Features September 2011 Issue

Study Shows Link Between High-Dose Statins and Diabetes Risk

But health experts caution that the cholesterol-lowering drugs are still a powerful and valuable ally against heart disease.

If you have high cholesterol it’s likely that your physician has prescribed a statin. For more than two decades statins have helped reduce cardiovascular problems in many patients at risk for heart attack or stroke. But a report in the June 22/29 issue of The Journal of the American Medical Association noted that an analysis of five statin trials found that intensive-dose therapy increased the risk of type 2 diabetes.

If you are prescribed statin therapy, how concerned should you be?

Reviewing the Risk
Cleveland Clinic’s Chairman of Cardiovascular Medicine, Steven Nissen MD, says it’s important to realize that the study showed a small additional risk and “the trigger for a diabetes diagnosis may be very slight so that a few people will cross that threshold between non-diabetes and diabetes.” 

To put the diabetes diagnosis into context, Dr. Nissen gives an example: “If we look at a diagnosis point of a 110 mg/dL fasting blood sugar, then going from 109 to 111 with the statin may raise the blood sugar just enough that now they are diagnosed with diabetes.” 

In fact, this newest report that high doses of statins can increase the risk for Type 2 diabetes does not come as a surprise, says Stephen J. Nicholls, PhD, Clinical Director of the Cleveland Clinic Center for Cardiovascular Diagnostics and Prevention. Experts have known of studies leading up to the most recent report and taken them into account. “A diabetes risk with statins has been emerging in the last few years, but the most important thing to realize is that statins are good drugs to lower cholesterol and have a profound impact against heart attack and stroke and death.”

Intensive Dose vs Moderate Use
It’s especially relevant to recognize that the studies involved in the report compared intensive doses of statin therapy to moderate doses. A dosage of 80 mg was used to define intensive therapy. To put that dose into perspective, the most commonly prescribed statin drugs, both generic and branded with names such as Lipitor, Crestor, Zocor and others, are available in much smaller doses which are more commonly used that the high doses in the statin/diabetes study.

Crestor, for example, is available in doses as small as 5 mg increasing to 10, 20 or 40 mg; Lipitor is available in 10, 20, 40 and does go up to 80 mg.  But Dr. Nicolls points out that most people are never prescribed in the higher range. “There are muscle side effects to higher doses anyway so most people are not treated with those doses.  The average person is taking a dose of 20 mg.”

A few patients may be prescribed with higher statin doses but they are the ones at very high risk for cardiovascular problems says Dr. Nissen.  “Either they have a large risk of heart attack and have had one, or they have extremely high levels of LDL that warrant the high doses.”

Weighing the Benefits
If your blood cholesterol levels warrant statin therapy, the drug can help reduce your “bad” LDL, reduce triglycerides and may even slightly increase your “good” HDL cholesterol to help prevent major cardiovascular events.

And, although he does not want to minimize diabetes, Dr. Nichols notes that, compared to the serious risk of heart attack, stroke or death that some patients face, a case of diabetes can be manageable. Just knowing the connection between statin therapy and diabetes helps, he says. “Doctors will probably monitor patients closer so, even if a patient gets diabetes, it will be recognized early and blood sugar control can be very effectively managed.”