Pancreatic steatosis in humans: cause or marker of lipotoxicity?

Hormonal regulation in diabetes: Special emphasis on sex hormones and metabolic traits

Diabetes constitutes a significant global public health challenge that is rapidly reaching epidemic proportions. Among the non-communicable diseases, the incidence of diabetes is rising at an alarming rate. The International Diabetes Federation has documented a 9.09% prevalence of diabetes among individuals aged between 20 and 79 years. The interplay of gonadal hormones and gender differences is critical in regulating insulin sensitivity and glucose tolerance, and this dynamic is particularly crucial because of the escalating incidence of diabetes. Variations in insulin sensitivity are observed across genders, levels of adiposity, and age groups. Both estrogen and testosterone are seen to influence glucose metabolism and insulin sensitivity. This chapter surveys the present knowledge of sex differences, sex hormones, and chromosomes on insulin imbalance and diabetes development. It further highlights the influence of metabolic traits in diabetes and changes in sex hormones during diabetic pregnancy. Notably, even stressful lifestyles have been acknowledged to induce hormonal imbalances. Furthermore, it discusses the potential of hormonal therapy to help stabilize sex hormones in diabetic individuals and focuses on the most recent research investigating the correlation between sex hormones and diabetes.

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).

Intra-pancreatic fat is associated with high circulating glucagon and GLP-1 concentrations following whey protein ingestion in overweight women with impaired fasting glucose: A randomised controlled trial

AIM

Intra-pancreatic fat deposition (IPFD) while hypothesised to impair beta-cell function, its impact on alpha-cells remains unclear. We evaluated the association between IPFD and markers of pancreatic cells function using whey protein.

METHODS

Twenty overweight women with impaired fasting glucose (IFG) and low or high IPFD (<4.66% vs ≥4.66%) consumed 3 beverage treatments: 0 g (water control), 12.5 g (low-dose) and 50.0 g (high-dose) whey protein, after an overnight fast, in randomised order. Blood glucose, insulin, C-peptide, glucagon, gastric-inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and amylin were analysed postprandially over 4 h. Incremental area-under-the-curve (iAUC), incremental maximum concentration (iCmax), and time to maximum concentration (Tmax) for these were compared between IPFD groups using repeated measures linear mixed models, also controlled for age (pcov).

RESULTS

iAUC and iCmax glucose and insulin while similar between the two IPFD groups, high IPFD and ageing contributed to higher postprandial glucagon (iAUC: p = 0.012; pcov = 0.004; iCmax: p = 0.069; pcov = 0.021) and GLP-1 (iAUC: p = 0.006; pcov = 0.064; iCmax: p = 0.011; pcov = 0.122) concentrations.

CONCLUSION

In our cohort, there was no evidence that IPFD impaired protein-induced insulin secretion. Conversely, IPFD may be associated with increased protein-induced glucagon secretion, a novel observation which warrants further investigation into its relevance in the pathogenesis of dysglycaemia and type-2 diabetes.

Longitudinal changes in pancreatic volume and pancreatic fat with weight gain in Japanese without diabetes: An analysis using health check-up data

Aims/introduction

There have been few reports about the longitudinal changes in pancreas volume (PV) or pancreatic steatosis (PS) in response to obesity. In this longitudinal analysis using health check-up data, we explored changes in PV, PS and glucose metabolic indices that occurred after weight gain in Japanese without diabetes.

Materials/methods

Clinical data on 37 Japanese subjects with a ≥1 kg/m² increase in body mass index between two health check-ups and without diabetes were collected. PV, pancreas attenuation (PA) and splenic attenuation (SA) were evaluated using computed tomography (CT) images. The pancreas area was outlined by hand in multiple images with slice thickness of 2 mm, and the PV was computed by summing these areas. PS was defined as the difference between SA and PA (SA-PA). Medical records were collected, including findings on immunoreactive insulin (IRI), homeostasis model assessment of insulin resistance (HOMA-R) and beta cell function (HOMA-β). Paired t-test and Spearman's correlation coefficient were used in the analyses.

Results

The median follow-up period was 21.1 months and the mean BMI was increased from 25.5 ± 3.3 kg/m² to 27.0 ± 3.3 kg/m². PV (53.5 ± 15.9 cm³ vs. 56.2 ± 16.4 cm³) and SA-PA (8.7 ± 9.1 HU vs. 13.6 ± 10.9 HU) increased significantly after weight gain (both, P < 0.001). There were significant increases of IRI and HOMA-R with the weight gain (both, P < 0.05), whereas HOMA-β exhibited only a nonsignificant trend of increase (55.4％ (41.5-65.5) vs. 56.8％ (46.2-83.7), P = 0.07).

Conclusions

Both PV and PS were increased longitudinally with weight gain in Japanese without diabetes.

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.

Cellular Senescence in Obesity and Associated Complications: a New Therapeutic Target

PURPOSE OF REVIEW

Obesity has increased worldwide recently and represents a major global health challenge. This review focuses on the obesity-associated cellular senescence in various organs and the role of these senescent cells (SnCs) in driving complications associated with obesity. Also, the ability to target SnCs pharmacologically with drugs termed senotherapeutics as a therapy for these complications is discussed.

RECENT FINDINGS

Several studies have shown a positive correlation between obesity and SnC burden in organs such as adipose tissue, liver, and pancreatic-β-cells. These SnCs produce several secretory factors which affect other cells and tissues in a paracrine manner resulting in organ dysfunction. The accumulation of SnCs in adipocytes affects their lipid storage and impairs adipogenesis. The inflammatory senescence-associated secretory phenotype (SASP) of SnCs downregulates the antioxidant capacity and mitochondrial function in tissues. Senescent hepatocytes cannot oxidize fatty acids, which leads to lipid deposition and senescence in β-cells decrease function. These and other adverse effects of SnCs contribute to insulin resistance and type-2 diabetes. The reduction in the SnC burden genetically or pharmacologically improves the complications associated with obesity. The accumulation of SnCs with age and disease accelerates aging. Obesity is a key driver of SnC accumulation, and the complications associated with obesity can be controlled by reducing the SnC burden. Thus, senotherapeutic drugs have the potential to be an effective therapeutic option.

Clinical Significance of Pancreatic Fat in Children: A Single-Center Experience

OBJECTIVES

Recently, interest in pancreatic fat has increased, and fatty pancreas is considered to be related to nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. We aimed to evaluate the prevalence of echogenic pancreas in children and its related factors.

METHODS

We retrospectively analyzed the data of patients aged 5 to 18 years who had undergone abdominal sonography between January 2020 and December 2020. Patients with chronic or pancreatic diseases were excluded.

