Study On The Correlation Between Serum Trace Elements And Inflammatory Bowel Disease

Background:Inflammatory bowel disease（IBD）is a chronic recurrent non-specific inflammatory disease that mainly involves intestinal involvement.Clinically,it mainly includes Crohn’s disease and ulcerative colon.The pathogenesis is currently unclear.In recent years,with the deteriorating environment,westernization of diet,antibiotic abuse,and life stress,the incidence of IBD patients in my country has been increasing year by year^[1].Although its pathogenesis is not clear,studies have found that protein energy is insufficient,vitamins,minerals,and trace elements are closely related to the occurrence and development of IBD^[2,3].It is worth noting that there are few reports of nutrient deficiency in patients with IBD^[4],especially the lack of trace elements.Therefore,the purpose of this study is to explore the content of serum trace elements in patients with IBD and their correlation with disease activity,with a view to early assessment and treatment of the severity of IBD patients,thereby improving the quality of life of patients and improving the prognosis of the disease.MethodsThe study included 200 IBD patients（100 CD patients and 100 UC patients）who were hospitalized in the Gastroenterology Department of the First Affiliated Hospital of Anhui Medical University from March 2019 to April 2020,and 100 healthy people who had a physical examination during the same period were used as the normal control group.Use atomic absorption spectrometry to determine the content of serum trace elements zinc,copper,iron,magnesium,and calcium.The content difference of each index between each group and its correlation with the degree of inflammation were statistically analyzed,and the diagnostic efficacy of each index was compared through the area under receiver operating characteristic curve（AUROC）.Results1.Compared with the healthy control group,the contents of Zn and Fe in serum of UC and CD patients were decreased,while the contents of Cu and the ratio of Cu and Zn in serum were significantly increased（P<0.05）;There was no significant difference in the contents of Mg and Ca in serum among the three groups（P>0.05）.2.There were significant differences in serum Zn,Fe contents and Cu/Zn ratio among CD patients with different disease activity levels.Serum Zn,Fe contents in patients in remission stage were significantly higher than those in severe and moderate activity groups（P<0.05）;The ratio of serum copper and zinc in severe activity group was significantly higher than that in remission stage,mild activity group and moderate activity group,and the difference was significant（P<0.05）.3.There were significant differences in the contents of trace elements Zn,Cu,Fe and the ratio of Cu and Zn in serum of UC patients with different disease activity levels.The contents of Zn and Fe in serum of patients in remission stage were significantly higher than those of mild,moderate and severe activity groups,with significant differences（P<0.05）;Serum Cu content and Cu/Zn ratio in severely active patients were higher than those in mild and moderate active groups,and the differences were significant（P<0.05）.4.The Cu/Zn ratio in CD patients was positively correlated with fecal calprotectin and C-reactive protein（r=0.697,0.586;P<0.05）was not correlated with erythrocyte sedimentation rate（r=0.134;P>0.05）,the ratio of copper and zinc in UC patients was positively correlated with fecal calprotectin and erythrocyte sedimentation rate（r=0.488,0.452;P<0.05）,but there was no significant correlation with C-reactive protein（r=0.099,P>0.05）.5.Serum Fe content in CD patients was positively correlated with fecal calprotectin（r=0.556,P<0.05）,but not with C-reactive protein and erythrocyte sedimentation rate（r=0.748,0.325;P>0.05）,the serum Fe content of UC patients was positively correlated with fecal calprotectin（r=0.526,P<0.05）,but had no significant correlation with C-reactive protein and erythrocyte sedimentation rate（r=0.219,0.197;P>0.05）.6.The critical values of CD activity were≥1.76,≥9.5（mg/L）and≥20.5（mm/h）for serum Cu/Zn ratio,C-reactive protein and erythrocytic sedimentation rate,respectively.The highest efficiency of erythrocytic sedimentation rate in the diagnosis of CD activity was found with an AUC of 0.830,sensitivity was 69%and specificity was 86.2%.The cut-off values of serum copper and zinc ratio,C-reactive protein and erythrocytic sedimentation rate in the diagnosis of UC activity were≥1.63,≥13.79（mg/L）and≥13.50（mm/h）,respectively.Copper and zinc ratio had the highest efficiency in the diagnosis of UC activity,and AUC value was 0.862,in which sensitivity was 73%and specificity was 90%.ConclusionsThis study investigated the changes of serum trace element content in patients with IBD.It was found that compared with healthy control group,serum trace element content of Zn,Fe,Cu in patients with IBD was correlated with disease.There are significant differences of serum Zn,Fe and the ratio of serum copper and zinc in patients with different disease activity levels of IBD.With the aggravation of disease inflammation,the ratio of serum copper and zinc is significantly increased.Therefore,the ratio of serum copper and zinc is expected to be used as a biomarker for predicting disease activity in patients with IBD,especially in patients with UC,which is more specific.