Proton pump inhibitors are associated with incident type 2 diabetes mellitus in a prospective population-based cohort study

Aim: To investigate the association between proton pump inhibitors (PPIs) and risk of incident diabetes in a follow-up study and to investigate its potential mechanisms. Methods: A total of 9531 individuals without type 2 diabetes (T2DM) at baseline were included from the Rotterdam Study, a prospective population-based cohort of 14 926 individuals aged 45 years or older. During the study period (1 April 1997 to 1 January 2012) all incident cases of T2DM were enrolled. We used multivariable linear regression analysis to investigate the associations of baseline PPI use and various serum biomarkers (eg, serum magnesium, insulin-like growth factor 1) which might modify the association. Thereafter, we excluded prevalent PPI users and performed a Cox proportional hazard regression analysis to explore the time-varying effect of incident PPI use on T2DM during follow-up. Results: Baseline use of a PPI was associated with increased serum levels of fasting insulin (0.091 pmoL/L, 95% confidence interval [CI] 0.049, 0.133), homeostasis model assessment-insulin resistance (0.100, 95% CI 0.056, 0.145) and C-reactive protein (0.29 mg/L, 95% CI 0.198, 0.384), but decreased levels of magnesium (-0.009 mmol/L, 95% CI -0.014, -0.004) and IGF-1 (-0.805 nmoL/L, 95% CI -1.015, -0.595). After adjustment for risk factors such as physical activity and body mass index/waist-to-hip ratio, current use of PPI was associated with an increased risk of incident T2DM (hazard ratio [HR] 1.69, 95% CI 1.36-2.10). The effect was dose-dependent with the highest risk (HR 1.88, 95% CI 1.29-2.75) in those on more than one defined daily dose. Conclusion: New users of PPIs during follow-up had a significantly higher dose-dependent risk of incident diabetes. We suggest vigilance regarding their potential adverse effect on glucose homeostasis.