Turpeinen A K, Kuikka J T, Vanninen E, Uusitupa M I
Department of Clinical Nutrition, University of Kuopio, Finland.
Diabetologia. 1997 May;40(5):541-9. doi: 10.1007/s001250050713.
Increased triglyceride accumulation has been observed in the diabetic heart, but it is not known whether the abnormalities in myocardial fatty acid metabolism differ between insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetic patients or whether they are present even prior to overt diabetes. Therefore, we studied myocardial fatty acid kinetics with single-photon emission tomography using 123I-heptadecanoic acid (HDA) in four groups of men: impaired glucose tolerance (IGT) (n = 13, age 53 +/- 2 years, mean +/- SEM), IDDM (n = 8, age 43 +/- 3 years), NIDDM (n = 10, age 51 +/- 2 years) and control subjects (n = 8, age 45 +/- 4 years). Echocardiography and myocardial perfusion scintigraphy (IGT and NIDDM groups) were performed to study cardiac function and flow. In the IGT subjects, myocardial HDA beta-oxidation index was reduced by 53% (4.6 +/- 0.4 vs 9.7 +/- 1.0 mumol .min-1.100 g-1, p < 0.01) and HDA uptake by 34% (3.7 +/- 0.2 vs 5.6 +/- 0.3% of injected dose 100g, p < 0.01) compared with the control subjects. The fractional HDA amount used for beta-oxidation was lower in the IGT compared with the control subjects (43 +/- 4 vs 61 +/- 4%, p < 0.05). NIDDM patients also tended to have a lowered HDA beta-oxidation index, whereas IDDM patients had similar myocardial HDA kinetics compared to the control subjects. Myocardial perfusion imaging during the dipyridamole-handgrip stress was normal both in the IGT and NIDDM groups, indicating that abnormal myocardial perfusion could not explain abnormal fatty acid kinetics. In conclusion, even before clinical diabetes, IGT subjects show abnormalities in myocardial fatty acid uptake and kinetics. These abnormalities may be related to disturbed plasma and cellular lipid metabolism.
在糖尿病心脏中已观察到甘油三酯蓄积增加，但尚不清楚胰岛素依赖型（IDDM）和非胰岛素依赖型（NIDDM）糖尿病患者心肌脂肪酸代谢异常是否存在差异，或者这些异常在显性糖尿病之前是否就已存在。因此，我们使用123I-十七烷酸（HDA）通过单光子发射断层扫描研究了四组男性的心肌脂肪酸动力学：糖耐量受损（IGT）组（n = 13，年龄53±2岁，平均值±标准误）、IDDM组（n = 8，年龄43±3岁）、NIDDM组（n = 10，年龄51±2岁）和对照组（n = 8，年龄45±4岁）。进行了超声心动图和心肌灌注闪烁显像（IGT和NIDDM组）以研究心脏功能和血流。与对照组相比，IGT受试者的心肌HDAβ-氧化指数降低了53%（4.6±0.4对9.7±1.0μmol·min-1·100g-1，p<0.01），HDA摄取降低了34%（3.7±0.2对5.6±0.3%注射剂量/100g，p<0.01）。与对照组相比，IGT组用于β-氧化的HDA分数较低（43±4对61±4%，p<0.05）。NIDDM患者的HDAβ-氧化指数也有降低的趋势，而IDDM患者的心肌HDA动力学与对照组相似。在IGT和NIDDM组中，双嘧达莫-握力应激期间的心肌灌注显像均正常，表明心肌灌注异常无法解释脂肪酸动力学异常。总之，即使在临床糖尿病之前，IGT受试者的心肌脂肪酸摄取和动力学就已出现异常。这些异常可能与血浆和细胞脂质代谢紊乱有关。
