Viljanen Antti P M, Karmi Anna, Borra Ronald, Pärkkä Jussi P, Lepomäki Virva, Parkkola Riitta, Lautamäki Riikka, Järvisalo Mikko, Taittonen Markku, Rönnemaa Tapani, Iozzo Patricia, Knuuti Juhani, Nuutila Pirjo, Raitakari Olli T
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Am J Cardiol. 2009 Jun 15;103(12):1721-6. doi: 10.1016/j.amjcard.2009.02.025. Epub 2009 Apr 16.
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.
肥胖与心肌脂肪酸摄取增加有关，这可能对心脏功能产生有害影响。本研究的目的是评估体重减轻如何影响肥胖成年人的心肌代谢和心脏做功。34名肥胖（平均体重指数33.7±0.7kg/m²）但其他方面健康的受试者食用极低热量饮食6周。在饮食前后测量心脏底物代谢和做功。使用氟-18-氟-6-硫代十七烷酸和正电子发射断层扫描在18名受试者中测量心肌脂肪酸摄取，使用氟-18-2-氟-2-脱氧葡萄糖在16名受试者中测量心肌葡萄糖摄取。使用磁共振成像测量心肌结构和心脏功能。食用极低热量饮食使体重下降（-11.2±0.6kg，p<0.0001）。心肌脂肪酸摄取从4.2±0.4降至2.9±0.2μmol/100g/min（p<0.0001）。心肌质量下降7%（p<0.005），心脏做功下降26%（p<0.0001）。全身胰岛素敏感性增加33%（p<0.01），但胰岛素刺激的心肌葡萄糖摄取保持不变（p=0.90）。心肌甘油三酯含量下降31%（n=8，p=0.076）。总之，体重减轻与心肌质量和心脏做功平行降低心肌脂肪酸摄取。这些结果表明，肥胖患者心脏中增加的脂肪酸摄取可通过体重减轻得到逆转。
