Dementia and Alzheimer's disease risks in patients with autoimmune disorders

Dietary salt, vascular dysfunction, and cognitive impairment

Excessive salt consumption is a major health problem worldwide leading to serious cardiovascular events including hypertension, heart disease, and stroke. Additionally, high-salt diet has been increasingly associated with cognitive impairment in animal models and late-life dementia in humans. High-salt consumption is harmful for the cerebral vasculature, disrupts blood supply to the brain, and could contribute to Alzheimer's disease pathology. Although animal models have advanced our understanding of the cellular and molecular mechanisms, additional studies are needed to further elucidate the effects of salt on brain function. Furthermore, the association between excessive salt intake and cognitive impairment will have to be more thoroughly investigated in humans. Since the harmful effects of salt on the brain are independent by its effect on blood pressure, in this review, I will specifically discuss the evidence, available in experimental models and humans, on the effects of salt on vascular and cognitive function in the absence of changes in blood pressure. Given the strong effects of salt on the function of immune cells, I will also discuss the evidence linking salt consumption to gut immunity dysregulation with particular attention to the ability of salt to disrupt T helper 17 (Th17) cell homeostasis. Lastly, I will briefly discuss the data implicating IL-17A, the major cytokine produced by Th17 cells, in vascular dysfunction and cognitive impairment.

Increased risk of dementia in Type 1 diabetes: A systematic review with meta-analysis

This systematic review and meta-analysis aimed to synthesize evidence on the association between Type 1 diabetes mellitus (Type 1 diabetes) and dementia risk. A systematic search of CINAHL, EMBASE, MEDLINE, PSYCINFO, and Web of Science databases identified 19 relevant studies for inclusion. Studies, published in English, were assessed for quality using the QUADAS-2 tool, and data were extracted for synthesis. A meta-analysis of six studies reporting hazard ratios (HR) for dementia risk in individuals with Type 1 diabetes versus controls was conducted. The pooled HR for all-cause dementia was 1.50 (95 % CI: 1.25-1.80, p < 0.001), indicating a 50 % increased risk of dementia in people with Type 1 diabetes compared to controls. This review provides robust evidence linking Type 1 diabetes to increased dementia risk and highlights the need for targeted screening and preventive strategies for this population. Further research is necessary to explore the mechanisms underlying the association between Type 1 diabetes and dementia.

Exposure to autoimmune disorders is associated with increased Alzheimer's disease risk in a multi-site electronic health record analysis

Autoimmunity has been proposed to increase Alzheimer's disease (AD) risk, but evaluating the clinical connection between autoimmune disorders and AD has been difficult in diverse populations. We investigate risk relationships between 26 autoimmune disorders and AD using retrospective observational case-control and cohort study designs based on electronic health records for >300,000 individuals at the University of California, San Francisco (UCSF) and Stanford University. We discover that autoimmune disorders are associated with increased AD risk (odds ratios [ORs] 1.4-1.7) across study designs, primarily driven by endocrine, gastrointestinal, dermatologic, and musculoskeletal disorders. We also find that autoimmune disorders associate with increased AD risk in both sexes, but the AD sex disparity remains in those with autoimmune disorders: women exhibit higher AD prevalence than men. This study identifies consistent associations between autoimmune disorders and AD across study designs and two real-world clinical databases, establishing a foundation for exploring how autoimmunity may contribute to AD risk.

Association between ankylosing spondylitis and neurodegenerative diseases: Systematic review and meta-analysis

BACKGROUND

Increasing evidence indicates the mechanism of overlapping immune dysfunction and inflammation disorder shared by ankylosing spondylitis (AS) and neurodegenerative diseases (NDs). However, the exact correlation between the two is still unclear. Different studies have reported inconsistent results about how AS and NDs are related.

OBJECTIVE

This study aimed to investigate the association between AS and risk of NDs.

METHODS

We searched electronic databases including PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify studies reporting relationship between NDs risk and AS published before April 10th, 2024. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were estimated. All analyses were conducted using Stata V.12.0 software.

RESULTS

A total of 15 comparisons out of 10 studies involving 851,936 participants were included. The results showed that the risk of NDs was higher among AS patients than those who were not (OR: 1.36, 95% CI: 1.15-1.60, P<0.001). In addition, subgroup analysis showed that AS was associated with an increased risk of Parkinson's disease (PD) development (OR: 1.55, 95% CI: 1.31-1.83, P<0.001), whereas there is no observed association with Alzheimer's disease (AD) and dementia (OR: 1.22, 95% CI: 0.96-1.55, P=0.098; OR: 1.34, 95% CI: 0.96-1.87, P=0.089, respectively).

CONCLUSION

The current meta-analysis identified AS as a risk factor for the development of NDs. Clinicians should be aware of the potential association between these diseases. Further research is necessary to confirm the causal relationship and underlying mechanisms between AS and NDs.

Association between autoimmune diseases and Alzheimer's disease: analysis using big data tools

OBJECTIVE

The objective is to analyze the prevalence of Alzheimer's disease in patients with and without a diagnosis of different autoimmune diseases and the possible association between both pathologies.

PATIENTS AND METHODS

A multicenter, retrospective, cohort study was conducted to study the prevalence of Alzheimer's disease among patients diagnosed with various autoimmune diseases compared to the general population. Data from electronic medical records from the Castilla-La Mancha healthcare system were analyzed using Natural Language Processing through the Savana Manager® artificial intelligence clinical platform. A total of 1,028,356 patients were analyzed, including 28,920 individuals with Alzheimer's disease and 999,436 control patients.

RESULTS

Out of the 12 autoimmune diseases analyzed, 5 showed a significant association with Alzheimer's disease with p < 0.05. Myasthenia gravis had an increased prevalence of AD with OR 1.49 (95% CI 1.11-2), systemic lupus erythematosus with OR 2.42 (95% CI 2.02-2.88), rheumatoid arthritis with OR 1.38 (95% CI 1.24-1.54), polymyalgia rheumatica with OR 2.01 (95% CI 1.08-2.23), and pernicious anemia with OR 2.06 (95% CI 1.59-2.66). The remaining autoimmune diseases analyzed did not show a higher prevalence of Alzheimer's disease compared to the general population.

CONCLUSIONS

There may be an association between certain systemic autoimmune diseases and Alzheimer's disease. Further studies are needed to confirm our findings, establish causality, and explore the underlying mechanisms of this association.

Causal relationships between rheumatoid arthritis and neurodegenerative diseases: a two-sample univariable and multivariable Mendelian randomization study

Background

Observational research has highlighted a potential relationship between rheumatoid arthritis (RA) and neurodegenerative diseases (NDs). However, the confirmation of a causal connection is impeded by the inherent limitations of such studies, including vulnerability to confounding factors and the possibility of reverse causality. This study employs a two-sample Mendelian randomization (MR) approach to assess the causal impact of RA on three NDs, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).

Methods

We aggregated data from genome-wide association studies (GWASs) targeting RA or NDs within populations of European descent. Single nucleotide polymorphisms (SNPs) with robust associations to RA were identified as instrumental variables (IVs). To estimate the association between RA and AD, PD, and ALS, we utilized the inverse variance weighted (IVW) method in our univariable MR (UVMR) analysis. Validation of the IVW results ensued through supplementary analyses using MR-Egger and weighted median methods. The multivariable MR (MVMR) analysis was conducted, adjusting for body mass index (BMI), alcohol drinking, and type 2 diabetes mellitus (T2DM).

