Correlates of acute insulin resistance in the early phase of non-diabetic ST-elevation myocardial infarction

The relationship between insulin secretion and acute insulin resistance (as assessed by Homeostatic Model Assessment [HOMA] index) and clinical and biochemical parameters in the early phase of non-diabetic ST-elevation myocardial infarction (STEMI) is so far unexplored. We aimed at assessing this relation in 286 consecutive STEMI patients without previously known diabetes submitted to primary percutaneous coronary intervention (PCI). Insulin resistance (as indicated by HOMA) was detectable in 67.1%. Non-parametric correlation showed that HOMA index was significantly correlated with BMI (r = 0.242; p < 0.0001) and HbA_1c (r = 0.189; p < 0.001). At multivariable backward linear regression analysis, glycaemia was directly related to leukocyte count (p = 0.0003), age (p = 0.0001), creatine kinase isoform MB (CK-MB) (p = 0.00278) and lactate (p < 0.0001). Insulin was directly and significantly related to glycaemia (p = 0.0006), body mass index (BMI) (p = 0.00028) and lactate (p = 0.0096) In the early phase of STEMI without previously known diabetes the acute glucose dysmetabolism is quite complex, comprising increased glucose values and the development of acute insulin resistance. While insulin secretion is strictly related to BMI, apart from glucose levels, increased glucose values can be mainly related to the acute inflammatory response (as indicated to leukocyte count and C-RP), to age and to the degree of myocardial damage (as inferred by CK-MB)