Association Between Psoriasis and Dementia: Current Evidence

Epidemiology of lipid disturbances in psoriasis: An analysis of trends from 2006 to 2023

INTRODUCTION

A strong link has been established between psoriasis and lipid disturbances; however, no study has systematically examined their global epidemiology.

METHODS

We searched six databases from their inception up to October 1, 2023. Data analysis was conducted using Stata SE 15.1. We performed subgroup, meta-regression, and sensitivity analyses to assess the heterogeneity of the pooled studies.

RESULTS

Our review included 239 studies comprising 15,519,570 participants. The pooled prevalence rate of dyslipidemia among individuals with psoriasis was 38 %.

CONCLUSION

Patients with severe psoriasis should undergo screening for lipid abnormalities. This can facilitate the early detection of lipid dysfunction and associated cardiovascular comorbidities.

T cell-mediated skin-brain axis: Bridging the gap between psoriasis and psychiatric comorbidities

Psoriasis, a chronic inflammatory skin condition, is often accompanied by psychiatric comorbidities such as anxiety, depression, suicidal ideation, and other mental disorders. Psychological disorders may also play a role in the development and progression of psoriasis. The intricate interplay between the skin diseases and the psychiatric comorbidities is mediated by the 'skin-brain axis'. Understanding the mechanisms underlying psoriasis and psychiatric comorbidities can help improve the efficacy of treatment by breaking the vicious cycle of diseases. T cells and related cytokines play a key role in the pathogenesis of psoriasis and psychiatric diseases, and are crucial components of the 'skin-brain axis'. Apart from damaging the blood-brain barrier (BBB) directly, T cells and secreted cytokines could interact with the hypothalamic-pituitary-adrenal axis (HPA axis) and the sympathetic nervous system (SNS) to exacerbate skin diseases or mental disorders. However, few reviews have systematically summarized the roles and mechanisms of T cells in the interaction between psoriasis and psychiatric comorbidities. In this review, we discussed several key T cells and their roles in the 'skin-brain axis', with a focus on the mechanisms underlying the interplay between psoriasis and mental commodities, to provide data that might help develop effective strategies for the treatment of both psoriasis and psychiatric comorbidities.

Genetic overlap between Alzheimer's disease and immune-mediated diseases: an atlas of shared genetic determinants and biological convergence

The occurrence of immune disease comorbidities in Alzheimer's disease (AD) has been observed in both epidemiological and molecular studies, suggesting a neuroinflammatory basis in AD. However, their shared genetic components have not been systematically studied. Here, we composed an atlas of the shared genetic associations between 11 immune-mediated diseases and AD by analyzing genome-wide association studies (GWAS) summary statistics. Our results unveiled a significant genetic overlap between AD and 11 individual immune-mediated diseases despite negligible genetic correlations, suggesting a complex shared genetic architecture distributed across the genome. The shared loci between AD and immune-mediated diseases implicated several genes, including GRAMD1B, FUT2, ADAMTS4, HBEGF, WNT3, TSPAN14, DHODH, ABCB9, and TNIP1, all of which are protein-coding genes and thus potential drug targets. Top biological pathways enriched with these identified shared genes were related to the immune system and cell adhesion. In addition, in silico single-cell analyses showed enrichment of immune and brain cells, including neurons and microglia. In summary, our results suggest a genetic relationship between AD and the 11 immune-mediated diseases, pinpointing the existence of a shared however non-causal genetic basis. These identified protein-coding genes have the potential to serve as a novel path to therapeutic interventions for both AD and immune-mediated diseases and their comorbidities.

Altered brain activity and cognitive impairment in patients with psoriasis

BACKGROUND

Patients with psoriasis may have cognitive impairment. However, there is limited information regarding intrinsic brain activity and cognitive function in patients with psoriasis.

OBJECTIVES

This study aim to assess alterations of intrinsic brain activity and its association with cognitive function in patients with psoriasis.

METHODS

A total of 222 patients with psoriasis aged 18-70 years and 144 age and gender-matched healthy controls (HCs) were enrolled into this study. All subjects underwent brain resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological testing. The rs-fMRI data were analysed for both intrinsic brain activity as indicated by amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC). Correlative analysis of brain activity with cognitive assessment was performed.

