The Association between Helicobacter pylori Infection and Glycated Hemoglobin A in Diabetes: A Meta-Analysis

BACKGROUND: The association between Helicobacter pylori infection and glycated hemoglobin A has been confirmed in many studies, but these conclusions are still contradictory and controversial. Therefore, we conducted a meta-analysis to resolve the problem of inconsistent results in diabetes. METHODS: A comprehensive search was conducted on related researches published in PubMed, Embase, and China Academic Journal Full-text Database (CNKI) from the inception of each database to April 2019. Fixed or random effects model was used to pool the weighted mean difference with 95% confidence interval from individual studies. Subgroup and sensitivity analyses were also performed. Publication bias was estimated by funnel plot, Egger's test, and fail-safe numbers. RESULTS: 35 studies with 4,401 participants with diabetes were included in the meta-analysis. Glycated hemoglobin A levels were elevated in patients with Helicobacter pylori infection compared with patients without Helicobacter pylori infection (WMD = 0.50, 95% CI: 0.28-0.72, p < 0.001). In subgroup analysis by the subtype of diabetes, there was a correlation between Helicobacter pylori infection and elevated glycated hemoglobin A in type 1 diabetes (I(2) = 74%, p < 0.001, WMD = 0.46, 95% CI: 0.12-0.80), and in type 2 diabetes (I(2) = 90%, p < 0.001, WMD = 0.59, 95% CI: 0.28-0.90, p < 0.001). In subgroup analysis by the study design, there was a correlation in cross-sectional study (I(2) = 89%, p < 0.001, WMD = 0.42, 95% CI: 0.16-0.69, p ≤ 0.003) and in case-control study (I(2) = 83%, p < 0.001, WMD = 0.39, 95% CI: 0.14-0.64, p ≤ 0.003). By different methods for detecting Helicobacter pylori, there was a correlation in the biopsy group (I(2) = 83%, p < 0.001, WMD = 0.6, 95% CI: 0.11-1.09, p ≤ 0.03) and in other groups of test methods (I(2) = 87%, p < 0.001, WMD = 0.37, 95% CI: 0.17-0.56, p < 0.001). Sensitivity analysis showed that our results were reliable, and no evidence of substantial publication bias was detected. CONCLUSION: The meta-analysis might indicate a correlation between Helicobacter pylori infection and glycated hemoglobin A levels in diabetes.