Association between insulin resistance and reduced coronary vasoreactivity in healthy subjects.
BACKGROUND
Insulin resistance appears to be an important risk factor for coronary artery disease.


OBJECTIVE
To examine the role of insulin resistance on coronary vasoreactivity in healthy subjects.


METHODS
Myocardial blood flow was quantitated using positron emission tomography and oxygen-15-labelled water in 10 healthy, nonobese men. The perfusion measurements were performed basally and during adenosine infusion, which has been used as a measure of coronary vasoreactivity. After perfusion measurements were taken, whole-body glucose uptake was determined using the euglycemic hyperinsulinemic clamp technique.


RESULTS
Basal myocardial blood flow was 0.89+/-0.21 mL.g(-1).min(-1); adenosine significantly increased the flow to 4.00+/-1.13 mL.g(-1).min(-1). Adenosine-stimulated myocardial blood flow was inversely associated with fasting serum insulin concentration (r=-0.69, P<0.05). Concordantly, hyperemic blood flow was associated with whole-body glucose uptake during euglycemic hyperinsulinemic conditions (r=0.64, P<0.05). Basal myocardial blood flow was not affected by insulin resistance.


CONCLUSIONS
The results of the present study demonstrate the novel finding that insulin resistance is associated with reduced coronary vasoreactivity, even in healthy subjects.
Sundell
Jan
J
Turku PET Centre, Turku University Central Hospital, Finland. jan.sundell@utu.fi
Luotolahti
Matti
M
D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015309:Glucose Clamp Technique; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D012016:Reference Values; D012307:Risk Factors; D013223:Statistics as Topic; D014055:Tomography, Emission-Computed; D014664:Vasodilation / Q000502:physiology*; D014665:Vasodilator Agents / Q000008:administration & dosage
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D014665:Vasodilator Agents; D000241:Adenosine