There were significant differences in insulin resistance markers except fasting plasma insulin levels among three groups, and diabetic CAD group had higher levels of insulin resistance than non-diabetic CAD group (HOMA-IR, 2.1 ± 1.3 vs. 1.2 ± 0.9, P = 0.0075; insulin levels at the 2nd hour, 33.8 ± 8.5 vs. 23.7 ± 7.1, P = 0.0183). This evidence concerns the gene INS and Insulin resistance.