Comparative Risk of Alzheimer Disease and Related Dementia Among Medicare Beneficiaries With Rheumatoid Arthritis Treated With Targeted Disease-Modifying Antirheumatic Agents

Optimising the use of electronic medical records for large scale research in psychiatry

The explosion and abundance of digital data could facilitate large-scale research for psychiatry and mental health. Research using so-called "real world data"-such as electronic medical/health records-can be resource-efficient, facilitate rapid hypothesis generation and testing, complement existing evidence (e.g. from trials and evidence-synthesis) and may enable a route to translate evidence into clinically effective, outcomes-driven care for patient populations that may be under-represented. However, the interpretation and processing of real-world data sources is complex because the clinically important 'signal' is often contained in both structured and unstructured (narrative or "free-text") data. Techniques for extracting meaningful information (signal) from unstructured text exist and have advanced the re-use of routinely collected clinical data, but these techniques require cautious evaluation. In this paper, we survey the opportunities, risks and progress made in the use of electronic medical record (real-world) data for psychiatric research.

Association of Tumor Necrosis Factor-α Inhibitors with Incident Dementia: Analysis Based on Population-Based Cohort Studies

BACKGROUND AND OBJECTIVE

Preliminary evidence suggests a possible preventive effect of tumor necrosis factor-α inhibitors (TNFi) on incident dementia. The objective of the analysis was to investigate the association between TNFi and the risk of incident dementia in a population undergoing treatment for rheumatological disorders.

METHODS

We followed patients aged ≥ 65 years with dementia and rheumatological conditions in two cohort studies, DANBIO (N = 21,538), a Danish clinical database, and AOK PLUS (N = 7112), a German health insurance database. We defined incident dementia using diagnostic codes and/or medication use and used Cox regression to compare the associations of TNFi with other rheumatological therapies on the risk of dementia. To ensure that the patients were receiving long-term medication, we included patients with rheumatic diseases and systemic therapies.

RESULTS

We observed similar trends towards a lower risk of dementia associated with TNFi versus other anti-inflammatory agents in both cohorts (hazard ratios were 0.92 [95% confidence interval 0.76, 1.10] in DANBIO and 0.89 [95% confidence interval 0.63, 1.24] in AOK PLUS, respectively).

CONCLUSIONS

Tumor necrosis factor-α inhibitors may decrease the risk of incident dementia although the association did not reach statistical significance in this analysis. Further research, ideally with randomization, is needed to gauge the potential of repurposing TNFi for dementia prevention and/or treatment.

JAK1/2 Regulates Synergy Between Interferon Gamma and Lipopolysaccharides in Microglia

Microglia, the resident immune cells of the brain, regulate neuroinflammation which can lead to secondary neuronal damage and cognitive impairment under pathological conditions. Two of the many molecules that can elicit an inflammatory response from microglia are lipopolysaccharide (LPS), a component of gram-negative bacteria, and interferon gamma (IFNγ), an endogenous pro-inflammatory cytokine. We thoroughly examined the concentration-dependent relationship between LPS from multiple bacterial species and IFNγ in cultured microglia and macrophages. We measured the effects that these immunostimulatory molecules have on pro-inflammatory activity of microglia and used a battery of signaling inhibitors to identify the pathways that contribute to the microglial response. We found that LPS and IFNγ interacted synergistically to induce a pro-inflammatory phenotype in microglia, and that inhibition of JAK1/2 completely blunted the response. We determined that this synergistic action of LPS and IFNγ was likely dependent on JNK and Akt signaling rather than typical pro-inflammatory mediators such as NF-κB. Finally, we demonstrated that LPS derived from Escherichia coli, Klebsiella pneumoniae, and Akkermansia muciniphila can elicit different inflammatory responses from microglia and macrophages, but these responses could be consistently prevented using ruxolitinib, a JAK1/2 inhibitor. Collectively, this work reveals a mechanism by which microglia may become hyperactivated in response to the combination of LPS and IFNγ. Given that elevations in circulating LPS and IFNγ occur in a wide variety of pathological conditions, it is critical to understand the pharmacological interactions between these molecules to develop safe and effective treatments to suppress this process.