RESULTS

Of 102 patients, 27 (26.5%) had echogenic pancreas and 55 (53.9%) had NAFLD. Among the 55 patients with NAFLD, 18 (32.7%) had an echogenic pancreas. Patients with echogenic pancreas had significantly higher fasting glucose, low-density lipoprotein cholesterol, and triglyceride levels than those without echogenic pancreas. The proportion of NAFLD and obesity was higher in the echogenic group; however, only the proportion of obese subjects showed a significant difference. In multivariate analysis, family history of diabetes mellitus (DM) and/or dyslipidemia and presence of DM and/or dyslipidemia were factors related to the presence of echogenic pancreas.

CONCLUSIONS

Echogenic pancreas is relatively common in children. Echogenic pancreas, typically observed in patients with a family history of DM and/or dyslipidemia, was strongly associated with metabolic syndrome, even in the absence of fatty liver.

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.

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.

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.

Pancreatic steatosis: A frequent finding in a Chilean population

INTRODUCTION AND AIMS

Pancreatic steatosis is an incidental radiologic finding in asymptomatic patients, and its clinical importance is unclear. Primary aim: to study the prevalence of pancreatic steatosis (PS) in consecutive patients registered at our hospital, that underwent computed axial tomography (CAT) scanning of the abdomen and pelvis, excluding known pancreatic diseases. Secondary aim: to review the association of PS with the demographic and clinical data of the patients, as well as with hepatic steatosis (HS).

MATERIALS AND METHODS

An observational study was conducted on adult patients that had CAT scans of the abdomen and pelvis.

DEFINITIONS

a) tissue density was measured in Hounsfield units (HU) in five 1 cm² areas of the pancreas, three areas of the spleen, and in segments VI and VII of the liver; b) fatty pancreas: a difference < -10 HU between the mean pancreas and mean spleen densities; and c) fatty liver: density < 40 HU. We registered the epidemiologic and laboratory data of the patients. The association of those factors with the presence of PS was analyzed using SPSS version 24.0 software, and statistical significance was set at a p < 0.05.

RESULTS

Of the 203 patients, PS was found in 61 (30%). The patients with PS were significantly older and had a higher body mass index. We found no significant association with the rest of the parameters studied, nor with HS (55 patients). None of the patients had symptoms attributable to a disease of the exocrine pancreas.

CONCLUSIONS

Fatty infiltration of the pancreas is a frequent finding in CAT scans, and its clinical importance is unclear. Aging of the population and the increase in obesity underline the need for future studies on PS.

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.

Reducing the risk of postoperative pancreatic fistula in radical gastrectomy: pre-assessment with computed tomography for the diagnosis of pancreatic steatosis

PURPOSE

To determine whether pancreatic steatosis (PS) is associated with the risk of postoperative pancreatic fistula (POPF) after radical gastrectomy, and if so, to investigate whether pre-assessment by diagnostic imaging can mitigate the risk.

METHODS

The clinical records of 276 patients with cStage I gastric cancer who underwent laparoscopic gastrectomy with D1 + lymphadenectomy between 2012 and 2015 were reviewed. In the first phase up to July 2013 (n = 138), PS was classified from computed tomography (CT) findings into type S (superficial fat deposition) or type D (diffuse fatty replacement) and examined for association with POPF. In the second phase (n = 138), the preoperative CT assessment of PS was routinized. Separate samples from pancreatoduodenectomy consistent with each type were histologically examined.

RESULTS

In the first phase, the incidence of POPF was significantly higher in group S, but not in group D, compared with normal pancreas (16.3% and 9.1% vs. 3.6%, respectively; P = 0.03). The drain amylase level was lowest in group D, reflecting exocrine insufficiency. Histologically, the loose connective-tissue space between the fat infiltrating the pancreas and the peripancreatic fat containing the lymph nodes was unclear in type D but conserved in type S. In the second phase, surgery was performed with more intention on accurately tracing the dissection plane and significantly lowered incidence of POPF in Group S (16.3% to 2.1%; P = 0.047).

CONCLUSION

Peripancreatic lymphadenectomy is more challenging and likely to cause POPF in patients with PS. However, the risk may be reduced using appropriate dissection techniques based on the CT pre-assessment findings.

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.

Fatty Pancreas: An Underappreciated Intersection of the Metabolic Profile and Pancreatic Adenocarcinoma

Although the prevalence of pancreatic cancer is increasing, treatment strategies remain limited, and success is rare. A growing body of evidence links pancreatic cancer to pre-existing metabolic disorders, including, but not limited to, type 2 diabetes mellitus and obesity. An infrequently described finding, fatty pancreas, initially described in the context of obesity in the early 20th century, appears to be at the crossroads of type 2 diabetes and obesity on the one hand, and the development of pancreatic cancer on the other. Similarly, other conditions of the pancreas, such as intrapancreatic mucinous neoplasms, also seem to be related to diabetes while increasing the subsequent risk of pancreatic cancer. In this review, the author explores the diagnostic criteria for, and prevalence of, fatty pancreas and the potential link to other pancreatic conditions, including pancreatic cancer. Diagnostic limitations, and areas of controversy are also addressed, as are potential therapeutic approaches to fatty pancreas intended to reduce the subsequent risk of pancreatic cancer.

Beta-Cell Mass in Obesity and Type 2 Diabetes, and Its Relation to Pancreas Fat: A Mini-Review

Type 2 diabetes (T2DM) is characterized by insulin resistance and beta-cell dysfunction. Although insulin resistance is assumed to be a main pathophysiological feature of the development of T2DM, recent studies have revealed that a deficit of functional beta-cell mass is an essential factor for the pathophysiology of T2DM. Pancreatic fat contents increase with obesity and are suggested to cause beta-cell dysfunction. Since the beta-cell dysfunction induced by obesity or progressive decline with disease duration results in a worsening glycemic control, and treatment failure, preserving beta-cell mass is an important treatment strategy for T2DM. In this mini-review, we summarize the current knowledge on beta-cell mass, beta-cell function, and pancreas fat in obesity and T2DM, and we discuss treatment strategies for T2DM in relation to beta-cell preservation.

Research status and prgoress of nonalcoholic fatty pancreatic disease

Nonalcoholic fatty pancreatic disease (NAFPD) is a disease characterized by an increase in pancreatic fat accumulation. It is a component of the metabolic syndrome and often coexists with nonalcoholic fatty liver disease. Once the diagnosis is established, it is closely related to acute and chronic pancreatitis, type 2 diabetes mellitus, pancreatic fibrosis, and pancreatic cancer. In recent years, it has been confirmed that NAFPD is closely related to cardiovascular disease, liver fibrosis, and liver cancer. The prevalence of NAFPD ranges between 11% and 69%, and increases with age. It is worth noting that the prevalence in obese children is twice as high as that in non-obese children. The high prevalence rate and complexity of the disease have aroused people's high attention. Therefore, to improve the understanding of NAFPD, fully understand the clinical significance of NAFPD, and further study its pathogenesis, diagnosis, and treatment require the collaboration and joint efforts of multiple disciplines, including hepatopathy, gastroenterology, endocrine metabolism, cardiovascular disease, imaging, pathology, and others. In this paper, we review the clinical significance, pathogenesis, and imaging diagnosis of NAFPD and propose our personal understanding of the key points in future research.

