The association of zonulin-related proteins with prevalent and incident inflammatory bowel disease

Background Current evidence regarding the association of serum zonulin-related proteins (ZRP) levels with prevalent inflammatory bowel disease (IBD) is contradictory. Moreover, the association with the subsequent risk of incident IBD is still unexplored. This study aimed to investigate the association of serum ZRP levels with both prevalent and incident IBD. Method The study included a total of 130 women (51-61 years) from the Women's Health in Lund Area (WHILA) study, which included 18 prevalent IBD (diagnosed before baseline) and 47 incident IBD diagnosed during the 17 years (median) follow-up and age- and sampling time-matched controls. Serum ZRP was tested in all participants by ELISA. Results The serum ZRP levels were significantly higher in prevalent IBD compared to their matched controls (63.2 ng/ml vs 57.0 ng/ml, p = 0.02), however, no evidence of a difference in ZRP levels was found between the women who developed IBD during the follow-up period and their matched controls (61.2 ng/ml vs 59.7 ng/ml, p = 0.34). Using linear mixed models, we found that the association between serum ZRP levels and prevalent IBD (beta = 6.2, p = 0.01), remained after adjusting for potential confounders. Conditional logistic regression models showed no evidence of an association between ZRP level and incident IBD (OR 1.03, p = 0.34). Conclusion Higher serum ZRP levels were associated with prevalent IBD, but not with incident IBD in our study samples.