Current guidelines recommend statin therapy for all patients who have type 2 diabetes, are 40 to 75 years of age, and have elevated levels of low-density lipoprotein (LDL) cholesterol. Statin use, however, is associated with increased insulin resistance and higher blood glucose levels. A retrospective matched-cohort study was undertaken to evaluate the association between statin initiation and diabetes progression in a national cohort of patients covered by the U.S. Department of Veterans Affairs (VA).

The cohort included patients diagnosed with diabetes during the study period who were 30 years of age or older and were regular users of the VA health system. From 705,774 eligible patients, the investigators matched 83,022 pairs of statin users with active comparators who didn't use statins.

Statin users had significantly higher odds of diabetes progression (odds ratio, 1.37) than nonusers. Each component of the diabetes progression composite outcome was significantly higher in statin users, including an increase in the number of glucose-lowering medication classes, new insulin initiation, new persistent hyperglycemia, and new diagnosis of ketoacidosis or uncontrolled diabetes. Higher-intensity LDL-cholesterol lowering was associated with a higher risk of diabetes progression.

The investigators weren't able to determine whether the association of statin use with diabetes progression was due to the use of statins themselves or to their cholesterol-lowering effects. The definition of the study's composite outcome also had some limitations. Furthermore, the study data couldn't reliably differentiate between diabetes types.