Association of dietary sodium intake with IL-17-mediated diseases

Summary: Abstract Body: IL-17-mediated diseases (psoriasis, psoriatic arthritis, ankylosing spondylitis, hidradenitis suppurativa, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis) have great global burden. Mechanistic data suggests that excess sodium can trigger IL-17 mediated inflammation, but population-based data on the association between salt intake and IL-17 mediated diseases are limited. We conducted a population-based cross-sectional study using data from the UK Biobank to understand if higher dietary sodium intake is associated with higher prevalence of IL-17-mediated disease. Dietary sodium intake was estimated with urine biomarkers using the International Study of Electrolyte Secretion and Blood Pressure (INTERSALT) equation. A 1-gram increase in estimated daily sodium intake was found to be associated with greater odds of having an IL-17-mediated disease (adjusted odds ratio [OR] 1.08, 95% CI 1.06-1.10) as well as more IL-17-mediated conditions (rate ratio 1.08, 95% CI 1.06-1.10). Sub-analyses showed variable associations of sodium intake with individual diseases. Among dermatological conditions, increased sodium intake was associated with the largest odds of hidradenitis suppurativa (OR 2.07, 95% CI 1.76-2.44). Our findings show that a higher dietary sodium intake was associated with an increased odds of having an IL-17-mediated disease. Prospective studies are needed to confirm these findings and evaluate whether change in dietary sodium intake is associated with disease severity among people with IL-17-mediated conditions. Joshua Z. Xian¹, Brenda Chiang¹, Aileen Chang¹, Adam Faye², Charles E. McCulloch³, Erin L. Van Blarigan^{3, 4}, Katrina Abuabara^{1, 5} 1. Department of Dermatology, University of California San Francisco, San Francisco, CA, United States. 2. Division of Gastroenterology, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States. 3. Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States. 4. Department of Urology, University of California San Francisco, San Francisco, CA, United States. 5. Division of Epidemiology and Biostatistics, University of California Berkeley, Berkeley, CA, United States. Clinical Research: Epidemiology and Observational Research