Acute diabetes mellitus does not impair survival rate in rats submitted to left coronary artery ligation.

This study was designed to assess whether the acute metabolic disturbances associated with diabetes mellitus of three-days duration could influence the survival of rats submitted to experimental myocardial infarction. Diabetes was induced with streptozotocin (50 mg/kg) in male Wistar rats and three days later left coronary artery ligation was performed in both control (n = 34) and diabetic (n = 31) animals. Diabetic rats had significant alterations in plasma levels of glucose (424 +/- 6 vs 143 +/- 3 mg/dL; p less than 0.001), insulin (10 +/- 1 vs 32 +/- 2 microU/mL; p less than 0.001) and free carnitine (37 +/- 2 vs 52 +/- 2 microM; p less than 0.001). There was no significant difference in the survival rate of diabetic animals, either early after coronary artery ligation (32 vs 42% at 20 min; p greater than 0.1) or later (21 vs 25% at 1 week; p greater than 0.1). This suggests that the increased mortality rate found in diabetic subjects suffering from myocardial infarction is due to some long-term changes associated with chronic diabetes mellitus rather than to the acute metabolic disturbances present at the time of this event.