Association between disease-modifying antirheumatic drugs for rheumatoid arthritis and risk of incident dementia: a systematic review with meta-analysis

BACKGROUND

Dysregulation of several inflammatory cytokines including tumour necrosis factor (TNF) in dementia patients has also been identified as a key factor in the pathogenesis of rheumatoid arthritis (RA). We aimed to investigate the association of disease-modifying antirheumatic drugs (DMARDs) therapy for RA with risk of incident dementia.

METHODS

Electronic database searches of PubMed, EMBASE and Cochrane Library were performed. Observational studies that assessed the association of dementia with DMARDs in RA were included. Pooled risk ratios (RRs) with 95% CIs were used as summary statistic. The certainty of evidence was judged by using the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

Overall, 14 studies involving 940 442 patients with RA were included. Pooled RR for developing dementia was 0.76 (95% CI 0.72 to 0.80) in patients taking biological DMARDs overall versus those taking conventional synthetic DMARDs, with 24% for TNF inhibitors (RR 0.76, 95% CI 0.71 to 0.82), 24% for non-TNF biologics (RR 0.76, 95% CI 0.70 to 0.83), separately. There was a significant subgroup effect among different types of TNF inhibitors (RR 0.58 [95%CI 0.53 to 0.65], 0.65 [95% CI 0.59 to 0.72], 0.80 [95% CI 0.72 to 0.88] for etanercept, adalimumab, infliximab, respectively; p value between groups=0.002). However, compared with non-users of DMARDs or investigative treatment, no significant effect on dementia incidence was observed in those receiving conventional synthetic DMARDs overall (RR 0.84, 95% CI 0.59 to 1.20), methotrexate (RR 0.78, 95% CI 0.54 to 1.12), hydroxychloroquine (RR 0.95, 95% CI 0.63 to 1.44), except for sulfasalazine (RR 1.27, 95% CI 1.06 to 1.50).

CONCLUSIONS

Biological DMARDs for RA are associated with decreased dementia risk, while protective effect is not observed in conventional synthetic DMARDs. Controlled clinical trials on TNF inhibitors are necessary to test their neuroprotective potentials.

Janus kinase inhibitors in atopic dermatitis: an umbrella review of meta-analyses

Background

Clinicians and healthcare policymakers have been drenched with a deluge of overlapping meta-analyses (MAs), and the necessity for comprehensive and clearly defined evidence of Janus kinase inhibitors (JKIs) in atopic dermatitis (AD) is urgent.

Methods

Six databases were searched for MAs published until October 2023. Qualitative description of MAs was mainly used, and Investigator's Global Assessment response (IGA response), the 75% improvement in Eczema Area and Severity Index (the EASI75), peak pruritus Numerical rating score (PP-NRS), and adverse effects were cited to describe the efficacy and safety of JKIs. The methodological quality of the included MAs was assessed by A Measurement Tool to Assess Systematic Reviews II (AMSTAR II), and the quality of evidence was evaluated by the grading of recommendations, assessment, development, and evaluation (GRADE).

Results

Sixteen MAs were pooled in this review, of which five studies appraised JKIs, five appraised systemic JKIs, five papers assessed abrocitinib only, and one assessed baricitinib. Two studies were of "high" methodological quality and 14 MAs were of "moderate" quality. Eleven MAs integrated the results of JKIs and reported that JKIs provide faster onset of IGA response (RR=2.83, 95% CI [2.25, 3.56], high-quality evidence). Similarly, 10 MAs showed that JAK inhibitors were more effective in improving the EASI75 (RR=2.84, 95% CI [2.2, 3.67], high-quality evidence). Results from 12 MAs showed JKIs were active in reducing the PP-NRS (SMD=-0.49, 95% CI [-0.67, -0.32]). All MAs affirmed JKIs added no adverse effects leading to discontinuation and serious adverse events (P<0.05). However, 200mg of abrocitinib had a higher risk of acne (RR=4.34, 95% CI [1.61, 11.71), herpes zoster (RR=1.64, 95% CI [0.42, 6.39]), headache (RR=1.76, 95% CI [1.03, 3]), and nausea (RR=7.81, 95% CI [3.84, 15.87]). Upadacitinib was known to increase acne (RR=6.23, 95% CI [4.08, 9.49]), nasopharyngitis (RR=1.36, 95% CI [1.03, 1.8]) and blood creatine phosphokinase (blood CPK) (RR=2.41, 95% CI [1.47, 3.95]). Baricitinib at 2mg was associated with increased blood CPK (RR=2.25, 95% CI [1.1, 2.97]).