Results

The UVMR analysis, based on the IVW method, revealed a significantly positive causal association between RA and late-onset (LO) AD (OR [95% CI] = 1.084 [1.020-1.153]; p = 9.980 × 10-3), while suggesting a possible inverse relationship with PD (OR [95% CI] = 0.727 [0.563-0.938]; p = 0.014). Our study did not detect any causal connections between RA and early-onset (EO) AD, atypical or mixed (AM) AD, and ALS (all p > 0.05). The MVMR analysis results indicated that after adjusting for alcohol drinking, RA remains a risk factor for LOAD (OR [95% CI] = 1.094 [1.024-1.169]; p = 0.008). However, MVMR analysis revealed no causal connections between RA and PD after adjustments for BMI, alcohol drinking, or T2DM (all p > 0.05). Sensitivity analyses showed no evidence of heterogeneity and horizontal pleiotropy.

Conclusions

This research provides genetic evidence indicating that RA potentially causes an increased risk of developing LOAD and PD. Such a revelation underscores the importance for individuals suffering from RA to be vigilant about the potential emergence of LOAD and PD. Ongoing monitoring and prompt detection are essential for successfully managing and intervening in this possible risk.

Rheumatic and Musculoskeletal Diseases and Risk of Dementia: A Nested Case-Control Study

OBJECTIVE

To investigate the associations between rheumatic and musculoskeletal diseases (RMDs) and incident dementia using population register-based data.

METHODS

This nested case-control study was conducted based on a cohort of residents in the Skåne region, Sweden, aged 50 years and older in 2009 without doctor-diagnosed dementia during 1998 to 2009 (n = 402,825). Individuals with a new main diagnosis of dementia during 2010 to 2019 were identified as incident patients with dementia (n = 22,131). Controls without diagnosed dementia were randomly matched 1:1 by sex, age, and Elixhauser comorbidity index using incidence density sampling. Separate conditional logistic regression analyses adjusted for confounders were fitted for the following RMDs, diagnosed at least 2 years before dementia diagnosis as exposure: gout, osteoarthritis, rheumatoid arthritis, spondyloarthropathies (SpA), and systemic connective tissue disorders. Subgroup analyses by dementia subtype, sex, age, comorbidity, and RMDs/dementia identification were conducted.

RESULTS

Although gout (adjusted rate ratio 0.88; 95% confidence interval 0.79-0.97), osteoarthritis (0.92; 0.88-0.96), and systemic connective tissue disorders (0.91; 0.83-0.99) were associated with decreased risk of dementia, the associations for rheumatoid arthritis (1.05; 0.92-1.19) and SpA (1.17; 0.94-1.45) were inconclusive. The associations between RMDs and incident dementia were similar across sex, age, and comorbidity subgroups with a few exceptions (eg, an adjusted rate ratio of 0.99 [95% confidence interval 0.71-1.39] in males vs 1.31 [0.99-1.74] in female patients for SpA).

CONCLUSION

Persons with diagnosed RMDs seem to have comparable or slightly lower risks of developing dementia compared with those without known RMD.

Essential New Complexity-Based Themes for Patient-Centered Diagnosis and Treatment of Dementia and Predementia in Older People: Multimorbidity and Multilevel Phenomenology

Dementia is a highly prevalent condition with devastating clinical and socioeconomic sequela. It is expected to triple in prevalence by 2050. No treatment is currently known to be effective. Symptomatic late-onset dementia and predementia (SLODP) affects 95% of patients with the syndrome. In contrast to trials of pharmacological prevention, no treatment is suggested to remediate or cure these symptomatic patients. SLODP but not young onset dementia is intensely associated with multimorbidity (MUM), including brain-perturbating conditions (BPCs). Recent studies showed that MUM/BPCs have a major role in the pathogenesis of SLODP. Fortunately, most MUM/BPCs are medically treatable, and thus, their treatment may modify and improve SLODP, relieving suffering and reducing its clinical and socioeconomic threats. Regrettably, the complex system features of SLODP impede the diagnosis and treatment of the potentially remediable conditions (PRCs) associated with them, mainly due to failure of pattern recognition and a flawed diagnostic workup. We suggest incorporating two SLODP-specific conceptual themes into the diagnostic workup: MUM/BPC and multilevel phenomenological themes. By doing so, we were able to improve the diagnostic accuracy of SLODP components and optimize detecting and favorably treating PRCs. These revolutionary concepts and their implications for remediability and other parameters are discussed in the paper.

Exposure to autoimmune disorders increases Alzheimer's disease risk in a multi-site electronic health record analysis

Molecular studies of Alzheimer's disease (AD) implicate potential links between autoimmunity and AD, but the underlying clinical relationships between these conditions remain poorly understood. Electronic health records (EHRs) provide an opportunity to determine the clinical risk relationship between autoimmune disorders and AD and understand whether specific disorders and disorder subtypes affect AD risk at the phenotypic level in human populations. We evaluated relationships between 26 autoimmune disorders and AD across retrospective observational case-control and cohort study designs in the EHR systems at UCSF and Stanford. We quantified overall and sex-specific AD risk effects that these autoimmune disorders confer. We identified significantly increased AD risk in autoimmune disorder patients in both study designs at UCSF and at Stanford. This pattern was driven by specific autoimmunity subtypes including endocrine, gastrointestinal, dermatologic, and musculoskeletal disorders. We also observed increased AD risk from autoimmunity in both women and men, but women with autoimmune disorders continued to have a higher AD prevalence than men, indicating persistent sex-specificity. This study identifies autoimmune disorders as strong risk factors for AD that validate across several study designs and EHR databases. It sets the foundation for exploring how underlying autoimmune mechanisms increase AD risk and contribute to AD pathogenesis.

Unraveling brain diseases: The promise of brain-on-a-chip models

Brain disorders, encompassing a wide spectrum of neurological and psychiatric conditions, present a formidable challenge in modern medicine. Despite decades of research, the intricate complexity of the human brain still eludes comprehensive understanding, impeding the development of effective treatments. Recent advancements in microfluidics and tissue engineering have led to the development of innovative platforms known as "Brain-on-a-Chip" (BoC) i.e., advanced in vitro systems that aim to replicate the microenvironment of the brain with the highest possible fidelity. This technology offers a promising test-bed for studying brain disorders at the cellular and network levels, providing insights into disease mechanisms, drug screening, and, in perspective, the development of personalized therapeutic strategies. In this review, we provide an overview of the BoC models developed over the years to model and understand the onset and progression of some of the most severe neurological disorders in terms of incidence and debilitation (stroke, Parkinson's, Alzheimer's, and epilepsy). We also report some of the cutting-edge therapeutic approaches whose effects were evaluated by means of these technologies. Finally, we discuss potential challenges, and future perspectives of the BoC models.

The two-directional prospective association between inflammatory bowel disease and neurodegenerative disorders: a systematic review and meta-analysis based on longitudinal studies

Objective

Previous studies reported possible connections between inflammatory bowel disease (IBD) and several neurodegenerative disorders. However, the comprehensive relationships between IBD and various neurodegenerative disorders were not summarized. We executed a meta-analysis of longitudinal studies to provide an estimate of the strength of the two-directional prospective association between IBD and neurodegenerative disorders.

Methods

We accomplished a thorough bibliographic search of PubMed, Web of Science, Embase, PsycINFO, and Cochrane Library databases until June 2023 to locate relevant longitudinal studies. The extracted data were then analyzed via meta-analysis using either a fixed or random effects model.

Results

The final analysis encompassed 27 studies. Individuals with IBD faced an increased risk of developing four neurodegenerative disorders than the general public, namely, Alzheimer's disease (hazard ratio[HR] = 1.35, 95% confidence interval [CI]: 1.03-1.77, P=0.031), dementia (HR =1.24, 95% CI: 1.13-1.36, P<0.001), multiple sclerosis (HR =2.07, 95% CI:1.42-3.02, P<0.001) and Parkinson's disease (HR =1.23, 95% CI:1.10-1.38, P<0.001). Two articles reported an increased incidence of amyotrophic lateral sclerosis or multiple system atrophy in IBD patients. Three studies investigated the prospective association between multiple sclerosis and IBD, revealing an elevated risk of the latter in patients with the former. (HR=1.87, 95% CI:1.66-2.10, P<0.001).

