Clopidogrel delays gastric ulcer healing in rats

Progression of Gastrointestinal Injury During Antiplatelet Therapy After Percutaneous Coronary Intervention: A Secondary Analysis of the OPT-PEACE Randomized Clinical Trial

Importance

Gastrointestinal injury progression induced by antiplatelet therapy in patients after percutaneous coronary intervention (PCI) has not been well studied.

Objective

To assess the association of aspirin, clopidogrel, and their combination with gastrointestinal injury progression among patients without high bleeding risk after PCI.

Design, Setting, and Participants

This secondary analysis assessed data from the Optimal Antiplatelet Therapy for Prevention of Gastrointestinal Injury Evaluated by ANKON Magnetically Controlled Capsule Endoscopy (OPT-PEACE) double-masked, placebo-controlled, multicenter randomized clinical trial. The OPT-PEACE trial was conducted at 28 centers in China, and recruitment took place from July 13, 2017, to July 13, 2019. The trial included patients with stable coronary artery disease or acute coronary syndromes without ST-segment elevation after PCI. Statistical analysis was conducted from September 13, 2022, to January 23, 2023.

Interventions

Patients underwent magnetically controlled capsule endoscopy (MCE) at baseline and after 6 months of dual antiplatelet therapy (DAPT) with aspirin (100 mg/d) plus clopidogrel (75 mg/d). Those with no evidence of gastrointestinal ulcers or bleeding (ie, the intention-to-treat [ITT] cohort) were randomized (1:1:1) to aspirin (100 mg/d) plus matching placebo (aspirin alone), clopidogrel (75 mg/d) plus matching placebo (clopidogrel alone), or DAPT for an additional 6 months. A third MCE was performed 12 months after PCI.

Main Outcomes and Measures

The primary outcome was the rate of gastric injury progression as assessed with the results of the 3 MCEs (at baseline, 6 months, and 12 months) in the modified intention-to-treat (mITT) population. The key secondary outcome was the rate of small-intestinal injury progression. Gastric or small-intestinal injury progression was defined as a quantitative increase in erosions or ulcers between the second and third MCEs (at 6 and 12 months, respectively).

Results

This study included the 394 patients in the mITT cohort. Their mean (SD) age was 56.9 (8.7) years, and most were men (296 [75.1%]). A total of 132 patients were randomized to aspirin alone, 132 to clopidogrel alone, and 130 to DAPT. Gastric injury progression occurred in 49 aspirin users (37.1%), 64 clopidogrel users (48.5%), and 69 DAPT users (53.1%) (P = .02), reflecting a lower rate of gastric injury progression among aspirin users vs DAPT users (risk ratio [RR], 0.70 [95% CI, 0.49-0.99]; P = .009). No significant difference was observed between clopidogrel alone and DAPT (48.5% vs 53.1%; P = .46) or between aspirin alone and clopidogrel alone (37.1% vs 48.5%; P = .06). A total of 51 aspirin users (38.6%), 65 clopidogrel users (49.2%), and 71 DAPT users (54.6%) (P = .03) developed progressive small-intestinal injury, reflecting a lower rate of small-intestinal injury among aspirin users vs DAPT users (RR, 0.71 [95% CI, 0.50-0.99]; P = .01). No difference was observed between patients treated with clopidogrel vs DAPT (49.2% vs 54.6%; P = .38) or with aspirin vs clopidogrel (38.6% vs 49.2%; P = .08).

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, ongoing use of aspirin, clopidogrel, or their combination between 6 and 12 months after PCI was associated with progressive gastric and small-intestinal injury in a substantial proportion of patients, more so with DAPT than with monotherapy. Clopidogrel was at least as likely as aspirin to induce gastrointestinal injury progression. Future research is warranted to determine what impact the findings from MCEs would have on decision-making of antiplatelet therapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT03198741.

