Proton Pump Inhibitors and Dementia: Physiopathological Mechanisms and Clinical Consequences

Signal of dementia with proton pump inhibitor after minimizing competition bias: an updated disproportionality analysis

OBJECTIVE

The association between proton pump inhibitor (PPI) and dementia was controversial. The aim of the current study was to perform an updated pharmacovigilance analysis of the association between dementia event and PPI treatment after minimizing competition bias.

METHODS

We gathered cases reported with PPI treatment based on the United States Food and Drug Administration Adverse Event Reporting System database from 2004 to 2023. We employed disproportionality algorithms, including reporting odds ratio (ROR) and the information component (IC), to detect the association between dementia event and PPI. We investigated the affection of event competition bias on the current disproportionality signal detection.

RESULTS

We finally included a total of 776,191 PPI cases, and 1813 cases in the dementia group. Analyzing primary suspect PPIs, we detected a significant association between dementia and PPI (ROR = 1.38, 95%CI 1.22 to 1.56; IC = 0.46, 95%CI 0.04 to 0.86). After excluding the PPI case with renal injury events, the strength of the dementia signal increased. Omeprazole (589 cases), pantoprazole (514 cases), and esomeprazole (386 cases) were the top three PPI reported with dementia events.

CONCLUSION

The current pharmacovigilance study identified a significant association between dementia and PPIs, except vonoprazan and tegoprazan, especially taking competition bias into account. Further high-quality prospective study still needed.

Gastroesophageal reflux disease with 6 neurodegenerative and psychiatric disorders: Genetic correlations, causality, and potential molecular mechanisms

The comorbidities between gastroesophageal reflux disease (GERD) and various neurodegenerative and psychiatric disorders have been widely reported. However, the genetic correlations, causal relationships, and underlying mechanisms linking GERD to these disorders remain largely unknown. Here, we conducted a bidirectional Mendelian randomization (MR) analysis to determine the causality between GERD and 6 neurodegenerative and psychiatric disorders. Sensitivity analyses and multivariable MR were performed to test the robustness of our findings. Linkage disequilibrium score regression was used to assess the genetic correlation between these diseases as affected by heredity. Multiple bioinformatics tools combining two machine learning algorithms were applied to further investigate the potential mechanisms underlying these diseases. We found that genetically predicted GERD significantly increased the risk of Alzheimer's disease, major depressive disorder, and anxiety disorders. There might be a bidirectional relationship between GERD and insomnia. GERD has varying degrees of genetic correlations with AD, ALS, anxiety disorders, insomnia, and depressive disorder. Bioinformatics analyses revealed the hub shared genes and the common pathways between GERD and 6 neurodegenerative and psychiatric disorders. Our findings demonstrated the complex nature of the genetic architecture across these diseases and clarified their causality, highlighting that treatments for the cure or remission of GERD may serve as potential strategies for preventing and managing neurodegenerative and psychiatric disorders.

Proton Pump Inhibitors and Cognitive Health: Review on Unraveling the Dementia Connection and Co-morbid Risks

Dementia, an international health issue distinguished by the impairment of daily functioning due to cognitive decline, currently affects more than 55 million people worldwide, with the majority residing in low-income and middle-income countries. Globally, dementia entails significant economic burdens in 2019, amounting to a cost of 1.3 trillion US dollars. Informal caregivers devote considerable hours to providing care for those affected. Dementia imposes a greater caregiving and disability-adjusted life-year burden on women. A recent study has established a correlation between prolonged Proton Pump Inhibitor (PPI) usage and dementia, in addition to other neurodegenerative conditions. PPIs are frequently prescribed to treat peptic ulcers and GERD (gastroesophageal reflux disease) by decreasing stomach acid secretion. They alleviate acid-related symptoms through the inhibition of acid-secreting H+-K+ ATPase. In a number of observational studies, cognitive decline and dementia in the elderly have been linked to the use of PPIs. The precise mechanism underlying this relationship is unknown. These drugs might also alter the pH of brain cells, resulting in the accumulation of amyloid-beta (Aβ) peptides and the development of Alzheimer's disease (AD). Despite the compelling evidence supporting the association of PPIs with dementia, the results of studies remain inconsistent. The absence of a correlation between PPI use and cognitive decline in some studies emphasizes the need for additional research. Chronic PPI use can conceal underlying conditions, including cancer, celiac disease, vitamin B12 deficiency, and renal injury, highlighting dementia risk and the need for further investigations on cognitive health.

Long-Term Use of Proton-Pump Inhibitors: Unravelling the Safety Puzzle

Globally, over 25% of the population suffers from acid-related disorders such as dyspepsia or gastroesophageal reflux disease (GERD), and around 7.6% of Indians report having GERD symptoms on a frequent enough basis to warrant a diagnosis. Over the past three decades, proton-pump inhibitors (PPIs) have been the mainstay of medical therapy for acid-peptic diseases like GERD, etc. Additionally, they are frequently prescribed for prophylactic purposes and in conjunction with non-steroidal anti-inflammatory drugs. PPIs are generally prescribed for four to eight weeks. However, it may be prescribed for patients with comorbidities and multiple medications for a longer period of time. While this remains true in terms of effectiveness, concerns have been raised about the safety of long-term PPI use and the serious adverse effects that may result. Some of the observational and population-based cohort studies have shown an association between long-term use of PPIs and an increased risk of pneumonia, major cardiovascular events, dementia, vitamin B12 deficiency, bone fractures, gastric cancer, and kidney injury, among others. This review analyzes the clinical data supporting the long-term use of PPIs and takes a deep dive into whether these several emerging long-term concerns apply to the currently available PPIs in India. We have summarized a vast array of studies, including randomized trials, cohort studies, and meta-analyses, that report low or high incidences of major health risks linked with PPIs and have assessed their appropriateness over a given period.

High-throughput target trial emulation for Alzheimer's disease drug repurposing with real-world data

Target trial emulation is the process of mimicking target randomized trials using real-world data, where effective confounding control for unbiased treatment effect estimation remains a main challenge. Although various approaches have been proposed for this challenge, a systematic evaluation is still lacking. Here we emulated trials for thousands of medications from two large-scale real-world data warehouses, covering over 10 years of clinical records for over 170 million patients, aiming to identify new indications of approved drugs for Alzheimer's disease. We assessed different propensity score models under the inverse probability of treatment weighting framework and suggested a model selection strategy for improved baseline covariate balancing. We also found that the deep learning-based propensity score model did not necessarily outperform logistic regression-based methods in covariate balancing. Finally, we highlighted five top-ranked drugs (pantoprazole, gabapentin, atorvastatin, fluticasone, and omeprazole) originally intended for other indications with potential benefits for Alzheimer's patients.

Different effects of chronic omeprazole use on osteoporotic fractures rate in the elderly

AIMS

To investigate the potential association of chronic use of omeprazole with the occurrence of osteoporotic fractures (OF) in community-dwelling elderly subjects.

METHODS

The cohort consisted of community-dwelling residents aged >65 years registered with a large health maintenance organization in Israel between January 2002 and December 2016. Data were retrospectively collected from the electronic medical files on demographics, parameters known to be associated with OF, diagnoses of osteoporotic hip, wrist, and vertebral fractures, and chronic use of omeprazole (>11 prescriptions/year). Time to OF/death/end of study was calculated from the beginning of the study (2002). The risk of fractures in the chronic users of omeprazole was analyzed by multivariate Cox proportional hazard regression model.

RESULTS

In total, 46 805 subjects were included (41% men), mean age 83.4±6.4 years, of whom 10 272 (21.9%) were chronic users of omeprazole. During 14 years of follow-up, OF were diagnosed in 414 (4.0%) omeprazole users and 1007 (2.8%) omeprazole nonusers (p < 0.001). In a Cox regression model adjusted for age and gender only, chronic use of omeprazole was associated with a 16% excess of OF. However, when parameters known to be associated with OF were entered into the multivariate Cox regression model, chronic use of omeprazole was not found to be an independent risk factor for OF, either overall (adjusted hazard ratio = 0.965, 95% confidence interval 0.86-1.08, P = .55) or specifically, in the ≥85 years age group (adjusted hazard ration = 0.780, 95% confidence interval 0.635-0.958, P < .05) in which an inverse correlation between omeprazole use and OF, was demonstrated.

