The glucose dysmetabolism in the acute phase of non-diabetic ST-elevation myocardial infarction: from insulin resistance to hyperglycemia.

In the setting of acute myocardial infarction, hyperglycemia and acute insulin resistance may represent a stress response to myocardial injury mainly related to acute catecholamine release. By measuring glucose values and insulin resistance (Homeostatic Model Assessment index-HOMA), we evaluated in 356 non-diabetic patients with ST-elevation myocardial infarction (STEMI) undergone mechanical revascularization: (a) the acute glycometabolic response by evaluating insulin resistance, glucose levels, and their combination and (b) whether insulin resistance and increased glucose values (and their combination) are able to affect in-Intensive Cardiac Care Unit (ICCU) mortality and complications. In the overall population, 226 (63.5%) patients showed glucose values ≤140 mg/dl (group B), while 130 patients had glucose values >140 mg/dl (group A) (36.5%). Within group B, insulin resistance (as inferred by positive HOMA index) was present in 125 patients (55.3%), whereas 101 patients (44.7%) exhibited normal values of HOMA index. Within group A, 109 patients (83.8%) were insulin resistant, while 21 patients (16.2%) had normal values of HOMA index. At multivariable analysis, glucose values were independently associated with in-ICCU mortality (OR: 7.387; 95% CI 2.701-20.201; P < 0.001) and complications (OR: 1.786; 95% CI 1.089-2.928; P = 0.022). In the early phase of STEMI, the acute glycometabolic response to stress is heterogeneous (ranging from no insulin resistance to glucose levels >140 mg/dl and, finally, to the combination of increased glucose values and insulin resistance). Increased glucose values are stronger prognostic factors since they are independently associated with in-ICCU mortality and complications.