Chronic Pancreatitis Is Characterized by Elevated Circulating Periostin Levels Related to Intra-Pancreatic Fat Deposition

Background

Periostin is a matricellular protein that induces fibrillogenesis and activates cell migration. It is overexpressed in common fibrotic diseases and is also associated with abdominal adiposity/ectopic fat phenotypes. The study aimed to investigate circulating levels of periostin in health and after an attack of pancreatitis, as well as their associations with abdominal adiposity/ectopic fat phenotypes.

Methods

Blood samples were obtained from healthy controls, as well as definite chronic pancreatitis (CP) and acute pancreatitis (AP) individuals during follow-up visits. Fat depositions in the pancreas, liver, skeletal muscle, as well as visceral and subcutaneous fat volumes, were quantified with the use of magnetic resonance imaging. A series of multivariable analyses were conducted, accounting for possible confounders.

Results

A total of 121 individuals were included. Periostin levels were significantly higher in the CP group compared with the other groups in both unadjusted (F = 3.211, P = 0.044) and all adjusted models (F = 4.165, P = 0.019 in the most adjusted model). Intra-pancreatic fat deposition (but not the other fat phenotypes) was significantly associated with periostin concentration in the CP group (β = 49.63, P = 0.034) and explained most of its variance (32.0%).

Conclusions

Individuals with CP, but not healthy individuals or those after clinical resolution of AP, are characterized by elevated circulating levels of periostin that are positively associated with intra-pancreatic fat deposition.

Longitudinal association of fatty pancreas with the incidence of type-2 diabetes in lean individuals: a 6-year computed tomography-based cohort study

BACKGROUND

Only a few studies have longitudinally evaluated whether fatty pancreas increases the risk of type-2 diabetes (T2D), and their results were inconsistent. Fatty pancreas is closely linked to overweight and obesity, but previous studies did not exclude overweight or obese individuals. Therefore, in this cohort study, we investigated the association between fatty pancreas and T2D incidence in lean individuals.

METHODS

Between 2008 and 2013, 1478 nondiabetic lean individuals (i.e. body-mass index < 25 kg/m²) underwent health examinations including computed tomography (CT) and were followed for a median of 6.19 years. Fatty pancreas was evaluated by a histologically-validated method using pancreas attenuation (Hounsfield units [HU]) on CT at baseline; lower pancreas attenuation indicates more pancreatic fat. To detect incident T2D, we used fasting plasma glucose, HbA1c, and self-reports of prescribed anti-diabetes medications. Odds ratios (OR) for the association between pancreas attenuation and incident T2D were estimated using logistic regression models adjusted for likely confounders.

RESULTS

T2D occurred in 61 participants (4.13%) during the follow-up period. Lower pancreas attenuation (i.e. more pancreatic fat) at baseline was associated with incident T2D (unadjusted OR per 10 HU lower attenuation: 1.56 [95% CI 1.28-1.91], p < 0.001). The multivariable-adjusted analysis revealed a similar association (adjusted OR per 10 HU lower attenuation: 1.32 [95% CI 1.06-1.63], p = 0.012).

CONCLUSIONS

T2D was likely to develop in lean individuals with the fatty pancreas. Among people who are neither obese nor overweight, the fatty pancreas can be used to define a group at high risk for T2D.

The influence of Glucose-dependent Insulinotropic Polypeptide (GIP) on human adipose tissue and fat metabolism: Implications for obesity, type 2 diabetes and Non-Alcoholic Fatty Liver Disease (NAFLD)

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon like peptide (GLP-1) are the two incretin hormones secreted by the enteroendocrine system in response to nutrient ingestion. Compared with GLP-1, GIP is less well studied as a hormone or as a potential pharmacological treatment. Beyond its insulinotropic effects in the pancreas, GIP has important biological actions in many other tissues but its role in dietary fat metabolism and lipid storage in adipose tissue has been most studied. It is still unclear if such effects of GIP on adipose tissue/fat metabolism are protective or deleterious in the long term. Antagonising GIP actions through genetic and chemical disruption in mice models prevented diet induced obesity and improved insulin sensitivity. Whilst such effects of GIP antagonism are yet to be evaluated in humans, recent studies using combined GIP and GLP-1 agonists have shown weight reduction and improved glycaemic control in people with type 2 diabetes (T2D). Therapeutic manipulation of GIP physiology is intriguing in that both agonists and antagonists of GIP are being investigated to explore their potential weight-reducing and other metabolic benefits in people with obesity, T2D and non-alcoholic fatty liver disease (NAFLD). This review will discuss the physiological effects of GIP on fat metabolism in human adipose and other non-adipose tissues such as liver, pancreas, skeletal muscle and heart, describe where the actions of GIP may contribute to the pathophysiology of obesity, T2D and NAFLD and finally describe the therapeutic implications of GIP antagonism and agonism in these conditions.

Bredemolic Acid Ameliorates Selected Liver Function Biomarkers in a Diet-Induced Prediabetic Rat Model

BACKGROUND

Prediabetes is an intermediary hyperglycaemic state that precedes type 2 diabetes mellitus (T2DM) in which abnormal metabolism of glucose and lipids occurs in organs such as the liver. Evidence has shown that, about 70% of T2DM patients develop hepatic dysfunction which is found to begin during the prediabetic stage. Bredemolic acid, a pentacyclic triterpene, has been found to improve insulin sensitivity in diet-induced prediabetic rats. The effects of this compound on liver function, however, are unknown. This study was therefore designed to investigate the effects of BA on liver function in high fat-high carbohydrate (HFHC) diet-induced prediabetic rats.

METHODS

Thirty-six (36) male rats that weigh 150 g-180 g were divided into two groups, the non-prediabetic (n = 6) and the prediabetic groups (n = 6) and the prediabetic groups (n = 6) and the prediabetic groups (.

RESULTS

The induction of prediabetes resulted in increased release of liver enzymes (AST and ALT), increased liver glycogen and triglyceride, lipid peroxidation, and decreased sterol regulatory element-binding protein (SREBP1c) and antioxidant enzymes. However, the administration of BA decreased liver enzyme concentrations, decreased hepatic oxidative stress, and improved antioxidant enzymes such as SOD and GPx.

CONCLUSION

BA administration improved liver function in diet-induced prediabetic rats in the presence or absence of dietary intervention.