CONCLUSIONS

Chronic use of omeprazole was not associated with the occurrence of OF in elders.

Association between proton pump inhibitor use and neurological or psychiatric disorders: a systematic review protocol

OBJECTIVE

The objective of this review is to examine the association between proton pump inhibitors (PPIs) and neurological and/or psychiatric disorders in adults.

INTRODUCTION

The association between PPIs and neurological and/or psychiatric disorders remains unclear, despite the widespread use of the medications. A systematic review is required to investigate the risk of developing neurological and/or psychiatric disorders following the use of PPIs.

INCLUSION CRITERIA

Studies including participants aged ≥18 years and using any PPIs, including participants with comorbid conditions or using other medications, will be considered for inclusion. Randomized controlled trials, quasi-experimental studies, and observational studies examining the association of neurological and/or psychiatric disorders with the use of PPIs among adults will be included.

METHODS

MEDLINE, Embase, PsycINFO, CINAHL, and Cochrane CENTRAL databases will be searched from inception until the present. Two authors will independently screen and review the titles, abstracts, and full texts. The methodological quality of included studies will be assessed using the JBI critical appraisal checklists. Study characteristics, populations, type and duration of PPI usage, status of existing neurological and/or psychiatric disorders, comorbidity conditions, use of other medications, identification of neurological and/or psychiatric disorders (International Classification of Diseases codes vs others), and estimation of the associated neurological and/or psychiatric disorders will be extracted. Studies will be pooled using statistical meta-analysis where available; otherwise, the findings will be presented in narrative format. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach for grading the certainty of evidence will be followed.

REVIEW REGISTRATION

PROSPERO CRD42022355543.

Should evidence of an autolysosomal de-acidification defect in Alzheimer and Parkinson diseases call for caution in prescribing chronic PPI and DMARD?

Nearly fifty million older people suffer from neurodegenerative diseases, including Alzheimer (AD) and Parkinson (PD) disease, a global burden expected to triple by 2050. Such an imminent "neurological pandemic" urges the identification of environmental risk factors that are hopefully avoided to fight the disease. In 2022, strong evidence in mouse models incriminated defective lysosomal acidification and impairment of the autophagy pathway as modifiable risk factors for dementia. To date, the most prescribed lysosomotropic drugs are proton pump inhibitors (PPIs), chloroquine (CQ), and the related hydroxychloroquine (HCQ), which belong to the group of disease-modifying antirheumatic drugs (DMARDs). This commentary aims to open the discussion on the possible mechanisms connecting the long-term prescribing of these drugs to the elderly and the incidence of neurodegenerative diseases.Abbreviations: AD: Alzheimer disease; APP-βCTF: amyloid beta precursor protein-C-terminal fragment; BACE1: beta-secretase 1; BBB: brain blood barrier; CHX: Ca2+/H+ exchanger; CMI: cognitive mild impairment; CQ: chloroquine; DMARD: disease-modifying antirheumatic drugs; GBA1: glucosylceramidase beta 1; HCQ: hydroxychloroquine; HPLC: high-performance liquid chromatography; LAMP: lysosomal associated membrane protein; MAPK/JNK: mitogen-activated protein kinase; MAPT: microtubule associated protein tau; MCOLN1/TRPML1: mucolipin TRP cation channel 1; NFE2L2/NRF2: NFE2 like bZIP transcription factor 2; NRBF2: nuclear receptor binding factor 2; PANTHOS: poisonous flower; PD: Parkinson disease; PIK3C3: phosphatIdylinositol 3-kinase catalytic subunit type 3; PPI: proton pump inhibitor; PSEN1: presenilin 1, RUBCN: rubicon autophagy regulator; RUBCNL: rubicon like autophagy enhancer; SQSTM1: sequestosome 1; TMEM175: transmembrane protein 175; TPCN2: two pore segment channel 2; VATPase: vacuolar-type H+-translocating ATPase; VPS13C: vacuolar protein sorting ortholog 13 homolog C; VPS35: VPS35 retromer complex component; WDFY3: WD repeat and FYVE domain containing 3; ZFYVE1: zinc finger FYVE-type containing 1.

Proton Pump Inhibitor Use and Cognitive Function in the Boston Puerto Rican Health Study

BACKGROUND

There is a lack of consensus among studies on the association between proton pump inhibitor (PPI) use and cognitive impairment. This association is not well studied among minority populations, including among Puerto Ricans. Therefore, we sought to examine this association among Boston-area Puerto Ricans.

METHODS

The Boston Puerto Rican Health Study is an ongoing longitudinal cohort that enrolled 1499 Boston-area Puerto Rican adults, aged 45-75 years at baseline. Complete outcome and exposure data was available for 1290 baseline participants. Covariate-adjusted linear regression and linear mixed effects models were used to examine the association between PPI use, and global cognition, executive function, and memory cross-sectionally and longitudinally over ~12.7 years of follow-up. Furthermore, we examined the cross-sectional association between long-term PPI use (continuous use of ~6.2 years) and global cognition, executive function, and memory.

RESULTS

Among 1 290 participants at baseline, 313 (24.3%) self-reported PPI use. Baseline PPI use was not associated with baseline global cognition, executive function, or memory. Baseline PPI use also did not alter the trajectory of global cognition, executive function, or memory over ~12.7 years of follow-up. Long-term PPI use was not associated with global cognition, executive function, or memory over ~12.7 years of follow-up.

CONCLUSION

In this study of Boston-area Puerto Ricans, we did not observe an association between PPI use and global cognition, executive function, or memory either cross-sectionally or over 12.7 years of follow-up.

Time-Varying Use of Proton Pump Inhibitors and Cognitive Impairment and Dementia: A Real-World Analysis from Germany

BACKGROUND

Cumulative evidence of dementia risk in patients taking proton pump inhibitors (PPIs) is still inconclusive, probably due to a variety of study designs.

OBJECTIVE

This study aimed to compare how the association between dementia risk and use of PPIs differs by different outcome and exposure definitions.

METHODS

We conceptualized a target trial using claims data with 7,696,127 individuals aged 40 years or older without previous dementia or mild cognitive impairment (MCI) from the Association of Statutory Health Insurance Physicians in Bavaria. Dementia was defined as either including or excluding MCI to compare how the results alter by different outcome definitions. We used weighted Cox models to estimate the PPI initiation effect on dementia risk and weighted pooled logistic regression to assess the effect of time-varying use versus non-use during 9 years of study period, including 1 year of wash-out period (2009-2018). The median follow-up time of PPI initiators and non-initiators was 5.4 and 5.8 years, respectively. We also evaluated the association between each PPI agent (omeprazole, pantoprazole, lansoprazole, esomeprazole, and combined use) and dementia risk.

RESULTS

A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk. A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.A total of 105,220 (3.6%) PPI initiators and 74,697 (2.6%) non-initiators were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.04 [95% confidence interval (CI) 1.03-1.05]. The HR for time-varying PPI use versus non-use was 1.85 (1.80-1.90). When MCI was included in the outcome, the number of outcomes increased to 121,922 in PPI initiators and 86,954 in non-initiators, but HRs remained similar, showing 1.04 (1.03-1.05) and 1.82 (1.77-1.86), respectively. Pantoprazole was the most frequently used PPI agent. Although the estimated HRs for the time-varying use effect of each PPI showed different ranges, all agents were associated with an increased dementia risk.

CONCLUSION

Our large study supports existing evidence that PPI use is related to an increased risk of dementia.

Is vitamin B12 deficiency a risk factor for gastroparesis in patients with type 2 diabetes?

BACKGROUND

Diabetic gastroparesis is a severe diabetic complication refers to delayed gastric emptying in the absence of mechanical obstruction of the stomach. Vitamin B12 affects the dynamics of autonomic nervous system and its deficits has been linked to cardiovascular autonomic neuropathy therefore, vitamin B12 deficiency was hypothesized to be implicated in the development of diabetic gastroparesis. This study was conducted to explore the possible association between vitamin B12 deficiency and gastroparesis in patients with type 2 diabetes (T2D).