Conclusion

Compared to placebo or dupilumab, the administration of JKIs can ameliorate IGA response more effectively, improve the EASI75, and relieve pruritus without severe adverse effect, while accompanied by more acne, nasopharyngitis, headache, and digestive disturbances. The curative effect of 200 mg of abrocitinib is significant and more caution should be given in patients with gastrointestinal dysfunction, herpes zoster, and those who are acne-prone. Baricitinib and upadacitinib should be avoided in populations at high risk for cardiovascular events.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=369369, PROSPERO (CRD42022369369).

Artificial intelligence and open science in discovery of disease-modifying medicines for Alzheimer's disease

The high failure rate of clinical trials in Alzheimer's disease (AD) and AD-related dementia (ADRD) is due to a lack of understanding of the pathophysiology of disease, and this deficit may be addressed by applying artificial intelligence (AI) to "big data" to rapidly and effectively expand therapeutic development efforts. Recent accelerations in computing power and availability of big data, including electronic health records and multi-omics profiles, have converged to provide opportunities for scientific discovery and treatment development. Here, we review the potential utility of applying AI approaches to big data for discovery of disease-modifying medicines for AD/ADRD. We illustrate how AI tools can be applied to the AD/ADRD drug development pipeline through collaborative efforts among neurologists, gerontologists, geneticists, pharmacologists, medicinal chemists, and computational scientists. AI and open data science expedite drug discovery and development of disease-modifying therapeutics for AD/ADRD and other neurodegenerative diseases.

TNF-α Levels Are Increased in Patients with Subjective Cognitive Impairment and Are Negatively Correlated with β Amyloid-42

The role of tumor necrosis factor-α (TNF-α) in Alzheimer's disease (AD) has recently become a topic of debate. TNF-α levels increase in the blood of patients with AD, and amyloid beta (Aβ) plaques contain TNF-α deposits. The therapeutic efficacy of blocking TNF-α in patients with AD remains controversial as it is mostly based on preclinical studies. Thus, whether and how TNF-α contributes to amyloidogenic processes in AD is still an open question to be addressed. We analyzed plasma TNF-α and Aβ42 levels in patients with subjective cognitive impairment (SCI), mild cognitive impairment (MCI), and AD, and in healthy volunteers (HLT). In addition, we performed correlation analysis to evaluate whether changes in plasma TNF-α levels correlate with cognitive decline, Aβ42 levels, age, and BMI, which are all factors considered to contribute to or predispose individuals to AD. We found that TNF-α and Aβ42 plasma levels were higher in patients with AD than in HLT individuals. High TNF-α levels were also observed in patients with SCI, in whom TNF-α and Aβ42 levels were negatively correlated. Notably, TNF-α did not affect the amyloidogenic pathway in human microglial cultures exposed to 48 h of incubation, although it did trigger neuroinflammatory processes. These results imply that high TNF-α levels are more likely to be a clinical condition linked to AD than are direct contributors. Nonetheless, elevated levels of TNF-α in early-stage patients, like those with SCI and MCI, may provide a distinguishing feature for identifying clinical profiles that are at risk of having a poorer outcome in AD and could benefit from tailored therapies.

