Coexistence of insulin resistance and inflammation effectively predicts cardiac disease but not stroke in Japanese patients with type 2 diabetes mellitus

It is well known that insulin resistance (IR) and inflammation (IF) are associated with macroangiopathy. However, whether IR and IF are related to cardiac disease (myocardial infarction, angina pectoris, and heart failure), stroke or both remains elusive. The present hospital-based prospective study was designed to investigate this issue. The study subjects were 300 Japanese patients with type 2 diabetes mellitus and negative history of cardiac disease and stroke. IR (K index of insulin tolerance test; KITT) and IF (high-sensitivity C-reactive protein [hs-CRP]) were measured in each patient at baseline. Patients were followed-up for a mean period of 5.5 years. The time of first evidenced cardiac disease or stroke was monitored. During the follow-up, 35 patients developed cardiac disease and 26 patients developed stroke. Age, smoking, KITT, and hs-CRP were independently related to cardiac disease, while age, systolic blood pressure, low HDL, and anti-platelet drug use were independently related to stroke. When patients were subdivided into IR(−) and IR(+), and IF(−) and IF(+), Kaplan-Meier survival analysis showed that the rate of cardiac disease, but not of stroke, was significantly higher in IR(+)IF(+) than IR(−)IF(−) patients (p < 0.01). In conclusion, coexistence of IR and IF effectively predicted cardiac disease but not stroke in Japanese patients with type 2 diabetes mellitus.