METHODS

A total of 100 T2D patients with diabetes duration > 10 years and 50 healthy controls matched for age and sex were recruited for this study. T2D patients were divided into 2 groups: patients with gastroparesis and patients without gastroparesis. The diagnosis of gastroparesis was based on Gastroparesis Cardinal Symptom Index (GCSI) Score ≥ 1.9 and ultrasonographic findings including gastric emptying ˂ 35.67% and motility index ˂ 5.1. Anthropometric measurements, plasma glucose, glycosylated hemoglobin (HbA1c), lipids profile, vitamin B12 and transabdominal ultrasonography were assessed.

RESULTS

The frequency of vitamin B12 deficiency in total patients with T2D was 35% (54.5% in patients with gastroparesis vs. 11.1% in patients without gastroparesis, P < 0. 001). Vitamin B12 level was negatively correlated with GCSI Score whereas, it was positively correlated with gastric emptying and motility index. Vitamin B12 deficiency was an independent predictor for gastroparesis in patients with T2D; it predicts gastroparesis at a cut off value of 189.5 pmol/L with 69.1% sensitivity and 64.4% specificity, P = 0.002.

CONCLUSIONS

Beside the known risk factors of diabetic gastroparesis, vitamin B12 deficiency is an independent predictor of diabetic gastroparesis in patients with T2D.

Mechanistic Insight into the Inhibition of Choline Acetyltransferase by Proton Pump Inhibitors

Various pharmacoepidemiological investigational studies have indicated that Proton Pump Inhibitors (PPIs) may increase the likelihood of developing Alzheimer's disease (AD) and non-AD related dementias. Previously, we have reported the inhibition of the acetylcholine biosynthesizing enzyme choline acetyltransferase (ChAT) by PPIs, for which omeprazole, lansoprazole, and pantoprazole exhibited IC₅₀ values of 0.1, 1.5, and 5.3 μM, respectively. In this study we utilize a battery of computational tools to perceive a mechanistic insight into the molecular interaction of PPIs with the ChAT binding pocket that may further help in designing novel ChAT ligands. Various in-silico tools make it possible for us to elucidate the binding interaction, conformational stability, and dynamics of the protein-ligand complexes within a 200 ns time frame. Further, the binding free energies for the PPI-ChAT complexes were explored. The results suggest that the PPIs exhibit equal or higher binding affinity toward the ChAT catalytic tunnel and are stable throughout the simulated time and that the pyridine ring of the PPIs interacts primarily with the catalytic residue His₃₂₄. A free energy landscape analysis showed that the folding process was linear, and the residue interaction network analysis can provide insight into the roles of various amino acid residues in stabilization of the PPIs in the ChAT binding pocket. As a major factor for the onset of Alzheimer's disease is linked to cholinergic dysfunction, our previous and the present findings give clear insight into the PPI interaction with ChAT. The scaffold can be further simplified to develop novel ChAT ligands, which can also be used as ChAT tracer probes for the diagnosis of cholinergic dysfunction and to initiate timely therapeutic interventions to prevent or delay the progression of AD.

Modifiable contributing factors to COVID-19: A comprehensive review

The devastating complications of coronavirus disease 2019 (COVID-19) result from an individual's dysfunctional immune response following the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Multiple toxic stressors and behaviors contribute to underlying immune system dysfunction. SARS-CoV-2 exploits the dysfunctional immune system to trigger a chain of events ultimately leading to COVID-19. The current study identifies eighty immune system dysfunction-enabling toxic stressors and behaviors (hereafter called modifiable contributing factors (CFs)) that also link directly to COVID-19. Each CF is assigned to one of the five categories in the CF taxonomy shown in Section 3.3.: Lifestyle (e.g., diet, substance abuse); Iatrogenic (e.g., drugs, surgery); Biotoxins (e.g., micro-organisms, mycotoxins); Occupational/Environmental (e.g., heavy metals, pesticides); Psychosocial/Socioeconomic (e.g., chronic stress, lower education). The current study shows how each modifiable factor contributes to decreased immune system capability, increased inflammation and coagulation, and increased neural damage and neurodegeneration. It is unclear how real progress can be made in combatting COVID-19 and other similar diseases caused by viral variants without addressing and eliminating these modifiable CFs.

Association of suicidal ideation and depression with the use of proton pump inhibitors in adults: a cross-sectional study

Proton pump inhibitors (PPIs) were found to be associated with depression. This study aimed to find the cross-sectional association between recent PPI use and suicidal ideation. Item 9 of Patient Health Questionnaire-9 (PHQ-9) of the US National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018 was used to categorize whether or not the participants had suicidal ideation. The secondary outcome of this study was depression and the scores of the PHQ-9 were used as the depression diagnostic instrument. The study population included 16,881 participants who were over 20 years old. The bivariate Rao-Scott χ² test showed a significant association between PPI use and suicidal ideation (P < 0.001) and a stronger association was observed between PPIs and depression (P < 0.001). Multiple logistic regression analysis of the education, gender, race and age-adjusted model revealed that the PPI users had a 2.34 (95% CI 1.66-3.31) greater risk of having suicidal ideation than the non-PPI users. Middle-aged participants (40-49 years) showed the greatest number of differences in suicidal ideation between PPI and non-PPI users (P < 0.001). Future research should continue to consider the psychiatric effects of taking PPIs.

Association between Migraines and Prior Proton Pump Inhibitor Use: A Nested Case-Control Study Using a National Health Screening Cohort

The effect of proton pump inhibitor (PPI) use on migraine risk remains controversial. We explored the odds of migraines in relation to prior PPI use and treatment duration. Data from the Korean National Health Insurance Service-Health Screening Cohort (2002−2015) were analyzed in this nested case-control study involving 28,159 participants with incident migraines and 112,636 controls (1:4 matched by sex, age, income, and residential region). The baseline covariates were balanced by performing propensity score overlap weighting-based adjustments, and the effect of prior PPI use (past vs. current) and treatment duration (<30 and 30−365 days vs. ≥365 days) on incident migraines was evaluated using logistic regression. In past and current PPI users, prior PPI use raised the likelihood of migraines (adjusted odds ratio [95% confidence interval]: 2.56 [2.36−2.79] and 4.66 [4.29−5.06], respectively). Participants who used PPI for <30, 30−365, or ≥365 days exhibited high odds of migraines (2.49 [2.29−2.72], 4.41 [4.05−4.79], and 4.14 [3.77−4.54], respectively). Incident migraines with or without aura also increased independently of PPI use history or duration. In summary, prior PPI use, irrespective of the elapsed time since use and the duration of use, is possibly associated with incident migraines with or without aura.

Benzimidazole Derivatives as New Potential NLRP3 Inflammasome Inhibitors That Provide Neuroprotection in a Rodent Model of Neurodegeneration and Memory Impairment

Objective

The study investigated the effect of newly synthesized benzimidazole derivatives against ethanol-induced neurodegeneration. According to evidence, ethanol consumption may cause a severe insult to the central nervous system (CNS), resulting in mental retardation, neuronal degeneration, and oxidative stress. Targeting neuroinflammation and oxidative stress may be a useful strategy for preventing ethanol-induced neurodegeneration.

Methodology

Firstly, the newly synthesized compounds were subjected to molecular simulation and docking in order to predict ligand binding status. Later, for in vivo observations, adult male Sprague Dawley rats were used for studying behavioral and oxidative stress markers. ELIZA kits were used to analyse tumour necrosis factor-alpha (TNF-), nuclear factor-B (NF-B), interleukin (IL-18), and pyrin domain-containing protein 3 (NLRP3) expression, while Western blotting was used to measure IL-1 and Caspase-1 expression.

Results

Our findings suggested that altered levels of antioxidant enzymes were associated with elevated levels of TNF-α, NF-B, IL-1, IL-18, Caspase-1, and NLRP3 in the ethanol-treated group. Furthermore, ethanol also caused memory impairment in rats, as measured by behavioural tests. Pretreatment using selected benzimidazole significantly increased the combat of the brain against ethanol-induced oxidative stress. The neuroprotective effects of benzimidazole derivatives were promoted by their free radical scavenging activity, augmentation of endogenous antioxidant proteins (GST, GSH), and amelioration of lipid peroxide (LPO) and other pro-inflammatory mediators. Molecular docking and molecular simulation studies further supported our hypothesis that the synthetic compounds Ca and Cb had an excellent binding affinity with proper bond formation with their targets (TNF-α and NLRP3).

