Regression Of Gastric Intestinal Metaplasia After Eradication Of Helicobacter Pylori Infection:a Meta-analysis

Objective: Whether intestinal metaplasia(IM)is reversible after eradication of Helicobacter pylori(H.pylori)remains controversial.The purpose of this meta-analysis is to systematically review the regression of IM after eradication of H.pylori,and whether time or geolocation has effect on the regression of IM.Methods: English-language articles in the medical literature containing information about the association between infection with H.pylori and IM identified by searching the Embase,PubMed and Medline databases with suitable key words up to June 2017.Review Manager 5.3was used for this meta-analysis.Results: Twelve studies containing a total of 3,323 patients were included in the first meta-analysis,six of which were randomized control studies while the rest were observational studies.(1)Meta-analysis for all the twelve studies,results showed that after H.pylori eradication the pooled weighted mean difference(WMD)for antral and corpus were 0.14,95%confidence interval(95%CI)(0.09,0.19),P<0.01 and 0.01,95%CI(-0.05,0.06),P=0.73,which indicated that antral IM improved after H.pylori eradication but corpus IM had no difference.(2)Meta-analysis for these six of high quality randomized control studies,when comparing the treatment group and control group,results showed that the pooled WMD for antral and corpus IM with 95%CI were 0.07,95%CI(0.00,0.14),P<0.01 and-0.07,95%CI(-0.22,0.08),P=0.34,which indicated that antral IM in the treatment group improved,but corpus IM had no difference between the two groups.(3)Dividing into follow-up?1year?1-3years and>3years three subgroups based on the follow-up years,results showed that after H.pylori eradication the pooled WMD for antral IM were 0.20,95%CI(0.16,0.23),P<0.01 ? 0.20,95%CI(0.12,0.29),P<0.01 ?0.06,95%CI(-0.05,0.16),P=0.27,the pooled WMD for corpus IM were0.04,95%CI(-0.03,0.11),P=0.24?0.00,95%CI(-0.08,0.08),P=0.97?-0.05,95%CI(-0.15,0.05),P=0.32 respectively,which indicated that antral IM had improved within 3 years but had no difference over 3 years while corpus IM had no difference over time.(4)Dividing into Asia and non-Asia groups based on the geographical location,results showed that after H.pylori eradication the pooled WMD for antral IM in both groups were0.18,95%CI(0.16,0.20),P<0.01?0.07,95%CI(0.03,0.12),P=0.001,the pooled WMD for corpus IM in Asia group was 0.03,95%CI(-0.02,0.08),P=0.29,and in non-Asia group was-0.13,95%CI(-0.22,-0.05),P<0.01,whichindicated that antral IM for both groups improved,but corpus IM in Asia group had no difference before and after H.pylori eradication while in non-Asia group progressed after H.pylori eradication.Conclusion:The results shows improvement of IM in the antral after H.pylori eradication within 3 years while there was no difference for IM in the corpus,but both had no obvious change over 3 years.For non-Asia group,IM in the corpus progressed after H.pylori eradication.