Interpretation

These findings verified the two-directional relationship between the brain-gut axis, specifically demonstrating a heightened risk of various neurodegenerative diseases among IBD patients. It may be profitable to prepare screening strategies for IBD patients to find neurodegenerative diseases during the long-term course of treatment for IBD with a view to potential earlier diagnosis and treatment of neurodegenerative diseases, reducing public health and social burden.

Systematic Review Registration

PROSPERO (CRD42023437553).

Graves disease is associated with increased risk of clinical Alzheimer's disease: evidence from the Medicare system

BACKGROUND

Identification of modifiable risk factors for Alzheimer's Disease (AD) onset is an important aspect of controlling the burden imposed by this disease on an increasing number of older U.S. adults. Graves disease (GD), the most common cause of hyperthyroidism in the U.S., has been hypothesized to be associated with increased AD risk, but there is no consensus. In this study, we explore the link between GD and risk of clinical AD.

METHODS

Cox and Fine-Grey models were applied to a retrospective propensity-score-matched cohort of 19,798 individuals with GD drawn from a nationally representative 5% sample of U.S. Medicare beneficiaries age 65 + over the 1991-2020 period.

RESULTS

Results showed that the presence of GD was associated with a higher risk of AD (Hazard Ratio [HR]:1.19; 95% Confidence Interval [CI]:1.13-1.26). Competing risk estimates were consistent with these findings (HR:1.14; CI:1.08-1.20) with the magnitude of associated risk varying across subgroups: Male (HR:1.25; CI:1.07-1.47), Female (HR:1.09; CI:1.02-1.16), White (HR:1.11; CI:1.03-1.19), and Black (HR:1.23; CI:1.02-1.49).

CONCLUSIONS

Our results indicate a robust and consistent association between a diagnosis of GD and a subsequent diagnosis of AD in later stages of life. The precise biological pathways that could potentially connect these two conditions remain unclear as is the role of treatment in this relationship. Replications of these findings on datasets with both biomarkers and laboratory test results, especially in underrepresented groups is vital.

Risk of Major Types of Dementias Following Hospital-Diagnosed Infections and Autoimmune Diseases

Background

Population-based studies have shown an increased risk of dementia after infections, but weaker links were reported for autoimmune diseases. Evidence is scarce for whether the links may be modified by the dementia or exposure subtype.

Objective

We aimed to investigate the association between infections and/or autoimmune diseases and rates of major types of dementias in the short- and long terms.

Methods

Nationwide nested case-control study of dementia cases (65+ years) diagnosed in Denmark 2016-2020 and dementia-free controls. Exposures were hospital-diagnosed infections and autoimmune diseases in the preceding 35 years. Two groups of dementia cases were those diagnosed in memory clinics (MC) and those diagnosed outside memory clinics (non-memory clinic cases, NMC).

Results

In total, 26,738 individuals were MC and 12,534 were NMC cases. Following any infection, the incidence rate ratio (IRR) for MC cases was 1.23 (95% CI 1.20-1.27) and 1.70 for NMC cases (1.62-1.76). Long-term increased rates were seen for vascular dementia and NMC cases. IRRs for autoimmune diseases were overall statistically insignificant.

Conclusions

Cases with vascular dementia and not Alzheimer's disease, and a subgroup of cases identified with poorer health have increased long-term risk following infections. Autoimmune diseases were not associated with any type of dementia. Notably increased risks (attributed to the short term) and for NMC cases may indicate that immunosenescence rather than de novo infection explains the links. Future focus on such groups and on the role of vascular pathology will explain the infection-dementia links, especially in the long term.

Polyamine Dysregulation and Nucleolar Disruption in Alzheimer's Disease

A hypothesis of Alzheimer's disease etiology is proposed describing how cellular stress induces excessive polyamine synthesis and recycling which can disrupt nucleoli. Polyamines are essential in nucleolar functions, such as RNA folding and ribonucleoprotein assembly. Changes in the nucleolar pool of anionic RNA and cationic polyamines acting as counterions can cause significant nucleolar dynamics. Polyamine synthesis reduces S-adenosylmethionine which, at low levels, triggers tau phosphorylation. Also, polyamine recycling reduces acetyl-CoA needed for acetylcholine, which is low in Alzheimer's disease. Extraordinary nucleolar expansion and/or contraction can disrupt epigenetic control in peri-nucleolar chromatin, such as chromosome 14 with the presenilin-1 gene; chromosome 21 with the amyloid precursor protein gene; chromosome 17 with the tau gene; chromosome 19 with the APOE4 gene; and the inactive X chromosome (Xi; aka "nucleolar satellite") with normally silent spermine synthase (polyamine synthesis) and spermidine/spermine-N1-acetyltransferase (polyamine recycling) alleles. Chromosomes 17, 19 and the Xi have high concentrations of Alu elements which can be transcribed by RNA polymerase III if positioned nucleosomes are displaced from the Alu elements. A sudden flood of Alu RNA transcripts can competitively bind nucleolin which is usually bound to Alu sequences in structural RNAs that stabilize the nucleolar heterochromatic shell. This Alu competition leads to loss of nucleolar integrity with leaking of nucleolar polyamines that cause aggregation of phosphorylated tau. The hypothesis was developed with key word searches (e.g., PubMed) using relevant terms (e.g., Alzheimer's, lupus, nucleolin) based on a systems biology approach and exploring autoimmune disease tautology, gaining synergistic insights from other diseases.

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.

The association between bullous pemphigoid and cognitive outcomes in middle-aged and older adults: A systematic review and meta-analysis

BACKGROUND

Bullous pemphigoid (BP) is a rare autoimmune skin condition that causes large fluid-filled blisters on the skin, especially in older adults. BP has been linked to various diseases and medications, but its association with cognitive outcomes is unclear.

METHODS

We conducted a systematic review and meta-analysis of studies investigating the association between BP and cognitive outcomes, such as all-cause dementia, Alzheimer's disease, and vascular dementia in middle-aged and older adults. We searched PubMed, Embase, and Web of Science databases for relevant studies published up to March 2023. We included studies that reported odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) for the association between BP and cognitive outcomes. We pooled the ORs, or HRs using random-effects models and performed subgroup and sensitivity analyses to explore potential sources of heterogeneity.

RESULTS

The study selection process identified 13 studies for inclusion in the analysis, 11 studied arms of which used a case-control design and 7 studied arms of which used a cohort design. The studies were conducted primarily in Europe, with a few from Asia and the United States. The meta-analysis found that BP was associated with higher odds of all-cause dementia in middle-aged and older participants in both cohort studies(HR = 1.41,95% CI: 1.20-1.66, P = 0.000) and case-control (OR = 4.25, 95% CI, 2.73-6.61; P = 0.000). The study found no significant publication bias in the included studies. The meta-regression analyses identified some subgroups associated with significantly reported odds ratios in case-control association analysis, including Europe, BP diagnosed based on clinical, histology, immunofluorescence, and both adjustment status of NO and YES.

CONCLUSIONS

Our meta-analysis suggests that BP is associated with an increased risk of all-cause dementia in middle-aged and older adults. Further studies are needed to elucidate the underlying mechanisms and causal relationship between BP and cognitive outcomes.