Conclusion

It is revealed that these benzimidazole derivatives can reduce ethanol-induced neuronal toxicity by regulating the expression of cytokines, antioxidant enzymes, and the inflammatory cascade.

Rebuilding trust in proton pump inhibitor therapy

Introduction of proton pump inhibitor (PPI) therapy into clinical practice has revolutionized treatment approach to acid-related diseases. With its clinical success came a widespread use of PPI therapy. Subsequently, several studies found that PPIs were oftentimes overprescribed in primary care and emergency setting, likely attributed to seemingly low side-effect profile and physicians having low threshold to initiate therapy. However, now there is a growing concern over PPI side-effect profile among both patients and providers. We would like to bring more awareness to the currently available guidelines on PPI use, discuss clinical indications for PPIs and the evidence behind the reported side-effects. We hope that increased awareness of proper PPI use will make the initiation or continuation of therapy a well informed and an evidence-based decision between patient and physician. We also hope that discussing evidence behind the reported side-effect profile will help clarify the growing concerns over PPI therapy.

Chronic omeprazole use in the elderly is associated with decreased risk of dementia and cognitive decline

BACKGROUND

The association between proton pump inhibitor (PPI) use and increased risk of dementia is controversial.

AIM

Investigating this issue in a large population of community-dwelling elders.

METHODS

Our database was retrospectively searched for all community-dwelling patients aged ≥65 years who newly diagnosed with dementia/cognitive decline (DCD) between January 2002 - December 2012. Receiving ≥11 prescriptions of PPIs/year was categorized as PPI users. Clinical data were collected from the medical files. Risk of DCD in PPI users was analyzed by Cox regression models.

RESULTS

Included 48,632 elders of whom 8,848 were diagnosed with DCD (18.2%). PPI use was documented in 10,507, of whom 1,959 were subsequently diagnosed with DCD (18.6%). Among 38,125 non-PPI users, 6,889 (18.1%) were diagnosed with DCD. The hazard ratio for occurrence of DCD in PPI users compared to non-users was 0.85 (95% CI: 0.81-0.89, P <0.001) in an un-adjusted Cox regression model and 0.83 in a Cox regression model adjusted for age and sex (95% CI: 0.79-0.87, P <0.001). Multivariate Cox regression accounting for background diseases, marital status, and socioeconomic state yielded a hazard ratio of 0.77 (95% CI: 0.73-0.81, P <0.001).

CONCLUSION

PPI use wasn't associated with DCD development in chronic PPI users.

Proton pump inhibitors therapy and risk of hyperprolactinemia with associated sexual disorders

Proton pump inhibitors (PPIs) are the most widely prescribed medications in the world. According to numerous studies, PPIs have been linked to hyperprolactinemia, which can lead to a variety of sexual and reproductive issues. This review summarizes the effects of numerous PPIs on the blood prolactin levels and associated sexual dysfunctions, which have an effect on the patient's life quality and fertility. The study is taken into account all the available resources till January 31, 2021. Out of total 364, only 27 relevant resources were involved in this review. In certain studies, short-term PPIs use has been shown to have little or no effect on the blood prolactin and other reproductive hormones levels. PPIs have been linked to the development of hyperprolactinemia in several case studies with varying degrees of the blood prolactin levels increase seen in individuals taking PPI alone or in combination with medications, like prokinetics. The relative risk of the sexual consequences development, such as gynecomastia, has been documented using lansoprazole and omeprazole in various cohort studies. On the other hand, other bits of data are insufficient to establish a definite relationship that can turn a possibility into certainty. The majority of the literature data is comprising of double-blind, randomized, crossover studies, case reports, and adverse drug reaction incidents reported to various pharmacovigilance centers. To investigate this link, high-quality studies in patients taking PPIs for a longer time period are needed. We conclude this article with a comprehensive discussion of the hyperprolactinemia clinical implications and the PPIs' function.

Influence of Drugs on Mild Cognitive Impairment in Parkinson's Disease: Evidence from the PACOS Study

BACKGROUND

polytherapy and the anticholinergic activity of several drugs negatively influence cognition in the elderly. However, little is known on the effect on Mild Cognitive Impairment (MCI) in Parkinson's Disease (PD).

METHODS

patients with PD belonging to the baseline PACOS cohort with full pharmacological data have been included in this study. MCI diagnosis was made according to the MDS level II criteria. Polytherapy was defined as patients assuming ≥6 drugs. The anticholinergic burden has been calculated using the Anticholinergic Drug Scale (ADS). Molecules have been classified according to the ATC classification. Association with MCI has been assessed with a multivariate logistic regression analysis with MCI as the dependent variable.

RESULTS

pharmacological data were available for 238 patients (mean age 64.7±9.7). One hundred (42.0%) were diagnosed with MCI. No association was found in the full multivariate model (correcting for age, sex, disease duration, education, UPDRS-ME, LEDD-DAs) with either polytherapy or the ADS. Concerning drug classes, anti-hypertensive medications were positively associated with PD-MCI (OR 2.02;95%CI 1.04-3.89; p=0.035) while gastroprotective agents were negatively associated (OR 0.51; 95%CI 0.27-0.99; p=0.047).

CONCLUSION

the magnitude of polytherapy and anticholinergic drugs burden does not appear to modulate MCI risk in PD, probably due to cautious prescription patterns. The effect of antihypertensive and gastroprotective agents on PD-MCI risk, while needing further confirmations, could be relevant for clinical practice.

SAFETY OF LONG-TERM PROTON PUMP INHIBITORS: FACTS AND MYTHS

BACKGROUND

Proton pump inhibitors (PPIs) are one of the most prescribed drugs in the world. Frequent use and long-term maintenance of these drugs drew the attention of researchers for sporadic adverse effects reports.

OBJECTIVE

The purpose of this narrative review is to discuss appropriate data and causality related to these adverse events and PPIs.

METHODS

A narrative review was conducted by systematizing information about safety and adverse events on PPIs from 2015 to 2020. A structured search on Pubmed was performed to identify systematic reviews and meta-analysis investigating the following situations: a) gastric cancer; b) micronutrients deficiency; c) acid rebound; d) infections; e) fractures; f) dementia; g) kidney disease; and h) sudden death and cardiovascular changes.

RESULTS

Recent studies have potentially associated PPIs with some adverse events as osteoporosis-related fractures. There are also reports of intestinal infections, including Clostridium difficile, besides poor vitamins absorption and minerals such as vitamin B12, magnesium, and iron. Furthermore, there are some dementia, pneumonia, kidney disease, myocardial infarction, and stroke reports. For kidney diseases, studies consistently suggest that the use of PPI may be associated with an increased risk of adverse kidney events, especially in the elderly, with long-term PPI use and pre-existing kidney disease. Another additional question is whether chronic PPI use would also lead to the onset of gastric cancer. The abrupt discontinuation of PPIs is also related to increased gastric acid production above pre-PPI treatment levels; this phenomenon is called acid rebound.

CONCLUSION

The key to mitigate adverse effects is the rational use of PPIs at the lowest effective dose and in the shortest possible duration. Although these adverse effects have a potential clinical impact, their causal association is still subject to validation.

Association between Proton Pump Inhibitor Use and Parkinson's Disease in a Korean Population

Few studies have shown an increased risk of Parkinson’s disease (PD) with the use of proton pump inhibitors (PPIs), and the pathophysiological mechanism for this association has not been unveiled. This study examined the relationship between PPI use and PD in a Korean population. We investigated 3026 PD patients and 12,104 controls who were matched by age, sex, income, and region of residence at a ratio of 1:4 in the Korean National Health Insurance Service, National Sample Cohort between 2002 and 2015. We estimated the associations between current and past use of PPIs and PD using odds ratios (ORs) and 95% confidence intervals (CIs) in a conditional/unconditional logistic regression after adjusting for probable confounders. Compared with PPI nonusers, both current users and past users had significantly greater odds of having PD, with ORs of 1.63 (95% CI = 1.44−1.84) and 1.12 (95% CI = 1.01−1.25), respectively. A significant association with PD was observed in individuals who used PPIs for 30−90 days and ≥90 days (OR = 1.26 and 1.64, 95% CI = 1.12−1.43 and 1.43−1.89) but not among those who used PPIs for <30 days. Both current and past use of PPIs associated with a higher probability of PD in the Korean population. Our study provides evidence regarding the association between PPI exposure and PD, but further investigation and possible explanations are warranted.