Pancreatic Fat is not significantly correlated with β-cell Dysfunction in Patients with new-onset Type 2 Diabetes Mellitus using quantitative Computed Tomography

Objective: Type 2 diabetes mellitus (T2DM) is a chronic condition resulting from insulin resistance and insufficient β-cell secretion, leading to improper glycaemic regulation. Previous studies have found that excessive fat deposits in organs such as the liver and muscle can cause insulin resistance through lipotoxicity that affects β-cell function. The relationships between fat deposits in pancreatic tissue, the function of β-cells, the method of visceral fat evaluation and T2DM have been sought by researchers. This study aims to elucidate the role of pancreatic fat deposits in the development of T2DM using quantitative computed tomography (QCT), especially their effects on islet β-cell function. Methods: We examined 106 subjects at the onset of T2DM who had undergone abdominal QCT. Estimated pancreatic fat and liver fat were quantified using QCT and calculated. We analysed the correlations with Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) scores and other oral glucose tolerance test-derived parameters that reflect islet function. Furthermore, correlations of estimated pancreatic fat and liver fat with the area under the curve for insulin (AUC_INS) and HOMA-IR were assessed with partial correlation analysis and demonstrated by scatter plots. Results: Associations were found between estimated liver fat and HOMA-IR, AUC_INS, the modified β-cell function index (MBCI) and Homeostatic Model Assessment β (HOMA-β). However, no significant differences existed between estimated pancreas fat and those parameters. Similarly, after adjustment for sex, age and body mass index, only estimated liver fat was correlated with HOMA-IR and AUC_INS. Conclusions: This study suggests no significant correlation between pancreatic fat deposition and β-cell dysfunction in the early stages of T2DM using QCT as a screening tool. The deposits of fat in the pancreas and the resulting lipotoxicity may play an important role in the late stage of islet cell function dysfunction as the course of T2DM progresses.

Association of pancreatic fat content with type II diabetes mellitus

AIM

To determine the association between regional fat content in the pancreas and the presence or absence of type II diabetes mellitus (T2DM), the value of regional pancreatic fat quantification in identifying patients at risk of T2DM, and whether pancreatic fat content is associated with glycaemic control in T2DM.

MATERIALS AND METHODS

A retrospective survey of a radiology database identified 45 patients with T2DM, and 81 "at risk for T2DM" patients who developed diabetes, between 0.6 and 3.7 years after magnetic resonance imaging (MRI). A control group who did not develop diabetes during a 5-year follow-up and without known metabolic syndrome, liver, or pancreatic diseases were also identified. Fat content was measured by placing regions of interest (ROIs) on in-phase and out-of-phase chemical shift MRI images. Multiple clinical parameters including body mass index, cholesterol levels, blood pressure, glycated haemoglobin (HbA1c; in T2DM group) were collected.

RESULTS

There was a significant difference between the T2DM and control groups for fat fraction in the pancreatic head (p=0.043), body (p=0.015), and tail (p=0.001), but not liver (p=0.107). On regression analysis, only the fat fraction within the pancreatic tail was significantly different between control group and "at risk" for T2DM group (p=0.007). A pancreatic tail fat content of >10% had a sensitivity of 45.5% and specificity of 81.3% for predicting development of T2DM within 4 years. Pancreatic fat content was not associated with glycaemic control.

CONCLUSIONS

Increased fat in the pancreatic tail may identify patients at risk for T2DM.

Pancreatic Steatosis: An Emerging Clinical Entity

Pancreatic steatosis is an emerging clinical entity whose pathophysiology, natural history, and long-term complications are poorly characterized in the current literature. Epidemiological and prospective studies have described prevalence rates between 16% and 35%. Although the natural history is not well known, there are strong associations with obesity, metabolic syndrome, type 2 diabetes mellitus, and nonalcoholic fatty liver disease. Ectopic fat accumulation of the pancreas can cause chronic, low-grade inflammation from adipocytokine imbalances that involve beta cells and acinar cells. This mechanism can lead to pancreatic endocrine and exocrine dysfunction and initiate carcinogenesis. Although it is associated with morbid conditions, pancreatic steatosis may be amendable to treatment with a healthy diet, less meat consumption, exercise, and smoking cessation. Pancreatic steatosis should factor into clinical decision-making and prognostication of patients with pancreatic and systemic disease. This review seeks to describe the pathophysiology, natural history, diagnosis, and complications of this emerging clinically relevant entity.

Non-alcoholic fatty pancreas disease - practices for clinicians

Obesity is a growing health burden worldwide, increasing the risk for several diseases featuring the metabolic syndrome - type 2 diabetes mellitus, dyslipidemia, non-alcoholic fatty liver disease and cardiovascular diseases. With the increasing epidemic of obesity, a new pathologic condition has emerged as a component of the metabolic syndrome - that of non-alcoholic fatty pancreas disease (NAFPD). Similar to non-alcoholic fatty liver disease (NAFLD), NAFPD comprises a wide spectrum of disease - from deposition of fat in the pancreas - fatty pancreas, to pancreatic inflammation and possibly pancreatic fibrosis. In contrast with NAFLD, diagnostic evaluation of NAFPD is less standardized, consisting mostly in imaging methods. Also the natural evolution of NAFPD and its association with pancreatic cancer is much less studied. Not least, the clinical consequences of NAFPD remain largely presumptions and knowledge about its metabolic impact is limited. This review will cover epidemiology, pathogenesis, diagnostic evaluation tools and treatment options for NAFPD, with focus on practices for clinicians.

Type 2 diabetes: Prescription patterns and treatment outcomes of IDMPS survey in Argentina

AIM

To assess prescription patterns for treatment of type 2 diabetes (T2D) and their outcomes in the IDMPS survey in Argentina.

METHODS

Data from 2551 people with T2D recruited from 210 physicians participating in IDMPS surveys in Argentina (2006 to 2012 waves) were recorded, including medical history, medications, glycemic control, blood pressure, and lipid status.

RESULTS

Most people were treated with oral glucose-lowering drugs (OGLDs) (65%), followed by combinations of these drugs plus insulin (22%) and only insulin (13%). These percentages varied according to T2D duration, the frequency of OGLDs decreasing while contrastingly and only insulin increasing (under 5 years versus over 10 years of disease duration, respectively). Average systolic blood pressure (SBP), HbA1c and LDL-c were significantly higher in patients treated with insulin either alone or associated with OGLDs. The percentage of people at target values for these parameters was also lower in these two groups. The percentage of people that reached simultaneous goal treatment values for BP, HbA1c and LDL-c levels was markedly low.

CONCLUSION

Prescription patterns for treatment of T2D follows a chronological trend and the percentage of people at goal values (HbA1c, BP and LDL-c values) was significantly lower in people receiving insulin. These data must be carefully considered by health and academic authorities in order to implement effective strategies to modify this situation.

