Association between the Frailty Index and psoriasis: a cross-sectional study of the U.S. NHANES 2003-2006.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease often accompanied by various comorbidities, but its relationship with frailty remains understudied. The Frailty Index (FI), calculated based on 49 health deficits across multiple systems (e.g., cognition, function, comorbidities, laboratory values) was used as a continuous measure. OBJECTIVES: We investigated the association between psoriasis and the Frailty Index (FI), providing evidence to support the implementation of frailty screening and potential interventions in patients with psoriasis. DESIGN AND SETTING: This cross-sectional study used data from the 2003-2006 U.S. National Health and Nutrition Examination Survey (NHANES) including 6532 participants. MEASUREMENTS: We analyzed the psoriasis-FI relationship using weighted nested regression, supplemented by subgroup analyses and restricted cubic spline regression to test for nonlinear relationships. RESULTS: The FI was significantly higher in patients with psoriasis (n = 162) than in those without (n = 6370; P < 0.001). Weighted nested regression analysis showed a significant positive association between FI and psoriasis (OR 2.22; 95% CI 1.14-4.35; P = 0.02). The association was stronger for male patients, those with normal body mass index, hypertension, and diabetes. Nonlinear relationships were observed between FI and psoriasis. CONCLUSIONS: The present study validates the association between psoriasis and frailty using a nationally representative sample and provides empirical support for integrating frailty evaluations into psoriasis care. Our findings are consistent with the hypothesis that chronic inflammatory pathways may underlie the association between psoriasis and frailty.