PT - JOURNAL ARTICLE AU - Prabha Ranganathan AU - Shokoufeh Khalatbari AU - Srilakshmi Yalavarthi AU - Wendy Marder AU - Robert Brook AU - Mariana J. Kaplan TI - Vitamin D Deficiency, Interleukin 17, and Vascular Function in Rheumatoid Arthritis AID - 10.3899/jrheum.130012 DP - 2013 Jul 01 TA - The Journal of Rheumatology PG - jrheum.130012 4099 - http://www.jrheum.org/content/early/2013/06/27/jrheum.130012.short 4100 - http://www.jrheum.org/content/early/2013/06/27/jrheum.130012.full AB - Objective Vitamin D deficiency is associated with increased cardiovascular (CV) disease risk in the general population. We examined the association between vitamin D deficiency and CV risk in rheumatoid arthritis (RA). Methods We measured large artery compliance by pulse wave velocity and microvascular function by the reactive hyperemia index in patients with stable RA (n = 87). We quantified CV risk factors, serum 25-hydroxyvitamin D [25(OH)D], and interleukin 17 (IL-17), and RA disease activity by Disease Activity Score of 28 joints. We used linear regression to test associations between serum 25(OH)D and CV risk factors. Results The mean serum 25(OH)D level in the cohort was 27.1 ± SD 13.6 ng/ml. Fifty-nine patients (68%) were vitamin D-insufficient (25(OH)D < 30 ng/ml; mean 20.2 ± 5.9 ng/ml) and of these, 25 (29%) were vitamin D-deficient (25(OH)D < 20 ng/ml; mean 14.4 ± 3.4 ng/ml). In the whole cohort and the vitamin D-insufficient group, serum 25(OH)D was inversely associated with IL-17 (log IL-17; β = –0.83, p = 0.04; β = –0.63, p = 0.004, respectively) by univariate analysis, which persisted after adjustment for season, and in multivariate analysis after adjustment for confounders (log IL-17; β = –0.74, p = 0.04; β = –0.53, p = 0.02). In vitamin D-deficient patients, serum 25(OH)D was positively associated with microvascular function by univariate and multivariate analysis after adjustment for confounders (β = 2.1, p = 0.04; β = 2.7, p = 0.04). Conclusion Vitamin D deficiency in RA may affect Th17 responses and microvascular function. Maintaining normal serum vitamin D levels may protect against IL-17-mediated inflammation and vascular dysfunction in RA.