We have much evidence now that there is development of atherosclerosis beginning in infancy.  From the Bogalusa Heart Study, we have overwhelming proof that fatty streaks form in infancy, followed by fibrous plaques, and eventually full blown atherosclerosis.  The rates at which this occurs depend on risk factors such as obesity, physical inactivity, hypertension, diabetes,hypercholesterolemia, smoking and of course family history, racial group and socioeconomic factors.

Berenson et al. N Engl J Med 1998; 338:1650-56.