RESULTS

Compared with the HCs, patients with psoriasis had worse cognitive performance in the Trail Making Test, Digit Span Test and Stroop Color-Word Test (p < 0.05). Patients with psoriasis showed decreased ALFF in the left superior frontal gyrus, the left medial superior frontal gyrus and the right precuneus gyrus; as well as enhanced ALFF in the left paracentral lobule (pFWE  < 0.05). Significant correlations were noted between the altered ALFF in the four brain regions and cognitive assessment (p < 0.05). Moreover, patients with psoriasis had increased FC between the four brain regions with altered ALFF (seeds) and the left prefrontal gyrus, the left anterior cingulate gyrus, left superior parietal lobule and default mode network (DMN) regions such as the right precuneus gyrus, left inferior parietal lobule, right angular gyrus and bilateral inferior temporal gyrus (pFWE  < 0.05).

CONCLUSIONS

Patients with psoriasis had altered brain activity and connectivity in the key brain areas within the DMN-prefrontal circuit. These brain changes may be the underlying neural correlates for cognitive functioning in patients with psoriasis.

Comparison of metabolic and neurological comorbidities in Asian patients with psoriasis and atopic dermatitis

Although various comorbidities have been noted to be associated with atopic dermatitis (AD) and psoriasis, few studies have compared comorbidities between the two diseases, and little is known about whether these comorbidities vary by the subtypes of psoriasis. In this study of 1:1 age- and sex-matched pair analysis between patients diagnosed with either psoriasis or AD at Asan Medical Center between 1991 and 2020, comorbidities, as determined by the International Classification of Diseases-10 codes, and likelihood ratios of metabolic and neurologic comorbidities in psoriasis compared with AD were studied using a logistic regression model. Among a total of 14,128 patients, the psoriasis group had higher odds of obesity (odds ratio [95% confidence interval]: 1.49 [1.34-1.66]), hypertension (1.14 [1.03-1.26]), diabetes mellitus (1.46 [1.29-1.66]), chronic kidney disease (1.59 [1.22-2.08]), and Parkinson's disease (2.1 [1.15-3.83]) than the AD group. Subgroup analysis revealed that patients with plaque psoriasis had higher odds of obesity (1.18 [1.05-1.33]), hypertension (1.18 [1.06-1.32]), diabetes mellitus (1.53 [1.34-1.75]), chronic kidney disease (1.66 [1.26-2.17]), and Parkinson's disease (2.12 [1.16-3.88]) compared with AD. Meanwhile, guttate psoriasis was associated with higher odds of dementia (3.63 [1.06-12.40]) and patients with generalized pustular psoriasis showed higher odds of diabetes mellitus (5.42 [1.56-18.83]) compared with AD. In conclusion, Asian patients with all types of psoriasis should be closely monitored for the development of metabolic and neurologic diseases, especially men and those aged ≥ 40 years.

Improvement in Cutaneous Conditions Can Benefit Some Health Conditions in the Elderly

As we are aging, a number of cutaneous and extracutaneous disorders will be developed. Although the pathogenesis of these aging-associated disorders is not clear yet, abnormalities in the skin are linked to some aging-associated disorders at least to some extent. Inflammatory dermatoses such as psoriasis and atopic dermatitis predispose to the development of cardiovascular diseases, obesity and type 2 diabetes. In addition, both chronologically aged skin and individuals with some aging-associated systemic conditions display altered epidermal function, such as reduced stratum corneum hydration levels, which can provoke cutaneous inflammation. Because aged skin exhibits higher expression levels of inflammatory cytokines, which play a pathogenic role in a variety of aging-associated health condition, the association of the skin with some aging-associated disorders is likely mediated by inflammation. This postulation is supported by the evidence that improvement in either epidermal function or inflammatory dermatoses can mitigate some aging-associated disorders such as mild cognitive impairment and insulin sensitivity. This perspective discusses the association of the skin with aging-associated disorders and highlights the potential of improvement in cutaneous conditions in the management of some health conditions in the elderly.