Emulating a target trial of proton pump inhibitors and dementia risk using claims data

BACKGROUND

Understanding the adverse effects of proton pump inhibitors (PPIs) is important due to their widespread use, but the available evidence for an increased dementia risk among patients taking PPIs is inconclusive. The present study aimed to estimate the causal effect of PPIs on the risk of dementia by target trial emulation and time-varying exposure modeling.

METHODS

Using claims data of 2,698,176 insured people of a large German statutory health insurer, we conceptualized a target trial in which individuals aged 40 years and older were classified as PPI initiators or non-initiators between 2008 and 2018, and followed until diagnosis of dementia, death, loss to follow-up or end of study. Incidence of dementia (ICD-10 codes F00, F01, F03, F05.1, G30, G31.0, G31.1, G31.9, and F02.8+G31.82) was defined applying a 1-year lag window. We used weighted Cox models to estimate the effect of PPI initiation vs. non-initiation on dementia risk and weighted pooled logistic regression to estimate the effect of time-varying use vs. non-use.

RESULTS

29,746 PPI initiators (4.4%) and 26,830 non-initiators (1.3%) were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio (HR) for dementia was 1.54 (95% confidence interval [CI]: 1.51-1.58). The HR for time-dependent PPI use vs. non-use was 1.56 (95% CI: 1.50-1.63). Differentiated subtypes, including unspecified dementia, Alzheimer's disease (AD), and vascular dementia (VaD), showed increased risk by PPI initiation and time-varying PPI use.

CONCLUSIONS

This study suggests that PPI initiation and time-varying PPI use may increase overall dementia risk.

Gastric acid suppressants and cognitive decline in people with or without cognitive impairment

INTRODUCTION

Studies suggest associations between proton pump inhibitors (PPIs) and dementia risk; however, many neither considered histamine-2 receptor antagonists (H2RAs) nor baseline cognitive status.

METHODS

Participants (National Alzheimer's Coordinating Center Database; 2005-2021) using a PPI or H2RA were compared. Covariate-adjusted Cox regression was used to estimate hazard ratios (HR) for progression from normal cognition to mild cognitive impairment (MCI), and from MCI to dementia over 5 years. In a propensity-score-matched subsample of mild-moderate Alzheimer's disease (AD), mixed-effects negative binomial regression was used to estimate decline in delayed recall memory.

RESULTS

Compared to PPI, H2RA use was associated with earlier progression from MCI to dementia (HR = 1.40 [1.09-1.81]; n = 1701), and with faster memory decline in AD over time (rate ratio = 0.76 [0.64-0.92]; n = 628), but not with progression from normal cognition to MCI (HR = 0.94 [0.71-1.24]; n = 2784).

DISCUSSION

Compared to PPIs, H2RAs were associated with cognitive decline, specifically among people with pre-existing cognitive impairment.

Mechanistic Link between Vitamin B12 and Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common form of dementia in the elderly population, affecting over 55 million people worldwide. Histopathological hallmarks of this multifactorial disease are an increased plaque burden and tangles in the brains of affected individuals. Several lines of evidence indicate that B12 hypovitaminosis is linked to AD. In this review, the biochemical pathways involved in AD that are affected by vitamin B12, focusing on APP processing, Aβ fibrillization, Aβ-induced oxidative damage as well as tau hyperphosphorylation and tau aggregation, are summarized. Besides the mechanistic link, an overview of clinical studies utilizing vitamin B supplementation are given, and a potential link between diseases and medication resulting in a reduced vitamin B12 level and AD are discussed. Besides the disease-mediated B12 hypovitaminosis, the reduction in vitamin B12 levels caused by an increasing change in dietary preferences has been gaining in relevance. In particular, vegetarian and vegan diets are associated with vitamin B12 deficiency, and therefore might have potential implications for AD. In conclusion, our review emphasizes the important role of vitamin B12 in AD, which is particularly important, as even in industrialized countries a large proportion of the population might not be sufficiently supplied with vitamin B12.

Long-term use of proton-pump inhibitor on Alzheimer’s disease: a real-world distributed network analysis of six observational Korean databases using a Common Data Model

Background:

Dementia has a crucial impact on the quality of life of elderly patients and their caregivers. Proton-pump inhibitors (PPIs) are the most frequently prescribed treatment, but they have been shown to be associated with dementia. The data are inconsistent, however.

Objective:

To investigate the association between PPIs use and Alzheimer’s disease (AD) or all-cause dementia in six observational Korean databases using a Common Data Model (CDM) and to perform a distributed network analysis.

Methods:

Subjects aged over 18 years between 1 January 2004 and 31 December 2020. Among 7,293,565 subjects from 6 cohorts, 41,670 patients met the eligibility criteria. A total of 2206 patients who were included in both cohorts or with a history of dementia were excluded. After propensity matching, 5699 propensity-matched pairs between the PPIs and histamine-2 receptor antagonist (H₂RA) users were included in this study. The primary outcome was the incidence of AD at least 365 days after drug exposure. The secondary outcome was the incidence of all-cause dementia at least 365 days after drug exposure.

Results:

In the 1:1 propensity score matching, the risk of AD or all-cause dementia was not significantly different between the PPIs and H₂RA groups in all six databases. In the distributed network analysis, the long-term PPI users (⩾365 days) were unassociated with AD [hazard ratio (HR) = 0.92, 95% confidence interval (CI) = 0.68–1.23; I² = 0%] and all-cause dementia (HR =1.04, 95% CI = 0.82–1.31; I² = 0%) compared with H₂RA users.

Conclusion:

In the distributed network analysis of six Korean hospital databases using Observational Medical Outcomes Partnership (OMOP)-CDM data, the long-term use of PPI was not associated with a statistically significantly increased risk of AD or all-cause dementia. Therefore, we suggest that physicians should not avoid these medications because of concern about dementia risk.

Drug-Drug Interactions in Vestibular Diseases, Clinical Problems, and Medico-Legal Implications

Peripheral vestibular disease can be treated with several approaches (e.g., maneuvers, surgery, or medical approach). Comorbidity is common in elderly patients, so polytherapy is used, but it can generate the development of drug-drug interactions (DDIs) that play a role in both adverse drug reactions and reduced adherence. For this reason, they need a complex kind of approach, considering all their individual characteristics. Physicians must be able to prescribe and deprescribe drugs based on a solid knowledge of pharmacokinetics, pharmacodynamics, and clinical indications. Moreover, full information is required to reach a real therapeutic alliance, to improve the safety of care and reduce possible malpractice claims related to drug-drug interactions. In this review, using PubMed, Embase, and Cochrane library, we searched articles published until 30 August 2021, and described both pharmacokinetic and pharmacodynamic DDIs in patients with vestibular disorders, focusing the interest on their clinical implications and on risk management strategies.

Proton-Pump Inhibitors: Do Children Break a Leg by Using Them?

ABSTRACT

The risk of bone fracture in children under proton-pump inhibitors (PPI) treatment has been the subject of recent publications and naturally raises concerns among prescribing doctors, patients and their parents.Currently, there is no consistency in those risk claims according to the available evidence and an update on it is beneficial to reduce anxiety on one hand, and prompt for well-planned studies addressing the issue on the other. Furthermore, common sense and well-founded prescriptions must be the general rule for this as for any other therapeutic drug.

No association between acid suppressant use and risk of dementia: an updated meta-analysis

PURPOSE

Findings from large observational studies on whether the use of acid suppressants increases the risk of dementia have been inconsistent. Since proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA) are the most commonly used acid suppressants in clinical practice, we performed a meta-analysis to examine the influence of PPI and H2RA on the risk of dementia.

METHODS

A systematic search was performed on the PubMed, EMBASE, and Cochrane Library databases to identify studies published up to April, 2021. Studies that reported adjusted hazard ratio (HR) with 95% confidence intervals (CI) for the associations of interest were included. Data in the included studies were pooled using the random-effects model for meta-analysis. Statistical analysis was performed using Stata version 12.0 software.

