From the Pittsburgh Epidemiology of Diabetes Complications Study, a 16-year study of 225 patients with type 1 diabetes, conducted at the University of Pittsburgh.On average, the patients were 42 years of age and had been diabetic for 34 years. Type 1 diabetes, or "juvenile" diabetes, is typically diagnosed in childhood and develops differently than type 2 diabetes does, which usually occurs in middle age.

Using special X-rays, the researchers examined the calcium build-up in the coronary arteries, the arteries than feed the heart muscle. This calcium build-up correlates with heart disease. In addition, body mass index, a measure of body weight in relation to height, and body fat levels were determined for all subjects.

As noted, as body weight and fat increased, the risk of heart disease appeared to rise as well. By contrast, as patients put on more and more weight, the severity of heart disease fell. This latter finding was evident even when other heart disease risk factors, such as high cholesterol levels, were present.

This double-edged association, which appears to be more pronounced in women, emphasizes the complex relationship between (body fat levels) and (heart disease) risk in diabetes.