Genetic overlap between Alzheimer's disease and immune-mediated diseases: An atlas of shared genetic determinants and biological convergence

The occurrence of immune disease comorbidities in Alzheimer's disease (AD) has been observed in both epidemiological and molecular studies, suggesting a neuroinflammatory basis in AD. However, their shared genetic components have not been systematically studied. Here, we composed an atlas of the shared genetic associations between 11 immune-mediated diseases and AD by analyzing genome-wide association studies (GWAS) summary statistics. Our results unveiled a significant genetic overlap between AD and 11 individual immune-mediated diseases despite negligible genetic correlations, suggesting a complex shared genetic architecture distributed across the genome. The shared loci between AD and immune-mediated diseases implicated several genes, including GRAMD1B, FUT2, ADAMTS4, HBEGF, WNT3, TSPAN14, DHODH, ABCB9 and TNIP1, all of which are protein-coding genes and thus potential drug targets. Top biological pathways enriched with these identified shared genes were related to the immune system and cell adhesion. In addition, in silico single-cell analyses showed enrichment of immune and brain cells, including neurons and microglia. In summary, our results suggest a genetic relationship between AD and the 11 immune-mediated diseases, pinpointing the existence of a shared however non-causal genetic basis. These identified protein-coding genes have the potential to serve as a novel path to therapeutic interventions for both AD and immune-mediated diseases and their comorbidities.

A novel peptide 'T14' reflects age and photo-aging in human skin

T14 is a 14mer peptide derived from the C-terminus of acetylcholinesterase (AChE). Once cleaved, it is independently bioactive of the parent molecule and enhances calcium influx in different cell types, in a range of scenarios: it binds to an allosteric site selectively on the alpha-7 receptor, where it modulates calcium influx and is thus a potential trophic agent, as already reported in a range of normal developmental scenarios. However, if inappropriately activated, this erstwhile beneficial effect converts to a toxic one, resulting in pathologies as disparate as Alzheimer's and various metastatic cancers. Given that epidermal keratinocyte cells have the same ectodermal origin as brain cells, as well as expressing AChE and the alpha-7 receptor, we have explored whether T14 plays a comparable role. Here we report that the T14 immunoreactivity is detectable in human keratinocytes with levels inversely related to age: this decrease is even more apparent with chronic photo-exposure and thus accelerated skin aging. We conclude that T14, an agent promoting cell growth and renewal in other parts of the body, also operates in skin, Moreover, monitoring of keratinocyte T14 levels might offer further insights into the now well reported link between degenerative diseases and epidermal cell profile.

Aberrant promoter methylation of Wnt inhibitory factor-1 gene is a potential target for treating psoriasis

Psoriasis is a chronic inflammatory skin disease mediated by immune and complex genetic factors. The wingless-related integration site (Wnt) signaling pathway plays a critical role in psoriasis, but how the Wnt pathway is regulated in psoriatic skin and whether it can be exploited for therapeutic benefits is unclear. By comparing biopsies from healthy and psoriatic skin, we found that Wnt inhibitory factor 1 (WIF1), an inhibitor of Wnt signaling, showed reduced expression at both mRNA and protein levels in psoriatic skin. We then quantified methylation of the WIF1 gene promoter by DNA methylation sequencing and found that the WIF1 promoter region was hypermethylated. We further showed that recombinant WIF1 injection ameliorates the imiquimod (IMQ) mouse model of psoriasis. We also revealed that treatment with the DNA methylation inhibitor, decitabine, inhibited proliferation of immortalized human keratinocytes (HaCaT) in a psoriasis-like inflammatory environment. Finally, we applied decitabine to the IMQ mouse model and demonstrated that treatment of mice with decitabine ameliorates the disease. Therefore, our study reveals that methylation of the WIF1 gene is associated with the pathogenesis of psoriasis, and suggests that pharmacological targeting of DNA methylation is a potential treatment strategy for psoriasis.

Epidemiology of mental health comorbidity in patients with psoriasis: An analysis of trends from 1986 to 2019

BACKGROUND

The prevalence of mental disorders such as depression, anxiety, and suicide has increased in patients with psoriasis, although no study has systematically analyzed the epidemiology worldwide.

OBJECTIVE

To explore the prevalence and incidence of psoriasis with comorbid mental disorders (i.e., depression, anxiety, and suicide).

METHODS

Five databases from establishment through May 2022 were searched. Stata SE 15.1 was used for the data analysis. Subgroup, meta-regression, and sensitivity analyses were used to evaluate the heterogeneity of pooled studies.

RESULTS

We evaluated 56 studies in our research. The prevalence of depression, anxiety, and suicide in adults with psoriasis was 20%, 21%, and 0.77%. Patients with psoriasis in North America had a higher prevalence of depression and suicide, whereas those in South America had a higher prevalence of anxiety. The incidence of depression, anxiety, and suicide was 42.1, 24.7, and 2.6 per 1000 person-years in adults with psoriasis, respectively.

