Sulfonylurea compounds uncouple the glucose dependence of the insulinotropic effect of glucagon-like peptide 1

Glucagon-like peptide (GLP)-1 mimetics have been reported to cause hypoglycemia when combined with sulfonylureas. This study investigated the impact of tolbutamide on the glucose dependence of the GLP-1-mediated effects on insulin, glucagon, and somatostatin secretion in the in situ perfused rat pancreas. At 3 mmol/l glucose, GLP-1 alone did not augment insulin secretion, whereas tolbutamide alone caused a rapid increase in insulin secretion. However, when GLP-1 and tolbutamide were administered simultaneously, insulin secretion increased significantly to 43.7 +/- 6.2 pmol/min (means +/- SE), exceeding the sum of the responses to GLP-1 (2.0 +/- 0.6 pmol/min; P = 0.019) and tolbutamide (11.3 +/- 3.8; P = 0.005) alone by a factor of 3.3. At 11 mmol/l glucose, co-infusion of GLP-1 and tolbutamide augmented insulin secretion to 141.7 +/- 10.3 vs. 115.36 +/- 14.1 (GLP-1) and 42.5 +/- 7.3 pmol/min (tolbutamide). Interestingly, increases in somatostatin secretion, both by glucose and GLP-1, were consistently paralleled by suppression of glucagon release. In conclusion, we demonstrate uncoupling of GLP-1 from its glucose dependence by tolbutamide. This uncoupling probably explains the tendency of GLP-1 to provoke hypoglycemia in combination with sulfonylureas. The results suggest that closure of ATP-sensitive K(+) channels by glucose might be involved in the glucose dependence of GLP-1's insulinotropic effect and that somatostatin acts as a paracrine regulator of glucagon release.

Defining the role of GLP-1 in the enteroinsulinar axis in type 2 diabetes using DPP-4 inhibition and GLP-1 receptor blockade

Understanding the incretin pathway has led to significant advancements in the treatment of type 2 diabetes (T2D). Still, the exact mechanisms are not fully understood. In a randomized, placebo-controlled, four-period, crossover study in 24 patients with T2D, dipeptidyl peptidase-4 (DPP-4) inhibition and its glucose-lowering actions were tested after an oral glucose tolerance test (OGTT). The contribution of GLP-1 was examined by infusion of the GLP-1 receptor (GLP-1r) antagonist exendin-9. DPP-4 inhibition reduced glycemia and enhanced insulin levels and the incretin effect (IE). Glucagon was suppressed, and gastric emptying (GE) was decelerated. Exendin-9 increased glucose levels and glucagon secretion, attenuated insulinemia and the IE, and accelerated GE. With the GLP-1r antagonist, the glucose-lowering effects of DPP-4 inhibition were reduced by ∼ 50%. However, a significant effect on insulin secretion remained during GLP-1r blockade, whereas the inhibitory effects of DPP-4 inhibition on glucagon and GE were abolished. Thus, in this cohort of T2D patients with a substantial IE, GLP-1 contributed ∼ 50% to the insulin excursion after an OGTT with and without DPP-4 inhibition. Thus, a significant DPP-4-sensitive glucose-lowering mechanism contributes to glycemic control in T2D patients that may be not mediated by circulating GLP-1.

GIP-(3-42) does not antagonize insulinotropic effects of GIP at physiological concentrations

Glucose-dependent insulinotropic polypeptide [GIP-(1-42)] is degraded by dipeptidyl peptidase IV (DPP IV), forming GIP-(3-42). In mice, high concentrations of synthetic GIP-(3-42) may function as a GIP receptor antagonist, but it is unclear whether this occurs at physiological concentrations. In COS-7 cells transiently transfected with the human GIP receptor, GIP-(1-42) and -(3-42) bind with affinities (IC(50)) of 5.2 and 22 nM, respectively. GIP-(1-42) was a potent agonist, stimulating cAMP accumulation (EC(50), 13.5 pM); GIP-(3-42) alone had no effect. When incubated together with native GIP, GIP-(3-42) behaved as a weak antagonist (IC(50), 92 and 731 nM for inhibition of cAMP accumulation elicited by 10 pM and 1 nM native GIP, respectively). In the isolated perfused rat pancreas, GIP-(3-42) alone had no effect on insulin output and only reduced the response to GIP (1 nM) when coinfused in >50-fold molar excess (IC(50), 138 nM). The ability of GIP-(3-42) to affect the antihyperglycemic or insulinotropic actions of GIP-(1-42) was examined in chloralose-anesthetized pigs given intravenous glucose. Endogenous DPP IV activity was inhibited to reduce degradation of the infused GIP-(1-42), which was infused alone and together with GIP-(3-42), at rates sufficient to mimic postprandial concentrations of each peptide. Glucose, insulin, and glucagon responses were identical irrespective of whether GIP-(1-42) was infused alone or together with GIP-(3-42). We conclude that, although GIP-(3-42) can weakly antagonize cAMP accumulation and insulin output in vitro, it does not behave as a physiological antagonist in vivo.