Graves Disease is Associated with Increased Risk of Clinical Alzheimer's Disease: Evidence from the Medicare System

Background

Identification of modifiable risk factors for Alzheimer's Disease (AD) onset is an important aspect of controlling the burden imposed by this disease on an increasing number of older U.S. adults. Graves disease (GD), the most common cause of hyperthyroidism in the U.S., has been hypothesized to be associated with increased AD risk, but there is no consensus. In this study, we explore the link between GD and risk of clinical AD.

Methods

Cox and Fine-Grey models were applied to a retrospective propensity-score-matched cohort of 15,505 individuals with GD drawn from a nationally representative 5% sample of U.S. Medicare beneficiaries age 65 + over the 1991-2017 period.

Results

Results showed that the presence of GD was associated with a higher risk of AD (Hazard Ratio [HR]:1.15; 95% Confidence Interval [CI]:1.07-1.23). Magnitude of associated risk varied across subgroups: Males (HR:1.19; CI:1.01-1.41), Females (HR:1.09; CI:1.02-1.18), Whites (HR:1.13; CI:1.04-1.20), Blacks (HR:1.33; CI:1.04-1.20). Competing risk estimates were consistent with these findings.

Conclusions

A potential mechanism connecting GD and AD may involve shared etiological factors between the two diseases. Although replication of our findings is needed, they suggest that GD prevention and treatment may contribute to reducing the burden of AD in U.S. older adults.

Association Between Psoriasis and Dementia: A Retrospective Cohort Study

Background

To date, no large study has examined the relationship between psoriasis and dementia in Germany.

Objective

The aim of this study was to assess the association between psoriasis and the risk of all-cause dementia in patients followed in general practices in Germany.

Methods

This retrospective cohort study is based on longitudinal data from the IQVIA^TM Disease Analyzer database and included patients with an initial diagnosis of psoriasis between January 1995 and December 2014 in 1,173 general practices in Germany. Patients without psoriasis were matched individually (1:1) to psoriasis patients using propensity scores. The main outcome of the study was the cumulative incidence of dementia diagnoses within up to 15 years of the index date. Univariate Cox proportional regression models were used to assess the relationship between psoriasis or psoriatic arthritis and dementia.

Results

The present study included 10,583 patients with a diagnosis of psoriasis and 10,583 controls without psoriasis. After 15 years of follow-up, 22.0% of the psoriasis patients and 19.1% (p < 0.001) of the non-psoriasis patients developed dementia. The incidence rate of dementia in 1,000 person-years was 15.0 in psoriasis patients and 11.9 in the non-psoriasis cohort. Psoriasis was significantly associated with a dementia risk (HR: 1.24; 95% CI: (1.14-1.35); p < 0.001). The association was stronger in patients with PsA (HR: 1.35; 95% CI: (0.98-1.86)) but this was not significant (p = 0.070).

Conclusion

The present study found a positive association between psoriasis and all-cause dementia in patients in general practices in Germany.

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.

Association between systemic rheumatic diseases and dementia risk: A meta-analysis

BACKGROUND AND AIMS

Epidemiological studies have been conducted on the relationship between systemic rheumatic diseases (SRDs) and dementia. Therefore, we focused on determining the extent of alliances bounded by SRDs, along with the risk of dementia.

MATERIALS AND METHODS

Two independent reviewers assessed all studies retrieved from the PubMed, EMBASE, Scopus, and Web of Science databases between January 1, 2000 and November 30, 2021. Only observational studies that estimated the possibility of dementia in participants with SRD were considered. The random-effects model was applied to forecast pooled risk ratios (RRs) and 95% confidence intervals (CI). Heterogeneity among the studies was evaluated using the Q and I2 statistics. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Funnel plots were used to calculate the risk of bias.

RESULTS

Seventeen observational studies with 17,717,473 participants were recruited. Our findings showed that among the participants with SRDs, those with osteoarthritis, systemic lupus erythematosus, and Sjogren's syndrome were highly related to an elevated risk of dementia (pooled RR: 1.31; 95% CI: 1.15-1.49, p<0.001; pooled RR: 1.43; 95% CI: 1.19-1.73, p<0.001; and pooled RR: 1.26; 95% CI: 1.14-1.39, p<0.001, respectively). However, participants with rheumatoid arthritis (RA) were not associated with an increased risk of dementia (pooled RR: 0.98; 95% CI: 0.90-1.07, p<0.001).

CONCLUSION

This systematic review and meta-analysis demonstrated an increased dementia risk among SRDs participants, except for RA.

Is hospitalization a risk factor for cognitive decline in older age adults?

OBJECTIVES

Many studies document cognitive decline following specific types of acute illness hospitalizations (AIH) such as surgery, critical care, or those complicated by delirium. However, cognitive decline may be a complication following all types of AIH. This systematic review will summarize longitudinal observational studies documenting cognitive changes following AIH in the majority admitted population and conduct meta-analysis (MA) to assess the quantitative effect of AIH on post-hospitalization cognitive decline (PHCD).

METHODS

We followed Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Selection criteria were defined to identify studies of older age adults exposed to AIH with cognitive measures. 6566 titles were screened. 46 reports were reviewed qualitatively, of which seven contributed data to the MA. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

The qualitative review suggested increased cognitive decline following AIH, but several reports were particularly vulnerable to bias. Domain-specific outcomes following AIH included declines in memory and processing speed. Increasing age and the severity of illness were the most consistent risk factors for PHCD. PHCD was supported by MA of seven eligible studies with 41,453 participants (Cohen's d = -0.25, 95% CI [-0.02, -0.49] I2 35%).

CONCLUSIONS

There is preliminary evidence that AIH exposure accelerates or triggers cognitive decline in the elderly patient. PHCD reported in specific contexts could be subsets of a larger phenomenon and caused by overlapping mechanisms. Future research must clarify the trajectory, clinical significance, and etiology of PHCD: a priority in the face of an aging population with increasing rates of both cognitive impairment and hospitalization.

Association of autoimmune diseases with Alzheimer's disease: A mendelian randomization study

BACKGROUND

Alzheimer's disease may have an autoimmune component, but the association is unclear.

OBJECTIVE

The objective of this Mendelian randomization (MR) study was to evaluate the association of liability to autoimmune diseases with Alzheimer's disease.

METHODS

A systematic search was done using PubMed to identify autoimmune diseases that have been suggested as associated with Alzheimer's disease. Genetic predictors of these autoimmune diseases were obtained from the largest and most recent genome-wide association studies (GWAS). Genetic associations with clinically-diagnosed Alzheimer's disease were obtained from the International Genomics of Alzheimer's Project GWAS (21982 cases; 41944 controls); and with parental and sibling history of Alzheimer's disease from the UK Biobank GWAS (27696 maternal, 14338 paternal and 2171 sibling cases). MR estimates were obtained using inverse variance weighting, MR-Egger and weighted median. To address possible selection bias due to inevitably recruiting only survivors, the analysis was repeated in younger people, i.e., UK Biobank siblings and adjusting for competing risk of Alzheimer's disease.

RESULTS

Of the 7 autoimmune diseases considered, liability to psoriasis and sarcoidosis were not associated with Alzheimer's disease. Some evidence was found for liability to multiple sclerosis being associated with higher risk and liability to Sjogren's syndrome with lower risk of Alzheimer's disease. Associations found for liability to giant cell arteritis, type 1 diabetes and rheumatoid arthritis were inconsistent in sensitivity analyses.

CONCLUSION

Liability to multiple sclerosis and Sjogren's syndrome could be associated with Alzheimer's disease. The underlying mechanisms, such as the role of myelin and neuroinflammation, should be further investigated.

