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

Abstract Background Based on increased cardio-metabolic comorbidities, inflammation and an overlap in genetics with Alzheimer’s disease, psoriasis patients may be at risk for cognitive dysfunction and dementia. Objective To compare cognition, magnetic resonance imaging (MRI)-markers and dementia risk in psoriasis and non-psoriasis participants in the population-based Rotterdam Study. Methods We identified 318 psoriatic and 9678 non-psoriatic participants (mean age: 66.1 years, 58% women). The association of psoriasis with cognitive function, mild cognitive impairment (MCI) 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, gender, education and cardio-vascular risk factors. Results Cognitive test scores and volumetric, microstructural, focal measures on brain MRI did not differ between psoriasis (28% systemic/UV treatment) and non-psoriasis participants and psoriasis was not associated with MCI (adjusted odd ratio 0.87, (95% Confidence Interval (CI): 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% CI: 0.28-0.91)). Limitations Limited dementia cases among psoriasis patients. Conclusions In this population-based study, psoriasis was not associated with preclinical markers or higher dementia risk.