Turku PET Centre, University of Turku, Turku, Finland.
Department of Cardiology, Turku University Hospital, Turku, Finland.
Diabetes Obes Metab. 2018 Apr;20(4):963-973. doi: 10.1111/dom.13183. Epub 2018 Jan 17.
To study myocardial substrate uptake, structure and function, before and after bariatric surgery, to clarify the interaction between myocardial metabolism and cardiac remodelling in morbid obesity.
We studied 46 obese patients (age 44 ± 10 years, body mass index [BMI] 42 ± 4 kg/m ), including 18 with type 2 diabetes (T2D) before and 6 months after bariatric surgery and 25 healthy age-matched control group subjects. Myocardial fasting free fatty acid uptake (MFAU) and insulin-stimulated myocardial glucose uptake (MGU) were measured using positron-emission tomography. Myocardial structure and function, and myocardial triglyceride content (MTGC) and intrathoracic fat were measured using magnetic resonance imaging and magnetic resonance spectroscopy.
The morbidly obese study participants, with or without T2D, had cardiac hypertrophy, impaired myocardial function and substrate metabolism compared with the control group. Surgery led to marked weight reduction and remission of T2D in most of the participants. Postoperatively, myocardial function and structure improved and myocardial substrate metabolism normalized. Intrathoracic fat, but not MTGC, was reduced. Before surgery, BMI and MFAU correlated with left ventricular hypertrophy, and BMI, age and intrathoracic fat mass were the main variables associated with cardiac function. The improvement in whole-body insulin sensitivity correlated positively with the increase in MGU and the decrease in MFAU.
In the present study, obesity and age, rather than myocardial substrate uptake, were the causes of cardiac remodelling in morbidly obese patients with or without T2D. Cardiac remodelling and impaired myocardial substrate metabolism are reversible after surgically induced weight loss and amelioration of T2D.
研究肥胖症患者在接受减重手术后心肌底物摄取、结构和功能的变化，以阐明心肌代谢与心脏重构之间的相互作用。
我们研究了 46 名肥胖患者（年龄 44±10 岁，体重指数 [BMI] 42±4kg/m²），包括 18 名合并 2 型糖尿病（T2D）的患者和 25 名年龄匹配的健康对照组。采用正电子发射断层扫描测量心肌空腹游离脂肪酸摄取（MFAU）和胰岛素刺激的心肌葡萄糖摄取（MGU）。使用磁共振成像和磁共振波谱测量心肌结构和功能以及心肌甘油三酯含量（MTGC）和胸腔内脂肪。
合并或不合并 T2D 的病态肥胖患者与对照组相比，存在心肌肥大、心肌功能和底物代谢受损。手术导致大多数患者体重明显减轻和 T2D 缓解。术后，心肌功能和结构改善，心肌底物代谢恢复正常。胸腔内脂肪减少，而 MTGC 减少。手术前，BMI 和 MFAU 与左心室肥厚相关，BMI、年龄和胸腔内脂肪量是与心脏功能相关的主要变量。全身胰岛素敏感性的改善与 MGU 的增加和 MFAU 的减少呈正相关。
在本研究中，肥胖和年龄是导致合并或不合并 T2D 的病态肥胖患者心脏重构的原因，而不是心肌底物摄取。在手术诱导的体重减轻和 T2D 改善后，心脏重构和受损的心肌底物代谢是可逆的。