RESULTS

Seventeen studies involving 1,251,562 participants were included. It was found that PPI users were not likely to develop dementia compared with those not taking PPI (HR = 0.98, 95% CI: 0.85-1.13). Subgroup analysis based on publication year, location, mean age, duration of PPI use, and female proportion also revealed no association between PPI use and dementia risk. Similarly, H2RA use was not associated with the risk of dementia, as indicated by the pooled HR of 1.20 (95% CI: 0.98-1.47).

CONCLUSION

Results of this meta-analysis suggest that PPI and H2RA do not increase the risk of dementia. These results may be used to inform the clinical application of acid suppressants. However, further randomized controlled trials are needed to confirm the present conclusions.

Proton Pump Inhibitor "Lansoprazole" Inhibits Locus Coeruleus's Neuronal Activity and Increases Rapid Eye Movement Sleep

Alteration of the bodily CO₂ concentration and proton pump activity affects the sleep architecture. The brainstem locus coeruleus (LC) area plays an essential role in rapid eye movement (REM) sleep generation and chemoregulation. Previously, we reported that lansoprazole injections (intraperitoneal) increased REM sleep in the rats. However, it is not known if proton pumps in the LC influence REM sleep. Here, we studied the effects of lansoprazole in the LC on the neuronal activity and REM sleep expression. Male Wistar rats (250-300 g) were surgically prepared for sleep recording and drug microinjections into the LC. We determined the localization of proton pumps and expression levels of cFOS in the LC neurons immunohistochemically. Sleep-wake was recorded before and after the microinjections of drugs/vehicles. Our results demonstrate (i) the presence of proton pumps in the LC neurons, (ii) that the microinjection of lansoprazole into the LC reduced the number of cFOS^+ve-TH^+ve double-labeled neurons in the LC by 52.6% (p < 0.001) compared to the vehicle and (iii) that low and high doses of lansoprazole significantly increased REM sleep by 32% (p < 0.001) and 60% (p < 0.001), respectively, compared to the vehicle. Our results suggest that the proton pumps modulate the LC's noradrenergic (NE-ergic) neuronal activity and REM sleep. The increased amount of REM sleep can be attributed to the inhibition of the LC NE-ergic activity. Further, the REM sleep amount increased after the lansoprazole microinjections into the LC with a significant increase in the REM sleep episode numbers. Overall, our results suggest that proton pumps in the LC may be involved in REM sleep generation.

The Janus-like Association between Proton Pump Inhibitors and Dementia

Early pharmacoepidemiological studies suggested that Proton Pump Inhibitors (PPIs) might increase the risk of Alzheimer’s Disease (AD) and non-AD related dementias. These findings were supported by preclinical studies, specifically stressing the proamyloidogenic and indirect anticholinergic effects of PPIs. However, further large-scale pharmacoepidemiological studies showed inconsistent results on the association between PPIs and dementia. Pharmacodynamically, these findings might be related to the LXR/RXR-mediated amyloid clearance effect and anti-inflammatory action of PPIs. Further aspects that influence PPI effects on AD are related to patient-specific pharmacokinetic and pharmacogenomic characteristics. In conclusion, a personalized (individualized) medicinal approach is necessary to model and predict the potential harmful or beneficial effects of PPIs in AD and non-AD-related dementias in the future.

Gut Microbiota and Neuroplasticity

The accumulating evidence linking bacteria in the gut and neurons in the brain (the microbiota-gut-brain axis) has led to a paradigm shift in the neurosciences. Understanding the neurobiological mechanisms supporting the relevance of actions mediated by the gut microbiota for brain physiology and neuronal functioning is a key research area. In this review, we discuss the literature showing how the microbiota is emerging as a key regulator of the brain's function and behavior, as increasing amounts of evidence on the importance of the bidirectional communication between the intestinal bacteria and the brain have accumulated. Based on recent discoveries, we suggest that the interaction between diet and the gut microbiota, which might ultimately affect the brain, represents an unprecedented stimulus for conducting new research that links food and mood. We also review the limited work in the clinical arena to date, and we propose novel approaches for deciphering the gut microbiota-brain axis and, eventually, for manipulating this relationship to boost mental wellness.

Management of Non-Variceal Upper GI Bleeding in the Geriatric Population: An Update

PURPOSE OF REVIEW

Upper gastrointestinal (GI) bleeding is a significant cause of morbidity and mortality in the geriatric (age > 65 years) population and presents a unique management challenge in the context of multiple medical comorbidities, polypharmacy, and increased risk of adverse outcomes and is confounded by an increased prevalence of obscure GI bleeds. A review of relevant guidelines, literature, and personal observations will enhance management strategies in the elderly.

RECENT FINDINGS

Non-variceal bleeding represents a significant proportion of upper GI bleeding (UGIB) in geriatric patients. Peptic ulcer disease (PUD) remains the most common cause in geriatric patients hospitalized for UGIB, but its incidence is decreasing. Esophagogastroduodenoscopy (EGD) is the gold standard for treating UGIB in geriatrics with a therapeutic yield of approximately 75%. Scoring systems such as Glasgow-Blatchford (GBS) and AIMS-65 may be useful for risk stratification but are not validated in trials. Obscure bleeds account for up to 30% of hospitalizations and must be considered during triage and management. Video capsule endoscopy (VCE) technology is efficacious for detecting obscure jejunal bleeding after failed EGD and may enhance the yield of balloon-assisted enteroscopy (BAE). The most significant factor for the increased morbidity and mortality in the geriatric population is the presence of multiple medical comorbidities and polypharmacy. An EGD should be done within 24 h of hospital presentation. If non-diagnostic, VCE may be a viable option for diagnosing an obscure small-bowel bleed, representing up to 30% of GI bleeds in this population.

The effects of proton pump inhibitors on neuropsychological functioning

OBJECTIVE

The current study investigated the effects of proton pump inhibitor use and apolipoprotein ε4 carrier status on changes in neuropsychological functioning in healthy adults with familial risk factors for dementia.

METHODS

As part of the Wisconsin Registry for Alzheimer's Prevention study, 1,573 subjects were administered questionnaires on their medical history, gave blood samples, and were administered neuropsychological assessments during four visits over a 10-15 year period. Linear mixed models assessed if non-users, subjects who stopped, started, or consistently used proton pump inhibitors differed in changes in working memory, verbal memory, psychomotor speed, and cognitive flexibility.

RESULTS

The models did not yield significant main effects for proton pump inhibitor use or interaction effects between proton pump inhibitor use and apolipoprotein ε4 carrier status on a decline in memory or processing speed. An interaction effect suggested stopping a proton pump inhibitor may be protective against declines in cognitive flexibility among non-carriers.

CONCLUSIONS

Although stopping a proton pump inhibitor use may have mild protective effects on executive functioning for non-apolipoprotein ε4 carriers, proton pump inhibitor use was not associated with memory decline in a sample of subjects with familial risk factors for dementia.

Adverse Effects Associated with Proton Pump Inhibitor Use

Proton pump inhibitors (PPIs) marked a before and after in the management of gastric acid-related disorders since their introduction to the market in 1989. Due to a novel, highly effective mechanism of action blocking the last converging step of gastric acid secretion by parietal cells and very few and mostly tolerable side effects, these drugs quickly displaced other pharmacological compounds such as H2 antagonists as the first treatment choice for peptic ulcer disease, gastroesophageal ulcers, Zollinger-Ellison syndrome, nonsteroidal anti-inflammatory drug-associated ulcers, and eradication of Helicobacter pylori, leading to an exponential increase in their prescription up to now. However, widespread PPI use has led to emerging evidence of long-term adverse effects not described previously, including increased risk of kidney, liver, and cardiovascular disease, dementia, enteroendocrine tumors of the gastrointestinal tract, susceptibility to respiratory and gastrointestinal infections, and impaired absorption of nutrients. Although the evidence published thus far has not established strong correlations, it has been relevant enough to raise new questions about PPIs' safety profile and reconsideration of their clinical indications. Hence, the aim of this review is to evaluate the association between PPI use and the risk of serious adverse effects given increasing concerns about the overuse of PPIs in the general population.

Lack of association between proton pump inhibitor use and brain aging: a cross-sectional study

Purpose

Due to conflicting scientific evidence for an increased risk of dementia by intake of proton pump inhibitors (PPIs), this study investigates associations between PPI use and brain volumes, estimated brain age, and cognitive function in the general population.

