[The prevalence and characteristics of anemia in Crohn's disease in the Chinese].

Objective: To investigate the prevalence and characteristics of anemia among patients with Crohn's disease (CD) in Chinese population and identify the possible risk factors.

Methods: A cross-sectional study was performed in 441 patients with CD enrolled from the First Affiliated Hospital of Sun Yat-Sen University between January 2003 and May 2012. The prevalence, severity, type of anemia in these patients was assessed when diagnosis was confirmed. A multivariate logistic regression including 122 patients was performed to screen risk factors of anemia.

Result: The prevalence of anemia was 64.4% (284/441) with 69.0% (196/284) mild anemia, 28.9% (82/284) moderate anemia and 2.1% (6/284) severe anemia. The most common morphological classification was hypochromic microcytic anemia (43.7%, 124/284). Multivariate logistic regression showed the predictive factors for anemia were higher levels of modified Crohn's disease activity index (CDAI) (OR = 1.007, 95% CI 1.002-1.013), platelet count (OR = 1.007, 95% CI 1.001-1.012), erythrocyte sedimentation rate (OR = 1.024, 95% CI 1.000-1.048), penetrating behavior (OR = 16.952, 95% CI 2.626-108.626), structuring behavior (OR = 6.717, 95% CI 1.583-28.507), older age at diagnosis (OR = 1.065, 95% CI 1.012-1.121),and lower body mass index (BMI) (OR = 0.769, 95% CI 0.633-0.935).

Conclusions: Anemia is a common complication in patients with CD among Chinese population. Activity of the underlying disease, older age at diagnosis, penetrating or structuring disease behavior and low BMI are the risk factors.