Biomarkers of neurodegeneration in neural autoantibody-associated psychiatric syndromes: A retrospective cohort study

Background

Autoantibody-associated psychiatric syndromes are a novel disease entity that is not fully understood. Several lines of evidence suggest that neurodegenerative processes are involved here. We are investigating whether autoantibody-positive psychiatric syndromes differ from those that are autoantibody-negative in cerebrospinal fluid (CSF) neurodegeneration markers.

Methods

We retrospectively analyzed data from 167 psychiatric patients at the University Medical Center Göttingen from 2017 to 2020. We divided this patient cohort into two, namely antibody-positive and antibody-negative. We compared various clinical features, neurodegeneration markers, and their autoantibody status in CSF and serum. We then compared both cohorts' neurodegeneration markers to a representative Alzheimer cohort. We subdivided the patients into their diverse psychiatric syndromes according to the manual to assess and document psychopathology in psychiatry (the AMDP), and compared the neurodegeneration markers.

Results

Antibody-associated psychiatric syndromes do not appear to reveal significantly greater neurodegeneration than their antibody-negative psychiatric syndromes. 71% of antibody-positive patients fulfilled the criteria for a possible and 22% for a definitive autoimmune encephalitis. Our autoantibody-positive patient cohort's relative risk to develop an possible autoimmune encephalitis was 9%. We also noted that phosphorylated tau protein 181 (ptau 181) did not significantly differ between antibody-associated psychiatric syndromes and our Alzheimer cohort. The psycho-organic syndrome usually exhibits the most prominent neurodegeneration markers, both in antibody-positive and antibody-negative psychiatric patients.

Discussion

We did not find hints for neurodegenerative processes in our antibody-positive versus AD cohort considering total tau or amyloid markers. However, our findings indicate that the neurodegeneration marker ptau181 does not differ significantly between antibody-positive and Alzheimer cohorts, further suggesting axonal neurodegeneration in antibody-positive patients as AD patients have an elevated ptau181. The evidence we uncovered thus suggests that axonal neurodegeneration might affect patients suffering from autoantibody-associated psychiatric syndromes.

Immune-mediated diseases are associated with a higher incidence of dementia: a prospective cohort study of 375,894 individuals

BACKGROUND

Immune system dysregulation plays a vital role in the pathogenesis of neurodegenerative diseases, even considered to be as important as classical pathological protein aggregation assumption. However, the associations of immune-mediated diseases with incident dementia are unclear and need to be clarified in prospective studies with a large population and long follow-up time.

METHODS

We investigated the relationship between any or individual immune-mediated diseases and incident dementia based on a prospective cohort UK Biobank. The risk for dementia was assessed with multivariable hazard ratio (HR) and 95% confidence interval (CI) after adjusting for various potential confounders using time-varying Cox proportional hazards regression. We also performed the subgroup Cox analysis stratified by time since immune-mediated diseases and gender. Causal mediation analyses with 1000 bootstrapped iterations were conducted to explore the mediation effects of peripheral immune cells on the associations of immune-mediated diseases with dementia.

RESULTS

A total of 375,894 participants were included in the study, among which 5291 developed dementia during a median follow-up of 9.08 years. Immune-mediated diseases were associated with an increased risk of dementia (HR, 1.10; 95% CI, 1.00-1.21), and the risk was highest between 1 and 2 years after immune-mediated diseases onset (HR, 2.74; 95% CI, 1.86-4.04). Females who suffered from immune-mediated diseases were more prone to AD, while males were more susceptible to VD. Four of the individual immune-mediated diseases including type I diabetes mellitus (HR, 2.49; 95% CI, 1.97-3.15), rheumatic fever or rheumatic heart diseases (HR, 1.36; 95% CI, 1.05-1.77), multiple sclerosis (HR, 2.87; 95% CI, 1.92-4.30), and necrotizing vasculopathies (HR, 1.71; 95%CI, 1.03-2.85) were significantly related to higher dementia incidence. The relationship between immune-mediated diseases and dementia was partially mediated by peripheral immune cells including neutrophils and lymphocytes.

CONCLUSIONS

In this large cohort study, immune-mediated diseases were proven to be significantly associated with an increased risk of incident dementia, especially for type I diabetes mellitus which was observed to be related to the higher incidence of all types of dementia. Our findings could provide new sights on dementia pathogenesis and intervention from the perspective of systemic immunology and immune-mediated diseases.

The Association Between Thyroid Diseases and Alzheimer's Disease in a National Health Screening Cohort in Korea

Objectives

Thyroid dysfunction is linked to an increased risk of cognitive impairment. However, studies on the relationships between thyroid diseases and Alzheimer's disease (AD) have reported conflicting results. We investigated the associations between several thyroid diseases and AD in a nested case-control study.

Methods

A total of 1,977 participants with AD were identified by claims data from 2002-2015 among a random sample of half a million people in the Korean National Health Insurance database. We recruited 16,473 age- and sex-matched (1:4 ratio) control participants and applied conditional logistic regression to estimate the relationships between thyroid diseases and AD, with adjustments for potential confounders, such as basic demographics, lifestyle factors, and various medical conditions or comorbidities.

Results

The prevalence rates of hypothyroidism (odds ratio [OR]=1.14, 95% confidence interval [CI]=1.00-1.30), thyroiditis (OR=1.22, 95% CI=1.05-1.40), and hyperthyroidism (OR=1.13, 95% CI=1.01-1.28) were significantly higher in participants with AD than in control participants after adjustment for confounders.

Conclusion

In this large national sample, we found significant relationships between several thyroid diseases and AD. Despite of the need for further investigation, these findings could better support to appreciate the pathophysiology of AD.

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.

Association between Cerebral Small Vessel and Alzheimer’s Disease

뇌소혈관질환은 뇌 자기공명영상에서 흔히 관찰되는 혈관성 변화로 뇌백질 고신호강도, 뇌미세출혈, 열공성 경색, 혈관주위공간 등을 포함한다. 이러한 혈관성 변화가 알츠하이머병(Alzheimer’s disease; 이하 AD)의 발병 및 진행과 관련되어 있고, 대표 병리인 베타 아밀로이드 및 타우 단백의 침착과도 연관되어 있다는 증거들이 축적되고 있다. 혈관성 변화는 생활 습관 개선이나 약물 치료를 통해 예방과 개선이 가능하기 때문에 뇌소혈관질환과 AD 및 AD 생체지표의 관련성을 연구하는 것이 중요하다. 본 종설에서는 AD와 AD 생체지표에 대해 간략히 소개하고, AD와 혈관성 변화의 관련성에 대해 축적된 증거들을 제시한 다음, 뇌소혈관질환의 병태 생리와 MR 영상 소견을 설명하고자 한다. 또 뇌소혈관질환과 AD 진단의 위험도 및 AD 생체지표와의 관련성에 대한 기존 연구 결과들을 정리하고자 한다.

Role of Autoantibodies in Neurodegenerative Dementia: An Emerging Association

OBJECTIVE

In the background of an emerging role for immune dysregulation in neurodegenerative dementias, this study aimed to investigate the relationship between systemic autoimmunity and dementia. The objective was to study the frequency and profile of disease-specific autoantibodies in Alzheimer's dementia (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB).

METHODS

Immunological testing was performed in a large cohort of neurodegenerative dementia diagnosed based on standard clinical and imaging criteria. Patients were evaluated for the presence of autoantibodies specific for systemic autoimmune diseases that included anti-extractable nuclear antibody profile, rheumatoid factor antibody (RA), perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA), and cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA) in serum.

RESULTS

Of 174 patients with degenerative dementia (FTD = 114, AD = 53, and DLB = 7) evaluated with immunological testing, 18.9% (n = 33) were seropositive for autoantibodies. The common antibodies detected were anti-Scl-70 (25%), anti-Ro-52 (18.7%), anti-nRNP-Sm (12.5%), and anti-CENP-B (9.3%). There were no significant systemic complaints in the majority of patients. A wider range of antibodies were positive in FTD compared to AD and DLB. While no difference was observed in the mean age, sex, or duration of illness between seropositive and negative patients, family history of dementia was more frequent among seronegative patients.