Panax Notoginseng Saponins Combined with Dual Antiplatelet Drugs Potentiates Anti-Thrombotic Effect with Alleviated Gastric Injury in A Carotid Artery Thrombosis Rat Model

OBJECTIVE

To observe the combination effects of Panax notoginseng saponins (PNS)and dual antiplatelet drugs (DAPT), and to explore the mechanism via cyclooxygenase /prostaglandin pathway.

METHODS

Right carotid artery thrombosis was induced in Wistar rats by infiltration with 70% FeCl₃, and the animals were randomly divided into sham group, model group, DAPT group and PNS + DAPT group, intragastrically treated for 4 weeks. The cerebral pia mater microcirculation was observed in vivo after anesthetizing by anatomical microscope. The wet weight of carotid artery thrombosis was measured. Gastric mucosal injury was observed by hematoxylin and eosin staining. Platelet aggregation rate was detected with adenosine diphosphate -induced turbidimetry. Platelet CD62p expression was detected by flow cytometry. Concentrations of 6-Ketoprostaglandin F1 alpha, prostaglandin E₂ in gastric mucosa and thromboxane B₂, 6-Ketoprostaglandin F1 alpha, tissue plasminogen activator, plasminogen activator inhibitor, and fibrin fragment D in the plasma were measured by radioimmunoassay.

RESULTS

PNS and DAPT increased the blood flow volume of cerebral pia mater and decreased erythrocyte aggregation and leukocyte adhesion of model rats. Compared to DAPT, PNS and DAPT further reduced the weight of carotid artery thrombosis with enhanced inhibition of platelet aggregation, increased tissue plasminogen activator levels and decreased fibrin fragment D levels. PNS and DAPT alleviated gastric injury induced by dual antiplatelet drugs and upregulated the expression of 6-Ketoprostaglandin F1 alpha in the gastric mucosa compared with DAPT.

CONCLUSIONS

PNS combined with DAPT increased anti-thrombosis effects of DAPT and mitigated DAPT-related gastric injury. The underlying mechanisms may be associated with enhanced antiplatelet aggregation and activation of the fibrinolytic system and up-regulation of 6-Ketoprostaglandin F1 alpha expression in gastric mucosa.

Validation of the BEST-J score, a prediction model for bleeding after endoscopic submucosal dissection for early gastric cancer: a multicenter retrospective observational study

BACKGROUND

A new scoring system, the BEST-J score, using ten risk factors to assign cases to different post-endoscopic submucosal dissection (ESD) risk groups for bleeding, has been shown to be accurate for risk stratification. We first aimed to validate the BEST-J score at four hospitals not specialized in performing ESD and then aimed to identify other risk factors for post-ESD bleeding.

METHODS

We evaluated the incidence of post-ESD bleeding in 791 cases of early gastric cancer (EGC) between October 2013 and December 2020 as a retrospective, multi-center observational study conducted at four hospitals. Multivariate logistic regression models to examine the effect of independent variables on post-ESD bleeding firstly included ten possible factors raised by the BEST-J score and secondly included statistically significant (p < 0.01) in univariate analysis. The prediction accuracy of the model was evaluated by receiver-operating characteristic analysis and the areas under the curve (AUC).

RESULTS

The incidence of post-ESD bleeding was 4.8% (38/791, 95% confidence interval [CI] 3.4-6.5%). On multivariate analysis, the risk factors were P2Y12 receptor antagonist (odds ratio [OR]: 5.870, 95% CI 1.624-21.219), warfarin (8.382, 1.658-42.322), direct oral anticoagulant (DOAC) (8.980, 1.603-50.322), and tumor location in lower third of stomach (2.151, 1.012-4.571), respectively. When we categorized cases into low-risk by BEST-J score, intermediate-risk, high-risk, and very high-risk groups, the bleeding rates were 2.8%, 7.3%, 12.8%, and 19.0%, respectively. The AUC for our cohort was 0.713 (95% CI 0.625-0.802) for the BEST-J score. In the multivariate analysis in our cohort, the risks were age, body mass index, P2Y12 receptor antagonist, warfarin, DOAC, respectively.