The RESIST Study: Examining Cognitive Change in Rheumatoid Arthritis Patients with Mild Cognitive Impairment Being Treated with a TNF-Inhibitor Compared to a Conventional Synthetic Disease-Modifying Anti-Rheumatic Drug

Background

Evidence suggests that TNF inhibitors (TNFi) used to treat rheumatoid arthritis (RA) may protect against Alzheimer's disease progression by reducing inflammation.

Objective

To investigate whether RA patients with mild cognitive impairment (MCI) being treated with a TNFi show slower cognitive decline than those being treated with a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD).

Methods

251 participants with RA and MCI taking either a csDMARD (N = 157) or a TNFi (N = 94) completed cognitive assessments at baseline and 6-month intervals for 18 months. It was hypothesized that those taking TNFis would show less decline on the primary outcome of Free and Cued Selective Reminding Test with Immediate Recall (FCSRT-IR) and the secondary outcome of Montreal Cognitive Assessment (MoCA).

Results

No significant changes in FCSRT-IR scores were observed in either treatment group. There was no significant difference in FCSRT-IR between treatment groups at 18 months after adjusting for baseline (mean difference = 0.5, 95% CI = -1.3, 2.3). There was also no difference in MoCA score (mean difference = 0.4, 95% CI = -0.4, 1.3).

Conclusions

There was no cognitive decline in participants with MCI being treated with TNFis and csDMARDs, raising the possibility both classes of drug may be protective. Future studies should consider whether controlling inflammatory diseases using any approach is more important than a specific therapeutic intervention.

Baricitinib and tofacitinib off-target profile, with a focus on Alzheimer's disease

INTRODUCTION

Janus kinase (JAK) inhibitors were recently identified as promising drug candidates for repurposing in Alzheimer's disease (AD) due to their capacity to suppress inflammation via modulation of JAK/STAT signaling pathways. Besides interaction with primary therapeutic targets, JAK inhibitor drugs frequently interact with unintended, often unknown, biological off-targets, leading to associated effects. Nevertheless, the relevance of JAK inhibitors' off-target interactions in the context of AD remains unclear.

METHODS

Putative off-targets of baricitinib and tofacitinib were predicted using a machine learning (ML) approach. After screening scientific literature, off-targets were filtered based on their relevance to AD. Targets that had not been previously identified as off-targets of baricitinib or tofacitinib were subsequently tested using biochemical or cell-based assays. From those, active concentrations were compared to bioavailable concentrations in the brain predicted by physiologically based pharmacokinetic (PBPK) modeling.

RESULTS

With the aid of ML and in vitro activity assays, we identified two enzymes previously unknown to be inhibited by baricitinib, namely casein kinase 2 subunit alpha 2 (CK2-α2) and dual leucine zipper kinase (MAP3K12), both with binding constant (K d) values of 5.8 μM. Predicted maximum concentrations of baricitinib in brain tissue using PBPK modeling range from 1.3 to 23 nM, which is two to three orders of magnitude below the corresponding binding constant.

CONCLUSION

In this study, we extended the list of baricitinib off-targets that are potentially relevant for AD progression and predicted drug distribution in the brain. The results suggest a low likelihood of successful repurposing in AD due to low brain permeability, even at the maximum recommended daily dose. While additional research is needed to evaluate the potential impact of the off-target interaction on AD, the combined approach of ML-based target prediction, in vitro confirmation, and PBPK modeling may help prioritize drugs with a high likelihood of being effectively repurposed for AD.

Highlights

This study explored JAK inhibitors' off-targets in AD using a multidisciplinary approach.We combined machine learning, in vitro tests, and PBPK modelling to predict and validate new off-target interactions of tofacitinib and baricitinib in AD.Previously unknown inhibition of two enzymes (CK2-a2 and MAP3K12) by baricitinib were confirmed using in vitro experiments.Our PBPK model indicates that baricitinib low brain permeability limits AD repurposing.The proposed multidisciplinary approach optimizes drug repurposing efforts in AD research.

