This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kates, A. M. Articles by Gropler, R. J. Search for Related Content PubMed PubMed Citation Articles by Kates, A. M. Articles by Gropler, R. J.

CLINICAL STUDY: CARDIAC IMAGING

Impact of aging on substrate metabolism by the human heart

Andrew M. Kates, MD, Pilar Herrero, MS^*, Carmen Dence, MS^*, Pablo Soto, MD, Muthayyah Srinivasan, MD, Deborah G. Delano, RN, MHS^*, Ali Ehsani, MD, FACC and Robert J. Gropler, MD, FACC^*,*

^* Cardiovascular Imaging Laboratory, Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, St. Louis, Missouri, USA
Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA

Manuscript received March 18, 2002; revised manuscript received July 22, 2002, accepted September 20, 2002.

^* Reprint requests and correspondence: Dr. Robert J. Gropler, Cardiovascular Imaging Laboratory, Mallinckrodt Institute of Radiology, 510 South Kingshighway Boulevard, St. Louis, Missouri 63110, USA.
GroplerR{at}mir.wustl.edu

BACKGROUND: Results of studies in experimental animals have shown that, with age, myocardial fatty acid metabolism decreases, and glucose metabolism increases. Whether similar changes occur in humans is unknown.

METHODS: Seventeen healthy younger normal volunteers (six males, 26 ± 5 years) and 19 healthy older volunteers (nine males, 67 ± 5 years) underwent positron emission tomography (PET) under resting conditions in the fasted state. Myocardial blood flow (MBF), myocardial oxygen consumption (MVO₂), myocardial fatty acid utilization (MFAU) and oxidation (MFAO), and myocardial glucose utilization (MGU) were quantified by PET with ¹⁵O-water, ¹¹C-acetate, ¹¹C-palmitate, and¹¹C-glucose, respectively.

RESULTS: Although MBF was similar between the groups, MVO₂ was higher in the older subjects (5.6 ± 1.6 µmol/g/min) compared with younger subjects (4.6 ± 1.0 µmol/g/min, p < 0.04). Rates of MFAU and MFAO (corrected for MVO₂) were significantly lower in older subjects than in younger subjects (MFAU/MVO₂: 35 ± 10 vs. 51 ± 20 nmol free fatty acids (FFA)/nmol O₂ x 10^–3, p < 0.005, and MFAO/MVO₂: 33 ± 10 vs. 48 ± 18 nmol FFA/nmol O₂ x 10^–3, p < 0.004). In contrast, the rates of MGU corrected for MVO₂ did not differ between the groups.

CONCLUSIONS: With aging, humans exhibit a decline in MFAU and MFAO. Although absolute rates of MGU do not increase, by virtue of the decline in MFAU there is likely an increase in relative contribution of MGU to substrate metabolism. The clinical significance of this metabolic switch awaits further study.

Abbreviations and Acronyms   FFA   free fatty acids   GLUT-4   glucose transporter isoform 4   MBF   myocardial blood flow   MFAO   myocardial fatty acid oxidation   MFAU   myocardial fatty acid utilization   MGU   myocardial glucose utilization   MVO2   myocardial oxygen consumption   PET   positron emission tomography

This article has been cited by other articles:

				P. F. Soto, P. Herrero, K. B. Schechtman, A. D. Waggoner, J. M. Baumstark, A. A. Ehsani, and R. J. Gropler Exercise training impacts the myocardial metabolism of older individuals in a gender-specific manner Am J Physiol Heart Circ Physiol, August 1, 2008; 295(2): H842 - H850. [Abstract] [Full Text] [PDF]

				L. R. Peterson, P. F. Soto, P. Herrero, B. S. Mohammed, M. S. Avidan, K. B. Schechtman, C. Dence, and R. J. Gropler Impact of Gender on the Myocardial Metabolic Response to Obesity. J. Am. Coll. Cardiol. Img., July 1, 2008; 1(4): 424 - 433. [Abstract] [Full Text] [PDF]

