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Mechanisms of Coronary Dysfunction in Obesity and Insulin Resistance
Author(s) -
Knudson Jarrod D.,
Dincer U. Deniz,
Bratz Ian N.,
Sturek Michael,
Dick Gregory M.,
Tune Johnathan D.
Publication year - 2007
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1080/10739680701282887
Subject(s) - endothelial dysfunction , vasoconstriction , vasodilation , insulin resistance , medicine , cardiology , coronary circulation , metabolic syndrome , coronary atherosclerosis , coronary arteries , endocrinology , insulin , obesity , blood flow , coronary artery disease , artery
The incidence of obesity and the metabolic syndrome has reached epidemic proportions and alterations in coronary microvascular function could contribute to the increased cardiovascular morbidity and mortality observed in these patients. This review highlights key mechanisms of impaired control of coronary blood flow in the metabolic syndrome. Specifically, coronary endothelial dysfunction, altered neurohumoral control, and the potential roles of smooth muscle ion channels are addressed. Recent studies indicate that alterations in endothelial‐dependent vasodilation or endothelial‐dependent vasoconstriction contribute little to obesity‐induced impairments in coronary vascular control. In contrast, augmented vasoconstriction in response to neurohumoral mediators appears to play a significant role in coronary vascular dysfunction. The authors conclude that coronary dysfunction in the metabolic syndrome is characterized by an imbalance between coronary blood flow and myocardial metabolism that may be mediated by sensitization of vasoconstrictor pathways. Further, they suggest that alterations in smooth muscle ion channels, Ca 2+ handling, and cell signaling may be important mechanisms leading to coronary microvascular dysfunction. Importantly, however, more research is needed to clearly delineate specific mechanisms and identify potential therapeutic targets.