Central and peripheral haemodynamic effects of hyperglycaemia, hyperinsulinaemia, hyperlipidaemia or a mixed meal

The aim of the present study was to evaluate the haemodynamic changes during hyperinsulinaemia, hyperglycaemia or hypertriglyceridaemia in relation to those following a mixed meal. Ten subjects were subjected to hypertriglyceridaemia (3.9 mmol/l) for 2 h by an infusion of Intralipid and heparin. Nine subjects received a hyperglycaemic clamp (12.5 mmol/l) with octreotide and low-dose insulin infusion to maintain normoinsulinaemia (10 m-units/l). Ten subjects received saline for 2 h as a control and, thereafter, 2 h of normoglycaemic hyperinsulinaemic clamp (80 m-units/l). Finally, ten subjects were evaluated for 2 h following an ordinary mixed meal. Calf blood flow was measured by venous occlusion plethysmography and cardiac index by thoracic bioimpedance. Both the mixed meal and normoglycaemic hyperinsulinaemia lowered total peripheral resistance, and increased calf blood flow and cardiac index, whereas blood pressure decreased (P <0.05-0.001). Both hyperglycaemia and hypertriglyceridaemia increased calf blood flow, but blood pressure was unchanged. Total peripheral resistance was unchanged in hypertriglyceridaemia, whereas hyperglycaemia induced a significant increase. Normoglycaemic hyperinsulinaemia induced a haemodynamic pattern similar, but to a lesser extent, to the pattern seen following a mixed meal. Hyperinsulinaemia seems to be a major mediator of the haemodynamic response, but other factors are obviously also of great importance. Hypertriglyceridaemia and hyperglycaemia induced haemodynamic responses that are not similar to those seen following a mixed meal.