Diabetes is a major health hazard in Oklahoma Indians. A further important aspect is the apparently high vulnerability of the diabetic Oklahoma Indians to atherosclerotic disease. In the mid 1980s, this group had the highest prevalence of 0-wave changes on the electrocardiogram and amputation for ischemic gangrene of all 14 international samples in the World Health Organization Multinational Study. Its cardiovascular mortality rates were 2-3 times those of other national samples. An epidemic of coronary heart disease was attacking this Indian population.