Statins Linked to Increased Diabetes Risk

Use of several statins appears to be associated with an increased risk of developing diabetes, and researchers advise that this risk be balanced against the drugs’ cardiovascular benefits.

Statins are commonly prescribed to prevent and treat cardiovascular disease, but according to the results of a study published online on May 23, 2013 in BMJ, use of the drugs is associated with an increased risk of new-onset diabetes.

In the retrospective study, researchers analyzed data from medical records of more than 1.5 million people in Ontario, Canada, to assess the correlation between individual statin use and incident diabetes. The study included patients aged 66 or older who began taking statins (atorvastatin, fluvastatin, lovastatin, rosuvastatin, or simvastatin) for the first time between August 1997 and March 2010 and had no history of diabetes at the time. More than half of the patients were prescribed atorvastatin. Patients were followed until death or a maximum of 5 years. Since pravastatin has been shown to reduce diabetes risk in animal models and clinical trials, patients treated with pravastatin were used as a comparison group.

The researchers collected data from the Ontario Drug Benefit database, the Ontario Health Insurance Plan database, the Ontario Registered Persons Database, and the Ontario Diabetes Database. Patients were defined as having new-onset diabetes based on a diagnosis in the Ontario Diabetes Database, prescription for blood glucose test strips, or prescription for antidiabetic drugs.

After adjusting for age, sex, medication history, and history of cardiac disease, researchers observed that, compared with patients taking pravastatin, those taking atorvastatin had a 22% increased risk for incident diabetes, those taking rosuvastatin had an 18% increased risk, and those taking simvastatin had a 10% increased risk. The increased risk was the same whether patients used the drugs for primary or secondary prevention. On the other hand, patients prescribed fluvastatin and lovastatin had a risk of developing diabetes that was decreased by 5% and 1%, respectively.

The researchers also analyzed the data based on dose and potency. When dose was considered, the increased risk of diabetes for patients treated with rosuvastatin became insignificant, suggesting that increased risk associated with rosuvastatin may be dependent on dose. Dose did not affect the risk associated with any other statin.

The authors note that impaired insulin secretion and release, as well as other factors affected by statins, may explain the increased risk of diabetes in older patients treated with the drugs. Along with the cardiovascular benefits statins may offer patients, the researchers advise health care professionals to consider their possible risks as well.