Histologic and Clinical Effects of Different Topical Corticosteroids for Eosinophilic Esophagitis: Lessons from an Updated Meta-Analysis of Placebo-Controlled Randomized Trials

BACKGROUND

Topical corticosteroids (TS) have become standard therapy for eosinophilic esophagitis (EoE). However, a variety of drug formulations have been used for which results of histological and clinical responses may be different. We aimed at determining the short-term histologic efficacy of TS for EoE based on randomized placebo-controlled trials and to review clinical response.

METHODS

We searched MEDLINE, ISI Web of Science, and clinicaltrials.gov for randomized controlled trials (RCTs) on TS versus placebo for active EoE published until June 2019. Treatment effects were calculated as risk ratios (RRs) comparing histologic remission between groups.

RESULTS

Nine RCTs (6 budesonide and 3 fluticasone) involving a total of 483 participants were included. A substantial overall effect of TS on acute histologic remission (RR 12.5, 95% confidence interval 6.0-25.9) was found despite varying definitions of histologic response. Indirect comparisons between drug and formulation types showed a trend for a better histologic efficacy of budesonide (RR 13.5 vs. 10.4 fluticasone) and for the orodispersible tablet (RR 46.2 vs. 11.5 suspension, and 10.4 nebulized formula/spray), but only based on small patient numbers. Scores used for clinical response assessment were different between studies, and short-term clinical results were less impressive: significant differences favoring TS were found in 4/9 RCTs (4/6 budesonide, 0/3 fluticasone).

CONCLUSIONS

TS are effective for short-term induction of histological remission in EoE with less impressive clinical response rates. The mode of drug delivery to the esophagus may be a relevant factor for the degree of histologic remission. Further trials should use uniform assessment criteria and long-term patient-centered outcomes.

Pneumatic balloon dilatation versus laparoscopic Heller myotomy for achalasia: a failed attempt at meta-analysis

INTRODUCTION

The advent of peroral endoscopic myotomy (POEM) shed some light on the role of the current standards in the treatment of idiopathic achalasia, namely endoscopic pneumatic dilatation (PD) and laparoscopic Heller myotomy (LHM). We analyzed the quality of the current evidence comparing LHM and PD.

METHODS

A systematic literature search was performed in Pubmed/Medline, Web of Science, Google Scholar and Cochrane for meta-analyses/systematic reviews comparing PD and LHM or open surgery, limited to English language full-text articles. After a detailed review of these meta-analyses, all studies included were analyzed further in depth with respect to treatment protocol, assessment of success, complications and sequelae such as gastroesophageal reflux (GER), as well as follow-up details.

RESULTS

Six randomized controlled trials (RCT), 5 with LHM and 1 with open surgery, were found, published in 10 papers. In contrast to a rather homogeneous LHM technique, PD regimens as well as the clinical dysphagia scores were different in every RCT; most RCTs also showed methodological limitations. There were nine meta-analyses which included a variable number of these RCTs or other cohort studies. Meta-analyses between 2009 and 2013 favored surgery, while the 4 most recent ones reached divergent conclusions. The main difference might have been whether repeated dilatation was regarded as part of the PD protocol or as failure.

CONCLUSIONS

The variability in PD techniques and in definition of clinical success utilized in the achalasia RCTs on PD versus LHM render the conclusions of meta-analyses unreliable. Further randomized studies should be based on uniform criteria; in the meantime, publication of even more meta-analyses should be avoided.