DISCUSSION

The BEST-J score is equally accurate in risk stratification of patients with EGC for post-ESD bleeding at non-specialized facilities for ESD as in specialized hospitals. BMI and age may be helpful additional risk factors at hospitals not specialized.

Panax Notoginseng Saponin Attenuates Gastric Mucosal Epithelial Cell Injury Induced by Dual Antiplatelet Drugs through COX and PI3K/Akt/ VEGF-GSK-3β-RhoA Network Pathway

OBJECTIVE

To elucidate the underlying mechanism of Panax notoginseng saponin (PNS) on gastric epithelial cell injury and barrier dysfunction induced by dual antiplatelet (DA).

METHODS

Human gastric mucosal epithelial cell (GES-1) was cultured and divided into 4 groups: a control, a DA, a PNS+DA and a LY294002+PNS+DA group. GES-1 apoptosis was detected by flow cytometry, cell permeability were detected using Transwell, level of prostaglandins E2 (PGE2), 6-keto-prostaglandin F1α (6-keto-PGF1α) and vascular endothelial growth factor (VEGF) in supernatant were measured by enzyme linked immunosorbent assay (ELISA), expression of phosphatidylinositide 3-kinase (PI3K), phosphorylated-PI3K (p-PI3K), Akt, phosphorylated-Akt (p-Akt), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), glycogen synthase kinase-3β (GSK-3β) and Ras homolog gene family member A (RhoA) were measured by Western-blot.

RESULTS

DA induced apoptosis and hyper-permeability in GES-1, reduced supernatant level of PGE2, 6-keto-PGF1α and VEGF (P<0.05). Addition of PNS reduced the apoptosis of GES-1 caused by DA, restored the concentration of PGE2, 6-keto-PGF1α and VEGF (P<0.05). In addition, PNS attenuated the alteration of COX-1 and COX-2 expression induced by DA, up-regulated p-PI3K/p-Akt, down-regulated RhoA and GSK-3β. LY294002 mitigated the effects of PNS on cell apoptosis, cell permeability, VEGF concentration, and expression of RhoA and GSK-3β significantly.

CONCLUSIONS

PNS attenuates the suppression on COX/PG pathway from DA, alleviates DA-induced GES-1 apoptosis and barrier dysfunction through PI3K/Akt/VEGF-GSK-3β-RhoA network pathway.

Increased Risk of Clopidogrel-Induced Gastric Mucosal Erosion in Elderly Chinese Men Harboring the ABCB1 3435T Allele

Background

It is uncertain whether long-term use of clopidogrel alone can cause gastric mucosal injury. This study aimed to evaluate the relationship between ABCB1 C3435T polymorphisms, which could affect the intestinal absorption of clopidogrel, and gastric mucosal erosion in elderly Chinese men who used clopidogrel alone.

Methods

We selected 298 male patients (aged between 68.2 and 89.5 years, average age 78); 201 of them constituted the control group, and 97 constituted the case group. Patients taking clopidogrel alone who had undergone endoscopic screening for gastric erosion were analyzed for ABCB1 C3435T polymorphisms by a TaqMan assay.

Results

The proportion of people carrying the ABCB1 3435T allele (n = 63, 64.9% vs n = 97, 48.3%, p = 0.007) was significantly higher in the case group than in the control group. After adjustments for significant factors were made, ABCB1 3435T allele carrier (OR 2.14, 95% CI 1.43–3.84, p <0.01) was found to be associated with gastric mucosal erosion in people who used clopidogrel alone.

Conclusion

Carrying the ABCB1 3435T allele may be a useful genetic predictor for clopidogrel-induced gastric mucosal erosion in elderly Chinese men.

Total triterpenes from the fruits of Chaenomeles speciosa (Sweet) Nakai protects against indomethacin-induced gastric mucosal injury: involvement of TFF1-mediated EGF/EGFR and apoptotic pathways

OBJECTIVES

Our previous studies indicated that the triterpenes from the fruits of Chaenomeles speciosa (Sweet) Nakai (TCS) owned effectively therapeutic effects on gastric ulcer patients and animals, but its mechanisms have not been fully understood. The current study was to further investigate its protective effect on indomethacin (IND)-damaged RGM-1 cells and rats, as well as its mechanisms involved.

