Cardiac function and sympathetic activity in young diabetics.

This study was aimed at evaluating cardiac function, both systolic and diastolic, in young type 1 diabetics with a mean duration of the disease of 10.9 +/- 6 years and without evidence of cardiac autonomic neuropathy and micro- or macroangiopathy. Thirteen diabetics, with good metabolic control, and 10 normal matched subjects were studied by echocardiography at rest and by radionuclide ventriculography both at rest and during effort. The level of plasma catecholamines was also determined. The echocardiographic data were comparable in the two groups. Scintigraphic data showed an increased peak ejection and peak filling rate (P less than 0.001) in diabetics while the other indices of cardiac function were comparable. Norepinephrine (P less than 0.01) and epinephrine (P less than 0.001) were higher in diabetics. A hypothesis is formulated that the higher indices of flow velocities in type 1 diabetics are supported by a sympathetic overactivity.