Decreased Frequency of Intestinal CD39+ γδ+ T Cells With Tissue-Resident Memory Phenotype in Inflammatory Bowel Disease

The ectoenzymes CD39 and CD73 play a major role in controlling tissue inflammation by regulating the balance between adenosine triphosphate (ATP) and adenosine. Still, little is known about the role of these two enzymes and ATP and its metabolites in the pathophysiology of inflammatory bowel disease (IBD). We isolated mononuclear cells from peripheral blood and lamina propria of the large intestine of patients diagnosed with IBD and of healthy volunteers. We then comprehensively analyzed the CD39 and CD73 expression patterns together with markers of activation (HLA-DR, CD38), differentiation (CCR7, CD45RA) and tissue-residency (CD69, CD103, CD49a) on CD4⁺, CD8⁺, γδ⁺ T cells and mucosa-associated invariant T cells using flow cytometry. CD39 expression levels of γδ⁺ and CD8⁺ T cells in lamina propria lymphocytes (LPL) were much higher compared to peripheral blood mononuclear cells. Moreover, the frequency of CD39⁺ CD4⁺ and CD8⁺, but not γδ⁺ LPL positively correlated with T-cell activation. The frequency of CD39⁺ cells among tissue-resident memory LPL (Trm) was higher compared to non-Trm for all subsets, confirming that CD39 is a marker for the tissue-resident memory phenotype. γδ⁺ Trm also showed a distinct cytokine profile upon stimulation – the frequency of IFN-γ⁺ and IL-17A⁺ cells was significantly lower in γδ⁺ Trm compared to non-Trm. Interestingly, we observed a decreased frequency of CD39⁺ γδ⁺ T cells in IBD patients compared to healthy controls (p = 0.0049). Prospective studies need to elucidate the exact role of this novel CD39⁺ γδ⁺ T-cell population with tissue-resident memory phenotype and its possible contribution to the pathogenesis of IBD and other inflammatory disorders.

Hyperammonemia by Ureaplasma urealyticum Pneumonia after Lung Transplantation

Ureaplasma urealyticum is a commensal of the female genital tract and can be detected as a pathogen in urethritis and vaginitis. Its importance as a respiratory pathogen beyond the field of neonatology remains controversial. We report a case of Ureaplasma-pneumonia in a recently lung-transplanted patient, with hyperammonemic syndrome.

The 51-year-old lung-transplanted female was admitted to the intensive care unit with new-onset reduction of her mental state due to hyperammonemia. A diagnostic bronchoscopy showed purulent bronchitis and multiple superficial ulcerations of the bronchial mucosa. The DNA-PCR from bronchoalveolar lavage confirmed the presence of Ureaplasma urealyticum in low concentration (about 5 * 10⁴ copies/ml), which was interpreted as evidence of infection and treated with Doxycycline intravenously. Ureaplasma was also identified by DNA-PCR in the biopsy specimens of the inflammatory enlarged mediastinal lymph nodes. Bilateral pleural effusions were found to be transudative and culturally sterile.

Ureaplasma-pneumonia can cause fatal hyperammonemia in lung-transplant patients and should be considered in the differential diagnosis of every unclear hyperammonemia with normal liver function. The early identification and treatment of the infection leads to clinical and biochemical resolution.

Designs of colonoscopic adenoma detection trials: more positive results with tandem than with parallel studies - an analysis of studies on imaging techniques and mechanical devices

BACKGROUND AND AIMS

Adenoma detection rate (ADR) has been shown to correlate with interval cancers after screening colonoscopy and is commonly used as surrogate parameter for its outcome quality. ADR improvements by various techniques have been studied in randomised trials using either parallel or tandem methodololgy.

METHODS

A systematic literature search was done on randomised trials (full papers, English language) on tandem or parallel studies using either adenoma miss rates (AMR) or ADR as main outcome to test different novel technologies on imaging (new endoscope generation, narrow band imaging, iScan, Fujinon intelligent chromoendoscopy/blue laser imaging and wide angle scopes) and mechanical devices (transparent caps, endocuff, endorings and balloons). Available meta analyses were also screened for randomised studies.

