Psoriasis is not associated with cognition, brain imaging markers, and risk for dementia: The Rotterdam Study

Background Based on increased cardiometabolic comorbidities, inflammation, and an overlap in genetics with Alzheimer disease, psoriasis patients might be at risk for cognitive dysfunction and dementia. Objective To compare cognition, magnetic resonance imaging (MRI)–markers, and dementia risk in psoriasis and nonpsoriasis participants in the population-based Rotterdam Study. Methods We identified 318 psoriasis and 9678 nonpsoriasis participants (mean age 66.1 years, 58% women). The association of psoriasis with cognitive function, mild cognitive impairment, and MRI-markers of brain damage was examined by linear and logistic regression. Dementia risk was calculated using Cox regression. Models were adjusted for age, sex, education, and cardiovascular risk factors. Results Cognitive test scores and volumetric, microstructural, focal measures on brain MRI did not differ between psoriasis (28% systemic and ultraviolet treatment) and nonpsoriasis participants, and psoriasis was not associated with mild cognitive impairment (adjusted odd ratio 0.87, 95% confidence interval 0.53-1.43). During 115.000 person-years of follow-up, 810 incident dementia cases (15 among psoriasis patients) occurred. After adjusting for confounders, psoriasis was associated with a lower risk of developing dementia (adjusted hazard ratio 0.50, 95% confidence interval 0.28-0.91). Limitations Limited dementia cases among psoriasis patients. Conclusion In this population-based study, psoriasis was not associated with preclinical markers or higher dementia risk.