Pancreatic Elastase Levels in Feces As A Marker of Exocrine Pancreatic Function in Patients With Diabetes Mellitus

Pancreatic biomarkers: role in diabetes mellitus

Diabetes mellitus refers to a group of diseases that cause high blood sugar levels. The most common type is type 2 diabetes, which is caused by insulin resistance and inadequate insulin production. However, diabetes can also result from conditions affecting the exocrine pancreas. Both type 1 and type 2 diabetes patients may experience changes in their pancreatic exocrine function, leading to reduced levels of fecal elastase-1 in many cases. This review article focuses on the role of specific pancreatic biomarkers in diabetes mellitus, including cholecystokinin, trypsin, chymotrypsin, carboxypeptidase, amylase, lipase, secretin, elastase-1, and retinol-binding protein 4 about recent advances and discoveries, significant gaps in the literature, current debates, and potential directions for future research related to these biomarkers about diabetes mellitus. This review article discusses various biomarkers related to pancreatic exocrine and endocrine function and their implications in diabetes. It suggests that gut cholecystokinin may play a role in lowering glucose synthesis through a neural network and resistance to it could contribute to hyperglycemia in diabetic patients. It also discusses the use of various markers such as serum trypsin concentration, amylase and lipase levels, pancreatic elastase levels, and fasting secretin levels to assess pancreatic exocrine function. Additionally, the article explores the role of carboxypeptidase E in the endocrine and neurological systems and its association with disorders. Moreover, it also highlights the involvement of retinol-binding protein 4 in the development of type 2 diabetes and insulin resistance.

Enzymatic Cleavage of Stx2a in the Gut and Identification of Pancreatic Elastase and Trypsin as Possible Main Cleavers

Shiga toxins (Stxs), especially the Stx2a subtype, are the major virulence factors involved in enterohemorrhagic Escherichia coli (EHEC)-associated hemolytic uremic syndrome (eHUS), a life-threatening disease causing acute kidney injury, especially in children. After oral transmission and colonization in the gut, EHEC release Stx. Intracellular cleavage of the Stx A subunit, when followed by reduction, boosts the enzymatic activity that causes damage to targeted cells. This cleavage was assumed to be mostly mediated by furin during Stx intracellular trafficking. To investigate whether this cleavage could occur in the intestine, even prior to entering target cells, Stx2a A subunit structure (intact or cleaved) was characterized after its exposure to specific host factors present in human stool. The molecular weight of Stx2a A subunit/fragments was determined by immunoblotting after electrophoretic separation under reducing conditions. In this study, it was demonstrated that Stx2a is cleaved by certain human stool components. Trypsin and chymotrypsin-like elastase 3B (CELA3B), two serine proteases, were identified as potential candidates that can trigger the extracellular cleavage of Stx2a A subunit directly after its secretion by EHEC in the gut. Whether the observed cleavage indeed translates to natural infections and plays a role in eHUS pathogenesis has yet to be determined. If so, it seems likely that a host's protease profile could affect disease development by changing the toxin's biological features.

Establishing the blood reference interval of pancreatic elastase-1: A prospective study

BACKGROUND AND AIM

Pancreatic elastase-1 (PE-1) has been investigated in pancreatic disorders. However, the reference interval (RI) of PE-1 in blood remains unconfirmed. We aimed to establish the blood RI of PE-1 in an adult population.

METHODS

In this prospective cross-sectional study, we enrolled 400 adults who had received the whole-body physical check-up program between May 1, 2019 and November 20, 2019. The serum and plasma PE-1 levels were measured by latex turbidimetric immunoassay in different storage conditions (fresh, refrigerated, and frozen). The 95% and 99% RI of PE-1 were calculated according to the Clinical & Laboratory Standards Institute guidelines. The correlations between PE-1 and other parameters were analyzed using multivariable regression models. Ultimately, 38 patients with acute pancreatitis were prospectively recruited as the validation cohort.