Methods

Two surveys of the population-based Study of Health in Pomerania (SHIP) conducted in Northeast Germany were used. In total, 2653 participants underwent brain magnetic resonance imaging (MRI) and were included in the primary analysis. They were divided into two groups according to their PPI intake and compared with regard to their brain volumes (gray matter, white matter, total brain, and hippocampus) and estimated brain age. Multiple regression was used to adjust for confounding factors. Cognitive function was evaluated by the Verbal Learning and Memory Test (VLMT) and the Nuremberg Age Inventory (NAI) and put in relation to PPI use.

Results

No association was found between PPI use and brain volumes or the estimated brain age. The VLMT score was 1.11 lower (95% confidence interval: − 2.06 to − 0.16) in immediate recall, and 0.72 lower (95% CI: − 1.22 to − 0.22) in delayed recall in PPI users than in non-users. PPI use was unrelated to the NAI score.

Conclusions

The present study does not support a relationship between PPI use and brain aging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-020-03068-8.

Update on Safety Profiles of Vitamins B1, B6, and B12: A Narrative Review

The neurotropic B vitamins B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) are essential for proper functioning of the nervous system. Deficiencies may induce neurological disorders like peripheral neuropathy (PN) and mainly occur in vulnerable populations (eg, elderly, diabetics, alcoholics). As epidemiologic cohort studies raised safety concerns about vitamin B6/B12 intake being potentially associated with increased risks of hip fracture (HF) and lung cancer (LC), we explored these aspects and performed comprehensive literature searches. However, we suggest not to neglect actual high-risk factors (eg, smoking in LC, higher age in HF) by focusing on individual nutrients, but to examine the complex interaction of numerous factors involved in disease development. Because it warrants continued consideration, we also provide an update on neurotoxicity associated with vitamin B6. We consider that neurological side effects due to vitamin B6 intake are rare and only occur with high daily doses and/or longer treatment duration. The benefit-risk ratio of high-dose treatment with neurotropic B vitamins in indications like PN is therefore considered advantageous, particularly if dosing recommendations are followed and serum levels monitored.

Roles for H+ /K+ -ATPase and zinc transporter 3 in cAMP-mediated lysosomal acidification in bafilomycin A1-treated astrocytes

Vacuolar ATPase (v-ATPase) is the main proton pump that acidifies vesicles such as lysosomes. Disruption in the lysosomal localization of v-ATPase leads to lysosomal dysfunction, thus contributing to the pathogenesis of lysosomal storage disorders and neurodegenerative diseases such as Alzheimer's disease. Recent studies showed that increases in cyclic AMP (cAMP) levels acidify lysosomes and consequently enhance autophagy flux. Although the upregulation of v-ATPase function may be the key mechanism underlying the cAMP-mediated lysosomal acidification, it is unknown whether a mechanism independent of v-ATPase may be contributing to this phenomenon. In the present study, we modeled v-ATPase dysfunction in brain cells by blocking lysosomal acidification in cortical astrocytes through treatment with bafilomycin A1, a selective v-ATPase inhibitor. We observed that cAMP reversed the pH changes via the activation of protein kinase A; interestingly, cAMP also increased autophagy flux even in the presence of bafilomycin A1, suggesting the presence of an alternative route of proton entry. Notably, pharmacological inhibitors and siRNAs of H⁺ /K⁺ -ATPase markedly shifted the lysosomal pH toward more alkaline values in bafilomycin A1/cAMP-treated astrocytes, suggesting that H⁺ /K⁺ -ATPase may be the alternative route of proton entry for lysosomal acidification. Furthermore, the cAMP-mediated reversal of lysosomal pH was nullified in the absence of ZnT3 that interacts with H⁺ /K⁺ -ATPase. Our results suggest that the H⁺ /K⁺ -ATPase/ZnT3 complex is recruited to lysosomes in a cAMP-dependent manner and functions as an alternative proton pump for lysosomes when the v-ATPase function is downregulated, thus providing insight into the potential development of a new class of lysosome-targeted therapeutics in neurodegenerative diseases.

[Updating in prescription of proton pump inhibitors. What to do and what not to do]

INTRODUCTION

Proton pump inhibitors (PPIs) are the most prescribed pharmacological subgroup of the National Health System and their use has been related to possible potentially serious adverse effects.

OBJECTIVE

To review the current indications for treatment with PPIs as well as the data related to their safety, in order to promote their adecuate use.

MATERIAL AND METHODS

A review of the literature focused on the following topics has been carried out: a) molecules and mechanism of action; b) current indications for treatment and adherence to them; c) adverse effects related to its use; d) drug interactions; e) alternatives in deprescription.

RESULTS

The current indications have not changed substantially in recent years and are well established, however, there is a high percentage of inappropriate prescription, mainly in individuals with low or no risk.

CONCLUSIONS

PPIs are safe drugs and generally well tolerated and their benefits are higher than possible adverse effects. Adhering to evidence-based recommendations represents the only rational approach to safe and effective therapy.

Proton pump inhibitors and dementia risk: Evidence from a cohort study using linked routinely collected national health data in Wales, UK

OBJECTIVES

Proton pump inhibitors (PPIs) are commonly prescribed for prevention and treatment of gastrointestinal conditions or for gastroprotection from other drugs. Research suggests they are linked to increased dementia risk. We use linked national health data to examine the association between PPI use and the development of incident dementia.

METHODS AND FINDINGS

A population-based study using electronic health-data from the Secure Anonymised Information Linkage (SAIL) Databank, Wales (UK) from 1999 to 2015. Of data available on 3,765,744 individuals, a cohort who had ever been prescribed a PPI was developed (n = 183,968) for people aged 55 years and over and compared to non-PPI exposed individuals (131,110). Those with prior dementia, mild-cognitive-impairment or delirium codes were excluded. Confounding factors included comorbidities and/or drugs associated with them. Comorbidities might include head injury and some examples of medications include antidepressants, antiplatelets and anticoagulants. These commonly prescribed drugs were investigated as it was not feasible to explore all drugs in this study. The main outcome was a diagnosis of incident dementia. Cox proportional hazard regression modelling was used to calculate the Hazard ratio (HR) of developing dementia in PPI-exposed compared to unexposed individuals while controlling for potential confounders. The mean age of the PPI exposed individuals was 69.9 years and 39.8% male while the mean age of the unexposed individuals was 72.1 years and 41.1% male. The rate of PPI usage was 58.4% (183,968) and incident dementia rate was 11.8% (37,148/315,078). PPI use was associated with decreased dementia risk (HR: 0.67, 95% CI: 0.65 to 0.67, p<0.01).

CONCLUSIONS

This study, using large-scale, multi-centre health-data was unable to confirm an association between PPI use and increased dementia risk. Previously reported links may be associated with confounders of people using PPI's, such as increased risk of cardiovascular disease and/or depression and their associated medications which may be responsible for any increased risk of developing dementia.

Pathophysiological Mechanisms of Cognitive Impairment and Neurodegeneration by Toxoplasma gondii Infection

Toxoplasma gondii is an obligate intracellular parasite considered one of the most successful pathogens in the world, owing to its ability to produce long-lasting infections and to persist in the central nervous system (CNS) in most warm-blooded animals, including humans. This parasite has a preference to invade neurons and affect the functioning of glial cells. This could lead to neurological and behavioral changes associated with cognitive impairment. Although several studies in humans and animal models have reported controversial results about the relationship between toxoplasmosis and the onset of dementia as a causal factor, two recent meta-analyses have shown a relative association with Alzheimer’s disease (AD). AD is characterized by amyloid-β (Aβ) peptide accumulation, neurofibrillary tangles, and neuroinflammation. Different authors have found that toxoplasmosis may affect Aβ production in brain areas linked with memory functioning, and can induce a central immune response and neurotransmitter imbalance, which in turn, affect the nervous system microenvironment. In contrast, other studies have revealed a reduction of Aβ plaques and hyperphosphorylated tau protein formation in animal models, which might cause some protective effects. The aim of this article is to summarize and review the newest data in regard to different pathophysiological mechanisms of cerebral toxoplasmosis and their relationship with the development of AD and cognitive impairment. All these associations should be investigated further through clinical and experimental studies.

