Dysglycemia in non-functioning pancreatic neuroendocrine tumors (NF-PNET): Further insights into an under recognized entity

Objective

Pancreatic neuroendocrine tumors (PNETs) are rare, but their incidence has risen significantly in recent years. Whereas diabetes mellitus (DM) is recognized in association with chronic pancreatitis and pancreatic cancer, it has not been well-characterized concerning non-functioning (NF)-PNETs.Study aim: to determine whether NF-PNETs are associated with DM/ Pre-DM and characterize the features of this putative association.

Methods

Retrospective study to evaluate rate of Pre-DM /DM in subjects with NF-PNETs.

Results

Study cohort of 129 patients with histologically confirmed NF-PNETs, ∼60% were men (M/F: 77/52). Abnormal glucose metabolism that preceded any treatment was seen in 70% of this cohort: overt DM in 34% and Pre-DM in 36% of the subjects. However, during follow-up, the overall prevalence rose to 80.6%, owing exclusively to newly diagnosed DM in subjects who received treatment.Patients with DM/Pre-DM were older (65 ± 11; 54 ± 14; p < 0.0001), the tumor was more commonly localized in the pancreatic body and tail (76.5% vs. 23.5% p = 0.03), while BMI (27 ± 6 vs. 28 ± 5 kg/m2), and tumor size (2.4 ± 2 vs. 2.9 ± 3.2 cm) were similar. The relative prevalence of DM in our cohort of NF-PNETs was 1.6 higher than that in the age and gender-adjusted general Israeli population (95 %CI: 1.197-2.212p = 0.03).

Conclusions

We found a high rate of impaired glucose metabolism, either DM or Pre-DM, in a large cohort of NF-PNETs. The high prevalence of diabetes/pre-diabetes was unrelated to obesity or tumor size. This observation should increase awareness of the presence of DM on presentation or during treatment of "NF"-PNETs.

Pancreatic Cancer-Associated Diabetes is Clinically Distinguishable From Conventional Diabetes

BACKGROUND

Type 3c diabetes mellitus (T3cDM) is diabetes secondary to other pancreatic diseases such as chronic pancreatitis, pancreatic resection, cystic fibrosis, and pancreatic ductal adenocarcinoma (PDA). Clinically, it may easily be confused with conventional type 2 diabetes mellitus (T2DM). A delay in pancreatic cancer diagnosis and treatment leads to a worse outcome. Therefore, early recognition of PDA-associated T3cDM and distinction from conventional T2DM represents an opportunity improve survival in patients with PDA.

METHODS

Six hundred and sixty four patients with PDA underwent pancreatic resection. Patients were classified as per whether or not they had diabetes. The specific type of diabetes was determined. T3cDM surgical patients (n = 127) were compared with a control group of medical patients with T2DM who did not have PDA (n = 127).

RESULTS

Patients with T3cDM were older (66 versus 61 y, P < 0.001), had lower body mass indices (25.9 versus 32.1, P < 0.001), more favorable hemoglobin A1c levels (7.0 versus 8.8, P < 0.001), higher alanine aminotransferase levels (39 versus 20, P < 0.001), and lower creatinine levels (0.8 versus 0.9 mg/dL, P < 0.001). In addition, they were more likely to be insulin dependent. In a subgroup analysis of surgical patients, T3cDM (versus surgical patients with T2DM and no diabetes) was not associated with surrogate markers of main pancreatic duct obstruction and glandular atrophy.

CONCLUSIONS

PDA-associated T3cDM has a distinctive presenting phenotype compared with medical patients with conventional T2DM. Greater attention to associated signs, symptoms, and biochemical data could identify patients at risk for harboring an underlying pancreatic malignancy and trigger diagnostic pathways leading to earlier PDA diagnosis and treatment.

