You may be at a higher risk of getting heart disease if you’re overweight or you smoke. But what can a diagonal crease in your earlobe tell you?

Whereas a “normal” earlobe is smooth, an earlobe with a crease has a fold, straight line, or wrinkle that appears to cut the earlobe in half. An open letter published in the New England Journal of Medicine in 1973 reported that a diagonal earlobe crease (ELC) was a potential indicator of coronary artery disease (CAD). This crease was later called “Frank’s sign,” after the letter writer, Dr. Sanders T. Frank.

Could such a small mark on your ear really have anything to do with heart disease?

Scientists aren’t sure how these two might be connected, but there are some theories.

Degeneration of the elastic tissue around the small blood vessels that carry blood to the earlobes produces the earlobe crease. This is the same type of change that happens with blood vessels associated with CAD. In other words, visible changes that show up in tiny blood vessels of the ear could indicate similar changes, that can’t be seen, in those blood vessels around the heart.

Rare disorders like Beckwith-Wiedemann syndrome (an overgrowth disorder) in children or genetic factors such as race and earlobe shape also can cause a crease. So how concerned should you be if you have an earlobe crease?

Several scientists have looked at the potential connection between earlobe creases and CAD. Some studies have shown a correlation, while others haven’t.

A study of 340 patients published in 1982 found an earlobe crease to be a sign associated with aging and CAD. The crease suggested the presence of a more severe form of heart disease in people who were showing symptoms.

The earlobe crease, the researchers wrote, “may identify a subset of patients prone to early aging and to the early development of coronary artery disease, whose prognosis might be improved by early preventative measures.”

Another study published in 1989 studied the bodies of 300 patients who had died from various causes. In this study, the diagonal creases were associated with cardiovascular causes of death.

The researchers wrote, “We found a strong association between earlobe creases and a cardiovascular cause of death in men and women after age, height, and diabetes had been controlled for.”

A 1991 study found similar results. So did a study published in 2006, which reported that an ear crease in people younger than age 40 was a sign of CAD in up to 80 percent of cases. In a 2012 study, 430 patients with no history of CAD were examined for ear creases and then given a CT scan for CAD. Those with an ear crease were more likely to have CAD.

Other studies have shown different results. A study in 1980 showed no significant relationship between ELC and CAD in American Indians. This indicates that “Frank’s sign” may not show the same correlation in some ethnic groups.

Another study of Japanese Americans living in Hawaii also found no connection. Studies have indicated that the sign may be less indicative in people who have other important risk factors for CAD, particularly diabetes.

Some studies have theorized that as people age, the presence of earlobe creases and heart disease increase — especially after they reach age 50. This doesn’t necessarily mean that one has to do with the other.

A study by the University of Massachusetts Medical School concluded that earlobe creases are a simple feature of the aging process in some people.

Enough studies have established a connection between earlobe creases and heart disease that it’s worth taking a wrinkle on your ear seriously.

A 2011 NYU School of Medicine student review of the studies concluded that ELC predicts CAD more often than traditional risk factors and that it may be useful for identifying patients with the disease.

Check with your doctor first. They’ll most likely test your blood pressure, cholesterol levels, and other risk factors.

Taking everything — including your ears — into account creates a clear overall picture of your risk and determines what steps you can take to protect your heart health.