CONCLUSION

Our findings indicate an emerging role for immune dysregulation in patients with classical neurodegenerative dementias, especially those with FTD. These autoantibodies could play a role in immune degradation of protein aggregates that characterize neurodegeneration. Study findings emphasize the need to explore the complex relationship between systemic autoimmunity and neurodegenerative dementia.

Peptidylarginine Deiminase and Alzheimer's Disease

Peptidylarginine deiminases (PADs) are indispensable enzymes for post-translational modification of proteins, which can convert Arg residues on the surface of proteins to citrulline residues. The PAD family has five isozymes, PAD1, 2, 3, 4, and 6, which have been found in multiple tissues and organs. PAD2 and PAD4 were detected in cerebral cortex and hippocampus from human and rodent brain. In the central nervous system, abnormal expression and activation of PADs are involved in the pathological changes and pathogenesis of Alzheimer's disease (AD). This article reviews the classification, distribution, and function of PADs, with an emphasis on the relationship between the abnormal activation of PADs and AD pathogenesis, diagnosis, and the therapeutic potential of PADs as drug targets for AD.

Up-regulated microRNA-132 reduces the cognition-damaging effect of sevoflurane on Alzheimer's disease rats by inhibiting FOXA1

OBJECTIVE

Some studies have implied the damaging effect of sevoflurane (sevo) on cognitive function in Alzheimer's disease (AD). This research was conducted to explore the effect of microRNA (miR)-132/forkhead-box A1 (FOXA1) axis on cognitive ability of sevo-treated AD rats.

METHODS

The condensed-matter Aβ_1-40-induced AD rats were injected with miR-132- or FOXA1-related plasmids, followed by inhalation with 3% sevo. Then, the cognitive functions of AD rats were assessed. miR-132 and FOXA1 levels in hippocampal tissues of AD rats, and their interaction were identified.

RESULTS

miR-132 expression was reduced and FOXA1 mRNA and protein levels were elevated in AD rats. miR-132 targeted FOXA1. Sevo treatment impaired cognitive function in AD rats. Elevated miR-132 or inhibited FOXA1 attenuated sevo-mediated injury in AD rats. Overexpressed FOXA1 rescued the effect of elevated miR-132 in AD rats with sevo treatment.

CONCLUSION

Up-regulated miR-132 reduces the cognition-damaging effect of sevo on AD rats by inhibiting FOXA1.

A comprehensive review on medicinal herbs and novel formulations for the prevention of Alzheimer's disease

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases reported in the aging population across the globe. About 46.8 million people are reported to have dementia, and AD is mainly responsible for dementia in aged people. Alzheimer's disease (AD) is thought to occur due to the accumulation of β-amyloid (Aβ) in the neocortex portion of the brain, nitric oxide mediated dysfunctioning of blood-brain barrier, reduced activity of serine racemase enzyme, cell cycle disturbances, damage of N-methyl-D-aspartate (NMDA) receptors and glutamatergic neurotransmission. Modern treatment methods target the pathways responsible for the disease. To date, solely symptomatic treatments exist for this disease, all making an attempt to counterbalance the neurotransmitter disturbance. Treatments able to prevent or at least effectively modifying the course of AD, referred to as 'disease-modifying' drugs, are still under extensive research. Effective treatments entail a better indulgence of the herbal bioactives by novel drug delivery systems. The herbal bioactive administered by novel drug delivery systems have proved beneficial in treating this disease. This review provides detailed information about the role of medicinal plants and their formulations in treating Alzheimer disease which will be highly beneficial for the researchers working in this area.

RETRACTED: Inhibition of interleukin-1β plays a protective role in Alzheimer's disease by promoting microRNA-9-5p and downregulating targeting protein for xenopus kinesin-like protein 2

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 2C, 4C, and 5B+E, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0 [docs.google.com]). The journal requested the corresponding author comment on these concerns and provide the raw data. However the authors were not able to satisfactorily fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Association between Inflammatory Conditions and Alzheimer's Disease Age of Onset in Down Syndrome

Adults with Down syndrome (DS) have an exceptionally high prevalence of Alzheimer disease (AD), with an earlier age of onset compared with the neurotypical population. In addition to beta amyloid, immunological processes involved in neuroinflammation and in peripheral inflammatory/autoimmune conditions are thought to play important roles in the pathophysiology of AD. Individuals with DS also have a high prevalence of autoimmune/inflammatory conditions which may contribute to an increased risk of early AD onset, but this has not been studied. Given the wide range in the age of AD onset in those with DS, we sought to evaluate the relationship between the presence of inflammatory conditions and the age of AD onset. We performed a retrospective study on 339 adults with DS, 125 who were cognitively stable (CS) and 214 with a diagnosis of AD. Data were available for six autoimmune conditions (alopecia, celiac disease, hypothyroidism, psoriasis, diabetes and vitamin B12 deficiency) and for one inflammatory condition, gout. Gout was associated with a significant delay in the age of AD onset by more than 2.5 years. Our data suggests that inflammatory conditions may play a role in the age of AD onset in DS. Further studies are warranted.

A Review of the Application of Hyperbaric Oxygen Therapy in Alzheimer's Disease

Alzheimer's disease (AD) is considered as the most common cause of dementia in elderly population. While the exact mechanism of AD has not been discovered, hyperbolic oxygen therapy (HBOT) has been proven to be effective in the treatment of this degenerative disease. The objectives of this article are to review the literature available on molecular and physiological mechanisms underlying HBOT and its efficacy in treating AD and to review the effectiveness of HBOT as an alternate treatment intervention in both human and animal models. 391 full text articles were included in the review after literature search between 1980-2021 from two online data base (ScienceDirect and PubMed). The following key words were used: 'hyperbaric oxygen therapy' and 'Alzheimer disease.' Based on the outcomes of clinical and experimental studies, this review advocates the use of HBOT for the treatment of AD. This review explores future directions and recommends further research into a treatment protocol that will maintain long-term cognitive health of AD patients.

Glucocorticoid Therapy is Associated with a Lower Risk of Dementia

BACKGROUND

Recent evidence indicates an important role for neuroinflammation in the pathological cascade of Alzheimer's disease (AD), and neuroinflammation is increasingly being recognized as a potential therapeutic target.

OBJECTIVE

To assess the impact of glucocorticoids on the risk of developing dementia.

METHODS

We used health insurance data of the largest German health insurer from 2004-2013 with a baseline sample of 176,485 persons aged 50 years and older to study the association of glucocorticoid treatment and incidence of dementia. Cox proportional-hazard models were calculated adjusting for sex, age, and comorbidities known to be major risk factors for dementia and were given as hazard ratios (HR) with 95% confidence intervals (CI). We further stratified glucocorticoid treatment by route of application and treatment duration.

RESULTS

Of the 176,485 dementia-free persons, 19,938 were diagnosed with dementia by the end of 2013. The risk of suffering from dementia was significantly lower for glucocorticoid users compared to non-users (HR = 0.81, CI = 0.78-0.84). The lowest risk was found among users of inhaled glucocorticoid (HR = 0.65, CI = 0.57-0.75), followed by nasal (HR = 0.76, CI = 0.66-0.87), other (HR = 0.84, CI = 0.80-0.88), and oral users (HR = 0.83, CI = 0.78-0.88). We found no difference in risk reduction between long- and short-term-users.

