(HealthDay)—Most older Americans qualify for treatment with statins under new guidelines for the treatment of blood cholesterol released late last year by the American College of Cardiology and the American Heart Association. The findings appear in a research letter published online Nov. 17 in JAMA Internal Medicine.

The new study of 6,088 black and white Americans aged 66 to 90 found that 70 percent were eligible for statin therapy, including 97 percent of those aged 66 to 75 and all of the men.

The guidelines recommend statins for people with cardiovascular disease, diabetes, or high , but also recommend the drugs for people who don't have these conditions but do have a higher than 7.5 percent risk of heart attack or stroke in the next 10 years based on a risk calculator. The guidelines do not offer a recommendation for or against statin therapy in people older than 75, but more than half of the study participants in that age group were taking the drugs. "Older individuals will likely cross the 7.5 percent threshold based on age alone, even if they have normal cholesterol levels and no other , and our study confirms this notion," Michael Miedema, M.D., M.P.H., a research cardiologist at the Minneapolis Heart Institute Foundation, said in a foundation news release.

"We don't have great data on the efficacy of statin medications in the elderly so the guidelines drew a cut-off for the recommendations at age 75. This is understandable, but it kind of leaves clinicians in the dark as to what to do with healthy elderly patients, who are often at high risk for heart attacks and strokes," Miedema said. "We clearly need more research looking at the best way to determine who should and should not take a statin, as well as the risks and benefits of in elderly patients."