LIMITATIONS

All of the included studies were published in Chinese and English, causing a degree of selection bias.

CONCLUSION

These findings demonstrate the incidence and prevalence of comorbid mental disorders in patients with psoriasis, which may raise awareness among physicians and patients regarding the mental problems associated with psoriasis.

Literature Overview of the Relation Between Psoriasis and Alzheimer

The most common type of dementia disease is Alzheimer, which placing a heavy burden on the healthcare system all over the world. At the same time, psoriasis is also one of the most common health problems, as a skin disease. Alzheimer's disease (AD) is more often in patients with psoriasis than in the general people. Several evidence has proved the relation between AD and psoriasis through immune-mediated pathophysiologic processes. This review aims to summary the potential relation between AD and psoriasis, and provide suggestions based on the relationship at the same time. Neurologists, dermatologists should pay attention to the relationship between Alzheimer's disease and psoriasis. Dermatology and neurology need referral each other when it is necessary.

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.

Inflammatory Diseases, Inflammatory Biomarkers, and Alzheimer Disease: An Observational Analysis and Mendelian Randomization

BACKGROUND AND OBJECTIVES

Whether chronic autoimmune inflammatory diseases causally affect the risk of Alzheimer disease (AD) is controversial. We characterized the relationship between inflammatory diseases and risk of AD and explored the role of circulating inflammatory biomarkers in the relationships between inflammatory diseases and AD.

METHODS

We performed observational analyses for chronic autoimmune inflammatory diseases and risk of AD using data from 2,047,513 participants identified in the UK Clinical Practice Research Datalink (CPRD). Using data of a total of more than 1,100,000 individuals from 15 large-scale genome-wide association study data sets, we performed 2-sample Mendelian randomizations (MRs) to investigate the relationships between chronic autoimmune inflammatory diseases, circulating inflammatory biomarker levels, and risk of AD.

RESULTS

Cox regression models using CPRD data showed that the overall incidence of AD was higher among patients with inflammatory bowel disease (hazard ratio [HR] 1.17; 95% CI 1.15-1.19; p = 2.1 × 10-4), other inflammatory polyarthropathies and systematic connective tissue disorders (HR 1.13; 95% CI 1.12-1.14; p = 8.6 × 10-5), psoriasis (HR 1.13; 95% CI 1.10-1.16; p = 2.6 × 10-4), rheumatoid arthritis (HR 1.08; 95% CI 1.06-1.11; p = 4.0 × 10-4), and multiple sclerosis (HR 1.06; 95% CI 1.04-1.07; p = 2.8 × 10-4) compared with the age (±5 years) and sex-matched comparison groups free from all inflammatory diseases under investigation. Bidirectional MR analysis identified relationships between chronic autoimmune inflammatory diseases and circulating inflammatory biomarkers. Particularly, circulating monokine induced by gamma interferon (MIG) level was suggestively associated with a higher risk of AD (odds ratio from inverse variance weighted [ORIVW] 1.23; 95% CI 1.06-1.42; p IVW = 0.007) and lower risk of Crohn disease (ORIVW 0.73; 95% CI -0.62 to 0.86; p IVW = 1.3 × 10-4). Colocalization supported a common causal single nucleotide polymorphism for MIG and Crohn disease (posterior probability = 0.74), but not AD (posterior probability = 0.03). Using a 2-sample MR approach, genetically predicted risks of inflammatory diseases were not associated with higher AD risk.

DISCUSSION

Our data suggest that the association between inflammatory diseases and risk of AD is unlikely to be causal and may be a result of confounding. In support, although inflammatory biomarkers showed evidence for causal associations with inflammatory diseases, evidence was weak that they affected both inflammatory disease and AD.

Impairment in cognitive function in patients with axial spondyloarthritis and psoriatic arthritis