				R. W. van der Meer, L. J. Rijzewijk, M. Diamant, S. Hammer, M. Schar, J. J. Bax, J. W.A. Smit, J. A. Romijn, A. de Roos, and H. J. Lamb The ageing male heart: myocardial triglyceride content as independent predictor of diastolic function Eur. Heart J., June 2, 2008; 29(12): 1516 - 1522. [Abstract] [Full Text] [PDF]

				P. Herrero, C. S. Dence, A. R. Coggan, Z. Kisrieva-Ware, P. Eisenbeis, and R. J. Gropler L-3-11C-Lactate as a PET Tracer of Myocardial Lactate Metabolism: A Feasibility Study J. Nucl. Med., December 1, 2007; 48(12): 2046 - 2055. [Abstract] [Full Text] [PDF]

				D. P.Y. Koonen, M. Febbraio, S. Bonnet, J. Nagendran, M. E. Young, E. D. Michelakis, and J. R.B. Dyck CD36 Expression Contributes to Age-Induced Cardiomyopathy in Mice Circulation, November 6, 2007; 116(19): 2139 - 2147. [Abstract] [Full Text] [PDF]

				I. Luptak, J. Yan, L. Cui, M. Jain, R. Liao, and R. Tian Long-Term Effects of Increased Glucose Entry on Mouse Hearts During Normal Aging and Ischemic Stress Circulation, August 21, 2007; 116(8): 901 - 909. [Abstract] [Full Text] [PDF]

				P. Herrero, Z. Kisrieva-Ware, C. S. Dence, B. Patterson, A. R. Coggan, D.-H. Han, Y. Ishii, P. Eisenbeis, and R. J. Gropler PET Measurements of Myocardial Glucose Metabolism with 1-11C-Glucose and Kinetic Modeling J. Nucl. Med., June 1, 2007; 48(6): 955 - 964. [Abstract] [Full Text] [PDF]

				M. J. Welch, J. S. Lewis, J. Kim, T. L. Sharp, C. S. Dence, R. J. Gropler, and P. Herrero Assessment of Myocardial Metabolism in Diabetic Rats Using Small-Animal PET: A Feasibility Study J. Nucl. Med., April 1, 2006; 47(4): 689 - 697. [Abstract] [Full Text] [PDF]

				P. Herrero, L. R. Peterson, J. B. McGill, S. Matthew, D. Lesniak, C. Dence, and R. J. Gropler Increased Myocardial Fatty Acid Metabolism in Patients With Type 1 Diabetes Mellitus J. Am. Coll. Cardiol., February 7, 2006; 47(3): 598 - 604. [Abstract] [Full Text] [PDF]

				W. C. Stanley, F. A. Recchia, and G. D. Lopaschuk Myocardial Substrate Metabolism in the Normal and Failing Heart Physiol Rev, July 1, 2005; 85(3): 1093 - 1129. [Abstract] [Full Text] [PDF]

				O. Lindner, J. Vogt, D. Baller, A. Kammeier, P. Wielepp, J. Holzinger, B. Lamp, D. Horstkotte, and W. Burchert Global and regional myocardial oxygen consumption and blood flow in severe cardiomyopathy with left bundle branch block Eur J Heart Fail, March 2, 2005; 7(2): 225 - 230. [Abstract] [Full Text] [PDF]

				L. R. Peterson, P. Herrero, K. B. Schechtman, S. B. Racette, A. D. Waggoner, Z. Kisrieva-Ware, C. Dence, S. Klein, J. Marsala, T. Meyer, et al. Effect of Obesity and Insulin Resistance on Myocardial Substrate Metabolism and Efficiency in Young Women Circulation, May 11, 2004; 109(18): 2191 - 2196. [Abstract] [Full Text] [PDF]

				P. F. Soto, P. Herrero, A. M. Kates, C. S. Dence, A. A. Ehsani, V. Davila-Roman, K. B. Schechtman, and R. J. Gropler Impact of aging on myocardial metabolic response to dobutamine Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H2158 - H2164. [Abstract] [Full Text] [PDF]