Type-3c Diabetes Mellitus, Diabetes of Exocrine Pancreas - An Update

BACKGROUND

The incidence of diabetes is increasing steeply; the number of diabetics has doubled over the past three decades. Surprisingly, the knowledge of type 3c diabetes mellitus (T3cDM) is still unclear to the researchers, scientist and medical practitioners, leading towards erroneous diagnosis, which is sometimes misdiagnosed as type 1 diabetes mellitus (T1DM), or more frequently type 2 diabetes mellitus (T2DM). This review is aimed to outline recent information on the etiology, pathophysiology, diagnostic procedures, and therapeutic management of T3cDM patients.

METHODS

The literature related to T3cDM was thoroughly searched from the public domains and reviewed extensively to construct this article. Further, existing literature related to the other forms of diabetes is reviewed for projecting the differences among the different forms of diabetes. Detailed and updated information related to epidemiological evidence, risk factors, symptoms, diagnosis, pathogenesis and management is structured in this review.

RESULTS

T3cDM is often misdiagnosed as T2DM due to the insufficient knowledge differentiating between T2DM and T3cDM. The pathogenesis of T3cDM is explained which is often linked to the history of chronic pancreatitis, pancreatic cancer. Inflammation, and fibrosis in pancreatic tissue lead to damage both endocrine and exocrine functions, thus leading to insulin/glucagon insufficiency and pancreatic enzyme deficiency.

CONCLUSION

Future advancements should be accompanied by the establishment of a quick diagnostic tool through the understanding of potential biomarkers of the disease and newer treatments for better control of the diseased condition.

Complications of Chronic Pancreatitis

Chronic pancreatitis is a disease that leads to irreversible changes in the pancreatic morphology and function. The loss of function can lead to diabetes mellitus and exocrine pancreatic insufficiency. The inflammation and fibrosis can also lead to other complications including a chronic abdominal pain syndrome, metabolic bone disease, and pancretic cancer. This article reviews our current understanding of the mechanisms and management of these complications of chronic pancreatitis.

Pancreatic polypeptide response to a mixed meal is blunted in pancreatic head cancer associated with diabetes mellitus

INTRODUCTION

Pancreatic polypeptide (PP) is a hormone secreted by islet cells of the ventral pancreas. It has been proposed that a blunted PP response to a mixed meal can distinguish diabetes mellitus (DM) secondary to pancreatic disease from other types of DM. We performed a proof of concept study to determine if PP response to a mixed meal discriminates DM secondary to pancreatic cancer (PaCDM) from type 2 DM (T2DM).

METHODS

We studied 18 subjects with new onset DM (PaCDM (n = 9) and T2DM (n = 9); matched for age and gender). Serum PP levels were measured at 0, 30, and 60 min following a mixed meal. Increases in PP levels from baseline were compared using the Wilcoxon test.

RESULTS

In PaCDM the PP increase following a mixed meal was less than T2DM at 30 min (median 60.0%, IQR, 33.0-119.8 vs. 134.5%, IQR, 117.5-265.9; p = 0.03), but statistically similar at 60 min (median 55.8%, interquartile range (IQR) 23.7-121.5 vs. 100.0%, IQR, 47.7-202.5; p = 0.17). In PaCDM subjects, the PP increase over baseline was smaller in those with a tumor located in the pancreatic head (n = 6) compared to the body/tail (n = 3) at 30 min (41.3% vs. 158.7%, p = 0.02) and at 60 min (37.4% vs. 167.4%,p = 0.04).

CONCLUSIONS

Subjects with PaCDM have a blunted PP response to a mixed meal compared to T2DM. However, the blunted PP response is only observed in those PaC subjects with a tumor located in the head of the pancreas. Confirmation in larger studies may suggest this could be used to aid screening for sporadic PaC.

Pharmacological attenuation of chronic alcoholic pancreatitis induced hypersensitivity in rats

AIM

To characterize an alcohol and high fat diet induced chronic pancreatitis rat model that mimics poor human dietary choices.