Increased risk of death associated with the use of proton-pump inhibitors in patients with dementia and controls - a pharmacoepidemiological claims data analysis

Background and purpose

The use of proton‐pump inhibitors (PPIs) was reported to be associated with increased mortality risk and has been proposed as a potential risk factor for neurodegenerative diseases. We aimed to assess the impact of PPI use on survival in patients with dementia as compared with controls.

Methods

This register‐based control‐matched cohort study included 28 428 patients with dementia ascertained by the prescription of antidementia drugs and two control individuals matched by sex, age and area of residence for each patient with dementia during the study period from 1 January 2005 to 30 June 2016. Cumulative defined daily doses (DDDs) of PPIs were extracted from the health insurance prescription registries. A multivariate Cox regression model for non‐proportional hazards was used to analyse mortality risk in dependence of PPI exposure, which was limited to 1 year preceding the date of cohort entry (index date) in order to avoid immortal time bias.

Results

The PPI exposure of 100 DDDs in the year before the index date was associated with an increased mortality risk in patients with dementia (adjusted hazard ratio, 1.07; 95% confidence intervals, 1.03–1.12), but also in controls (adjusted hazard ratio, 1.47; 95% confidence intervals, 1.31–1.64). The mortality risk in relation to PPI use was significantly lower in patients with dementia as compared with controls (P < 0.0001) and highest in the first 2 years after the index date in both cohorts.

Conclusions

Our findings promote more stringent pharmacovigilance strategies to avoid PPI use in cases lacking a clear indication for therapy or where potential risks outweigh the benefits.

No association between proton pump inhibitor use and risk of dementia: Evidence from a meta-analysis

BACKGROUND AND AIM

A growing body of literature suggests the association between dementia risk and proton pump inhibitor (PPI) use. Therefore, we aimed to investigate the association between PPI use and dementia risk.

METHODS

An extensive literature search was performed in PubMed, Embase, and Cochrane till March 31, 2019. All the studies (cohort and case-control) assessing the association between PPI use and dementia risk were eligible for inclusion. Articles were selected based on the screening of title and abstract, data were extracted, and risk of bias was assessed using Newcastle-Ottawa scale. The primary outcome was pooled risk of dementia among PPI user as compared with non-PPI user. Secondary outcomes include dementia risk based on subgroups. Statistical analysis was performed using review manager software.

RESULTS

Twelve studies (eight cohort and four case-control) were found to be eligible for inclusion. Majority of the studies were of high quality. Dementia was diagnosed based on International Classification of Diseases 9/10 codes in majority of the included studies. PPI use was not associated with the dementia risk, with a pooled relative risk (RR) of 1.05 (95% confidence interval [CI]: 0.96-1.15), P = 0.31. Subgroup analysis based on study design (cohort: P = 0.14; case-control: P = 0.14), sex (RR 1.25 [95% CI: 0.97-1.60], P = 0.08), histamine 2 receptor antagonist blockers (P = 0.93), and Alzheimer's disease (RR 1.00 [95% CI: 0.91-1.09], P = 0.93) revealed no significant association between PPI use and dementia risk.

CONCLUSION

We found no significant association between PPI use and the risk of dementia or Alzheimer's disease.

Beyond uncertainty: Negative findings for the association between the use of proton pump inhibitors and risk of dementia

OBJECTIVES

We investigated the risk of dementia associated with the use of proton pump inhibitors (PPIs) as compared with the use of histamine-2 receptor antagonist (H2RA).

METHODS

We conducted retrospective propensity score-matched cohort study using the National Health Insurance Service-National Sample Cohort. Subjects were defined as the patients newly prescribed with PPI or H2RA between 2003 and 2013 without prior prescriptions of PPI/H2RA or diagnosis of dementia from their history within the past 1 year. We followed up participants until dementia occurrence, death, or the end of the study, whichever occurred first, with an intention-to-treat approach. A 1-year lag time between exposure and outcome measure was used to reduce protopathic bias. The incidence rate per 1000 person-years was estimated. The incidence rate of PPI was compared with that of H2RA, defined as incidence rate ratio (IRR), calculated with a 95% confidence interval. To control for potential confounds, propensity score matching at a 1:1 ratio was conducted, and the crude IRR was adjusted by risk factors.

RESULTS

Our propensity score-matched cohort included 87 562 patients on PPIs and 87 562 patients on H2RAs. The IRR was 1.01 (95% confidence interval 0.96-1.06) with 1-year lag time. IRR showed the decreased trend as the longer lag time. Also, no treatment duration or dose-response relationship was observed.

CONCLUSIONS

Our finding demonstrated that PPIs did not associate with dementia more strongly than did H2RA. On this basis, we suggest that the previously reported risk for dementia associated with PPI may have been overestimated.

Brain tumor acidification using drugs simultaneously targeting multiple pH regulatory mechanisms

INTRODUCTION

Non-invasively distinguishing aggressive from non-aggressive brain tumors is an important clinical challenge. Intracellular pH (pH_i) regulation is essential for normal cell function and is normally maintained within a narrow range. Cancer cells are characterized by a reversed intracellular to extracellular pH gradient, compared to healthy cells, that is maintained by several distinct mechanisms. Previous studies have demonstrated acute pH modulation in glioblastoma detectable by chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) after blocking individual pH regulatory mechanisms. The purpose of the current study was to simultaneously block five pH regulatory mechanisms while also providing glucose as an energy substrate. We hypothesized that this approach would increase the acute pH modulation effect allowing the identification of aggressive cancer.

METHODS

Using a 9.4 T MRI scanner, CEST spectra were acquired sensitive to pH_i using amine/amide concentration independent detection (AACID). Twelve mice were scanned approximately 11 ± 1 days after implanting 10⁵ U87 human glioblastoma multiforme cells in the brain, before and after intraperitoneal injection of a combination of five drugs (quercetin, cariporide, dichloroacetate, acetazolamide, and pantoprazole) with and without glucose.

RESULTS

Two hours after combination drug injection there was a significant 0.1 ± 0.03 increase in tumor AACID value corresponding to a 0.4 decrease in pH_i. After injecting the drug combination with glucose the AACID value increased by 0.18 ± 0.03 corresponding to a 0.72 decrease in pH_i. AACID values were also slightly increased in contralateral tissue.

CONCLUSIONS

The combined drug treatment with glucose produced a large acute CEST MRI contrast indicating tumor acidification, which could be used to help localize brain cancer and monitor tumor response to chemotherapy.

Dementia-Related Results of "Costs of Medication in Older Patients: Before and After Comprehensive Geriatric Assessment"

Changes in the pharmacokinetics and pharmacodynamics of drugs in the presence of certain comorbidities and geriatric syndromes and reduced tolerability of potential drug side effects due to physiological changes with aging lead to difficulties in planning treatments in elderly adults, especially patients with dementia. The Comprehensive Geriatric Assessment has an important role in assessing polypharmacy and optimizing potentially inappropriate medications and potentially prescribing omissions in these patients. For this reason, we intend to reexamine our new study titled " Costs of medication in older patients: before and after comprehensive geriatric assessment," because most of these results are also very important for dementia practice.

Association between Proton Pump Inhibitor Use and CNS Infection Risk: A Retrospective Cohort Study

This study investigated the incidence of central nervous system (CNS) infection following the use of proton pump inhibitors (PPIs). A retrospective cohort study was conducted in Taiwan by using data from the National Health Insurance Research Database. We identified and enrolled 16,241 patients with CNS infection who used PPIs (PPI users). The patients were individually propensity score matched (1:1) according to age, sex, hypertension, hyperlipidemia, Charlson comorbidity index (CCI), H2 blocker, non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroid, and immunosuppressant use with 16,241 controls (PPI nonusers). A Cox proportional hazards model was used to estimate adjusted hazard ratio (aHR) for CNS infection in the PPI users and nonusers. After adjustment for other confounding factors, the incidence of CNS infection in the PPI users was 2.23-fold higher than that in the PPI nonusers (95% CI = 1.27⁻3.94). In addition, the PPI users exhibited a higher risk of CNS infection than the nonusers in the hypertension and CCI = 1 groups (aHR = 3.80, 95% CI = 1.40⁻10.32; aHR = 2.47, 95% CI = 1.07⁻5.70 in the PPI users and nonusers, respectively). In conclusions, according to these results, we concluded that the incidence of CNS infection was higher in the PPI users than in the nonusers.