A nation-wide study in Korea has found an increased risk of Alzheimer’s disease (AD) in individuals with psoriasis, though the elevation in risk was reduced in those who were receiving systemic treatment for their skin condition.
Published in Scientific Reports (Apr. 15, 2020, online), the study looked at data on 535,927 individuals with psoriasis, and 2,679,635 age- and sex-matched controls without psoriasis from the Korean National Health Insurance System database, who had undergone three or more health examinations between 2008 and 2014.
There were 50,209 cases of AD (1.87%) among those in the control group, and 11,311 cases (2.11%) in patients with psoriasis, with a median follow-up of 3.35 years.
In a multivariable-adjusted model, patients with psoriasis showed a significantly increased risk of AD (hazard ratio, 1.09; 95% CI, 1.07–1.12, p<0.0001) compared to controls without psoriasis.
Notably, the risk of AD was significantly increased in psoriasis patients not receiving systemic therapy compared to those receiving systemic therapy (hazard ratio, 1.10; 95% CI, 1.08–1.12 vs. hazard ratio, 0.99; 95% CI: 0.90–1.09, p < 0.0001).