A new study by the Medical School and Veterans Affairs Ann Arbor Healthcare System challenges the medical thinking that the lower the cholesterol, the better.

Tailoring treatment to a patient’s overall heart attack risk, by considering factors such as age, family history and smoking status, was more effective, and used fewer high-dose statins, than current strategies to drive down cholesterol to a certain target, according to the U-M study.

While study authors support the use of cholesterol-lowering statins, they conclude that patients and their doctors should consider all the factors that put them at risk for heart attack and strokes.

The findings will be released online today ahead of print in the Annals of Internal Medicine.

“We’ve been worrying too much about people’s cholesterol level and not enough about their overall risk of heart disease,” says Dr. Rodney Hayward, director of the Veterans Affairs Center for Health Services Research and Development and a professor of internal medicine at the Medical School.

The National Cholesterol Education Program recommends harmful LDL cholesterol levels should be less than 130 for most people. High-risk patients should be pushed even lower — to less than 70.

The study took a different approach, called tailored treatment, which uses a person’s risk factors and mathematical models to calculate the expected benefit of treatment, by considering:

• A person’s risk of a heart attack or stroke without treatment.

• How much a statin decreases the risk.

• Potential harms from the treatment.

“These are the three factors that determine the net benefit of a treatment. Our fixation on just one factor, LDL cholesterol, is leading us to often treat the wrong people,” Hayward says.

The bottom line message: knowing overall heart attack risk is more important than knowing a cholesterol level, Hayward says. “If your overall risk is elevated, you should probably be on a statin regardless of what your cholesterol is and if your risk is very high, should probably be on a high dose of statin.”

“However, if your LDL cholesterol is high, but your overall cardiac risk is low, taking a statin does not make sense for you,” Hayward says. “If your cholesterol is your only risk factor and you’re younger, you should work on diet and exercise.”

Research has increasingly emerged questioning the value of cholesterol targets and which of statins mechanisms is most important to preventing cardiac events. Cholesterol-lowering drugs work by blocking a key enzyme linked with LDL cholesterol production, but they initiate other changes in the body.

Additional U-M authors are Dr. Donna Zulman, Justin Timbie and Dr. Sandeep Vijan, all of the VA Center for Health Services Research and Development, VA Ann Arbor Health Care System.