METHODS

The gastroprotection of TCS was evaluated with IND-induced gastric lesions model in RGM-1 cells and rats. In vitro, the proliferation, migration, mitochondrial viability and apoptosis were assessed. In vivo, ulcer index, ulcer inhibition rate, gastric juice acidity, gastric wall mucus (GWM) and histopathology of gastric mucosa were detected. The gastroprotective effects of TCS through the TFF1-mediated EGF/EGFR and apoptotic pathways were measured by qRT-PCR and Western blot assays.

KEY FINDINGS

The results demonstrated that TCS had gastroprotective function, which was related to the amelioration in promoting IND-damaged RGM-1 cell proliferation and migration, hoisting gastric juice acidity and GWM, improving ulcer index and ulcer inhibition rate, attenuating the haemorrhage, oedema, epithelial cell loss and inflammatory cell infiltration of gastric mucosa, upregulating PCNA, Bcl-2, Bcl-xl mRNA and TFF1, EGF, p-EGFR, p-Src, pro-caspase-3, pro-caspase-9 protein expressions, mitochondrial viability, mitochondrial cytochrome c concentration and p-EGFR/EGFR, p-Src/Src, Bcl-2/Bax, Bcl-xl/Bad ratioes, downregulating Bax, Bad, Apaf-1 mRNA and cleaved-caspase-3, cleaved-caspase-9, cleaved PARP-1 protein expressions and cytosol cytochrome c concentration.

CONCLUSIONS

Our present study demonstrated that TCS's gastroprotective effect was closely connected with boosting TFF1 expression, activating TFF1-mediated EGF/EGFR pathway, thus restraining mitochondrial-dependent apoptosis, which provided new insights into interpreting its underlying mechanism and promised to act as a candidate drug to treat gastric mucosal injury.

Risk factors for delayed bleeding by onset time after endoscopic submucosal dissection for gastric neoplasm

Post-endoscopic submucosal dissection bleeding (PEB) is one of the important complications after endoscopic submucosal dissection (ESD), but still difficult to predict. The present study aimed to identify significant risk factors for PEB according to onset time. Between November 2008 and January 2016, a total of 1864 lesions resected via ESD were analyzed. PEB was classified as either early or late according to onset time (within or after 24 hours post-ESD, respectively). During second-look endoscopy, the artificial ulcer bed was subjected to Forrest classification. A high risk of stigma was defined as active spurting bleeding, oozing bleeding, and a non-bleeding visible vessel in the ulcer. The endoscopic factors and medications associated with PEB were analyzed. PEB occurred in 77 lesions (4.1%): early only in 46 (2.4%), late only in 22 (1.1%), and early and late in 9 (0.4%). Among 55 early PEB events, 25 were asymptomatic and diagnosed during second-look endoscopy. Age ≤65 years, resection size ≥30 mm, procedure time ≥20 min, lower third of the stomach, erosion, and clopidogrel use were significantly associated with early PEB. If the number of risk factors were ≤1, the risk of early PEB was 0.6%. For late PEB, the mid to upper third of the stomach, undifferentiated carcinoma, erosion, high risk of stigma during second-look endoscopy, history of early PEB, and clopidogrel use were significant risk factors. If risk factors were absent, the risk of late PEB was 0.1%. For patients at high risk of early PEB, selective second-look endoscopy might be a useful. For patients at high risk of late PEB, careful monitoring of bleeding should be considered.

