[The influence of physical training on metabolic indices in men with myocardial infarction and impaired glucose tolerance].

INTRODUCTION: Body mass reduction and regular physical training form part of a strategy to treat disorders of carbohydrate metabolism associated with obesity. Evidence shows that even a slight reduction in body mass may improve carbohydrate tolerance, lipid profile and insulin resistance, reduce insulin levels and finally delay or reduce risk of diabetes mellitus. Multiple studies, including prospective studies confirm the independent protective effects of physical training against future development of type 2 diabetes mellitus. Myocardial infarction is a severe complication of atherosclerosis. Patients with glucose intolerance have a 2-fold higher risk of dying. Impaired glucose tolerance is negatively associated with prognosis in patients after myocardial infarction. Glucose intolerance accompanies hyperinsulinemia, a major indicator of insulin resistance.

AIM: The aim of the study was to analyze the effect of physical training on hyperinsulinemia/ insulin resistance in patients after myocardial infarction (MI) with impaired glucose tolerance (IGT).

MATERIALS AND METHODS: 31 men aged 37-69 years (mean 51 +/- 7.4) with IGT 3.5 years after MI, in NYHA class I and II participated in the study. Group A (n=16 men) underwent supervised physical training and group B (n=15) received standard information on physical training. Tissue glucose disposal using normoglycemic glucose clamp technique, fasting insulinemia, glycemia during OGTT, lipid profile, BMI and body mass composition were obtained in all patients.

RESULTS: The groups were matched for age. There were no differences in BMI, percent fat content, blood pressure, diet, smoking status and pharmacotherapy. Glycemia during baseline OGTT did not differentiate the groups, either. Analysis of insulinemia and glycemia during OGTT at baseline and at 12 weeks after regular physical training showed lower levels of insulinemia and glycemia compared with baseline levels in group A (fasting glycemia 6.41+/-0.46 vs. 4.8+/-0.32 mmol/l, p<0.001; fasting insulinemia 59.42+/-38.9 vs. 27.42+/-26.5 umol/l, p<0.001). A similar analysis in group B did not reveal any significant differences (fasting glycemia 6.17+/-0.49 vs. 6.18+/-0.46 mmol/ l; fasting insulinemia 61.86+/-48.5 vs. 68.86+/-78.5 umol/l). Mean tissue glucose disposal in the whole study population was 2.96+/-1.03 mg/kg bm/min.

CONCLUSIONS: The present findings indicate the beneficial effects of regular physical training on the reduction of fasting insulinemia in patients after myocardial infarction with insulin resistance and improve lipid profile. In patients after myocardial infarction standard recommendations concerning physical activity are not well realized. It seems that better compliance, more strict control and motivation of patients can result in better metabolic control.