Interviews were conducted and clinical data collected on each index case and spouse, as well as on first degree relatives. Risk factor data included blood pressure, blood lipid levels, obesity, cigarette smoking, fasting blood sugar and diabetes, hormone use and menopause for women, physical activity, personality scores, and family history. Clinical data included the indications for coronary arteriography, history of use of lipid-lowering agents and insulin, presence of corneal arcus, xanthomata, and xanthelasma, and the electrocardiogram.