The Influence of Obese Insulin-Resistance on the Outcome of the Ischemia/Reperfusion Insult to the Heart

BACKGROUND: Obese insulin-resistance is one of the most important risk factor for cardiovascular diseases including ischemic heart disease (IHD). Growing evidences suggest that the susceptibility to myocardial ischemia-reperfusion (I/R) injury is increased in an obese insulin-resistance condition. Based on the currently available evidence from human and animal studies, this review mainly focuses on the influence of obese insulinresistance on the outcome of the I/R insult to the heart. Moreover, we have discussed whether improving insulin sensitivity by pharmacological interventions could ameliorate reperfusion induced myocardial injury. METHODS: The electronic database Pubmed was used as the source of selected peerreviewed research articles published in English. Both pre-clinical studies and clinical trials were obtained using obesity, insulin resistance, ischemia-reperfusion injury and myocardial infarction as keywords. RESULTS: Twenty-seven pre-clinical studies were obtained using obesity, insulin resistance, and cardiac ischemia-reperfusion injury as keywords, and five clinical trials were obtained using obesity, insulin resistance, and myocardial infarction as keywords. The underlying mechanisms responsible for the exacerbation of I/R injury in obese insulinresistance were the main subject of our review. CONCLUSION: The findings of this review suggest that the susceptibility to I/R injury is increased in an obese insulin-resistance condition. However, the underlying mechanisms responsible for the exacerbation of I/R injury in obese insulin-resistance have not been fully elucidated, but increased basal oxidative stress, the impairment of anti-oxidant capacities, insulin signaling and pro-survival signaling and increased inflammation, likely play an important role.