What role do fat cells play in pancreatic tissue?

Background

It is now generally accepted that obesity is a major risk factor for type 2 diabetes mellitus (T2DM). Hepatic steatosis in particular, as well as visceral and ectopic fat accumulation within tissues, is associated with the development of the disease. We recently presented the first study on isolated human pancreatic adipocytes and their interaction with islets [Gerst, F., Wagner, R., Kaiser, G., Panse, M., Heni, M., Machann, J., et al., 2017. Metabolic crosstalk between fatty pancreas and fatty liver: effects on local inflammation and insulin secretion. Diabetologia 60(11):2240–2251.]. The results indicate that the function of adipocytes depends on the overall metabolic status in humans which, in turn, differentially affects islet hormone release.

Scope of Review

This review summarizes former and recent studies on factors derived from adipocytes and their effects on insulin-secreting β-cells, with particular emphasis on the human pancreas. The adipocyte secretome is discussed with a special focus on its influence on insulin secretion, β-cell survival and apoptotic β-cell death.

Major Conclusions

Human pancreatic adipocytes store lipids and release adipokines, metabolites, and pro-inflammatory molecules in response to the overall metabolic, humoral, and neuronal status. The differentially regulated adipocyte secretome impacts on endocrine function, i.e., insulin secretion, β-cell survival and death which interferes with glycemic control. This review attempts to explain why the extent of pancreatic steatosis is associated with reduced insulin secretion in some studies but not in others.

Association of Pancreatic Steatosis With Chronic Pancreatitis, Obesity, and Type 2 Diabetes Mellitus

OBJECTIVE

The aim of this study was to determine the association of the pancreatic steatosis with obesity, chronic pancreatitis (CP), and type 2 diabetes mellitus.

METHODS

Patients (n = 118) were retrospectively identified and categorized into no CP (n = 60), mild (n = 21), moderate (n = 27), and severe CP (n = 10) groups based on clinical history and magnetic resonance cholangiopancreatography using the Cambridge classification as the diagnostic standard. Visceral and subcutaneous compartments were manually segmented, and fat tissue was quantitatively measured on axial magnetic resonance imaging.

RESULTS

Pancreatic fat fraction showed a direct correlation with fat within the visceral compartment (r = 0.54). Patients with CP showed higher visceral fat (P = 0.01) and pancreatic fat fraction (P < 0.001): mild, 24%; moderate, 23%; severe CP, 21%; no CP group, 15%. Patients with type 2 diabetes mellitus showed higher pancreatic steatosis (P = 0.03) and higher visceral (P = 0.007) and subcutaneous fat (P = 0.004). Interobserver variability of measuring fat by magnetic resonance imaging was excellent (r ≥ 0.90-0.99).

CONCLUSIONS

Increased visceral adipose tissue has a moderate direct correlation with pancreatic fat fraction. Chronic pancreatitis is associated with higher pancreatic fat fraction and visceral fat. Type 2 diabetes mellitus is associated with higher pancreatic fat fraction and visceral and subcutaneous adiposity.

Prediabetes and Type 2 Diabetes are Independent Risk Factors for Computed Tomography-Estimated Nonalcoholic Fatty Pancreas Disease

OBJECTIVES

Nonalcoholic fatty pancreas disease (NAFPD) is characterized by excessive fat deposition in the pancreas in the absence of alcohol consumption. In this study, we aimed to detect a possible relationship between adipose tissue accumulation, prediabetes and diabetes.

METHODS

This cross-sectional and retrospective study included 110 patients. Three groups were classified as controls, patients with prediabetes and patients with type 2 diabetes. The abdominal computed tomography (CT) attenuation measurement results of the pancreas were evaluated independently by two experienced radiologists. CT measurements and biochemical parameters were compared between study groups. The relationship between continuous variables was assessed by using one-way ANOVA. To determine the changes in the dependent variable for the effects on study groups, the independent variable was adjusted using ANCOVA. A p-value less than 0.05 was considered statistically significant.

RESULTS

The presence of prediabetes and type 2 diabetes was correlated with a decrease in the mean Hounsfield Unit (HU) value of the pancreas (p=0.002). Age was determined to be an independent risk factor and was correlated with NAFPD (p=0.0001). When compared to the controls (p=0.041), 71% of patients with prediabetes and 67% of patients with type 2 diabetes were observed to have an increased incidence of NAFPD. Decreased serum amylase was found to be correlated with the mean HU value of the pancreas (p=0.043).

CONCLUSION

NAFPD was independently correlated with both prediabetes and type 2 diabetes adjusted for age (p=0.0001) in this study. Additionally, age was determined to be an independent risk factor and was correlated with NAFPD.

No Correlation of Pancreatic Fat and β-Cell Function in Young Women With and Without a History of Gestational Diabetes

CONTEXT

Pancreatic steatosis may contribute to β-cell dysfunction in type 2 diabetes (T2D), but data are controversial. Women who had gestational diabetes mellitus (GDM) are at high risk for developing T2D.

OBJECTIVE

To examine the association of pancreatic fat content with early/first-phase insulin secretion (as markers of β-cell function).

DESIGN

Cross-sectional analysis of a subcohort of the monocentric, prospective cohort study titled Prediction, Prevention, and Subclassification of Type 2 Diabetes.

SETTING

Ludwig Maximilians University Hospital, Munich, Germany.

PARTICIPANTS

Ninety-seven women, 3 to 16 months after pregnancy [41 normoglycemic women post-GDM, 19 women post-GDM with pathological glucose metabolism, and 37 normoglycemic women after a normoglycemic pregnancy (controls)].

MAIN OUTCOME MEASURES

Correlation of MRI-measured pancreatic fat content with early insulin release in an oral glucose tolerance test (OGGT) [insulin increment within the first 30 minutes of the OGTT (IR30)] and first-phase insulin response (FPIR) in an intravenous glucose tolerance test (n = 65), both adjusted for insulin sensitivity index (ISI).

RESULTS

Pancreatic fat content did not correlate with IR30 and FPIR adjusted for ISI. It correlated positively with body mass index, waist circumference, liver fat, and intraabdominal fat volume.

CONCLUSION

Pancreatic fat content does not correlate with β-cell function in a cohort of young women with different degrees of T2D risk.

Obesity, metabolic disease and the pancreas-Quantitative imaging of pancreatic fat

The association between pancreatic fat, obesity and metabolic disease is well-documented, and although a potentially exciting target for novel therapies, remains poorly understood. Non-invasive quantitative imaging-derived biomarkers can provide insights into pathophysiology and potentially provide robust trial endpoints for development of new treatments. In this review, we provide an overview of the pathophysiology of non-alcoholic fatty pancreas disease and associations with metabolic factors, obesity and diabetes. We then explore approaches to pancreatic fat quantification using ultrasound, CT and MRI, reviewing the strengths, limitations and current published evidence in the assessment of pancreatic fat. Finally, we explore the broader challenges of pancreatic fat quantification as we move toward translating these methods into the clinical setting.