RESULTS

Overall, 24 randomised tandem trials with AMR (variable definitions and methodology) and 42 parallel studies using ADR (homogeneous methodology) as primary outcome were included. Significant differences in favour of the new method were found in 66.7% of tandem studies (8222 patients) but in only 23.8% of parallel studies (28 059 patients), with higher rates of positive studies for mechanical devices than for imaging methods. In a random-effects model, small absolute risk differences were found, but these were double in magnitude for tandem as compared with parallel studies (imaging: tandem 0.04 (0.01, 0.07), parallel 0.02 (0.00, 0.04); mechanical devices: tandem 0.08 (0.00, 0.15), parallel 0.04 (0.01, 0.07)). Nevertheless, 94.2% of missed adenomas in the tandem studies were small (<1 cm) and/or non-advanced.

CONCLUSIONS

A tandem study is more likely to yield positive results than a simple parallel trial; this may be due to the use of different parameters, variable definitions and methodology, and perhaps also a higher likelihood of bias. Therefore, we suggest to accept positive results of tandem studies only if accompanied by positive results from parallel trials.

Laparoscopic lymph node sampling: a new concept for patients with high-risk early esophagogastric junction cancer resected endoscopically

BACKGROUND AND AIMS

Endoscopic resection is considered a curative treatment for early upper GI cancers under certain histologic (low-risk) criteria. In tumors not completely fulfilling these criteria but resected R0 endoscopically, esophagectomy is still advised because of an increased risk of lymph node (LN) metastases (LNM). However, the benefit-risk ratio, especially in elderly patients at higher risk for radical surgery, can be debated. We now present the outcome of our case series of laparoscopic LN sampling (LLS) in patients with T1 esophagogastric junction tumors, which had been completely resected by endoscopy but did not fulfill the low-risk criteria (G1/2, m, L0, V0).

METHODS

Retrospective review was done of all patients with T1 cancer undergoing LLS with at least 1 high-risk parameter after endoscopic resection during an 8-year period. Repeated endoscopy with biopsy and abdominothoracic CT had been performed before. The patients were divided into 2 periods: before (n = 8) and after (n = 12) the introduction of an extended LLS protocol (additional resection of the left gastric artery). In cases of positive LN, patients underwent conventional oncologic surgery; if negative, follow-up was performed. The main outcome was the number of harvested LNs by means of LLS and the percentage of positive LNs found.

RESULTS

Twenty patients with cardia (n = 1) and distal esophageal/Barrett's cancer (n = 19) were included. The LN rate with use of the extended LLS technique increased by 12% (period 1: median 12 [range, 5-19; 95% CI, 3.4-15.4] vs period 2: median 17.5 [range, 12-40; 95% CI, 12.8-22.2]; P = .013). There were 2 adverse events: 1 inadvertent chest tube removal and 1 postoperative pneumonia. In 15% of cases, patients had positive LNs. and in 2 cases there was local recurrence at the endoscopic resection site, all necessitating surgery.

CONCLUSIONS

An extended technique of laparoscopic LN sampling appears to provide adequate LN numbers and is a safe approach with short hospital stay only. Only long-term follow-up of larger patient numbers will allow conclusions about miss rate as well as oncologic adequacy of this concept.

Prevalence and risk factors of undiagnosed diabetes mellitus among gastroenterological patients: a HbA1c-based single center experience

BACKGROUND

Diabetes mellitus is a major risk factor for microvascular disease, leading to chronic kidney injury or cardiovascular disease, but there is a tremendous proportion of patients worldwide who suffer from undiagnosed diabetes. Until now, little is known about the prevalence of undiagnosed diabetes in gastroenterology inpatients.

OBJECTIVE

To improve detection of undiagnosed diabetes, a routine screening procedure for gastroenterology inpatients, based on hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) measurement, was established.

METHODS

We conducted a retrospective analysis of the implemented diabetes screening. Diabetes mellitus was diagnosed according to the guideline of the German Diabetes Association in patients with an HbA1c of ≥6.5% anld/or fasting plasma glucose (FPG) ≥126 mg/dL. Univariate and multivariate analyses were performed to identify independent risk factors for undiagnosed diabetes.

RESULTS

Within a 3-month period, 606 patients were eligible for a diabetes screening. Pre-existing diabetes was documented in 120 patients (19.8 %), undiagnosed diabetes was found in 24 (3.9%), and 162 patients (26.7%) met the definition for prediabetes. Steroid medication use, age, and liver cirrhosis due to primary sclerosing cholangitis (PSC) were identified as risk factors for undiagnosed diabetes.

