Proton pump inhibitor use and the risk of cardiovascular complications and death in older adults with diabetes: a population-based cohort study

Background: The unfavorable effect of proton pump inhibitors (PPIs) on cardiovascular (CV) outcomes and mortality was reported in the general population. We investigated the impact of PPIs on CV outcomes and total mortality in older people with diabetes mellitus (DM) for whom evidence is missing. Methods: Using administrative health databases of the Lombardy Region, we analyzed the risk of myocardial infarction (MI), ischemic stroke and total mortality in individuals with DM (>= 65 years of age) exposed to PPIs in 2015 and followed up to 2021. The outcomes were analyzed using a multivariable-adjusted Cox proportional hazards model to compute hazard ratios (HRs) with 95% confidence intervals (CIs). HRs between PPI users and non-users were also estimated in selected subgroups. A sensitivity analysis was also performed in a 1:1 propensity score matching population. Results: A total of 284,068 patients were included in the analysis (49.4% PPI users, 50.6% non-PPI users). A higher prevalence of comorbidities and medications was reported in PPI users as compared with non-users. During a median follow-up of 6.7 years, the use of PPIs was associated with a higher risk for ischemic stroke (HR 1.14, 95% CI 95% 1.08-1.20), MI (HR 1.36, 95% CI 1.31-1.41) and total mortality (HR 1.24, 95% CI 1.22-1.26). These risks were higher in PPI users regardless of the PPI type. Among sexes, previous CV diseases, and insulin subgroups, the use of PPIs was correlated with a statistically significant increased risk of ischemic stroke in men, in individuals without a history of CV disease, and in those who were not treated with insulin. A significantly higher risk of MI was associated with PPIs for all subgroups, as well as for total mortality, with the exception of patients with a previous history of CV diseases. The sensitivity analysis confirmed the results of the unmatched cohort. Conclusions: Our findings confirmed an increased risk of CV events and all-cause mortality in a large population of older adults with DM exposed to PPIs. This could have an important impact on public health and costs for National Health Service, therefore a regular assessment of PPI appropriateness is recommended, particularly in this population.