Coronary heart disease (CHD) is the main cause of morbidity and mortality in type 2 diabetic subjects. Electron beam computed tomography (EBCT) of the coronary arteries provides a non-invasive method of detecting and quantifying coronary calcification (coronary calcium score), which is known to be an early marker of coronary atheroma in non-diabetic subjects. 600 type 2 diabetic subjects aged between 50 and 70 years of either sex will undergo EBCT. They will be followed-up for a mean period of four years. Recruitment started in September 2000 and preliminary results are expected in 2004. The primary aim is to assess the predictive power of the coronary calcium score for coronary events specifically in type 2 diabetic subjects. Secondary aims are to assess the relationship between coronary calcium score in type 2 diabetes and conventional risk factors, with novel risk markers, plasma homocysteine and C-reactive protein, and with key genetic markers of CHD.