[The diagnostic significance of insulinemia in the evaluation of myocardial torpor and hibernation in patients with coronary artery disease].

The aim of the study was to estimate the diagnostic significance of changes in insulin blood level for the evaluation of torpor and hibernation of the myocardium in patients with coronary artery disease (CAD). The subjects, 60 CAD male patients aged 49.60 +/- 7.45 were divided into two equal groups according to myocardial infarction (MI) background. The patients were examined by means of coronarography, dynamic Tl-199 single-photon emission computed tomography with intravenous adenosine administration, EchoCG, and veloergometry. Venous blood levels of insulin were measured using radioimmune assay at rest and after induced coronary insufficiency threshold physical load (TPL). In patients with hemodynamically significant stenosis of one to three magistral coronary arteries (MCA) mainly transient perfusion defects (TPD) of 18.3 to 20.6% myocardial area were registered prior to MI development. The manifestation of TPD, leading to torpor and a decrease in myocardial metabolic activity, was accompanied by moderate hyperinsulinemia (GI) (+/- 150 to 200%, p < 0.05 to 0.01). After MI, persistent perfusion defects (PPD) allowing for identification of hibernating myocardial regions of 10.3 to 63% myocardial area (p < 0.05 to 0.01) in correspondence with the number of magistral CA stenosis and/or cases of their occlusion, were found in the myocardium. GI of 350 to 400% the initial level was noted in patients with PPD in the course of myocardial ischemia worsening. The phenomena of torpor and hibernation, together with the progress of coronary and myocardial insufficiency, are characterized by changes in the intensity of myocardial carbohydrate exchange. This process is accompanied by the growth of insulinemia, especially under physical activity. The degree of GI under the conditions of TPL may reach the level of 200%; in patients with a hibernating myocardium GI may become as high as 400% or more the initial level. This allows considering torpor and hibernation to be consequent phases of ischemic myocardial metabolism remodeling, and considering the degree of insulinemia to be an indirect index of insulin reactivity, the preservation of insulin-producing function and thus the metabolic reserve of the organism.