[Study of the correlation between vitamin D status and cytokine levels in patients with Crohn's disease].

Objective: To investigate the correlations of serum total 25-hydroxyvitamin D (T-25 (OH) D) levels with serum cytokine levels including interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor α (TNF-α) and Crohn's disease activity index (CDAI) in patients with Crohn's disease (CD). Methods: A total of 60 patients with CD admitted in Peking Union Medical College Hospital from April 2014 to March 2019 who completed the tests for serum T-25 (OH) D and cytokines (IL-6, IL-8 and/or TNF-α) were retrospectively enrolled. Clinical data were collected for analysis. Results: Among 60 CD patients, there were 46 male patients, and the age was (34±13) years. There were 16 patients (26.7%) in remission and 44 cases (73.3%) in active status. The T-25(OH)D level was (16.0±7.7)μg/L. The prevalence of vitamin D sufficiency, insufficiency and deficiency was 26.7%, 40.0% and 33.3%, respectively. Correlation analysis showed that serum T-25 (OH) D level was negatively correlated with CDAI ( r= -0.363, P= 0.004), IL-6 level ( r= -0.360, P= 0.007), hsCRP level( r= -0.272, P= 0.043) and ESR level( r= -0.293, P= 0.024), while positively correlated with serum Alb level( r= 0.372, P= 0.003)、Hb( r= 0.330, P= 0.010) and BMI( r= 0.276, P= 0.033).Twenty-three cases (52.3%) of active CD patients accompanied with infection had a lower level of serum T-25 (OH) D than those without infection [(12.55±7.17) vs (17.41±6.49)μg/L, P= 0.023]. Conclusion: Serum T-25 (OH) D level was negatively correlated with CDAI, serum IL-6 level and inflammatory markers in patients with CD, and it was lower in active CD patients with infection than those without infection.