Pancreatic Aquaporin-7: A Novel Target for Anti-diabetic Drugs?

Aquaporins comprise a family of 13 members of water channels (AQP0-12) that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum. AQP1, AQP5, and AQP8 contribute to fluid secretion especially from ductal cells, whereas AQP12 allows the proper maturation and exocytosis of secretory granules in acinar cells of the exocrine pancreas. The endocrine pancreas (10% of the total pancreatic cells) is composed by the islets of Langerhans, which are distributed in α, β, δ, ε, and pancreatic polypeptide (PP) cells that secrete glucagon, insulin, somatostatin, ghrelin and PP, respectively. AQP7, an aquaglyceroporin permeated by water and glycerol, is expressed in pancreatic β-cells and murine studies have confirmed its participation in insulin secretion, triacylglycerol synthesis and proliferation of these endocrine cells. In this regard, transgenic AQP7-knockout mice develop adult-onset obesity, hyperinsulinemia, increased intracellular triacylglycerol content and reduced β-cell mass in Langerhans islets. Moreover, we have recently reported that AQP7 upregulation in β-cells after bariatric surgery, an effective weight loss surgical procedure, contributes, in part, to the improvement of pancreatic steatosis and insulin secretion through the increase of intracytoplasmic glycerol in obese rats. Human studies remain scarce and controversial, with some rare cases of loss-of function mutations of the AQP7 gene being associated with the onset of type 2 diabetes. The present Review is focused on the role of aquaporins in the physiology and pathophysiology of the pancreas, highlighting the role of pancreatic AQP7 as a novel player in the control of β-cell function and a potential anti-diabetic-drug.

Type 2 diabetes: Does pancreatic fat really matter?

With the increasing prevalence of obesity, the interest of research in nonalcoholic fatty pancreas disease (NAFPD) has grown. Even though the pancreas appears more susceptible to lipid accumulation compared with the liver, NAFPD has been less investigated due to the limits in detecting techniques. Several definitions and synonyms for NAFPD are used by authors and can be misleading. This, together with differences in methodology and ethnicity, make the integration and comparison of studies on this topic challenging. NAFPD could be used as an early indicator of ectopic fat deposition, which is recognized as a key factor of obesity cardio-metabolic complications. However, evidence that NAFPD has a pathogenetic role in type 2 diabetes is also emerging. This article reviews the current state of knowledge on the clinical and pathophysiologic relevance of NAFPD in β-cell function and insulin resistance.

The Clinical Implications of Fatty Pancreas: A Concise Review

Fatty pancreas is a newly recognized condition which is poorly investigated until today as compared to nonalcoholic fatty liver disease. It is characterized by pancreatic fat accumulation and subsequent development of pancreatic and metabolic complications. Association of fatty pancreas have been described with type 2 diabetes mellitus, acute and chronic pancreatitis and even pancreatic carcinoma. In this review article, we provide an update on clinical implications, pathogenesis, diagnosis, treatment and outcomes.

Pancreas Fat and β Cell Mass in Humans With and Without Diabetes: An Analysis in the Japanese Population

CONTEXT

The mechanisms by which β cell mass is reduced in patients with type 2 diabetes remain unclear. It has been postulated that ectopic fat deposits in the pancreas induce β cell apoptosis, leading to the development of diabetes.

OBJECTIVE

The aim of this study was to clarify the effects of intrapancreatic fat on β and α cell mass in humans with and without diabetes.

DESIGN AND SUBJECTS

Using our tissue database, pancreas sections of 72 Japanese nondiabetic (NDM) autopsy cases and 50 diabetic and 49 age- and body mass index (BMI)-matched NDM patients who underwent pancreatic surgery were analyzed. In addition to histological grading, intrapancreatic fat area (IPFA) was quantified as fractional intralobular, but not interlobular, fat area to the whole pancreas area.

RESULTS

Although IPFA was positively correlated with age and BMI, there was no significant difference in IPFA between cases with and without diabetes. Moreover, no association was found between IPFA and either β or α cell area, or glycated hemoglobin.

CONCLUSION

These findings suggest that pancreatic fat deposits have little effect on β cell mass and the development of diabetes in humans.

Non-alcoholic fatty liver disease: A sign of systemic disease

Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease and leading cause of cirrhosis in the United States and developed countries. NAFLD is closely associated with obesity, insulin resistance and metabolic syndrome, significantly contributing to the exacerbation of the latter. Although NAFLD represents the hepatic component of metabolic syndrome, it can also be found in patients prior to their presentation with other manifestations of the syndrome. The pathogenesis of NAFLD is complex and closely intertwined with insulin resistance and obesity. Several mechanisms are undoubtedly involved in its pathogenesis and progression. In this review, we bring together the current understanding of the pathogenesis that makes NAFLD a systemic disease.

Glucose and Lipid Dysmetabolism in a Rat Model of Prediabetes Induced by a High-Sucrose Diet

Glucotoxicity and lipotoxicity are key features of type 2 diabetes mellitus, but their molecular nature during the early stages of the disease remains to be elucidated. We aimed to characterize glucose and lipid metabolism in insulin-target organs (liver, skeletal muscle, and white adipose tissue) in a rat model treated with a high-sucrose (HSu) diet. Two groups of 16-week-old male Wistar rats underwent a 9-week protocol: HSu diet (n = 10)-received 35% of sucrose in drinking water; Control (n = 12)-received vehicle (water). Body weight, food, and beverage consumption were monitored and glucose, insulin, and lipid profiles were measured. Serum and liver triglyceride concentrations, as well as the expression of genes and proteins involved in lipid biosynthesis were assessed. The insulin-stimulated glucose uptake and isoproterenol-stimulated lipolysis were also measured in freshly isolated adipocytes. Even in the absence of obesity, this rat model already presented the main features of prediabetes, with fasting normoglycemia but reduced glucose tolerance, postprandial hyperglycemia, compensatory hyperinsulinemia, as well as decreased insulin sensitivity (resistance) and hypertriglyceridemia. In addition, impaired hepatic function, including altered gluconeogenic and lipogenic pathways, as well as increased expression of acetyl-coenzyme A carboxylase 1 and fatty acid synthase in the liver, were observed, suggesting that liver glucose and lipid dysmetabolism may play a major role at this stage of the disease.