RESULTS

The PE-1 levels in fresh serum were highly correlated with those in refrigerated (R²  = 0.998) or frozen (R²  = 0.942) samples; however, plasma should not be suggested in frozen conditions (plasma vs serum: R²  = 0.185). In the RI study population (202 male & 198 female participants), the median age was 52.6 (25-75% interquartile range: 43.1-61.0). The 95% and 99% RIs of PE-1 were 30.0-221.0 and 22.0-359.0 ng/dL, respectively. Triglycerides (β = 0.106, P = 0.033), lipase (β = 0.154, P = 0.007), and CA19-9 (β = 0.130, P = 0.008) were independent factors associated with PE-1. In the pancreatitis validation cohort, with a cut-off value of 359.0 ng/dL, the sensitivity and specificity were 100% and 99.8%, respectively.

CONCLUSION

The RI of PE-1 established in this study can be used for further applications. Serum is the suggested form for frozen sample storage.

Two sides of the pancreas: Exocrine insufficiency is correlated with endocrine dysfunction in type 2 diabetes

BACKGROUND

Recently, numerous studies validated frequent pancreatic exocrine dysfunction in patients with diabetes. However, the prevalence of pancreatic exocrine insufficiency (PEI) in diabetes mellitus (DM) varies widely among studies. This study aims to determine the prevalence of PEI in Chinese people with type 2 DM (T2DM) by measuring the fecal elastase-1 (FE-1) levels and further identify potential factors that influence pancreatic exocrine function in patients with T2DM.

METHODS

A total of 85 patients with T2DM without known exocrine pancreatic disorders or digestive system diseases were recruited. Fecal samples were submitted to measure FE-1 levels, and blood samples were collected to investigate pancreatic endocrine function and metabolic biomarkers in all participants. The multiple logistic regression analysis was established to evaluate the influencing factors of PEI in patients with T2DM. The potential predictors of PEI were examined using receiver operating characteristic (ROC) curves.

RESULTS

The prevalence of PEI measured by low FE-1 in T2DM was 18.8%. The Spearman correlation demonstrated that the FE-1 level was inversely correlated with DM duration (r =  - 0.360, P = 0.001) and glycated hemoglobin (HbA1c) level (r =  - 0.228, P = 0.036). A highly significant positive association was observed between FE-1 and fasting C-peptide (FCP) levels (r = 0.451, P < 0.001). Furthermore, the multiple logistic regression analysis showed that FCP was an independent influencing factor of PEI (OR = 0.204, P = 0.024, 95% CI: 0.051-0.813). The ROC analysis indicated that the FCP level had a predictive value for low FE-1 (AUC = 0.793, P < 0.001) with an optimal cutoff value of 1.20 ng/ml.

CONCLUSION

Chinese patients with T2DM show high PEI prevalence. FCP may be a potential predictor of pathological exocrine function in T2DM. The exocrine and endocrine functions of patients with T2DM in clinical practice should be evaluated. Further studies are needed to clarify the internal association between exocrine and endocrine pancreases.

The assessment of pancreatic exocrine function in patients with inoperable pancreatic cancer: In need of a new gold-standard

BACKGROUND

Pancreatic exocrine insufficiency is commonplace in patients with pancreatic cancer, adversely impacting on quality of life and survival. Whilst the management of exocrine insufficiency is well established, diagnosis remains challenging in clinical practice. A plethora of diagnostic tests exist. Nevertheless, a lack of consensus remains about the optimal diagnostic method, specifically in patients with pancreatic cancer. Research, to date, has primarily been undertaken in patients with chronic pancreatitis and cystic fibrosis. This manuscript will review the current literature and will examine the evidence around the diagnostic tests available for pancreatic exocrine insufficiency and whether any exists specifically for pancreatic cancer cohorts.

FINDINGS

Evidence to recommend an individual test for the diagnosis of pancreatic exocrine insufficiency in clinical practice is lacking. Direct testing (by direct sampling of pancreatic secretions) has the highest specificity and sensitivity but is no longer routinely deployed or feasible in practice. Indirect testing, such as faecal elastase, is less accurate with high false-positive rates, but is routinely available in clinical practice. The 13C-mixed triglyceride breath test and the gold-standard 72-h faecal fat test have high specificity for indirect tests, but are not routinely available and cumbersome to undertake. A combination approach including nutritional markers and faecal elastase has more recently been proposed.

CONCLUSION

Further research is required to identify the most optimal and accurate diagnostic tool to diagnose pancreatic exocrine insufficiency in patients with pancreatic cancer in clinical practice.

