Association between psoriasis and risk of dementia: A systematic review and meta-analysis

To the Editor: Psoriasis is a chronic inflammatory skin condition associated with psychiatric and neurologic disorders,1Amanat M. Salehi Rezaei N. Neurological disorders in psoriasis.Rev Neurosci. 2018; 29: 805-813Crossref PubMed Scopus (17) Google Scholar including dementia. Although etiology of many dementias are poorly understood, neuroinflammation vasculopathy hypothesized to play role. We conducted systematic review meta-analysis better characterize association between psoriasis registered protocol PROSPERO (CRD42020166789). searched MEDLINE Embase on January 25, 2020, using key terms for dementia (the search strategy provided Supplemental Tables I II; available via Mendeley at https://doi.org/10.17632/h5j8yrksch.2). included cross-sectional, case-control, cohort studies examining incidence or prevalence among adults compared without psoriasis. Case reports, abstracts, articles were excluded. Risk bias individual was assessed Newcastle-Ottawa scale.2Wells G.A. Shea B. O'Connell D. The Scale (NOS) Assessing Quality Non-randomized Studies Meta-analysis. Ottawa Health Research Institute, Ottawa, ON, Canada2019Google Random-effects meta-analyses pooled hazard ratios (HRs) performed. I2 statistic used assess heterogeneity across studies. A funnel plot evaluate potential publication bias. Analyses Review Manager, version 5.3 (The Nordic Cochrane Centre, Copenhagen, Denmark). total 8 met our eligibility criteria qualitative synthesis (Supplemental Fig 1, https://doi.org/10.17632/h5j8yrksch.2; Table I, citations removed due journal citation constraints from authors upon request). mean ages participants control individuals 59.7 47.9 years, respectively .Table IParticipant characteristics studiesStudyStudy designNumber participants% FemaleAge, y, (SD)Confounders adjusted forPsoriasisControlPsoriasisControlPsoriasisControlStudy 1Cohort360314,33051.459.652.19 (16.71)49.73 (19.33)Age, sexStudy 2Cross-sectional149—51.0—>70——Study 3Cohort382015,28036.436.4≥40≥40Sex, age, level urbanization residence, hypertension, heart disease, diabetes, hyperlipidemia, stroke, depressionStudy 4Cohort13,675141,04049.649.5——Birth year 5Cross-sectional188,08986,865,06647.658.659.88 (16.8)47.89 (28.00)Age, sex, race/ethnicity, insurance statusStudy 6Cohort318∗A 311 followed incident dementia.967855.658.366.86 (8.89)66.10 (10.87)Age, educationStudy 7Case control484435.435.442.92 (12.20)39.98 (11.45)—Study 8Cohort——44.7—56.5—Age strataSD, Standard deviation.Citations request.∗ Open table new tab SD, deviation. Citations request. Four reported effect measures quantitative analyses. Three examined any HR 1.13 (95% confidence interval [CI], 0.91-1.41) substantial 3 (I2 = 82%) (Fig 1). One (study 6) found negative association; sensitivity analysis where this study explore sources heterogeneity, increased 1.29 CI, 1.24-1.34), reduced 0% (Supplementary 2). significant vascular psoriasis, 1.43 1.35-1.53; 0%). Dementia Alzheimer type also have significant, but more modest, (HR, 1.08; 95% 1.01-1.16; 0%) Vasculopathy arterial stiffness impaired endothelial function, may predispose patients dementia, particularly dementia.3Yiu K.H. Yeung C.K. Chan H.T. et al.Increased active systemic inflammation.Br J Dermatol. 2011; 164: 514-520PubMed Oxidative stress proinflammatory cytokines, which elevated impair neurogenesis synaptic plasticity, promoting neurodegenerative processes contributing cognitive decline.4Maes Yirmyia R. Noraberg J. Brene S. Hibbeln Perini G. & (I ND) hypothesis depression: leads future research drug developments depression.Metab Brain Dis. 2009; 24: 27-53Crossref (626) Individuals been deficiencies executive functioning, suggesting some involvement prefrontal cortex.5Colgecen E. Celikbilek A. Keskin D.T. Cognitive impairment psoriasis: cross-sectional Montreal assessment.Am Clin 2016; 17: 413-419Crossref (21) Our limited by small number meta-analysis. these all studies, overall making firm conclusions difficult. In conclusion, findings support an modest associations other dementias. More needed understand impacts psoriatic inflammation predisposition disease risk cognition. would like thank staff consultation team McMaster University, Sciences Library, their assistance development strategy.