Pancreas volume reduction and metabolic effects in Japanese patients with severe obesity following laparoscopic sleeve gastrectomy

This study aimed to assess the relationship between the metabolic effect after laparoscopic sleeve gastrectomy (LSG) in morbidly obese Japanese patients, with or without type 2 diabetes mellitus (T2DM), and improved pancreatic steatosis (PS). The study enrolled 27 morbidly obese Japanese patients who were undergoing LSG. Their clinical and metabolic effects were evaluated at baseline and six months after LSG. Pancreas volume (PV), pancreatic attenuation (PA), and splenic attenuation (SA) were measured using a 64-row computed tomography (CT). Changes in PV, PA-SA, and PA/SA were evaluated. The mean body-weight loss, body mass index loss, and percentage of excess weight loss (%EWL) were -34.4 kg (p < 0.001), -11.0 kg/m² (p < 0.001), and 43.7%, respectively. The mean PV was 96.7 mL at baseline, and it decreased six months after LSG (-16.3mL, p < 0.001). The mean PA significantly increased six months after LSG (9.5 HU, p < 0.001). PA-SA (-23.2 HU vs. -13.3 HU, p = 0.003), and PA/SA (0.54 vs. 0.73, p < 0.001) also significantly increased six months after LSG. In T2DM patients, decreased PV correlated with decreased fasting blood sugar, decreased insulin, and reduced liver volume. In conclusion, PV significantly decreased after LSG in morbidly obese Japanese patients, and that decrease correlated with improvements in PS. In addition, PS plays an important role of development and progression of insulin resistance and T2DM.

Impact of non-alcoholic fatty pancreas disease on glucose metabolism

With the increasing global epidemic of obesity, the clinical importance of non-alcoholic fatty pancreas disease (NAFPD) has grown. Even though the pancreas might be more susceptible to ectopic fat deposition compared with the liver, NAFPD is rarely discussed because of the limitation of detection techniques. In the past, NAFPD was considered as an innocent condition or just part of clinical manifestations during the course of obesity. Recently, a growing body of research suggests that NAFPD might be associated with β-cell dysfunction, insulin resistance and inflammation, which possibly lead to the development of diabetes and metabolic syndrome. The present review summarized the current literature on the epidemiology, potential pathophysiology, diagnostic techniques, impact of NAFPD on β-cell function and insulin resistance, and the clinical relevance of the interplay between NAFPD and glucometabolic disorders.

Muscle Attenuation Is Associated With Newly Developed Hypertension in Men of African Ancestry

Increased ectopic adipose tissue infiltration in skeletal muscle is associated with insulin resistance and diabetes mellitus. We evaluated whether change in skeletal muscle adiposity predicts subsequent development of hypertension in men of African ancestry, a population sample understudied in previous studies. In the Tobago Health Study, a prospective longitudinal study among men of African ancestry (age range 40-91 years), calf intermuscular adipose tissue, and skeletal muscle attenuation were measured with computed tomography. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, or a diastolic blood pressure ≥90 mm Hg, or receiving antihypertensive medications. Logistic regression was performed with adjustment for age, insulin resistance, baseline and 6-year change in body mass index, baseline and 6-year change in waist circumference, and other potential confounding factors. Among 746 normotensive men at baseline, 321 (43%) developed hypertension during the mean 6.2 years of follow-up. Decreased skeletal muscle attenuation was associated with newly developed hypertension after adjustment for baseline and 6-year change of body mass index (odds ratio [95% confidence interval] per SD, 1.3 [1.0-1.6]) or baseline and 6-year change of waist circumference (odds ratio [95% confidence interval] per SD, 1.3 [1.0-1.6]). No association was observed between increased intermuscular adipose tissue and hypertension. Our novel findings show that decreased muscle attenuation is associated with newly developed hypertension among men of African ancestry, independent of general and central adiposity and insulin resistance. Further studies are needed to adjust for inflammation, visceral and other ectopic adipose tissue depots, and to confirm our findings in other population samples.

Exercise and ectopic fat in type 2 diabetes: A systematic review and meta-analysis

Ectopic adipose tissue surrounding the intra-abdominal organs (visceral fat) and located in the liver, heart, pancreas and muscle, is linked to cardio-metabolic complications commonly experienced in type 2 diabetes. A systematic review and meta-analysis was performed to determine the effect of exercise on ectopic fat in adults with type 2 diabetes. Relevant databases were searched to February 2016. Included were randomised controlled studies, which implemented≥4 weeks of aerobic and/or resistance exercise and quantified ectopic fat via magnetic resonance imaging, computed tomography, proton magnetic resonance spectroscopy or muscle biopsy before and after intervention. Risk of bias and study quality was assessed using Egger's funnel plot test and modified Downs and Black checklist, respectively. Of the 10,750 studies retrieved, 24 were included involving 1383 participants. No studies were found assessing the interaction between exercise and cardiac or pancreas fat. One study assessed the effect of exercise on intramyocellular triglyceride concentration. There was a significant pooled effect size for the meta-analysis comparing exercise vs. control on visceral adiposity (ES=-0.21, 95% CI: -0.37 to -0.05; P=0.010) and a near-significant pooled effect size for liver steatosis reduction with exercise (ES=-0.28, 95% CI: -0.57 to 0.01; P=0.054). Aerobic exercise (ES=-0.23, 95% CI: -0.44 to -0.03; P=0.025) but not resistance training exercise (ES=-0.13, 95% CI: -0.37 to 0.12; P=0.307) was effective for reducing visceral fat in overweight/obese adults with type 2 diabetes. These data suggest that exercise effectively reduces visceral and perhaps liver adipose tissue and that aerobic exercise should be a key feature of exercise programs aimed at reducing visceral fat in obesity-related type 2 diabetes. Further studies are required to assess the relative efficacy of exercise modality on liver fat reduction and the effect of exercise on pancreas, heart, and intramyocellular fat in type 2 diabetes and to clarify the effect of exercise on ectopic fat independent of weight loss.

Differential effects of angiotensin receptor blockers on pancreatic islet remodelling and glucose homeostasis in diet-induced obese mice

Obesity leads to adverse endocrine pancreas remodelling, reduced islet lifespan and early type 2 diabetes onset. AT1R blockade shows beneficial pleiotropic effects. This study sought to compare the effects of losartan and telmisartan on pancreatic islets remodelling and glucose homeostasis in diet-induced obese mice. High-fat diet yielded overweight, insulin resistance, islet apoptosis and hypertrophy. Suitable insulin levels and preserved endocrine pancreas structure were correlated to adequate AKT-FOXO1 pathway functioning in losartan-treated animals. Conversely, telmisartan yielded enhanced PDX1 and GLP-1 islet expression along with greater GLP-1 levels, with the consequent better islet glucose sensing and uptake. Greater islet vascularisation coupled with reduced apoptosis and macrophage infiltration seems to underlie the beneficial findings in both treatments. In conclusion, these results provide compelling evidence that two antihypertensive drugs (telmisartan and losartan) ameliorate pancreatic islet structure, glucose handling, and vascularisation in obese mice. Although only telmisartan countered overweight, both drugs yielded reduced apoptosis and islet preservation, with translational potential.