FBLIM1 enhances oral cancer malignancy via modulation of the epidermal growth factor receptor pathway

Filamin-binding LIM protein 1 (FBLIM1) is related to regulation of inflammatory responses, such as chronic recurrent multifocal osteomyelitis; however, the relevance of FBLIM1 in oral squamous cell carcinoma (OSCC) is unknown. The aim of the current study was to elucidate the possible role of FBLIM1 in the carcinogenesis of OSCC. We analyzed FBLIM1 expression using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), immunoblot analysis, and immunohistochemistry. The expression levels of FBLIM1 were up-regulated significantly (P < 0.05) in OSCC-derived cell lines and primary OSCCs specimens compared with normal counterparts. FBLIM1 expression also was correlated with the primary tumoral size (P < 0.05) and vascular invasion (P < 0.05). We then assessed tumoral progression after treatment with FBLIM1 siRNA and clopidogrel, an antiplatelet agent. Similar to the FBLIM1 knockdown effect, clopidogrel-treated cells had attenuated functions of proliferation, migration, and invasiveness. Interestingly, clopidogrel treatment led to down-regulation of epidermal growth factor receptor (EGFR) and FBLIM1. These findings identify FBLIM1 as a putative therapeutic target by using clopidogrel for inhibiting over activation of EGFR signaling to prevent OSCC malignancy.

Antiplatelet drug ticagrelor delays gastric ulcer healing in rats

Adenosine diphosphate P2Y₁₂ receptor antagonist clopidogrel is not sufficiently safe for the gastric mucosa in patients with high risk of peptic ulcer, since it may impair healing of gastric erosions. However, the safety of the novel P2Y₁₂ receptor antagonist ticagrelor in the gastric mucosa has not been elucidated to date. The present study aimed to examine whether ticagrelor delays gastric ulcer healing and to elucidate the involved mechanisms. Gastric kissing ulcers were produced in rats by luminal application of acetic acid solution, and ticagrelor was administered at dose of 10 or 20 mg/kg/day orally for 7 days. On day 8 after ulcer induction, the ulcer size, mucosal epithelial cell proliferation of the ulcer margin, expression levels of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF), and signal transduction pathways for cell proliferation and angiogenesis were measured and compared between the ticagrelor-treated and untreated model groups. The results revealed that the ulcer size was significantly greater in the ticagrelor-treated group compared with the model group, while the mucosal epithelial cell proliferation of the ulcer margin was significantly decreased in the ticagrelor-treated group. In addition, ticagrelor significantly decreased the ulcer-stimulated expression levels of EGF, VEGF, phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated P38 mitogen-activated protein kinase and nuclear factor-κB P65 at the ulcer margin (P<0.05). These findings suggested that ticagrelor delayed gastric ulcer healing. Furthermore, the possible mechanisms underlying the effect of ticagrelor were associated with its functions of attenuating the expression levels of VEGF and EGF, as well as suppressing the phosphorylation activation of ERK1/2, P38 and nuclear factor-κB P65. Finally, the gastric epithelial cell proliferation and angiogenesis were also inhibited.

Histamine-2 Receptor Antagonist Cannot Prevent Recurrent Peptic Ulcers in Patients With Atherosclerotic Diseases Who Receive Platelet ADP Receptor Antagonist Monotherapy: A Randomized-Controlled, Double-Blind, and Double-Dummy Trial

OBJECTIVES

Proton pump inhibitor can effectively prevent recurrent peptic ulcers among atherosclerotic patients receiving clopidogrel monotherapy. However, the interaction between proton pump inhibitors and clopidogrel has raised concerns over the safety of combined use of the two medicines in clinical practice. The aims of this randomized-controlled, double-blind and double-dummy trial were to investigate the efficacy of histamine-2 receptor antagonist (H2RA) in the prevention of recurrent peptic ulcer in patients undergoing thienopyridine monotherapy.

METHODS

From January 2012 to 2016, long-termed thienopyridine users with a peptic ulcer history who did not have peptic ulcers at initial endoscopy were randomly assigned to receive either famotidine (40 mg, before bedtime) or placebo (before bedtime) for 6 months. Follow-up endoscopy was performed at the end of the 6th month and whenever dyspepsia, hematemesis, or melena occurred.

