Blunted Coronary Vasoreactivity to Insulin Is an Early Alteration in Hypertension

Abstract

Insulin resistance in the heart is not localized to the myocardium, but may also occur in blood vessels. We studied the effects of insulin on coronary vasodilation in hypertension. Coronary vascular resistance was quantitated in 11 nonsmoking men with untreated mild essential hypertension and 9 healthy normotensive men using positron emission tomography and ¹⁵O-labeled water. The measurements were performed at baseline and during adenosine infusion (140 µg·kg^–1·min^–1) with or without simultaneous euglycemic physiological (serum insulin approximately 70 mU/l) and supraphysiological (serum insulin approximately 460 mU/l) hyperinsulinemia. Coronary resistance was significantly higher in hypertensive than normotensive subjects at baseline and during adenosine infusion. Physiological hyperinsulinemia decreased hyperemic coronary resistance significantly in both groups. Supraphysiological hyperinsulinemia further decreased the hyperemic coronary resistance in normotensive but not in hypertensive subjects, leading to higher hyperemic coronary resistance in hypertensive than normotensive subjects (27.2 ± 8.7 vs. 19.2 ± 4.9 mm Hg·min·g·ml^–1, p < 0.05). However, insulin-stimulated whole body glucose uptake values were similar between the groups during both insulin infusions. In conclusion, insulin-induced coronary vasodilation is blunted in young subjects with mild essential hypertension who are otherwise healthy. Coronary vascular resistance to insulin occurs although no change in peripheral glucose uptake can be detected. While we do not know whether the same results can be extrapolated to female or older subjects, these results indicate a novel defect in the regulation of coronary arteries in the early phase of hypertension.

Journal

Journal ID (publisher-id): JVR

Journal ID (nlm-ta): J Vasc Res

Journal ID (doi): 10.1159/issn.1018-1172

Title: Journal of Vascular Research

Publisher: S. Karger AG

ISSN (Print): 1018-1172

ISSN (Electronic): 1423-0135

Publication date Subscription-year: 2003

Publication date (Print): February 2003

Publication date (Electronic): 26 March 2003

Volume: 40

Issue: 1

Pages: 58-67

Affiliations

^aTurku PET Centre, Departments of ^bMedicine and ^cClinical Physiology, Turku University, Turku, Finland

Article

Publisher ID: 68939 Other ID: J Vasc Res 2003;40:58–67

DOI: 10.1159/000068939

PubMed ID: 12644726

Copyright statement: © 2003 S. Karger AG, Basel

License:

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Page count

Figures: 5, Tables: 3, References: 44, Pages: 10

Product

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Categories

Subject: Research Paper