Association Between a Body Shape Index and Body Roundness Index with Prevalence of Psoriasis: A Cross-Sectional Population-Based Study.

BACKGROUND

Previous studies have suggested an intimate association between obesity and psoriasis. This study aimed to evaluate and compare the association between traditional and novel obesity biomarkers - waist circumference (WC), body mass index (BMI), a body shape index (ABSI), and body roundness index (BRI) - and the risk of psoriasis.

METHODS

This cross-sectional study utilized data from the 2003-2006 and 2011-2014 National Health and Nutrition Examination Survey. The association between obesity biomarkers and psoriasis risk was evaluated using multivariate logistic regression and smoothed curve fitting. The diagnostic performance of various biomarkers for identifying psoriasis were calculated and compared using receiver-operating characteristic curves.

RESULTS

Overall, 12,406 participants without psoriasis, 287 with mild psoriasis, and 68 with moderate-severe psoriasis, were included. Compared to the lowest quartile of WC, BMI, and BRI, higher quartiles were associated with significantly higher risks of psoriasis (all P for trend < 0.05). The area under the curve for identifying psoriasis was highest for BRI, which was comparable to WC (0.581 vs 0.575, P=0.34) but significantly higher than that of ABSI (0.581 vs 0.546, P=0.04) and BMI (0.581 vs 0.569, P=0.007). The association between BRI and psoriasis risk was not influenced by participant's age, sex, smoking status, physical activity, hypertension and diabetes status.

CONCLUSION

BRI is positively associated with risk of psoriasis and outperforms BMI and ABSI in identifying psoriasis. Given the cross-sectional design of this study, future research employing prospectively designed longitudinal studies is necessary to validate our findings.