Insulin-mediated increase in calf blood flow is not related to blood pressure levels in patients with type 2 diabetes mellitus.
An association between insulin resistance and blood pressure levels has been found both in non-diabetic subjects and in type 2 diabetic patients. In non-diabetic subjects, infusion of insulin increases skeletal muscle blood flow, and it has been suggested that an attenuated flow-response to insulin may cause insulin resistance and may also serve as a mechanism relating insulin resistance to elevated blood pressure. We wanted to explore whether these findings could be extended to patients with type 2 diabetes. The effect of insulin infusion during a hyperinsulinaemic euglycaemic glucose clamp investigation on calf blood flow and its relationship to average diastolic blood pressure (DBPAVG), insulin sensitivity (GFRIlbm), body fat and total exercise capacity (TEC) was examined in 11 patients with type 2 diabetes. We found that insulin infusion increased median calf blood flow from 2.3 to 2.7 ml/min.100 g (p = 0.01). The change in blood flow (delta flow) did not correlate to the subjects' average blood pressure levels or their insulin sensitivity. Significant correlations between delta flow and leg fat %, fasting and clamp-insulin levels and total exercise capacity were observed. In conclusion, we found that insulin infusion increased calf blood flow significantly in patients with type 2 diabetes. However, our hypothesis that a negative correlation exists between blood pressure levels and insulin stimulated blood flow, was invalidated. Leg fat was identified as an important predictor of delta flow, GDRILBM and TEC in these patients.
Birkeland
K I
KI
Hormone Laboratory, Aker Hospital, Oslo, Norway.
Hanssen
K F
KF
Stranden
E
E
Falch
J A
JA
Vaaler
S
S
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000503:physiopathology*; D015444:Exercise; D005260:Female; D006801:Humans; D007328:Insulin / Q000008:administration & dosage*; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000187:drug effects
D007328:Insulin