Increased myocardial performance following acute hyperglycaemia in insulin-dependent diabetic patients. A consequence of increased peripheral blood flow?

Cardiac function during acute hyperglycaemia was investigated by means of echocardiography in eight insulin-dependent (type 1) diabetic patients without microvascular or cardiac disease. Blood glucose was raised from 5.1 +/- 0.8 to 13.0 +/- 0.9 mmol/l for 1 h and then to 20.1 +/- 1.2 mmol/l for 1 h. A saline control study was performed to obtain an equal amount of plasma volume expansion. The left ventricular end-diastolic diameter increased significantly in both studies, however, significantly more following glucose infusion (3.3% at blood glucose of 13.0 mmol/l, 5.4% at blood glucose of 20.1 mmol/l versus 2.7% after both saline infusions). At the blood glucose level of 20.1 mmol/l, fractional shortening of the left ventricle and cardiac output were increased as compared with the baseline level and the level during moderate hyperglycaemia, and also increased compared with values of non-diabetics. In conclusion acute hyperglycaemia is followed by increased myocardial performance, probably as a consequence of increased peripheral blood flow.