CONCLUSION

Longitudinal German health insurance data indicate that the use of glucocorticoids is associated with a lower risk of dementia. Prospective clinical trials will be necessary to determine whether glucocorticoids can have a positive impact on neuroinflammation and thus protect persons against dementia.

Patients with psoriasis have a higher risk of dementia: A systematic review and meta-analysis

BACKGROUND

Patients with psoriasis may have a higher risk of dementia because of the higher inflammatory burden, although results from previous epidemiological studies have been inconsistent.

AIMS

To determine the association between psoriasis and risk of dementia by pooling the evidence from previous studies.

METHODS

Potentially eligible studies were identified from Medline and EMBASE databases from inception to July 2019 using a search that comprised terms for "psoriasis" and "dementia." Studies were eligible for the meta-analysis if they were cohort studies that included psoriatic patients and individuals without psoriasis and followed them for incident dementia. Studies were also required to report standardized incidence ratio, hazard risk ratio or relative risk with related 95% confidence intervals (CI) comparing the incidence of dementia between the two cohorts. The retrieved point estimates with standard errors from each study were pooled into the final result by the random-effect model, generic inverse variance method.

RESULTS

A total of 8,861 articles were identified. After two rounds of independent review by three investigators, we included six cohort studies that met the eligibility criteria in the meta-analysis. The risk of dementia was significantly higher among psoriatic patients than in those without psoriasis with a pooled risk ratio of 1.16 (95% CI, 1.04-1.30; I2 95%). A funnel plot was relatively symmetric and was not suggestive of the presence of publication bias.

LIMITATIONS

Limited accuracy of diagnosis of psoriasis and dementia as four included studies were coding-based studies, and high statistical heterogeneity among studies.

CONCLUSION

This systematic review and meta-analysis indicates that psoriatic patients have a significantly elevated risk of developing dementia.

Peptidyl arginine deiminase 4 and its potential role in Alzheimer's disease

Alzheimer's disease (AD) is the main cause of dementia, and its pathogenesis is still not clear. Peptidyl arginine deiminases 4(PAD4) as one of the important members of PAD family, is the only protein with nuclear transfer function, it can regulate the expression of many proteins through citrullinating histone. PAD4 can also interact with many transcription factors, involved in regulating gene expression. PAD4 expression is closely related to the inflammatory factors secreted, cell autophagy, tumorigenesis and other neurodegenerative diseases. More importantly, PAD4 and its citrullinated protein were found in cortical and hippocampal neurons of AD patients. To study the expression and regulatory pathway of PAD4 in vivo and in vitro experiments on AD may be of helpful to elucidate the pathogenesis of AD. Meanwhile, detection of anti-citrullinated antibody will have potential value as novel biomarkers of AD.

Association between vitiligo and subsequent risk of dementia: A population-based cohort study

Increasing evidence suggests a positive association between autoimmune disorders and the subsequent risk of dementia, supporting the idea that neuroinflammation is a major contributor to dementia. However, whether or not adults with vitiligo have an increased risk of dementia remains unclear. We aimed to investigate the association between vitiligo and the subsequent risk of dementia. A total of 1320 patients with vitiligo and 5280 matched controls were identified from the Taiwan National Health Insurance Research Database between 1998 and 2011. Dementia was diagnosed by board-certificated psychiatrists or neurologists in the follow-up period. Cox proportional hazards models were used to estimate the adjusted hazard ratios (aHR) after controlling for age, sex, income-related monthly premium, residence and comorbidities associated with dementia. The incidence rate of dementia (per 100 000 person-years) was 502.8 among patients with vitiligo and 101.9 among the controls. Patients with vitiligo were more likely to develop any type of dementia (aHR, 5.30; 95% confidence interval [CI], 3.30-8.51), Alzheimer's disease (aHR, 12.22; 95% CI, 3.71-40.28) and vascular dementia (aHR, 3.99; 95% CI, 1.31-12.15) compared with the controls. In conclusion, middle-aged and old patients with vitiligo are more likely to develop dementia compared with those without vitiligo. This novel finding reminds physicians to be more careful about signs of dementia when managing patients with vitiligo and provides the basis for further investigations that clarify the underlying mechanisms.

Shape Profile of Corpus Callosum As a Signature to Phenotype Different Dementia

Background  Phenotyping dementia is always a complex task for a clinician. There is a need for more practical biomarkers to aid clinicians. Objective  The aim of the study is to investigate the shape profile of corpus callosum (CC) in different phenotypes of dementia. Materials and Methods  Our study included patients who underwent neuroimaging in our facility as a part of clinical evaluation for dementia referred from Geriatric Clinic (2017-2018). We have analyzed the shape of CC and interpreted the finding using a seven-segment division. Results  The sample included MPRAGE images of Alzheimer' dementia (AD) ( n = 24), posterior cortical atrophy- Alzheimer' dementia (PCA-AD) ( n = 7), behavioral variant of frontotemporal dementia (Bv-FTD) ( n = 17), semantic variant frontotemporal dementia (Sv-FTD) ( n = 11), progressive nonfluent aphasia (PNFA) ( n = 4), Parkinson's disease dementia (PDD) ( n = 5), diffuse Lewy body dementia ( n = 7), progressive supranuclear palsy (PSP) ( n = 3), and corticobasal degeneration (CBD) ( n = 3). We found in posterior dementias such as AD and PCA-AD that there was predominant atrophy of splenium of CC. In Bv-FTD, the genu and anterior half of the body of CC was atrophied, whereas in PNFA, PSP, PDD, and CBD there was atrophy of the body of CC giving a dumbbell like profile. Conclusion  Our study findings were in agreement with the anatomical cortical regions involved in different phenotypes of dementia. Our preliminary study highlighted potential usefulness of CC in the clinical setting for phenotyping dementia in addition to clinical history and robust biomarkers.

Alzheimer's Disease: Protective Effects of Mycobacterium vaccae, a Soil-Derived Mycobacterium with Anti-Inflammatory and Anti-Tubercular Properties, on the Proteomic Profiles of Plasma and Cerebrospinal Fluid in Rats

BACKGROUND

Alzheimer's disease (AD) is an inflammatory neurodegenerative disease that may be associated with prior bacterial infections. Microbial "old friends" can suppress exaggerated inflammation in response to disease-causing infections or increase clearance of pathogens such as Mycobacterium tuberculosis, which causes tuberculosis (TB). One such "old friend" is Mycobacterium vaccae NCTC 11659, a soil-derived bacterium that has been proposed either as a vaccine for prevention of TB, or as immunotherapy for the treatment of TB when used alongside first line anti-TB drug treatment.

OBJECTIVE

The goal of this study was to use a hypothesis generating approach to explore the effects of M. vaccae on physiological changes in the plasma and cerebrospinal fluid (CSF).

METHODS

Liquid chromatography-tandem mass spectrometry-based proteomics were performed in plasma and CSF of adult male rats after immunization with a heat-killed preparation of M. vaccae NCTC 11659 or borate-buffered saline vehicle. Gene enrichment analysis and analysis of protein-protein interactions were performed to integrate physiological network changes in plasma and CSF. We used RT-qPCR to assess immune and metabolic gene expression changes in the hippocampus.

RESULTS

In both plasma and CSF, immunization with M. vaccae increased proteins associated with immune activation and downregulated proteins corresponding to lipid (including phospholipid and cholesterol) metabolism. Immunization with M. vaccae also increased hippocampal expression of interleukin-4 (IL-4) mRNA, implicating anti-inflammatory effects in the central nervous system.

CONCLUSION

M. vaccae alters host immune activity and lipid metabolism. These data are consistent with the hypothesis that microbe-host interactions may protect against possible infection-induced, inflammation-related cognitive impairments.

