Evaluating causal influence of serum uric acid on psoriasis via observational study and transethnic Mendelian randomization analyses.

Psoriasis mimics uric acid in terms of inflammation, but the association has not been well defined. This study aimed to identify the causal link between serum uric acid (SUA) and psoriasis in an observational study using the National Health and Nutrition Examination Survey (NHANES, 2004-2006, and 2011-2014) and transethnic Mendelian randomization (MR) analyses. We utilized weighted multivariable-adjusted logistic regression and transethnic MR in European and East Asian populations to assess the association. Inverse variance weighted (IVW) was the main analysis. To test the robustness and pleiotropy, further sensitivity analyses were also conducted. Weighted regression analysis suggested that SUA positively related to psoriasis risk (OR = 1.339, 95% CI: 1.092-1.642, P = 0.006) in women. For all participants and males, neither association was significant. IVW showed that SUA levels were not significantly associated with psoriasis in Europeans (OR = 1.099, 95% CI: 0.963-1.254, P = 0.159) or East Asians (OR = 1.297, 95% CI: 0.576-2.918, P = 0.528). Furthermore, sensitivity analyses confirmed the robustness of the present MR results. In females, SUA and psoriasis were significantly correlated; findings from transethnic MR analysis did not indicate a causal relationship between SUA and psoriasis.