Exocrine pancreatic insufficiency in type 1 and type 2 diabetes mellitus: do we need to treat it? A systematic review

The exocrine and endocrine pancreata are very closely linked both anatomically and physiologically. Abdominal symptoms such as nausea, bloating, diarrhea, steatorrhea, and weight loss can often occur in diabetic patients. Impairments of the exocrine pancreatic function seem to be a frequent complication of diabetes mellitus; however, they are largely overlooked. The aim of this paper is to provide an overview of the current concepts of exocrine pancreatic insufficiency (PEI) in diabetes mellitus. The prevalence and symptoms of PEI in diabetes mellitus, the pathomechanism, and difficulties of diagnosis and therapy of PEI are summarized in this systematic review.

Exocrine pancreatic dysfunction is common in hepatocyte nuclear factor 1β-associated renal disease and can be symptomatic

Background

Heterozygous mutations in the HNF1B gene are the most common monogenic cause of developmental kidney disease. Extrarenal phenotypes frequently occur, including diabetes mellitus and pancreatic hypoplasia; the latter is associated with subclinical exocrine dysfunction. We measured faecal elastase-1 in patients with HNF1B-associated disease regardless of diabetes status and assessed the degree of symptoms associated with pancreatic exocrine deficiency.

Methods

Faecal elastase-1 was measured in 29 patients with a known HNF1B mutation. We defined a low faecal elastase-1 concentration based on the 2.5 percentile of 99 healthy control individuals (410 μg/g stool). Symptoms related to pancreatic exocrine dysfunction were assessed and a subset of the HNF1B cohort (n  =  6) underwent pancreatic imaging.

Results

Faecal elastase-1 was below the 2.5 percentile of the control cohort in 18/29 (62%) patients with HNF1B-associated renal disease. A total of 8/29 (28%) had a measurement suggestive of exocrine pancreatic insufficiency at  <200 μg/g stool; of these, 3 suffered with abdominal pain, loose stools and/or unintentional weight loss. All three experienced symptomatic improvement and weight gain after commencing pancreatic enzyme replacement therapy. Faecal elastase-1 was low in 7/15 (47%) HNF1B patients without diabetes compared with 11/14 (79%) of those with diabetes (P  =  0.1).

Conclusions

Faecal elastase-1 deficiency is a common feature of HNF1B-associated renal disease even when diabetes is not present and pancreatic exocrine deficiency may be more symptomatic than previously suggested. Faecal elastase-1 should be measured in all patients with known HNF1B-associated disease complaining of chronic abdominal pain, loose stools or unintentional weight loss. The discovery of a low faecal elastase-1 concentration in individuals with developmental kidney disease of uncertain cause should prompt referral for HNF1B genetic testing.

Exocrine pancreatic insufficiency is common in people living with HIV on effective antiretroviral therapy

OBJECTIVES

The primary aim of this prospective study was to determine the prevalence of exocrine pancreatic insufficiency (EPI) in people living with HIV (PLHIV) on suppressive antiretroviral therapy (ART).

METHODS

PLHIV ≥18 years of age and on ART for >6 months and with HIV RNA <50 copies/mL plasma were included. Faecal elastase-1 measurement was performed on a single stool sample, serum markers of malnutrition were collected, and participants answered a short questionnaire about gastrointestinal symptoms. Participants with EPI and symptoms were offered pancreatic enzyme replacement therapy (PERT), and the result of this therapy was also evaluated.

RESULTS

Of 100 participants, 32% had EPI (faecal elastase-1 < 200 μg/g) and 20% severe EPI (faecal elastase-1 < 100 μg/g). We did not find any correlation between self-reported symptoms and degree of EPI. Twelve out of the 32 participants with EPI accepted to start PERT. Nine out of 12 (75%) reported improvement or became asymptomatic within 14 days.

CONCLUSION

EPI is common in PLHIV on effective ART. We could, however, not find a correlation between gastrointestinal symptoms and the presence of EPI. Assessment of pancreatic exocrine function could be considered in PLHIV particularly in those with gastrointestinal discomfort, since there is a possible gain in treating them with relief of symptoms and improved quality of life. The effects of PERT in PLHIV on effective ART need further study.