THE DIABETIC HEART IS MORE SENSITIVE TO ISCHEMIC-INJURY

Clinical studies have suggested that the diabetic heart is more sensit ive to ischemic injury than the non-diabetic heart. However, results f rom a number of experimental studies using animal models of diabetes r eported no change, increased or decreased sensitivity to ischemia, The purpose of this review is to discuss the possible explanations for th is apparent discrepancy. Analysis of the conflicting literature on thi s subject reveals a pattern which suggests that the disparity of exper imental findings stems from differences in the duration and severity o f the diabetic state, the ischemic flow rate and whether fatty acids a re provided as an exogenous substrate. It appears that shea-term or mi ld diabetes is associated with decreased sensitivity to zero-flow isch emic injury. However, as the duration or severity of diabetes increase s, this beneficial effect disappears. The diabetic heart also appears to be more vulnerable to injury during low-flow ischemia and when elev ated fatty acids are present.