RESULTS

The cumulative incidence of recurrent peptic ulcer during the 6-month period was 7.0% in famotidine group (n=114) and 11.4% in the placebo group (n=114). The two patient groups had comparable cumulative incidence of peptic ulcer (difference, 4.4%; 95% confidence interval (CI), -11.7 to 2.9%; P=0.239). Additionally, there was no difference in the cumulative incidence of ulcer bleeding (2.6% vs. 1.8%; difference, 0.8%; 95% CI, -0.6 to 2.4%, P=1.000) between famotidine and placebo groups. However, the former had a lower incidence of gastroduodenal erosion than the latter (21.1% vs. 36.8%; difference, 15.7%; 95% CI, -27.3 to -4.1%; P=0.013).

CONCLUSIONS

Famotidine cannot decrease the incidence of peptic ulcer or ulcer bleeding in thienopyridine users with atherosclerotic disease and a history of peptic ulcer.

Effect of treatment with Puyuan Hewei capsules on microvessel density and epidermal growth factor expression in chronic gastritis with antral erosion

AIM: To evaluate the effect of treatment with Puyuan Hewei capsules on epidermal growth factor (EGF) expression and microvessel density (MVD) in chronic gastritis with antral erosion in patients without Helicobacter pylori (H. pylori) infection.

METHODS: Sixty patients with chronic gastritis and gastric antral erosion but without H. pylori infection were randomly divided into a study group and a control group, with 30 patients in each group. The study group was given Puyuan Hewei capsules and a placebo that is the same as teprenone in appearance, while the control group was given Puyuan Hewei capsules and teprenone. After 4 wk, MVD and EGF expression were compared between the two groups.

RESULTS: The positive rates of EGF expression in the area of gastric mucosal erosion in the study group and control group were 20.0% vs 16.7% before treatment and 56.7% vs 46.7% after treatment, and there were significant differences between before and after treatment in each group and between the two groups (P < 0.05). The positive rates of EGF expression in the area of erosion-adjacent gastric mucosa in the study group and control group were 10.0% vs 13.3% before treatment and 26.7% vs 16.7% after treatment, which had no statistical difference either between before and after treatment in each group or between the two groups. MVD in the area of gastric mucosal erosion in the treatment group and control group was 36.83 ± 9.36 vs 39.90 ± 9.03 before treatment and 50.07 ± 18.35 vs 48.93 ± 14.59 after treatment, which had statistical differences between before and after treatment in each group and between the two groups (P < 0.05). MVD in the area of erosion-adjacent gastric mucosa in the treatment group and control group was 25.37 ± 6.11 vs 25.87 ± 6.12 before treatment and 28.30 ± 6.23 vs 28.77 ± 5.70 after treatment, which had no statistical difference either between before and after treatment in each group or between the two groups.

CONCLUSION: Puyuan Hewei capsules could up-regulate MVD and EGF expression in erosive antral gastritis, which may be one of the mechanisms underlying the therapeutic effects of Puyuan Hewei capsules.

Clopidogrel inhibits angiogenesis of gastric ulcer healing via downregulation of vascular endothelial growth factor receptor 2

BACKGROUND/PURPOSE

Although clopidogrel does not cause gastric mucosal injury, it does not prevent peptic ulcer recurrence in high-risk patients. We explored whether clopidogrel delays gastric ulcer healing via inhibiting angiogenesis and to elucidate the possible mechanisms.

METHODS

Gastric ulcers were induced in Sprague Dawley rats, and ulcer healing and angiogenesis of ulcer margin were compared between clopidogrel-treated rats and controls. The expressions of the proangiogenic growth factors and their receptors including basic fibroblast growth factor (bFGF), bFGF receptor (FGFR), vascular endothelial growth factor (VEGF), VEGFR1, VEGFR2, platelet-derived growth factor (PDGF)A, PDGFB, PDGFR A, PDGFR B, and phosphorylated form of mitogenic activated protein kinase pathways over the ulcer margin were compared via western blot and reverse transcription polymerase chain reaction. In vitro, human umbilical vein endothelial cells (HUVECs) were used to elucidate how clopidogrel inhibited growth factors-stimulated HUVEC proliferation.

