The presence of apolipoprotein (Apo) e4 allele is reported to be associated with the increased risk of coronary artery disease (CAD), as well as the impairment of endothelium-dependent arterial dilation in type 2 diabetes mellitus. Therefore, we hypothesized that Apo e4 allele increases the death risk from coronary artery disease in type 2 diabetes with ischaemia electrocardiographic change. From January 1993 to December 1999, 46 type 2 diabetic patients with e4/4 or e4/3, 96 with e3/3 and 45 with e2/2 or e3/2 genotypes were recruited. All subjects were unrelated elderly type 2 diabetic patients with ischaemia electrocardiographic change, aged 60-87 years, and their cardiac function were all the class I stage at their time of enrollment. A follow-up study of 3-10 years was undergone. The results are as follows: At baseline, serum total cholesterol and low-density lipoprotein (LDL) cholesterol concentrations were higher in subjects with e4/3 or e4/4 than in subjects with e2/2 or e3/2 (p<0.05). Lipoprotein(a) concentration was lower in subjects with e2/2 or e3/2 than in subjects with e3/3 and e4/3 or e4/4 (p < 0.05). During the 3-10 years follow-up period, a total of 55 patients who died from CAD were recorded in this sample. Compared with patients with e3/3 (p = 0.024) and patients with e2/2 or e2/3 genotypes (p = 0.002), the mortality rate of CAD in patients with e4/3 or e4/4 genotypes was the highest (47.8%). Stepwise discriminant analysis revealed that in the diabetic population studied Apo e4 allele was independently and significantly associated with CAD death (B = 0.65). However, the strength of the association decreased (B = 0.44) when total cholesterol, LDL-cholesterol and lipoprotein(a) were included in the model. Therefore, we concluded that Apo e4 allele increases the risk of CAD death in elderly type 2 diabetes mellitus with ischaemia electrocardiographic change.