Diabetes
56:468-475,
2007
DOI: 10.2337/db06-0635
© 2007 by the American Diabetes Association
Impact of Type 2 Diabetes on Nitric Oxide and Adrenergic Modulation of Myocardial Perfusion
Mette M. Madsen1,
Hanne M. Søndergaard1,
Morten Bøttcher1,
Niels H. Buus2,
Ole Schmitz2,3,
Hans E. Bøtker1, and
Torsten T. Nielsen1
1 Department of Cardiology B, Aarhus University Hospital, Aarhus, Denmark
2 Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark
3 Department of Endocrinology M, Aarhus University Hospital, Aarhus, Denmark
Address correspondence and reprint requests to Mette Marie Madsen, MD, Department of Cardiology, Skejby Sygehus, Aarhus University Hospital, DK-8200 Aarhus N, Denmark. E-mail: mette.marie{at}dadlnet.dk
Abbreviations:
L-NAME, NG-nitro-L-arginine methyl ester; MVR, myocardial vascular resistance; PET, positron emission tomography; RPP, rate-pressure product
Type 2 diabetic patients are characterized by a reduced adenosine-induced hyperemic myocardial perfusion, which may contribute to their increased cardiovascular morbidity. We hypothesized that the reduced hyperemia can be explained by functional changes in endothelial or autonomic nervous regulation. In 12 type 2 diabetic patients without signs of ischemic heart disease and 14 age-matched control subjects, myocardial perfusion was measured at rest, during adenosine, and during adenosine and -receptor blockade (phentolamine) using positron emission tomography on two separate days: 1) with, and 2) without nitric oxide (NO) inhibition with NG-nitro-L-arginine methyl ester. Myocardial perfusion during adenosine was lower in type 2 diabetic patients compared with control subjects (P = 0.05). No significant effect of NO inhibition on myocardial perfusion during adenosine was found in any of the groups. In control subjects, -receptor blockade increased hyperemic myocardial vascular resistance during NO inhibition, whereas no effect was observed in type 2 diabetic patients. At rest, a significant correlation was observed between rate-pressure product and myocardial perfusion in control subjects. NO inhibition and type 2 diabetes abolished this correlation. Endothelial and cardiac autonomic nerve function seems to play only a minimal role in the reduced hyperemic myocardial perfusion in type 2 diabetic patients. However, the linear correlation between resting perfusion and cardiac work appears to be abolished in type 2 diabetes and during NO synthase inhibition.

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Copyright © 2007 by the American Diabetes Association.
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