Do all diabetics need to be on statins? Maybe not

By Deborah Kotz, Globe Staff

Doctors often tell those with type 2 diabetes that they have about a 20 percent risk of suffering a heart attack or other serious cardiac event in the next 10 years and that they should take a cholesterol-lowering statin to reduce this risk. But a study published this week in the Archives of Internal Medicine confirms that the risk is actually much lower in some with the disease and that a routine blood test to measure glucose levels in the blood might be helpful in calculating an individual’s risk.

The researchers found that the blood test, called hemoglobin A1C, can help predict with better certainty which diabetics are at greater risk of having a heart attack in the next 10 years -- especially in younger women with diabetes, who tend to have lower heart disease risks because of their age and gender.

“We found that every percentage point increase in A1C raised a woman’s 10-year heart disease risk by 17 percent and a man’s risk by about 10 percent,” said study author Nina Paynter, an epidemiologist at Brigham and Women’s Hospital. She couldn’t explain why the test was more predictive in women but said researchers have known for some time that soaring blood sugar levels are a stronger predictor of heart problems in women than in men.

Using a new risk calculation tool that incorporated A1C levels into other measurements such as blood pressure and cholesterol levels, the researchers found that nearly one-fifth of the 685 diabetic women who participated in the study actually had a risk of heart disease that was very low: less than 5 percent over the next 10 years.

This raises the question: Should women in this low-risk category be prescribed statins?

Experts say that’s tough to answer. “Individuals with diabetes have substantially higher longer-term/lifetime cardiovascular disease risk,” wrote Dr. Mark Pletcher, a professor of general medicine at the University of California, San Francisco, in an editorial that accompanied the study. And statins have been shown lower the rate of heart attacks and deaths in those with a 10-year heart attack risk of 20 percent or greater.

But there’s a lack of evidence to determine one way or the other whether treating diabetics -- who have low heart disease risks due to, for example, their young age -- earlier with cholesterol-lowering medications will help prevent heart attacks or heart disease deaths down the road.

The cost of the drugs must be considered along with side effects like muscle aches, sleep difficulties, headaches, and gastrointestinal upset. Although statins are considered to be very safe drugs, in very rare cases, they can lead to muscle and kidney damage.

“I don’t think we should lump all diabetics into the same high-risk category,” said Dr. Om Ganda, head of the Joslin Diabetes Center Lipid Clinic. “Clinicians really need to use their judgement and consider other factors like age, family history of heart disease, blood pressure and cholesterol levels, and smoking habits.”

Those with diabetes who are younger -- under 60 for a woman and under 50 for a man -- may want to discuss their own individual risks with their doctor to determine the appropriate age to begin a statin, Ganda added.

The decision process may soon become easier with new heart disease prevention guidelines that are slated to be issued later this year by the National Heart Lung and Blood Institute. Experts are expecting the guidelines -- updated for the first time in a decade -- to incorporate newer screening tools like A1C and other biomarkers to help better discern heart disease risks in the general population as well as in those with diabetes.