Patients who take strong cholesterol-lowering drugs called statins may be at greater risk of developing diabetes, a Canadian study has found.
Stroke and heart attack patients face a 15 per cent higher risk of developing diabetes within two years of starting high-potency statin treatments, when compared to low-potency statin patients, the study found.
Researchers from the Canadian Network for Observational Drug Effect Studies conducted the study by analyzing records for 136,966 patients over the age of 40 in Canada, the United States, and the United Kingdom.
Two-thirds of the patients were prescribed high-potency statins after suffering a major cardiovascular event such as a heart attack or stroke. Doctors considered more than 10mg of rosuvastatin, sold as Crestor, 20mg of atorvastatin, sold as Lipitor, or 40mg of simvastatin, sold as Zocor, to be high. All other statin prescriptions were considered low-potency.
The study concluded that, compared with patients taking low-potency statins, those prescribed high-potency treatments had a 15 per cent relative increase in risk of diabetes over two years. Physicians don’t know why or how the cholesterol-lowering drugs are raising the risk of diabetes, but studies are underway to figure it out.
Statin user Aggie Vizjak said the findings are “devastating.”
“To take something I thought was benefiting me and now to find out that it’s actually created even more problems for me, I find that very devastating and very upsetting,” Vizjak told CTV News.
Vizjack was prescribed statin a decade ago. This year, she was diagnosed with Type 2 diabetes. She wonders if there is a link.
“If I had known that it was possible that I would get diabetes in the future, I would not have taken the medications at all,” she said.
Between three and four million Canadians take statins to lower their cholesterol.
The paper’s lead author, Dr. Colin Dormuth, said in light of the findings, doctors should consider their prescriptions very carefully.
“Doctors need to consider the possibility that high doses of statins will increase the risk of diabetes in such patients,” Dormuth said in a statement.
In the meantime, statin users may want to discuss the doses with their doctors.
Statin drugs are widely-prescribed to lower the amount of cholesterol in a patient’s blood, easing cardiovascular stress. The paper maintains that statins are a proven life-saver for patients with heart disease, but the consequences of overprescribing must also be considered.
“The health consequences of a diabetes diagnosis can be significant,” co-author Dr. Lorraine Lipscombe said in a statement. “Following a heart attack or stroke, doctors are more likely to prescribe a high-potency statin, but a lower-strength statin may be a better choice for many patients.”
The CNODES study is published in the latest issue of the British Medical Journal.
In early 2013, Health Canada called on statin makers to update their labels to include a warning about the small increased risk of diabetes from statins. The agency added that it believed the benefits of statins still outweigh their risk, but urged doctors to carefully monitor patients taking statins who are at risk for diabetes.
A year earlier, the U.S. Food and Drug Administration called for safety warnings on statins, saying the drugs posed an elevated risk of inducing memory loss and raising blood sugar levels. Elevated blood sugar levels have been linked to diabetes.
