Prediabetes and diabetes in relation to risk of gastric adenocarcinoma

BACKGROUND: Whether prediabetes or diabetes increases the risk of gastric adenocarcinoma is not clear. METHODS: This cohort study included 111,198 participants in the Northern Swedish Health and Disease Study. The participants were followed up from November 1985 to April 2017. The exposure to prediabetes or diabetes was assessed by oral glucose tolerance tests and self-reports. The incidence of the outcome gastric adenocarcinoma was identified from the Swedish Cancer Registry. Multivariable Cox regressions were used to analyse the associations between prediabetes or diabetes and the risk of gastric adenocarcinoma, providing hazard ratios (HR) with 95% confidence intervals (CI), with adjustment for sex, age, calendar year, body mass index, tobacco smoking and education level. RESULTS: Compared with normoglycaemic participants, the risk of gastric adenocarcinoma was not increased among participants with prediabetes (HR 1.07, 95% CI 0.79–1.44), diabetes (HR 0.77, 95% CI 0.46–1.29) or any of these exposures (HR 0.96, 95% CI 0.73–1.27). No associations were identified between prediabetes or diabetes and the risk of gastric adenocarcinoma in stratified analyses or in analyses separating cardia and non-cardia gastric adenocarcinoma. CONCLUSIONS: This study does not support the hypothesis that prediabetes or diabetes increases the risk of gastric adenocarcinoma.