Inflammation, Autoimmunity and Neurodegenerative Diseases, Therapeutics and Beyond

Neurodegenerative disease (ND) incidence has recently increased due to improved life expectancy. Alzheimer's (AD) or Parkinson's disease (PD) are the most prevalent NDs. Both diseases are poly genetic, multifactorial and heterogenous. Preventive medicine, a healthy diet, exercise, and controlling comorbidities may delay the onset. After the diseases are diagnosed, therapy is needed to slow progression. Recent studies show that local, peripheral and age-related inflammation accelerates NDs' onset and progression. Patients with autoimmune disorders like inflammatory bowel disease (IBD) could be at higher risk of developing AD or PD. However, no increase in ND incidence has been reported if the patients are adequately diagnosed and treated. Autoantibodies against abnormal tau, β amyloid and α- synuclein have been encountered in AD and PD and may be protective. This discovery led to the proposal of immune-based therapies for AD and PD involving monoclonal antibodies, immunization/ vaccines, pro-inflammatory cytokine inhibition and anti-inflammatory cytokine addition. All the different approaches have been analysed here. Future perspectives on new therapeutic strategies for both disorders are concisely examined.

Neuropathologic evaluation of cerebrovascular disease in patients with rheumatoid arthritis

OBJECTIVES

Active RA has been associated with an increased risk of both cardiovascular and peripheral vascular disease. We aimed to compare cerebrovascular changes in patients with and without RA, both with and without a neuropathologic diagnosis of neurodegenerative disease.

METHODS

Patients with RA (n = 32) who died and underwent autopsy between 1994 and 2021 were matched to non-RA controls (n = 32) on age, sex and level of neurodegenerative proteinopathy. Routine neuropathologic examination was performed at the time of autopsy. Cerebrovascular disease severity was evaluated using modified Kalaria and Strozyk scales. Clinical dementia diagnoses were manually collected from patients' medical records.

RESULTS

Prior to death, 15 (47%) RA patients and 14 (44%) controls were diagnosed with dementia; 9 patients in each group (60% and 64%, respectively) had Alzheimer's disease. The prevalence of cerebral amyloid angiopathy, microinfarcts, infarcts or strokes was found to be similar between groups. Patients with RA were more likely to have more severe vascular changes in the basal ganglia by Kalaria scale (P = 0.04), but not in other brain areas. There were no significant differences in the presence of large infarcts, lacunar infarcts or leukoencephalopathy by Strozyk scale. Among patients with RA and no clinical diagnosis of dementia, the majority had mild-moderate cerebrovascular abnormalities, and a subset of patients had Alzheimer's disease neuropathologic changes.

CONCLUSION

In this small series of autopsies, patients with and without RA had largely similar cerebrovascular pathology when controlling for neurodegenerative proteinopathies, although patients with RA exhibited more pronounced cerebrovascular disease in the basal ganglia.

Drug repurposing for Alzheimer's disease from 2012-2022-a 10-year literature review

Background: Alzheimer's disease (AD) is a debilitating neurodegenerative condition with few treatment options available. Drug repurposing studies have sought to identify existing drugs that could be repositioned to treat AD; however, the effectiveness of drug repurposing for AD remains unclear. This review systematically analyzes the progress made in drug repurposing for AD throughout the last decade, summarizing the suggested drug candidates and analyzing changes in the repurposing strategies used over time. We also examine the different types of data that have been leveraged to validate suggested drug repurposing candidates for AD, which to our knowledge has not been previous investigated, although this information may be especially useful in appraising the potential of suggested drug repurposing candidates. We ultimately hope to gain insight into the suggested drugs representing the most promising repurposing candidates for AD. Methods: We queried the PubMed database for AD drug repurposing studies published between 2012 and 2022. 124 articles were reviewed. We used RxNorm to standardize drug names across the reviewed studies, map drugs to their constituent ingredients, and identify prescribable drugs. We used the Anatomical Therapeutic Chemical (ATC) Classification System to group drugs. Results: 573 unique drugs were proposed for repurposing in AD over the last 10 years. These suggested repurposing candidates included drugs acting on the nervous system (17%), antineoplastic and immunomodulating agents (16%), and drugs acting on the cardiovascular system (12%). Clozapine, a second-generation antipsychotic medication, was the most frequently suggested repurposing candidate (N = 6). 61% (76/124) of the reviewed studies performed a validation, yet only 4% (5/124) used real-world data for validation. Conclusion: A large number of potential drug repurposing candidates for AD has accumulated over the last decade. However, among these drugs, no single drug has emerged as the top candidate, making it difficult to establish research priorities. Validation of drug repurposing hypotheses is inconsistently performed, and real-world data has been critically underutilized for validation. Given the urgent need for new AD therapies, the utility of real-world data in accelerating identification of high-priority candidates for AD repurposing warrants further investigation.

