BACKGROUND: Obesity is a risk factor for impaired cardiac performance, particularly in women. Animal studies suggest that alterations in myocardial fatty acid metabolism and efficiency in obesity can cause decreased cardiac performance. In the present study, we tested the hypothesis that myocardial fatty acid metabolism and efficiency are abnormal in obese women. METHODS AND RESULTS: We studied 31 young women (body mass index [BMI] 19 to 52 kg/m2); 19 were obese (BMI >30 kg/m2). Myocardial oxygen consumption (MVO2) and fatty acid uptake (MFAUp), utilization (MFAU), and oxidation (MFAO) were quantified by positron emission tomography. Cardiac work was measured by echocardiography, and efficiency was calculated as work/MVO2. BMI correlated with MVO2 (r=0.58, P=0.0006), MFAUp (r=0.42, P<0.05), and efficiency (r=-0.40, P<0.05). Insulin resistance, quantified by the glucose area under the curve (AUC) during an oral glucose tolerance test, correlated with MFAUp (r=0.55, P<0.005), MFAU (r=0.62, P<0.001), and MFAO (r=0.58, P<0.005). A multivariate, stepwise regression analysis showed that BMI was the only independent predictor of MVO2 and efficiency (P=0.0005 and P<0.05, respectively). Glucose AUC was the only independent predictor of MFAUp, MFAU, and MFAO (P<0.05, <0.005, and <0.005, respectively). CONCLUSIONS: In young women, obesity is a significant predictor of increased MVO2 and decreased efficiency, and insulin resistance is a robust predictor of MFAUp, MFAU, and MFAO. This increase in fatty acid metabolism and decrease in efficiency is concordant with observations made in experimental models of obesity. These metabolic changes may play a role in the pathogenesis of decreased cardiac performance in obese women.
BACKGROUND:Obesity is a risk factor for impaired cardiac performance, particularly in women. Animal studies suggest that alterations in myocardial fatty acid metabolism and efficiency in obesity can cause decreased cardiac performance. In the present study, we tested the hypothesis that myocardial fatty acid metabolism and efficiency are abnormal in obesewomen. METHODS AND RESULTS: We studied 31 young women (body mass index [BMI] 19 to 52 kg/m2); 19 were obese (BMI >30 kg/m2). Myocardial oxygen consumption (MVO2) and fatty acid uptake (MFAUp), utilization (MFAU), and oxidation (MFAO) were quantified by positron emission tomography. Cardiac work was measured by echocardiography, and efficiency was calculated as work/MVO2. BMI correlated with MVO2 (r=0.58, P=0.0006), MFAUp (r=0.42, P<0.05), and efficiency (r=-0.40, P<0.05). Insulin resistance, quantified by the glucose area under the curve (AUC) during an oral glucose tolerance test, correlated with MFAUp (r=0.55, P<0.005), MFAU (r=0.62, P<0.001), and MFAO (r=0.58, P<0.005). A multivariate, stepwise regression analysis showed that BMI was the only independent predictor of MVO2 and efficiency (P=0.0005 and P<0.05, respectively). Glucose AUC was the only independent predictor of MFAUp, MFAU, and MFAO (P<0.05, <0.005, and <0.005, respectively). CONCLUSIONS: In young women, obesity is a significant predictor of increased MVO2 and decreased efficiency, and insulin resistance is a robust predictor of MFAUp, MFAU, and MFAO. This increase in fatty acid metabolism and decrease in efficiency is concordant with observations made in experimental models of obesity. These metabolic changes may play a role in the pathogenesis of decreased cardiac performance in obesewomen.
Authors: Janet B McGill; Linda R Peterson; Pilar Herrero; Ibrahim M Saeed; Carol Recklein; Andrew R Coggan; Amanda J Demoss; Kenneth B Schechtman; Carmen S Dence; Robert J Gropler Journal: J Nucl Cardiol Date: 2011-04-23 Impact factor: 5.952
Authors: Xiangping Fang; Rengasamy Palanivel; Justin Cresser; Kristin Schram; Riya Ganguly; Farah S L Thong; Joseph Tuinei; Aimin Xu; E Dale Abel; Gary Sweeney Journal: Am J Physiol Endocrinol Metab Date: 2010-08-24 Impact factor: 4.310
Authors: Zhude Tu; Shihong Li; Terry L Sharp; Pilar Herrero; Carmen S Dence; Robert J Gropler; Robert H Mach Journal: Bioconjug Chem Date: 2010-11-11 Impact factor: 4.774
Authors: Sihem Boudina; Heiko Bugger; Sandra Sena; Brian T O'Neill; Vlad G Zaha; Olesya Ilkun; Jordan J Wright; Pradip K Mazumder; Eric Palfreyman; Timothy J Tidwell; Heather Theobald; Oleh Khalimonchuk; Benjamin Wayment; Xiaoming Sheng; Kenneth J Rodnick; Ryan Centini; Dong Chen; Sheldon E Litwin; Bart E Weimer; E Dale Abel Journal: Circulation Date: 2009-02-23 Impact factor: 29.690
Authors: Matthew R Lyons; Linda R Peterson; Janet B McGill; Pilar Herrero; Andrew R Coggan; Ibrahim M Saeed; Carol Recklein; Kenneth B Schechtman; Robert J Gropler Journal: Am J Physiol Heart Circ Physiol Date: 2013-09-16 Impact factor: 4.733