Study

BACKGROUND Metabolic syndrome affects 35% of the adult population in developed countries associated with non-alcoholic steatohepatitis, insulin resistance, and cardiovascular events. Fatty infiltration of the pancreas, or pancreatic steatosis, is a risk factor for acute pancreatitis, pancreatic malignancies, and diabetes mellitus, yet its relationship with metabolic syndrome is not well defined. METHODS We performed a single-centered retrospective observational study of 322 healthy subjects (subjects volunteering to be kidney transplant donors, mean age=46.3±13.5, 163 men and 159 women) in the last 2 years (July 2018-February 2020) from our institution. Pancreatic steatosis and hepatosteatosis were confirmed by computed tomography. RESULTS Pancreatic steatosis was present in 26.3% (85/322) of the subjects, and this finding correlated with age, body mass index (BMI), male sex, a family history of diabetes, creatinine, cystatin C, uric acid, low-density lipoprotein (LDL) cholesterol, triglycerides, glycemia, hemoglobin, transverse body diameter, and subcutaneous fat thickness levels by univariable logistic regression. On multiple linear regression only age (95% CI 1.01, 1.06), BMI (95% CI 1.01, 1.19), male sex (95% CI 1.49-5.99), uric acid (95% CI 1.01, 1.76), and subcutaneous fat thickness levels (95% CI 1.21-2.36) remained independently associated with pancreatic steatosis. CONCLUSION Pancreatic steatosis is common and associated with obesity, elevated serum uric acid, subcutaneous fat thickness, and male sex. Future studies are needed to evaluate if there are specific clinical consequences to the presence of pancreatic steatosis.

Pancreatic fat accumulation is associated with decreased β-cell function and deterioration in glucose tolerance in Korean adults

AIMS

This study was designed to investigate the association between pancreatic fat content (PFC) and insulin secretory capacity as well as glucose tolerance in Korean adults.

MATERIALS

A total of 39 participants (mean age 49.9 years, 53% males) without a previous history of diabetes, or those previously diagnosed as having diabetes but with less than 10 years of disease duration and no medication history were included. They were stratified according to the results of the oral glucose tolerance test (OGTT): normal glucose tolerance, prediabetes, and diabetes.

METHODS

All participants underwent the proton magnetic resonance spectroscopy (¹ H-MRS) to assess PFC. Insulin sensitivity and β-cell function were measured by the frequently sampled intravenous glucose tolerance tests (FSIVGTT) and OGTT-derived indices.

RESULTS

As glucose tolerance deteriorated, parameters such as Stumvoll index, oral glucose insulin sensitivity index, homeostatic model assessment (HOMA)-β, insulinogenic index and oral disposition index from the OGTT, and acute insulin response to glucose (AIR) and disposition index (DI) from the FSIVGTT were decreased. PFC increased with deterioration in glucose tolerance (NGT: 12.0%, prediabetes: 23.7%, and diabetes: 31.9%). Correlation analysis indicated that glucose levels at 60 and 120 min during the OGTT were positively correlated with PFC. Also, there was a significant negative correlation between PFC and DI as well as AIR derived from the FSIVGTT.

CONCLUSIONS

PFC evaluated by ¹ H-MRS in Korean adults was higher in those diagnosed with diabetes than those with normal glucose tolerance status. PFC also showed a significant negative correlation with indices reflecting beta cell function.

The β Cell in Diabetes: Integrating Biomarkers With Functional Measures

The pathogenesis of hyperglycemia observed in most forms of diabetes is intimately tied to the islet β cell. Impairments in propeptide processing and secretory function, along with the loss of these vital cells, is demonstrable not only in those in whom the diagnosis is established but typically also in individuals who are at increased risk of developing the disease. Biomarkers are used to inform on the state of a biological process, pathological condition, or response to an intervention and are increasingly being used for predicting, diagnosing, and prognosticating disease. They are also proving to be of use in the different forms of diabetes in both research and clinical settings. This review focuses on the β cell, addressing the potential utility of genetic markers, circulating molecules, immune cell phenotyping, and imaging approaches as biomarkers of cellular function and loss of this critical cell. Further, we consider how these biomarkers complement the more long-established, dynamic, and often complex measurements of β-cell secretory function that themselves could be considered biomarkers.

Nonalcoholic fatty pancreas disease: An emerging clinical challenge

Nonalcoholic fatty pancreas disease (NAFPD) is an emerging disease that has gained an increasing amount of attention in recent years. It describes fat accumulation in the pancreas with insignificant alcohol consumption, but the pathogenesis is largely unknown. A wide range of terms have been used to describe the phenomenon of pancreatic fat accumulation, but NAFPD remains an under-recognized and non-independent disorder. Obesity, age, sex, race, and unhealthy lifestyle are established independent risk factors for NAFPD, which is strongly associated with metabolic syndrome, type 2 diabetes, pancreatitis, pancreatic fistula, pancreatic cancer, and nonalcoholic fatty liver disease. At present, imaging techniques are common diagnostic aids, but uniform criteria and consensus are lacking. Therapeutically, healthy diet, weight loss, and exercise are the mainstays to reduce pancreatic fat accumulation. It can be seen that there is a limited understanding of NAFPD at this stage and further exploration is needed. Previous studies have revealed that NAFPD may directly affect diagnosis and clinical decision-making. Therefore, exploring the pathophysiological mechanism and clinical associations of NAFPD is a major challenge for researchers and clinicians.