Statins can increase serum glucose and increase the risk of developing diabetes in certain patients, but that doesn’t mean your diabetic patients shouldn’t take them. In fact, the American College of Cardiology (ACC)/ American Heart Association (AHA) cholesterol treatment guidelines say that the “occurrence of a major ASCVD event represents a much greater harm to health status than does an increase in blood glucose.” The Food and Drug Administration concurs, noting in its safety label change on statins that the cardiovascular benefits of the widely used drugs typically outweighs the disadvantages of modestly higher blood sugar levels or incident diabetes.
Still, when you’re treating a patient with diabetes, you would rather have all the medications working to improve blood glucose levels. Careful selection of the right statin can keep from reversing some hard-earned progress in reducing HbA1c levels, according to a study published online ahead of print in the December issue of Current Cardiovascular Risk Reports.
The Data
Researchers examined the connection between statins, glucose homeostasis and insulin resistance. They found that both dose and type of statin affected the risk of newly diagnosed diabetes and overall elevation of blood glucose levels, based on a review of 12 previous studies. Atorvastatin (10 or 20 mg) had a greater effect on blood sugar than the same doses of pravastatin or simvastatin in one study, while another showed that the higher-intensity statins such as atorvastatin, rosuvastatin and simvastatin increased the risk of newly diagnosed diabetes compared to treatment with fluvastatin or lovastatin over a 14-year period. Higher dose atorvastatin and simvastatin (80 mg) increased the risk of incident diabetes 12% compared to lower doses of atorvastatin in 5 trials, while patients treated with atorvastatin experienced a 22% increase in diabetes risk compared to those treated with pravastatin. Pravastatin appeared to have the lowest risk and rosuvastatin had the highest, according to a meta-analysis reviewed by the authors.
While the study authors examined the increase risk of developing diabetes in conjunction with statin use in depth, they noted that patients with diabetes may experience increases in blood glucose levels of 0.1-0.15 percentage points when taking the drugs. Overall, the high-intensity statins—atorvastatin and rosuvastatin—had the greatest impact on HbA1c. The low-intensity statins—pravastatin, fluvastatin and lovastatin—had minimal effect on serum glucose. The researchers noted that while the bulk of studies appear to confirm a link, 3 other studies found little or no correlation between statin use and increased HbA1c.
Results
Because patients with diabetes also have an increased risk of ASCVD events, statins may provide a greater benefit to them than to patients without diabetes and should be recommended in keeping with current guidelines. Selection of an agent with less effect on serum glucose provides an opportunity to potentially prevent a stroke or myocardial infarction without worsening a patient’s HbA1c and increasing the risks associated with hyperglycemia.
The authors noted that, while the mean increase in serum glucose appears mild to moderate, “further evaluation of long-term effects of statin-induced diabetes is warranted including the effect of statin therapy on microvascular complications of diabetes.” In the meantime, an emphasis on healthy eating and regular physical activity can reduce the risk of both cardiovascular events and diabetic complications with no adverse effects.
