[Hypoglycemic therapy in heart disease patients with type 2 diabetes mellitus]

In type 1 diabetes, insulin treatment reduces complications related to microvascular disease and atherosclerosis. The same holds true in patients with short duration of type 2 diabetes, treated either with oral antidiabetic drugs or with insulin. Conversely, in patients with long-standing type 2 diabetes, advanced age or history of cardiovascular disease, treatment with oral diabetic drugs or insulin must be given with caution because of the unfavorable risk-benefit profile when these drugs are used with too aggressive aims. In the last year, several studies have clearly demonstrated that an excessive reduction of glycated hemoglobin exposes the patient at risk of hypoglycemia and fattening, with neutral results about clinical events or even with a paradoxical increase of cardiovascular events (hospitalization and mortality). The glycemic goal in heart disease and diabetic patients should be settled on higher values (probably 7-8%). There are no significant differences among drugs that reduce insulin resistance and drugs that stimulate its secretion. The only drug that proved to be effective in reducing cardiovascular events is metformin, which increases AMP-activated protein kinase activity and has a potent cardioprotective effect against ischemia-reperfusion injury. These findings should be confirmed in larger longitudinal studies in heart disease patients. Patients in intensive care units should be treated with intravenous insulin with a glycemic target <180 mg/dl (mean 142 mg/dl) because more aggressive goals may lead to increased mortality. These results demand important considerations about the management of heart disease patients with type 2 diabetes, also because self-monitoring of blood glucose concentration seems to induce an increase in depression. Conversely, an aggressive multifactorial intervention (improvement of lifestyle, blood pressure and dyslipidemia control, platelet aggregation inhibitors in secondary prevention) reduces effectively cardiovascular events and mortality.