RESULTS

The ulcer sizes were significantly larger and the angiogenesis of ulcer margin was significantly diminished in the clopidogrel (2 and 10 mg/kg/d) treated groups. Ulcer induction markedly increased the expression of phosphorylated form of extracellular signal-regulated kinase (pERK), FGFR2, VEGF, VEGFR2, and PDGFRA when compared with those of normal mucosa. Clopidogrel treatment significantly decreased pERK, FGFR2, VEGF, VEGFR2, and PDGFRA expression at the ulcer margin when compared with those of the respective control group. In vitro, clopidogrel (10(-6)M) inhibited VEGF-stimulated (20 ng/mL) HUVEC proliferation, at least, via downregulation of VEGFR2 and pERK.

CONCLUSION

Clopidogrel inhibits the angiogenesis of gastric ulcer healing at least partially by the inhibition of the VEGF-VEGFR2-ERK signal transduction pathway.

Alendronate, a bisphosphonate, increased upper and lower gastrointestinal bleeding: risk factor analysis from a nationwide population-based study

Patients receiving alendronate for osteoporosis carry a significantly higher risk of developing upper gastrointestinal bleeding (GIB) and lower GIB (hazard ratio 1.32 and 1.84, respectively) after adjusting for potential confounding factors such as age, gender, co-morbidity, and some medications. The risk factors associated with GIB were further analyzed.

INTRODUCTION

Patients receiving alendronate, a type of bisphosphonate, for osteoporosis have a higher risk of developing upper gastrointestinal bleeding (UGIB). Whether patients receiving alendronate also have a higher risk of lower gastrointestinal bleeding (LGIB) has not been studied. In this study, we investigated the association between GIB and alendronate use and to identify the possible risk factors of GIB among alendronate users.

METHODS

Using the National Health Insurance (NHI) Research Database of Taiwan, 3,000 alendronate users and 12,000 age-, sex-, and enrollment time-matched controls were extracted for analysis from a cohort data set of 1,000,000 randomly sampled subjects. Cox proportional hazard regression models were used to identify the risk factors for UGIB and LGIB in all enrollees and alendronate users after adjustments for age, gender, comorbidity (hypertension, diabetes mellitus, coronary heart disease, heart failure, chronic renal disease, chronic obstructive pulmonary disease, peptic ulcer, and cirrhosis), and medications (nonsteroidal anti-inflammatory drugs [NSAIDs], aspirin, steroids, clopidogrel, ticlopidine, warfarin, and selective serotonin reuptake inhibitors).

RESULTS

During a median of 1.30-year follow-up, patients receiving alendronate had significant higher risk of UGIB and LGIB after adjusting for age, gender, and potential confounding factors such as comorbidity and medications. Age, chronic renal disease, NSAID, and clopidogrel use may be independent risk factors for UGIB among alendronate users. Age, male gender, clopidogrel, and ticlopidine use may be independent risk factors for LGIB among alendronate users.

CONCLUSION

Patients receiving alendronates seemed to carry a higher risk for UGIB and LGIB, respectively, after adjustment for age, sex, underlying comorbidity, and certain medications.

Gastroduodenal mucosal defense

PURPOSE OF REVIEW

To review recent developments in the field of gastroduodenal mucosal defense.

RECENT FINDINGS

Research in the field of gastroduodenal mucosal defense has focused on continued elucidation of molecular mechanisms that protect the mucosa and influence healing at the cellular level. Review of literature over the past year reveals focus on familiar processes such as superoxide dismutase, nitric oxide, heme oxygenase-1, neutrophil infiltration, cysteamine, mucin, hydrogen sulfide, ghrelin, adiponectin and the influence of Helicobacter pylori, but also brings into light new processes such as the balance between apoptosis and cellular proliferation, as well as the influence of other organ systems such as the bone marrow and central nervous system on the gastrointestinal tract.

