Helicobacter pylori infection and increased diabetes prevalence were the risks of colorectal adenoma for adults: A systematic review and meta-analysis (PRISMA-compliant article)

BACKGROUND: Helicobacter pylori infection and hyperglycemia are associated with an increased risk of colorectal neoplasm, and may have a synergistic effect in combination. However, these 2 factors that affect colorectal neoplasm remain controversial. We aimed to carry out a meta-analysis to evaluate the study population diabetes prevalence rate and H pylori infection rate with colorectal adenoma risk for adults. METHODS: We conducted systemic research through English databases for medical reports. We also recorded the diabetes prevalence and H pylori infection prevalence in each study. We classified these studies into 4 subgroups as their background population diabetes prevalence <6% (Group 1); between 6% and 8% (Group 2); between 8% and 10% (Group 3), and more than 10% (Group 4). The random-effects model had used to calculate pooled prevalence estimates with 95% confidence interval (CI). RESULTS: Twenty-seven studies were finally eligible for meta-analysis. The random-effects model of the meta-analysis was chosen, showing pooled odds ratio (OR) equal to 1.51 (95% CI 1.39–1.63). The subgroup meta-analyses showed in Group 1 the H pylori infection associated colorectal adenoma risk OR was 1.24 (95% CI 0.86–1.78). As the diabetes rate exceed 6%, the H pylori infection became the more significant increased risk of colorectal adenoma (Group 2: OR 2.16 (95% CI 1.61–2.91); Group 3: OR 1.40 (95% CI 1.24–1.57); and Group 4: OR 1.52 (95% CI 1.46–1.57)). CONCLUSIONS: The results of this meta-analysis showed elevated diabetes prevalence combined H pylori infection increasing the risks of colorectal adenoma in the adult population.