Ankylosing spondylitis is associated with an increased risk of dementia: A systematic review and meta-analysis

OBJECTIVES

To investigate the relationship between ankylosing spondylitis (AS) and risk of dementia.

METHODS

Potentially eligible studies that compared the risk of developing dementia between patients with AS and individuals without AS were identified from MEDLINE and EMBASE databases from inception to May 2019 using a search strategy that comprised terms for "dementia" and "ankylosing spondylitis". Eligible studies could be either cohort studies or case-control studies. For cohort design, eligible studies included patients with AS and comparators without AS and followed them for incident dementia. For case-control design, eligible studies included cases with dementia and controls without dementia and explored prior history of AS in both groups. Effect estimate and standard error from each study were extracted and combined together using the random effect, generic inverse variance. Funnel plot was used to assess for publication bias.

RESULTS

A total of 7091 articles were identified using the aforementioned search strategy. After 2 rounds of independent review by 3 investigators, 4 studies fulfilled the inclusion criteria and were included into the meta-analysis. The risk of developing dementia was significantly higher among patients with AS than individuals without AS with the pooled relative risk of 1.19 (95% CI 1.01-1.41; I²  = 76%). The funnel plot was relatively symmetric and was not suggestive of presence of publication bias.

CONCLUSION

A significantly 1.2 fold higher risk of developing dementia among patients with AS was demonstrated by this systematic review and meta-analysis.

Alzheimer's disease; a review of the pathophysiological basis and therapeutic interventions

Alzheimer's disease (AD) is a neurodegenerative disorder and is identified as the most common cause for dementia. Despite huge global economic burden and the impact on the close family of the patients, there is no definitive cure and thus, improved treatment methods are of need. While memory and cognition are severely affected in AD, exact etiology is yet unknown. The β-Amyloid plaque formation and aggregation hypothesis is among the well-known hypotheses used to explain disease pathogenesis. Currently there are five Food and Drug Administration (FDA) approved drugs as treatment options. All these drugs are used for symptomatic treatment of AD. Thus, disease modifying therapies which can directly address the pathological changes in AD, are needed. Such therapies could be designed based on inhibiting key steps of pathogenesis. Currently there are novel AD drug candidates with various therapeutic mechanisms, undergoing different stages of drug development. Extensive research is being done globally to broaden understanding of the exact mechanisms involved in AD and to develop therapeutic agents that can successfully hinder the occurrence and progression of the disease. In this review, a comprehensive approach to understanding AD and suggestions to be considered in the development of therapeutics for it are presented.

Graves' Disease and Toxic Nodular Goiter, Aggravated by Duration of Hyperthyroidism, Are Associated with Alzheimer's and Vascular Dementia: A Registry-Based Long-Term Follow-Up of Two Large Cohorts

Background: Dementia is an increasing burden to the health care system. It is currently debated whether hyperthyroidism is associated with a risk of dementia. Our aim was to determine the risk of dementia in hyperthyroid individuals and whether this was associated with duration of hyperthyroidism. Methods: Risk of dementia in hyperthyroid individuals was evaluated in two cohorts and matched reference populations. The Danish National Patient Registry (DNPR) cohort is a registry-based Danish nationwide cohort followed for a median of 7.2 years (from 1995 to 2013), whereas the OPENTHYRO registry cohort comprises 235,547 individuals who had at least one serum thyrotropin (TSH) measurement in the period from 1995 to 2011 and was followed for a median of 7.3 years. Each hyperthyroid case was matched with four controls according to age and sex using density sampling. Hyperthyroidism was defined as either an International Classification of Diseases Version 10 (ICD-10) diagnosis of toxic nodular goiter (TNG) or Graves' disease (GD), or two measurements of a TSH below 0.3 mU/L in the DNPR and OPENTHYRO registry cohort, respectively. The primary outcome was all-cause dementia, defined as either an ICD-10 code of dementia or prescription of medicine for dementia, with subgroup analyses of vascular dementia and Alzheimer's disease. Results: The DNPR cohort had 56,128 patients with hyperthyroidism, 2689 of whom were registered with dementia. The reference population had 224,512 individuals, of whom 10,199 had dementia (hazard ratio 1.17; 95% confidence interval [CI]: 1.12-1.23). Risk of dementia, whether Alzheimer's or vascular, was higher in both GD and TNG. The OPENTHYRO registry cohort constituted 2688 hyperthyroid individuals and 10,752 euthyroid control individuals of whom 190 and 473 individuals, respectively, were subsequently diagnosed with dementia (HR 1.06; 95% CI: 0.89-1.26). For each 6 months of decreased TSH, the risk of all-cause dementia was significantly higher (HR 1.16; 95% CI: 1.12-1.22). Conclusions: Using large-scale registry-based data, we found increased risk of dementia in hyperthyroid individuals. Every 6 months of decreased TSH was associated with increased risk of dementia by 16%, compared with individuals with normal TSH. Our data support early diagnosis and intervention in patients with hyperthyroidism.

Systemic Immune Dyshomeostasis Model and Pathways in Alzheimer's Disease

Alzheimer's disease (AD) still remains an enigma for researchers and clinicians. The onset of AD is insidious, gradually progressive and multifactorial. The recent accumulated scientific evidences suggests that the pathological changes resemble the autoimmune-driven self-sustaining inflammatory process as a result of prolonged oxidative stress and immune dyshomeostasis. Apart from aging, during life span various other factors-mainly environmental, lifestyle, chronic stress, polymicrobial infections and neuroendocrine functions-affect the immune system. Here, we provide crosstalk among "trigger insults/inflammatory stimulus" i.e., polymicrobial infection, chronic stress, pro-inflammatory diet and cholinergic signaling to put forward a "Systemic Immune Dyshomeostasis" model as to connect the events leading to AD development and progression. Our model implicates altered cholinergic signaling and suggests pathological stages with various modifiable risk factors and triggers at different chronological age and stage of cognitive decline. The search of specific autoantibodies for AD which may serve as the suitable blood/CSF biomarkers should be actively pursued for the early diagnosis of AD. The preventive and therapeutic strategies should be directed towards maintaining the normal functioning of the immune system throughout the life span and specific modulation of the immune responses in the brain depending on the stage of changes in brain.

Association and Interaction Effects of Interleukin-12 Related Genes and Physical Activity on Cognitive Aging in Old Adults in the Taiwanese Population

Evidence suggests that the neuro-inflammation mechanisms associated with interleukin-12 (IL-12) may be linked to Alzheimer's diseases and cognitive aging. In this study, we speculate that single nucleotide polymorphisms (SNPs) in IL-12-associated genes, such as IL12A, IL12B, IL12RB1, and IL12RB2 genes, could be associated with cognitive aging individually and/or via complicated interactions in the elder Taiwanese population. There were totally 3,730 Taiwanese individuals with age ≥60 years from the Taiwan Biobank. Mini-Mental State Examination (MMSE) was analyzed for all participants. We employed MMSE scores to assess cognitive functions. Our analysis revealed that the IL12A gene (including rs116910715, rs78902931, and rs78569420), the IL12B gene (including rs730691), and the IL12RB2 gene (including rs3790558, rs4655538, rs75699623, and rs1874396) were associated with cognitive aging. Among these SNPs, the association with the IL12RB2 rs3790558 SNP remained significant after performing Bonferroni correction (P = 6.87 × 10⁻⁴). Additionally, we found that interactions between the IL12A and IL12RB2 genes influenced cognitive aging (P = 0.022). Finally, we pinpointed the effects of interactions between IL12A, IL12B, and IL12RB2 with physical activity (P < 0.001, = 0.002, and < 0.001, respectively). Our study suggests that the IL-12-associated genes may contribute to susceptibility to cognitive aging independently as well as through gene-gene and gene-physical activity interactions.