Promise and peril of claims-based dementia ascertainment in causal inference

Festa and colleagues highlight underrecognized factors that may bias research, policy, and population health strategies predicated upon claims-based ascertainment of Alzheimer’s Disease and Related Dementias within the United States.

Alzheimer's Disease Treatment: The Search for a Breakthrough

As the search for modalities to cure Alzheimer's disease (AD) has made slow progress, research has now turned to innovative pathways involving neural and peripheral inflammation and neuro-regeneration. Widely used AD treatments provide only symptomatic relief without changing the disease course. The recently FDA-approved anti-amyloid drugs, aducanumab and lecanemab, have demonstrated unclear real-world efficacy with a substantial side effect profile. Interest is growing in targeting the early stages of AD before irreversible pathologic changes so that cognitive function and neuronal viability can be preserved. Neuroinflammation is a fundamental feature of AD that involves complex relationships among cerebral immune cells and pro-inflammatory cytokines, which could be altered pharmacologically by AD therapy. Here, we provide an overview of the manipulations attempted in pre-clinical experiments. These include inhibition of microglial receptors, attenuation of inflammation and enhancement of toxin-clearing autophagy. In addition, modulation of the microbiome-brain-gut axis, dietary changes, and increased mental and physical exercise are under evaluation as ways to optimize brain health. As the scientific and medical communities work together, new solutions may be on the horizon to slow or halt AD progression.

Hydroxychloroquine lowers Alzheimer's disease and related dementias risk and rescues molecular phenotypes related to Alzheimer's disease

We recently nominated cytokine signaling through the Janus-kinase-signal transducer and activator of transcription (JAK/STAT) pathway as a potential AD drug target. As hydroxychloroquine (HCQ) has recently been shown to inactivate STAT3, we hypothesized that it may impact AD pathogenesis and risk. Among 109,124 rheumatoid arthritis patients from routine clinical care, HCQ initiation was associated with a lower risk of incident AD compared to methotrexate initiation across 4 alternative analyses schemes addressing specific types of biases including informative censoring, reverse causality, and outcome misclassification (hazard ratio [95% confidence interval] of 0.92 [0.83-1.00], 0.87 [0.81-0.93], 0.84 [0.76-0.93], and 0.87 [0.75-1.01]). We additionally show that HCQ exerts dose-dependent effects on late long-term potentiation (LTP) and rescues impaired hippocampal synaptic plasticity prior to significant accumulation of amyloid plaques and neurodegeneration in APP/PS1 mice. Additionally, HCQ treatment enhances microglial clearance of Aβ_1-42, lowers neuroinflammation, and reduces tau phosphorylation in cell culture-based phenotypic assays. Finally, we show that HCQ inactivates STAT3 in microglia, neurons, and astrocytes suggesting a plausible mechanism associated with its observed effects on AD pathogenesis. HCQ, a relatively safe and inexpensive drug in current use may be a promising disease-modifying AD treatment. This hypothesis merits testing through adequately powered clinical trials in at-risk individuals during preclinical stages of disease progression.

