Hemodynamics variables (heart rate, arterial blood pressure, cardiac output, hepato-splanchnic blood flow, forearm blood flow, and plasma catecholamines) were measured during good (median blood glucose 4.7 mmol/L) and poor (median blood glucose 16.3 mmol/L) metabolic control in eight young, short-term, insulindependent diabetic patients. The measurements were performed twice within 2 wk, in random order. Continuous subcutaneous insulin infusion (CSII) was applied for 1 wk in order to obtain good control. All eight patients had elevated cardiac output (median 9%) and forearm blood flow (median 34%) during poor compared with good metabolic control, P < 0.01. In contrast, hepato-splanchnic blood flow was lower (median 12%) during poor compared with good metabolic control, P < 0.05. Heart rate remained unchanged, while mean arterial blood pressure was slightly higher during poor control, P < 0.05. Five of six patients had elevated plasma noradrenaline concentration during poor metabolic control. Due to the small number of patients investigated, no valid conclusion regarding the activity of the sympathoadrenal system can be drawn.
Our study suggests that both increased cardiac output and reduced hepato-splanchnic blood flow (redistribution) contribute to the elevated blood flow previously demonstrated in various other organs and tissues in diabetic patients during poor metabolic control.