Mitchell Elkind of Columbia University Medical Center in New York and colleagues examined data on almost 3,300 people to see who developed diabetes and who had strokes.
Elkind said compared with people who never had diabetes, stroke risk was 70 percent higher in people who had diabetes for less than five years, but three times as high for people who had diabetes 10 years or more.
"The longer people have diabetes, the higher the risk," Elkind said in a statement. "But it is important to remember that even those who had diabetes for a few years still had an increase in risk."
The findings were published in the journal Stroke.