State-of-the-art therapy for Down syndrome

In the last decade, an important effort was made in the field of Down syndrome to find new interventions that improve cognition. These therapies have added to the traditional symptomatic treatments and to the drugs for treating Alzheimer disease in the general population repurposed for Down syndrome. Defining next-generation therapeutics will involve biomarker-based therapeutic decision-making, and preventive and multimodal interventions. However, translation of specific findings into effective therapeutic strategies has been disappointingly slow and has failed in many cases at the clinical level, leading to reduced credibility of mouse studies. This is aggravated by a tendency to favour large-magnitude effects and highly significant findings, leading to high expectations but also to a biased view of the complex pathophysiology of Down syndrome. Here, we review some of the most recent and promising strategies for ameliorating the cognitive state of individuals with Down syndrome. We studied the landscape of preclinical and clinical studies and conducted a thorough literature search on PubMed and ClinicalTrials.gov for articles published between June 2012 and August 2022 on therapies for ameliorating cognitive function in individuals with Down syndrome. We critically assess current therapeutic approaches, why therapies fail in clinical trials in Down syndrome, and what could be the path forward. We discuss some intrinsic difficulties for translational research, and the need for a framework that improves the detection of drug efficacy to avoid discarding compounds too early from the companies' pipelines.

Rheumatoid Arthritis and Cognitive Impairment or Dementia: An Updated Review of Epidemiological Data

Rheumatoid arthritis (RA) is hypothesized to be associated with cognitive impairment and dementia, including Alzheimer's disease, through shared biological processes related to inflammation. It is important to elucidate this potential relationship as both conditions confer increased morbidity and even mortality among older adults. This narrative review provides a survey of recent epidemiologic studies, examining the association between rheumatoid arthritis and either dementia or cognitive impairment. Sixteen studies were included after searching in PubMed and EMBASE. All were published between 2012 and 2022 and were characterized as epidemiologic studies (either cohort, cross-sectional, or case-control). Studies varied in location, design, measures of exposure and outcome, and covariates considered. Of the 16 studies included, only five found statistically significant positive associations between RA and dementia or cognitive impairment. One study found an inverse relationship, while five studies found no associations at all. The remaining five studies found variable statistically significant associations between demographic or RA disease characteristics and cognitive measures. Given these mixed findings, further studies at both the mechanistic and population level are needed to clarify the possible shared biological underpinnings of these two conditions.

Risk Factors for Dementia in Patients With Incident Rheumatoid Arthritis: A Population-Based Cohort Study

OBJECTIVE

Growing evidence suggests that patients with rheumatoid arthritis (RA) have increased risk for dementia. We assessed risk factors for incident dementia in an inception cohort of patients with RA.

METHODS

This retrospective population-based cohort study included residents of 8 counties in Minnesota who were ≥ 50 years of age when they met 1987 American College of Rheumatology criteria for incident RA between 1980 and 2014 and were followed until death/migration or December 31, 2019. Patients with dementia before RA incidence were excluded. Incident dementia was defined as 2 relevant International Classification of Diseases, 9th or 10th revision codes at least 30 days apart. Data on sociodemographics, disease characteristics, cardiovascular/cerebrovascular disease (CVD) risk factors, and comorbidities were abstracted from medical records.

RESULTS

The study included 886 patients with RA (mean age 65.1 yrs, 65.2% female). During the follow-up period (median 8.5 yrs), 103 patients developed dementia. After adjusting for age, sex, and calendar year of RA incidence, older age at RA incidence (HR 1.14 per 1 year increase, 95% CI 1.12-1.17), rheumatoid nodules (HR 1.76, 95% CI 1.05-2.95), hypertension (HR 1.84, 95% CI 1.19-2.85), presence of large joint swelling (HR 2.03, 95% CI 1.14-3.60), any CVD (HR 2.25, 95% CI 1.38-3.66), particularly ischemic stroke (HR 3.16, 95% CI 1.84-5.43) and heart failure (HR 1.82, 95% CI 1.10-3.00), anxiety (HR 1.86, 95% CI 1.16-2.97), and depression (HR 2.63, 95% CI 1.76-3.93) were associated with increased risk of dementia. After adjusting for CVD risk factors and any CVD, all covariates listed above were still significantly associated with risk of dementia.

