Methods:

This was a retrospective matched control study, using data from a large national cohort of Veterans Affairs (VA) patients between 2003 and 2015. Patients who were 30 years or older, diagnosed with diabetes (during the study period), and regular users of the VA health system were included. Patients who initiated statins (during the study period) were matched to an active comparator group, comprising those who initiated H2-blockers or proton pump inhibitors (PPIs) also during the study period. Patients who had filled medications from these classes (statins, H2-blocker, or PPI) in the prior 12 months were excluded. For any patient in the active comparator group who filled a statin prescription during the follow-up period, their follow-up ended as a nonuser (on the date of statin initiation), and they were crossed over to the statin user group (the date of statin initiation became their new index date). The primary outcome of interest was the progression of diabetes defined by a composite outcome of new insulin use, increase in the number of glucose-lowering medication classes, the incidence of ≥5 measurements of blood glucose of ≥200 mg/dl, or a new diagnosis of ketoacidosis or uncontrolled diabetes.