Comparison of local and systemic effects of insulin on myocardial glucose extraction in ischemic heart disease

• Published in: American journal of physiology. Heart and circulatory physiology 2000-03, Vol.278 (3), p.H741-H747
• Main Author: McNulty, Patrick H
• Format: Article
• Language: English
• Subjects: Aged; Blood Glucose - metabolism; Coronary Vessels; Fatty Acids, Nonesterified - blood; Fatty Acids, Nonesterified - metabolism; Glucose - metabolism; Heart - drug effects; Hemodynamics - drug effects; Humans; Infusions, Intravenous; Insulin - administration & dosage; Insulin - blood; Insulin - pharmacology; Lactic Acid - metabolism; Male; Middle Aged; Myocardial Ischemia - metabolism; Myocardium - metabolism
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.2000.278.3.h741

Section of Cardiovascular Medicine, Veterans Affairs Connecticut Medical Center and Yale University School of Medicine, New Haven, Connecticut 06520 Physiological increases in circulating insulin level significantly increase myocardial glucose uptake in vivo. To what extent this represents a direct insulin action on the heart or results indirectly from reduction in circulating concentrations of free fatty acids (FFA) is uncertain. To examine this, we measured myocardial glucose, lactate, and FFA extraction in 10 fasting men (ages 49-76 yr) with stable coronary artery disease during sequential intracoronary (10 mU/min, coronary plasma insulin = 140 ± 20 µU/ml) and intravenous (100 mU/min, systemic plasma insulin = 168 ± 26 µU/ml) insulin infusion. Basally, hearts extracted 2 ± 2% of arterial glucose and extracted 27 ± 6% of FFA. Coronary insulin infusion increased glucose extraction to 5 ± 3% ( P