Social Determinants of Health as a Predictor of Psoriasis Risk: Preliminary Findings from a National Survey

Background: Social determinants of health (SDOH) profoundly influence disease risk, but their specific relationship with psoriasis remains unclear. This study aimed to examine the association between SDOH with psoriasis risk, as well as the mediating role of metabolic syndrome. Methods: We analyzed data of 16,083 adults participating in the 2003-2006 and 2009-2014 National Health and Nutrition Examination Survey. A composite SDOH score (range 0-8) was constructed from eight subcomponents across five domains: economic stability, neighborhood and built environment, education, social context, and healthcare access. The association between the SDOH score and psoriasis was assessed using multivariable logistic regression, and a mediation analysis was conducted to quantify the contribution of metabolic syndrome. Results: The overall prevalence of psoriasis was 2.46%. Restricted cubic spline curves indicated a non-linear relationship between SDOH and psoriasis. Piece-wise regression analysis indicated that the odds ratios (95% confidence intervals) for SDOH of 0-2, 3-5 and 6-8 were 0.57 (0.35-0.94), 1.13 (0.93-1.36), and 0.48 (0.36-0.63), respectively. The protective effect of a higher SDOH for psoriasis risk was stronger in participants taking statins (P for interaction = 0.03). Mediation analysis indicated that metabolic syndrome explained a modest yet significant 5.92% (95% CI 1.43-20.63%) of the association. Conclusion: The SDOH score exhibits a non-linear association with psoriasis risk in US adults, which is partially mediated by metabolic syndrome. These findings underscore the complex role of socioeconomic and environmental factors in psoriasis etiology. Future prospective studies are needed to establish temporality and assess whether SDOH-targeted interventions can mitigate psoriasis risk.