THURSDAY, Aug. 9 (HealthDay News) -- The cardiac benefits of statins outweigh any increased chances for developing diabetes, even among those who run the highest risk of developing the blood sugar disease, Harvard researchers report.

The concern that these cholesterol-lowering drugs, which include the widely prescribed medications Lipitor, Crestor and Zocor, increased the risk for diabetes prompted the U.S. Food and Drug Administration to require labeling that warns users of the risk.

"Earlier this year, concern was raised that patients taking statins had an increased risk of developing diabetes, and on that basis many patients stopped taking their medications," explained lead researcher Dr. Paul Ridker, director of the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital, in Boston. "Unfortunately, little if any data was available at that time to address not only the risks, but also the benefits of treatment. This is crucial since it is the benefit-to-risk ratio that physicians and their patients need to understand."

The clinical message of this new research is clear, Ridker noted. "The cardiovascular benefits of statin therapy outweigh the diabetes hazard, even among those with highest risks for diabetes," he said. "We hope these new data will better inform discussions between physicians and patients who are considering the use of statin drugs as a possible addition to diet, exercise and smoking cessation."

The report was published Aug. 9 in the online edition of The Lancet.

Ridker's team used data from a trial that was conducted to find out if one particular statin, Crestor (rosuvastatin), could prevent heart disease in patients who never had heart disease. The trial, which included nearly 18,000 patients, was the first to reveal the possibility that statins could increase the risk for diabetes.

However, Ridker's group found that the risk of developing diabetes while on Crestor was greatly influenced by a person's existing risk for developing diabetes.

Over the five years of the trial, patients taking Crestor who didn't have any risk factors for developing diabetes didn't show an increased risk for developing the disease.

Patients taking a statin who had one risk factor for diabetes, however, saw a 28 percent increase in their risk of developing the disease.

Moreover, although statins did increase the risk for diabetes among those with risk factors for diabetes, these patients were 39 percent less likely to develop heart disease and 17 percent less likely to die, the researchers found.

"Among those with one or more major risk factors for diabetes, there were 134 fewer heart attacks, strokes and other major cardiovascular events among those who got the statin, but this came with the hazard of 54 new cases of diabetes being diagnosed. This group is already at high risk for getting diabetes, a group who are already considered candidates for statin therapy," Ridker noted.

Patients taking statins who were not at risk for diabetes had a 52 percent lower risk of developing heart disease and no increased risk of developing diabetes, the research team added.

"Among those with no risk factors for diabetes, there were 86 fewer heart attacks, stroke and other major vascular events among those who got the statin as compared to placebo, with no new cases of diabetes at all. So, for this group, there was cardiovascular benefit with no diabetes risk," Ridker said.

Dr. Gerald Watts, the Winthrop Professor of Medicine at the Cardiometabolic Research Center of the University of Western Australia and co-author of an accompanying journal editorial, said that "statins can lead to diabetes if you are predisposed to diabetes and this could be an issue when treating people at low risk of heart disease."

The benefit of statins in preventing heart disease, however, outweighs their risk in leading to diabetes, he added.

"Watch out for diabetes if you are on a statin and are at risk of diabetes," Watts said. Risk factors for diabetes include obesity, family history and abnormal blood sugar levels, he said. "If you are on a statin make sure you lead a healthy lifestyle," he added.

Another expert, Dr. Gregg Fonarow, a spokesman for the American Heart Association and a professor of cardiology at the University of California, Los Angeles, said that "statin therapy has been clearly demonstrated to prevent cardiovascular events and premature cardiovascular death in men and women."

"This study confirms there is substantial net benefit of statin therapy even when fully accounting for the diabetes risk," he said.

More information

For more information on statins, visit the U.S. National Library of Medicine.