Spondyloarthritis may contribute to deficits in cognition. The objective of this study was to compare cognitive abilities in patients with axial spondyloarthritis (axSpA) or psoriatic arthritis (PsA) with matched reference groups. This investigator-initiated, cross-sectional, exploratory study of adults with axSpA or PsA was conducted at two German rheumatology centres (November 2018-September 2019). All data on patient and disease characteristics and cognitive abilities were collected at a single visit. Cognitive function was assessed by the previously validated Memory and Attention Test subscores of selective attention, episodic working memory, and episodic short-term memory and compared with subscores from healthy age-, sex-, and education-matched reference subjects. The mean patient age was 51.1 and 55.8 years in the axSpA (n = 101) and PsA (n = 117) groups, respectively, and mean symptom duration was 13.7 and 10.3 years. Compared with matched reference subjects, axSpA and PsA patients showed significant impairments in selective attention (mean difference of -6.5 and -4.5, respectively, on a 45-point scale; P < 0.001 for both) and no significant differences in episodic working memory. The PsA cohort, but not the axSpA cohort, had significantly better episodic short-term memory subscores compared with matched reference subjects (mean change of 2.0 on a 15-point scale; P < 0.001). Explorative subgroup analyses were unable to identify factors influencing cognitive changes, including disease activity, pain, and function, but may have been underpowered. We conclude that impairments in selective attention may impact the ability of axSpA and PsA patients to process information. These findings warrant additional studies, including longitudinal analyses, in patients with spondyloarthritis.

Psoriasis and medical ramifications: A comprehensive analysis based on observational meta-analyses

Purpose

Based on a large number of systematic reviews and meta-analyses exploring the relationship between psoriasis and various health outcomes, we conducted an comprehensive analysis to assess the strength and evidence for the association between psoriasis and medical end-point ramifications in patients.

Methods

We searched related meta-analyses, investigating the links between psoriasis and medical ramifications from three databases. All summary effect sizes, 95% CIs, heterogeneity, and small-study effects in the included meta-analyses were recalculated. We assessed the methodological quality of included articles with the AMSTAR 2 tool and graded the epidemiological evidence. Subgroup analysis based on the severity of psoriasis and study design were also performed.

Results

A total of 38 articles comprising 85 unique meta-analyses were included in this study. Although 69 outcomes were statistically significant, only 8 outcomes (nonvascular dementia, ulcerative colitis, pediatric dyslipidemia, gestational diabetes, gestational hypertension, fracture, multiple sclerosis, and schizophrenia) showed a high quality of epidemiological evidence.

Conclusion

We found that psoriasis increased the risk of 69 health outcomes, and 8 outcomes were graded as high-quality evidence. No evidence was found that psoriasis was beneficial for any medical end point. However, to verify our results, more large-sample, multi-center prospective cohort studies are needed.

Cognitive Functions Associated with Brain Imaging Markers in Patients with Psoriasis

Psoriasis is a severe inflammatory disease associated with a higher comorbidity of depression, cognitive dysfunction and brain atrophy. The association between psoriasis, magnetic resonance imaging (MRI) markers and cognitive impairment has rarely been investigated, and the existing results are conflicting. Methods. This study included 89 subjects (53 patients with psoriasis and 36 healthy controls). The severity of psoriasis was evaluated using the Psoriasis Area and Severity Index (PASI) score; for depression, the Hospital Anxiety and Depression Scale (HADS) scale was used. Neuropsychological tests were also applied, including a Trail Making Test (TMT) as well as Digit Span, Stroop, Verbal Fluency and Rey Auditory Verbal Learning tests. MRI scans were performed using a 1.5 T scanner. Brain volumetry, white matter lesions, grey matter and white matter were evaluated. The extent of these changes was assessed on the Fazekas scale. The differences between groups were evaluated using a Student’s t-test and a Mann-Whitney U test, and a Pearson correlation analysis was also performed. Results. Patients with psoriasis presented worse achievements on all the neuropsychological tests and showed more intense changes on MRI compared to healthy controls. The severity of psoriasis as determined by PASI scores was associated with depression, and a greater psychomotor slowness severity of changes in the brain was associated with poorer results on the neurological tests. Conclusions. Our results indicate the possibility of progressive brain atrophy related to cognitive decline in psoriasis.

The Relationship Between Alzheimer's Disease and Skin Diseases: A Review

Alzheimer's disease is the most common type of dementia placing a heavy burden on the healthcare system worldwide. Skin diseases are also one of the most common health problems. Several skin diseases are associated with Alzheimer's disease through different mechanisms. This review summarizes the relationship between Alzheimer's disease and several types of skin diseases, including bullous pemphigoid, hidradenitis suppurativa, psoriasis, skin cancer, and cutaneous amyloidosis, and provides suggestions based on these associations. Neurologists, dermatologists, and general practitioners should be aware of the relationship between Alzheimer's disease and skin diseases. Dermatology/neurology consultation or referral is necessary when needed.

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.