Is obesity a risk factor for coronary atherosclerosis?

A group of 279 adult autopsy patients (66 obese with BMI 30, versus 213 nonobese with BMI < 30) was retrospectively studied for the relation between body weight and coronary artery atherosclerosis. In the obese group, there was slightly higher grade of coronary narrowing than in the nonobese (2.31/2.5 versus 2.12/2). With increasing BMI in the obese, there was a statistically significant trend for milder coronary atherosclerosis, with least involvement in the extremely obese (BMI > 50). It seems that increased body weight by itself has little impact on coronary atherosclerosis, and extreme obesity may even by protective from it.