SUMMARY

These new published findings contribute to our overall understanding of gastroduodenal defense and suggest innovative avenues of future research and possible novel therapeutic targets.

Risk factors of gastrointestinal bleeding in clopidogrel users: a nationwide population-based study

BACKGROUND

The risk factors for gastrointestinal bleeding (GIB) in clopidogrel users have not been identified.

AIM

To clarify whether clopidogrel use is a risk factor for upper GIB (UGIB) and lower GIB (LGIB) and identify the risk factors in clopidogrel users.

METHODS

Using the National Health Insurance Research Database of Taiwan, 3238 clopidogrel users and 12,952 age-, sex-, and enrolment time-matched controls in a 1:4 ratio were extracted for comparison from a cohort dataset of 1,000,000 randomly sampled subjects. Cox proportional hazard regression models were used to identify the independent risk factors for UGIB and LGIB in all enrollees and clopidogrel users after adjustments for age, gender, comorbidity [i.e., coronary artery disease, hypertension, diabetes, chronic obstructive pulmonary disease, chronic kidney disease (CKD), cirrhosis, uncomplicated peptic ulcer disease, and peptic ulcer bleeding (PUB)], and medications [e.g., nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 inhibitors, aspirin, steroids, selective serotonin reuptake inhibitors (SSRIs), warfarin and alendronate].

RESULTS

Cox proportional hazard regression analysis showed that use of clopidogrel increased the risk of UGIB [hazard ratio (HR): 3.66; 95% confidence interval (CI): 2.96-4.51] and LGIB [HR: 3.52, 95% CI: 2.74-4.52]. Age, CKD, PUB history, use of aspirin and NSAIDs were independent risk factors for UGIB in the clopidogrel users. Age, CKD, PUB history, use of aspirin and SSRIs were independent risk factors for LGIB.

CONCLUSIONS

In clopidogrel users, age, CKD, PUB history, use of aspirin and NSAIDs are independent risk factors for UGIB; age, CKD, PUB history, use of aspirin and SSRIs are independent risk factors for LGIB.

The diminished expression of proangiogenic growth factors and their receptors in gastric ulcers of cirrhotic patients

Objectives

The pathogenesis of the higher occurrence of peptic ulcer disease in cirrhotic patients is complex. Platelets can stimulate angiogenesis and promote gastric ulcer healing. We compared the expressions of proangiogenic growth factors and their receptors in the gastric ulcer margin between cirrhotic patients with thrombocytopenia and those of non-cirrhotic patients to elucidate possible mechanisms.

Methods

Eligible cirrhotic patients (n = 55) and non-cirrhotic patients (n = 55) who had gastric ulcers were enrolled. Mucosa from the gastric ulcer margin and non-ulcer areas were sampled and the mRNA expressions of the proangiogenic growth factors (vascular endothelial growth factor [VEGF], platelet derived growth factor [PDGF], basic fibroblast growth factor [bFGF]) and their receptors (VEGFR1, VEGFR2, PDGFRA, PDGFRB, FGFR1, FGFR2) were measured and compared. Platelet count and the expressions of these growth factors and their receptors were correlated with each other.

Results

The two groups were comparable in terms of gender, ulcer size and infection rate of Helicobacter pylori. However, the cirrhotic group were younger in age, had a lower platelet count than those in the non-cirrhotic group (p<0.05). The cirrhotic patients had diminished mRNA expressions of PDGFB, VEGFR2, FGFR1, and FGFR2 in gastric ulcer margin when compared with those of the non-cirrhotic patients (p<0.05). Diminished expressions of PDGFB and VEGFR2, FGFR1, and FGFR2 were well correlated with the degree of thrombocytopenia in these cirrhotic patients (ρ>0.5, p<0.001).

Conclusions

Our findings implied that diminished activity of proangiogenic factors and their receptors may contribute to the pathogenesis of gastric ulcers in cirrhotic patients.