Feb. 21, 2019&mdash;Doctors have long known that diabetes increases the risk of heart disease, the nation's No. 1 killer. But until recently, they weren't sure if the same could be said about an earlier condition: prediabetes. 

Prediabetes describes a blood sugar level that is higher than normal but not yet high enough to be considered type 2 diabetes. And it's very common. In fact, it's estimated that more than 1 out of 3 U.S. adults has it. Researchers wondered: Are people with prediabetes at higher risk for heart disease too? 

The surprising answer was no. In a comprehensive look at seven previous studies from 1960 to 2015, they found that prediabetes did not raise the risk of heart disease. 

But that doesn't mean people with prediabetes can disregard their heart health. Unless they take steps to return their blood sugar levels to a healthy range, most people with prediabetes go on to develop diabetes later in life. And the study confirmed that people with diabetes do carry a much higher risk of heart disease than those without it. 

So it's important to think of prediabetes as a chance to turn things around&mdash;and to work closely with your doctor to bring your blood sugar down to a normal level.

Lifestyle changes, like moving more and eating better, can help people with prediabetes avoid developing type 2 diabetes. And in the long run, that may help protect your heart as well. 

The study appeared in the journal <a target="_blank" href="http://care.diabetesjournals.org/content/early/2019/01/03/dc18-1773">Diabetes Care</a>.

Are you at risk for diabetes? 

Millions of people who have diabetes don't know they do. <a href="[BASEDOMAIN]/healthinfo/Story.aspx?StoryID=34302b70-1fa2-4fe4-b51f-c9d952ca755e">Take this quick diabetes assessment</a>, and share the results with your doctor.

Does prediabetes put your heart in danger?

While prediabetes may not hurt your heart, doing nothing about it can.