CONCLUSION

The prevalence of undiagnosed diabetes in gastroenterology inpatients is markedly elevated in comparison to the general population, and a substantial number of inpatients are in a prediabetic status, underlining the need for diabetes screening. In addition to previously described risk factors of patient age and steroid medication use, we identified PSC-related liver cirrhosis (but not liver cirrhosis due to another etiology) as an independent risk factor for undiagnosed diabetes.

Recognizing Post-Endoscopy Complications: A Database Filter Reduces Quality Assurance Workload for Inpatients

BACKGROUND AND AIMS

Documentation of complications of gastrointestinal endoscopy within the commonly used endoscopy documentation systems are mostly limited to acute complications during endoscopy included in the post-procedural endoscopy report. We tested a documentation system-based filter to reduce the workload by maintaining a high sensitivity to recognize post-endoscopy complications.

METHODS

Of all inpatient endoscopic resections during 1 year and all endoscopic retrograde cholangiopancreatography (ERCP) procedures during 4 months in 1 tertiary referral centre, post-procedural complications during hospital stay were individually analyzed retrospectively from the hospital databases (gold standard). In comparison, information technology-based filters were assessed searching for specific tests and data within 2 days after endoscopy and/or until discharge. These were second endoscopy, surgery, or an abdominal computed tomography (CT) or haemoglobin drop ≥2 g/dL for endoscopic resection. For ERCP cases, any case with lipase determination and post-ERCP CT scan was selected. Main outcomes were the sensitivity of these filters to recognize post-endoscopy complications and the percentage of workload reduction.

RESULTS

Three hundred twenty-two inpatients who underwent endoscopic resections and 302 ERCP cases (all inpatients) were included. Post-endoscopy complications occurred in 7.14% (endoscopic resection) and 3.7% (ERCP). The above-mentioned filters identified 100% of all resection and post-ERCP complications compared to detailed case file analysis, at the same time reducing the quality management workload to 14 and 31%, respectively.

CONCLUSIONS

Post-procedural monitoring of advanced endoscopic procedures performed on inpatient procedures has a high sensitivity (100%) and reduces case-by-case screening workload for complications by 70-85%. Outpatient interventions, however, require a different system for monitoring of post-endoscopy complications after discharge.

The value of CT imaging and CRP quotient for detection of postbariatric complications

Background

The diagnosis of major complications seems to be more challenging in obese patients. We aimed to show the relevance of routinely assessed clinical and paraclinical parameters as well as the relevance of CT scans in the diagnosis of major complications after bariatric procedures.

Methods

All patients who underwent operations (primary or revisional) in a 3-year period were retrospectively studied after bariatric surgery with a specific focus on the routinely assessed clinical parameters (tachycardia, temperature), paraclinical parameters on postoperative day (POD) 1 and 3 (C-reactive protein (CRP), leukocytes), and additional computed tomography (CT) scan results for the diagnosis of leakage, bleeding, intraabdominal abscess, superficial abscess, and other complications.

Results

A total of 587 patients were examined. In this cohort, 73 CT scans were performed due to suspected intraabdominal or pulmonary complication according to our hospital standard operating procedure. In total, 14 patients (2.4%) had a major complication (Clavien-Dindo grade IV/V). Of those, 10 patients (1.7%) had postoperative leakage. While the correct leakage diagnosis was only found in 33% of the patients by CT scan, the overall specificity of CT as a diagnostic tool for all kinds of complications remained high. Especially for abscess detection, CT scan showed a sensitivity and specificity of 100%. Multivariate analysis showed a significantly higher risk of leakage development characterized by a doubling of postoperative CRP level (odds ratio 4.84 (95% confidence interval 2.01–11.66, p < 0.001)). To simplify the use of CRP as a predictive factor for the diagnosis of leakage, a cut-off value of 2.4 was determined for the CRP quotient (POD3/POD1) with a sensitivity of 0.88 and a specificity of 0.89.

Conclusion

CT diagnostic after bariatric surgery has a high positive predictive value, especially for intraabdominal abscess formation. Nevertheless, CT scan for the diagnosis of leakage has a low sensitivity. Thus, a negative CT scan does not exclude the presence of a leakage. Using the described CRP quotient with a cut-off of 2.4, the risk of early leakage can be easily estimated. Furthermore, in any uncertain case of clinically suspected leakage, diagnostic laparoscopy should be performed.