title: Effect of caloric restriction on myocardial fatty acid uptake, left ventricular mass, and cardiac work in obese adults.
abstract: Obesity is associated with increased fatty acid uptake in the myocardium, and this may have deleterious effects on cardiac function. The aim of this study was to evaluate how weight loss influences myocardial metabolism and cardiac work in obese adults. Thirty-four obese (mean body mass index 33.7 +/- 0.7 kg/m(2)) but otherwise healthy subjects consumed a very low calorie diet for 6 weeks. Cardiac substrate metabolism and work were measured before and after the diet. Myocardial fatty acid uptake was measured in 18 subjects using fluorine-18-fluoro-6-thia-heptadecanoic acid and positron emission tomography, and myocardial glucose uptake was measured in 16 subjects using fluorine-18-2-fluoro-2-deoxyglucose. Myocardial structure and cardiac function were measured using magnetic resonance imaging. Consumption of the very low calorie diet decreased weight (-11.2 +/- 0.6 kg, p <0.0001). Myocardial fatty acid uptake decreased from 4.2 +/- 0.4 to 2.9 +/- 0.2 micromol/100 g/min (p <0.0001). Myocardial mass decreased by 7% (p <0.005), and cardiac work decreased by 26% (p <0.0001). Whole-body insulin sensitivity increased by 33% (p <0.01), but insulin-stimulated myocardial glucose uptake remained unchanged (p = 0.90). Myocardial triglyceride content decreased by 31% (n = 8, p = 0.076). In conclusion, weight reduction decreases myocardial fatty acid uptake in parallel with myocardial mass and cardiac work. These results show that the increased fatty acid uptake found in the hearts of obese patients can be reversed by weight loss.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland. antti.viljanen@utu.fi
authors.forename: Antti P M
authors.initials: AP
authors.lastname: Viljanen
authors.forename: Anna
authors.initials: A
authors.lastname: Karmi
authors.forename: Ronald
authors.initials: R
authors.lastname: Borra
authors.forename: Jussi P
authors.initials: JP
authors.lastname: Pärkkä
authors.forename: Virva
authors.initials: V
authors.lastname: Lepomäki
authors.forename: Riitta
authors.initials: R
authors.lastname: Parkkola
authors.forename: Riikka
authors.initials: R
authors.lastname: Lautamäki
authors.forename: Mikko
authors.initials: M
authors.lastname: Järvisalo
authors.forename: Markku
authors.initials: M
authors.lastname: Taittonen
authors.forename: Tapani
authors.initials: T
authors.lastname: Rönnemaa
authors.forename: Patricia
authors.initials: P
authors.lastname: Iozzo
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
authors.forename: Pirjo
authors.initials: P
authors.lastname: Nuutila
authors.forename: Olli T
authors.initials: OT
authors.lastname: Raitakari
mesh_terms: D000328:Adult; D002150:Caloric Tests; D018752:Diet, Fat-Restricted; D005227:Fatty Acids / Q000493:pharmacokinetics*; D005260:Female; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism*; D009765:Obesity / Q000150:complications / Q000178:diet therapy*; D049268:Positron-Emission Tomography; D011379:Prognosis; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D016277:Ventricular Function, Left / Q000502:physiology; D015431:Weight Loss / Q000502:physiology*
chemical_list: D005227:Fatty Acids; D005947:Glucose