CONCLUSION

Apart from age, hypertension, depression, and anxiety, all of which are universally recognized risk factors for dementia, clinically active RA and presence of CVD were associated with an elevated risk of dementia incidence among patients with RA.

Association of Autoimmune Disorders and Disease-modifying Antirheumatic Drugs: (DMARDs) with the Risk of Alzheimer's and/or Dementia: A Population Study Using Medicare Beneficiary Data

OBJECTIVES

Alzheimer's disease (AD) and/or dementia is a prevalent neurocognitive disorder primarily affecting individuals over the age of 65. Identifying specific causes of AD and/or dementia can be challenging, with emerging evidence suggesting a potential association with autoimmune inflammatory conditions such as rheumatoid arthritis (RA). This study aimed to assess the prevalence rate of AD and/or dementia among Medicare beneficiaries reporting an autoimmune disorder. Additionally, this study sought to identify the comparative prevalence of AD and/or dementia in patients with an autoimmune disorder who were using disease-modifying antirheumatic drugs (DMARDs) compared to those not using DMARDs.

METHODS

Cross-sectional secondary data analyses were conducted on Medicare Current Beneficiary Survey (MCBS) data from 2017 and 2018. The MCBS data consists of a nationally representative sample of the Medicare population, a population that is largely 65 and older, and provides de-identified patient information. Patients from this dataset with a self-reported autoimmune disorder were included in the analyses. Descriptive analyses were conducted on demographic variables, chronic conditions, and medication use. The prevalence of AD and/or dementia was compared between patients with and without an autoimmune disorder. A backward stepwise selection regression was used to identify the risk factors associated with the prevalence of AD and/or dementia.

RESULTS

The study included 18,929 Medicare beneficiaries, with 4,405 identified as having one autoimmune disorder. The prevalence of AD and/or dementia was significantly higher in patients with an autoimmune disorder. The multivariate regression showed that RA was significantly associated with a higher risk of AD and/or dementia. Other demographic factors, including advanced age, African-American or Hispanic ethnicity, low body mass index, and chronic conditions of ischemic heart disease, history of myocardial infarction, history of stroke, depression, mental health disorder(s), and traumatic brain injury also showed statistically significant associations with AD and/or dementia. Patients using DMARDs demonstrated a reduced likelihood of having AD and/or dementia, compared to patients not using DMARDs.

CONCLUSION

This study provides evidence of an association between RA and increased risk of AD and/or dementia. The findings suggest that DMARD use may have a protective effect against the development of AD and/or dementia in patients with an autoimmune disorder.

No association between initiation of phosphodiesterase-5 inhibitors and risk of incident Alzheimer's disease and related dementia: results from the Drug Repurposing for Effective Alzheimer's Medicines study

We evaluated the hypothesis that phosphodiesterase-5 inhibitors, including sildenafil and tadalafil, may be associated with reduced incidence of Alzheimer's disease and related dementia using a patient-level cohort study of Medicare claims and cell culture-based phenotypic assays. We compared incidence of Alzheimer's disease and related dementia after phosphodiesterase-5 inhibitor initiation versus endothelin receptor antagonist initiation among patients with pulmonary hypertension after controlling for 76 confounding variables through propensity score matching. Across four separate analytic approaches designed to address specific types of biases including informative censoring, reverse causality, and outcome misclassification, we observed no evidence for a reduced risk of Alzheimer's disease and related dementia with phosphodiesterase-5 inhibitors;hazard ratio (95% confidence interval): 0.99 (0.69-1.43), 1.00 (0.71-1.42), 0.67 (0.43-1.06), and 1.15 (0.57-2.34). We also did not observe evidence that sildenafil ameliorated molecular abnormalities relevant to Alzheimer's disease in most cell culture-based phenotypic assays. These results do not provide support to the hypothesis that phosphodiesterase-5 inhibitors are promising repurposing candidates for Alzheimer's disease and related dementia.