METHODS

Experimental rats were fed a modified Lieber-DeCarli alcohol (6%) and high-fat (65%) diet (AHF) for 10 wk while control animals received a regular rodent chow diet. Weekly behavioral tests determined mechanical and heat sensitivity. In week 10 a fasting glucose tolerance test was performed, measuring blood glucose levels before and after a 2 g/kg bodyweight intraperitoneal (i.p.) injection of glucose. Post mortem histological analysis was performed by staining pancreas and liver tissue sections with hematoxylin and eosin. Pancreas sections were also stained with Sirius red and fast green to quantify collagen content. Insulin-expressing cells were identified immunohistochemically in separate sections. Tissue staining density was quantified using Image J software. After mechanical and heat sensitivity became stable (weeks 6-10) in the AHF-fed animals, three different drugs were tested for their efficacy in attenuating pancreatitis associated hypersensitivity: a Group II metabotropic glutamate receptor specific agonist (2R,4R)-4-Aminopyrrolidine-2,4-dicarboxylate (APDC, 3 mg/kg, ip; Tocris, Bristol, United Kingdom), nociceptin (20, 60, 200 nmol/kg, ip; Tocris), and morphine sulfate (3 mg/kg, μ-opioid receptor agonist; Baxter Healthcare, Deerfield, IL, United States).

RESULTS

Histological analysis of pancreas and liver determined that unlike control rats, AHF fed animals had pancreatic fibrosis, acinar and beta cell atrophy, with steatosis in both organs. Fat vacuolization was significantly increased in AHF fed rats (6.4% ± 1.1% in controls vs 23.8% ± 4.2%, P < 0.05). Rats fed the AHF diet had reduced fasting glucose tolerance in week 10 when peak blood glucose levels reached significantly higher concentrations than controls (127.4 ± 9.2 mg/dL in controls vs 161.0 ± 8.6 mg/dL, P < 0.05). This concurred with a 3.5 fold higher incidence of single and small 2-10 cell insulin-positive cell clusters (P < 0.05). Insulin expressing islet of Langerhans cells appeared hypertrophied while islet number and area measurements were not different from controls. Weekly behavioral tests determined that mechanical and heat sensitivities were significantly increased by 4 wk on AHF diet compared to controls. Hypersensitivity was attenuated with efficacy similar to morphine with single dose treatment of either metabotropic glutamate receptor 2/3 agonist APDC, or nociceptin, the endogenous ligand for opioid-receptor-like 1 receptor.

CONCLUSION

The AHF diet induces a chronic alcoholic pancreatitis in rats with measurable features resembling clinical patients with chronic pancreatitis and type 3c diabetes mellitus.

A novel peptide nanomedicine for treatment of pancreatogenic diabetes

Pancreatogenic diabetes (PD) is a potentially fatal disease that occurs secondary to pancreatic disorders. The current anti-diabetic therapy for PD is fraught with adverse effects that can increase morbidity. Here we investigated the efficacy of novel peptide nanomedicine: pancreatic polypeptide (PP) in sterically stabilized micelles (SSM) for management of PD. PP exhibits significant anti-diabetic efficacy but its short plasma half-life curtails its therapeutic application. To prolong and improve activity of PP in vivo, we evaluated the delivery of PP in SSM. PP-SSM administered to rats with PD, significantly improved glucose tolerance, insulin sensitivity and hepatic glycogen content compared to peptide in buffer. The studies established the importance of micellar nanocarriers in protecting enzyme-labile peptides in vivo and delivering them to target site, thereby enhancing their therapeutic efficacy. In summary, this study demonstrated that PP-SSM is a promising novel anti-diabetic nanomedicine and therefore should be further developed for management of PD.

FROM THE CLINICAL EDITOR

Pancreatic peptide was earlier demonstrated to address pancreatogenic diabetes, but its short half-life represented major difficulties in further development for therapeutic use. PP-SSM (pancreatic polypeptide in sterically stabilized micelles) is a promising novel anti-diabetic nanomedicine that enables prolonged half-life and increased bioactivity of PP, as shown in this novel study, paving the way toward clinical studies in the near future.