Metabolic syndrome and the risk of psoriasis: a population-based cross-sectional study and Mendelian randomization analysis.

The association between metabolic syndrome (MetS) and psoriasis has been the subject of conflicting findings in previous studies, thus the relationship between them is unresolved. To examine the association between MetS and psoriasis based on a population-based cross-sectional study and assess the causal relationship between these two conditions using Mendelian randomization (MR) analysis. This population-based cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) to investigate the potential association between MetS and the risk of psoriasis, along with its key indicators, through logistic regression analysis. MR analysis was further conducted using MetS and psoriasis genome-wide association study (GWAS) data, primarily employing the inverse variance weighted (IVW) method. The observational study included a total of 15,668 individuals. Weighted multivariable adjusted logistic regression analysis revealed a correlation between MetS and psoriasis (OR=1.60, 95% CI: 1.23-2.01, p<0.05). The MR analysis using the IVW method also supported MetS as a risk factor for psoriasis (OR=1.52, 95% CI=1.23-1.88, p<0.05). Additionally, the study identified a close association between psoriasis and waist circumference, a core indicator of MetS. Metabolic syndrome increases the risk of developing psoriasis. However, further validation is needed through large-scale prospective cohort studies and long-term follow-up.