Earlier this year, we reported on a study showing an increased risk of developing Type 2 diabetes associated with using the cholesterol-lowering medicines known as statins. Now, further research is beginning to uncover the specific circumstances under which statin use is likely to raise a person’s risk of developing the condition.
In 2010, more than 255.4 million prescriptions were written for statins and other lipid-lowering medicines in the United States, according to IMS Health.To compare the rates of new-onset diabetes with cardiovascular risk reduction in people taking the drug atorvastatin (brand name Lipitor), researchers looked at data from 15,056 people with coronary disease but not diabetes at the start of the TNT and IDEAL trials (two prevention trials that included atorvastatin). In the TNT trial, people with stable coronary disease were randomly assigned to take either 10 milligrams (mg) or 80 mg of atorvastatin daily, while the IDEAL trial randomly assigned people who’d had a heart attack to take either 80 mg of atorvastation or 20–40 mg of simvastatin (Zocor) daily.
In an earlier study, the researchers had identified four factors associated with new-onset diabetes:
Most of the people in the TNT (53.7%) and IDEAL (63.6%) studies had no more than one of these factors, and were determined to be at low risk for developing diabetes. The rest of the participants had two or more of the factors and were considered at high risk of developing diabetes.
After reviewing the data, the researchers found that, compared to the lower doses of statins in the two trials, the 80-mg dose of atorvastatin increased the risk of developing diabetes only in those people who were already considered to be at high risk due to the presence of other risk factors. The 80-mg dose reduced the risk of cardiovascular events, both in people at high risk and those at low risk of developing diabetes.
These findings reflect those from an earlier analysis of the JUPITER trial (a study evaluating the use of rosuvastatin [Crestor] for the prevention of cardiovascular disease), which indicated that rosuvastatin only increased the risk of developing diabetes in people who had at least one risk factor for the condition.
“A patient with coronary disease who develops diabetes faces new blood glucose monitoring requirements, increased dietary restrictions, and usually additional chronic drug therapy. These limitations to quality of life are accompanied by the long-term threats of the macrovascular and microvascular complications of diabetes,” according to the study’s authors. “However, the impact of new-onset diabetes is relatively minor compared with the cardiovascular events included in this analysis: coronary heart disease death, MI [heart attack], resuscitated cardiac arrest, and fatal or nonfatal stroke.”
The researchers further note that the results of the study should “reassure physicians treating patients at low risk for diabetes.”
Limitations of the study include that most of the participants were white, HbA1c (a measure of blood glucose control over the previous 2–3 months) was not regularly measured, and diabetes was not a predefined endpoint considered in either TNT or IDEAL.
For more information, read the article “Diabetes–Statin Link Hinges on Risk Factors” or see the study’s abstract in the Journal of the American College of Cardiology. And to learn more about statins, read the article “Lower Cholesterol to Lower Heart Risk.”