Fatty Pancreas: Should We Be Concerned?

The metabolic consequences of visceral fat deposition are well known, and the presence of intrapancreatic fat (IPF) has been recognized for decades. However, our knowledge about the distribution of fat in the pancreas and its clinical implications is in a nascent stage. Various terms have been proposed to describe IPF; for the purpose of this narrative review, we chose the general term fatty pancreas. Herein, we describe the radiologic, endoscopic, and histopathologic aspects of diagnosing fatty pancreas and provide an overview of the diseases associated with this condition. Our purpose is to highlight diagnostic challenges and identify specific clinical questions that would benefit from further study. As evident in this review, IPF is associated with various metabolic diseases, pancreatitis, pancreatic cancer, and precancer-yet establishing causality needs careful, further study.

Lack of Independent Association Between Fatty Pancreas and Incidence of Type 2 Diabetes: 5-Year Japanese Cohort Study

OBJECTIVE

Previous cross-sectional studies have shown that attenuation in the pancreas seen on unenhanced computed tomography (CT) scans was inversely correlated with histologic pancreatic fat, and that fatty pancreas was associated with type 2 diabetes mellitus (T2DM). However, no longitudinal study has evaluated whether fatty pancreas increases the incidence of T2DM. We conducted a cohort study to investigate the association between fatty pancreas and the incidence of T2DM.

RESEARCH DESIGN AND METHODS

A total of 813 participants without diabetes underwent health checks by unenhanced CT scanning in 2008 and 2009, and were observed for a median follow-up period of 5.06 (interquartile range 3.01-5.92) years. Attenuation in three regions of the pancreas seen on an unenhanced CT scan was measured, and the mean pancreatic attenuation was calculated to evaluate fatty pancreas at baseline; the more severe the fatty pancreas, the lower the mean pancreatic attenuation. The incident T2DM hazard ratios (HRs) for the association between fatty pancreas and T2DM incidence were estimated by Cox proportional hazards models adjusted for age, sex, BMI, liver attenuation seen on unenhanced CT scan, and alcohol intake of ≥20 g/day.

RESULTS

T2DM occurred in 62 participants (7.6%) during the follow-up period. The higher pancreas attenuation (i.e., less pancreatic fat) at baseline was associated with decreased T2DM incidence in a univariate analysis (crude HR 0.97 [95% CI 0.96-0.99]); and fatty pancreas (lower pancreas attenuation) was positively associated with increased T2DM incidence. However, the association was substantially explained by the confounders (multivariate HR 1.00 [95% CI 0.98-1.02]).

CONCLUSIONS

Fatty pancreas was not independently associated with future T2DM.

Exploring the metabolic syndrome: Nonalcoholic fatty pancreas disease

After the first description of fatty pancreas in 1933, the effects of pancreatic steatosis have been poorly investigated, compared with that of the liver. However, the interest of research is increasing. Fat accumulation, associated with obesity and the metabolic syndrome (MetS), has been defined as “fatty infiltration” or “nonalcoholic fatty pancreas disease” (NAFPD). The term “fatty replacement” describes a distinct phenomenon characterized by death of acinar cells and replacement by adipose tissue. Risk factors for developing NAFPD include obesity, increasing age, male sex, hypertension, dyslipidemia, alcohol and hyperferritinemia. Increasing evidence support the role of pancreatic fat in the development of type 2 diabetes mellitus, MetS, atherosclerosis, severe acute pancreatitis and even pancreatic cancer. Evidence exists that fatty pancreas could be used as the initial indicator of “ectopic fat deposition”, which is a key element of nonalcoholic fatty liver disease and/or MetS. Moreover, in patients with fatty pancreas, pancreaticoduodenectomy is associated with an increased risk of intraoperative blood loss and post-operative pancreatic fistula.

Pancreas Volume and Fat Deposition in Diabetes and Normal Physiology: Consideration of the Interplay Between Endocrine and Exocrine Pancreas

The pancreas is comprised of exocrine and endocrine components. Despite the fact that they are derived from a common origin in utero, these two compartments are often studied individually because of the different roles and functions of the exocrine and endocrine pancreas. Recent studies have shown that not only type 1 diabetes (T1D), but also type 2 diabetes (T2D), is characterized by a deficit in beta-cell mass, suggesting that pathological changes in the pancreas are critical events in the natural history of diabetes. In both patients with T1D and those with T2D, pancreas mass and exocrine function have been reported to be reduced. On the other hand, pancreas volume and pancreatic fat increase with obesity. Increased beta-cell mass with increasing obesity has also been observed in humans, and ectopic fat deposits in the pancreas have been reported to cause beta-cell dysfunction. Moreover, neogenesis and transdifferentiation from the exocrine to the endocrine compartment in the postnatal period are regarded as a source of newly formed beta-cells. These findings suggest that there is important interplay between the endocrine and exocrine pancreas throughout life. This review summarizes the current knowledge on physiological and pathological changes in the exocrine and endocrine pancreas (i.e., beta-cell mass), and discusses the potential mechanisms of the interplay between the two compartments in humans to understand the pathophysiology of diabetes better.

Metforminium Decavanadate as a Potential Metallopharmaceutical Drug for the Treatment of Diabetes Mellitus

New potential drugs based on vanadium are being developed as possible treatments for diabetes mellitus (DM) and its complications. In this regard, our working group developed metforminium decavanadate (MetfDeca), a compound with hypoglycemic and hypolipidemic properties. MetfDeca was evaluated in models of type 1 and type 2 diabetes mellitus, on male Wistar rats. Alloxan-induction was employed to produce DM1 model, while a hypercaloric-diet was employed to generate DM2 model. Two-month treatments with 3.7 μg (2.5 μM)/300 g/twice a week for DM2 and 7.18 μg (4.8 μM)/300 g/twice a week for DM1 of MetfDeca, respectively, were administered. The resulting pharmacological data showed nontoxicological effects on liver and kidney. At the same time, MetfDeca showed an improvement of carbohydrates and lipids in tissues and serum. MetfDeca treatment was better than the monotherapies with metformin for DM2 and insulin for DM1. Additionally, MetfDeca showed a protective effect on pancreatic beta cells of DM1 rats, suggesting a possible regeneration of these cells, since they recovered their insulin levels. Therefore, MetfDeca could be considered not only as an insulin-mimetic agent, but also as an insulin-enhancing agent. Efforts to elucidate the mechanism of action of this compound are now in progress.