A study involving people with diabetes has shown that belly size is a stronger predictor of a dangerous kind of heart disease than body mass index, researchers said Saturday. The study released at the American College of Cardiology conference in Chicago was based on 200 people with diabetes who had not shown any symptoms of heart disease. “We specifically found that waist circumference appears to be a stronger predictor for left ventricle dysfunction than total body weight or body mass index,” said principal investigator Boaz Rosen, a doctor at Johns Hopkins University in Maryland.