[Heart involvement in diabetic patients].

Diabetic cardiomyopathy appears to be due to "premature ageing" of the myocardium which loses some of its compliance and becomes less sensitive to catecholamines. The condition seems to be severe mainly in those frequent cases where it is associated with hypertensive and/or ischaemic cardiomyopathy. Neuropathic denervation of the heart, usually partial and predominantly affecting the parasympathetic system, might play a part in the myocardial dysfunction. It has been held responsible for sudden death, but its real consequences in diabetic patients remain to be assessed. Coronary artery disease is the most common cardiac complication of diabetes mellitus: it accounts for 50 per cent of deaths among noninsulin-dependent, and 25 per cent among insulin-dependent diabetic subjects. Its incidence does not seem to decline and its severity, notably in women, is demonstrated by a mortality rate that is twice as high as that observed in the non-diabetic population; hence the importance of primary prevention and treatment of risk factors. However, the specificity to abnormal lipid metabolism, notably hypertriglyceridaemia, the potentiation by chronic hyperglycaemia of the harmful effects of arterial hypertension, and the possible responsibility of coagulation disorders and hyperinsulinism are points that have not yet been elucidated. We still do not know whether the objectives to be attained in terms of plasma cholesterol, triglycerides and fibrinogen levels, as well as of blood pressure values, should be different in diabetic and non-diabetic subjects. In any case, the treatment of risk factors should be accompanied by a systematic search for silent ischaemia which is 2 to 3 times more frequent among diabetic patients. Detection of silent ischaemia by electrocardiography during exercise and/or Holter recordings, and by echocardiography and/or thallium scintigraphy should be performed not only in diabetic patients with coronary artery disease but also to those with other risk factors or albuminuria.