Doria A, Nosadini R, Avogaro A, Fioretto P, Crepaldi G
Istituto di Medicina Interna, Policlinico Universitario, Padova, Italy.
Diabet Med. 1991;8 Spec No:S104-7. doi: 10.1111/j.1464-5491.1991.tb02168.x.
Myocardial exchange of metabolic substrates was investigated in eight Type 1 diabetic patients with angiographically normal coronary arteries and seven normal control subjects, after an overnight fast. Simultaneous samples of arterial and coronary sinus blood were collected for analysis of the major metabolic substrates. Myocardial blood flow was measured by the thermodilution technique. Although the Type 1 patients were hyperglycaemic (10.0 +/- 2.0 (+/- SE) mmol I-1) myocardial glucose uptake was lower than in control subjects (27 +/- 6 vs 42 +/- 5 mumol min-1 1.73 m-2, p less than 0.05). The net balance of lactate and pyruvate across the myocardium showed a net release in Type 1 patients (13.4 +/- 2.7 mumol min-1 1.73 m-2 and 1.3 +/- 0.2 mumol min-1 1.73 m-2, respectively) and a net uptake in control subjects (2.2 +/- 0.7 mumol min-1 1.73 m-2 and 3.5 +/- 0.3 mumol min-1 1.73 m-2, both p less than 0.01). Myocardial uptake of ketone bodies was significantly higher in diabetic patients (37.0 +/- 6.3) mumol min-1 1.73 m-2) than in control subjects (10.1 +/- 3.4 mumol min-1 1.73 m-2, p less than 0.01). Non-esterified fatty acid (NEFA) uptake was significantly greater in the diabetic patients than in control subjects (44.1 +/- 7.0) vs 24.1 +/- 5.1 mumol min-1 1.73 m-2, p less than 0.01). Net balance of glucose, lactate, and pyruvate across the myocardium was inversely and significantly related to that of NEFAs and ketone bodies (p less than 0.01). Myocardial carbohydrate uptake is markedly impaired in Type 1 diabetic patients with angiographically intact coronary vessels. Ketones and NEFA represent the major fuel for the diabetic myocardium. Thus, in diabetes, myocardial lactate metabolism may be profoundly altered independently of coronary artery disease.
在8名冠状动脉造影正常的1型糖尿病患者和7名正常对照受试者中，于禁食过夜后对心肌代谢底物的交换情况进行了研究。同时采集动脉血和冠状窦血样本，用于分析主要代谢底物。采用热稀释技术测量心肌血流量。尽管1型糖尿病患者血糖较高（10.0±2.0（±标准误）mmol·L⁻¹），但其心肌葡萄糖摄取低于对照受试者（分别为27±6与42±5 μmol·min⁻¹·1.73 m⁻²，p<0.05）。1型糖尿病患者心肌中乳酸和丙酮酸的净平衡显示为净释放（分别为13.4±2.7 μmol·min⁻¹·1.73 m⁻²和1.3±0.2 μmol·min⁻¹·1.73 m⁻²），而对照受试者为净摄取（分别为2.2±0.7 μmol·min⁻¹·1.73 m⁻²和3.5±0.3 μmol·min⁻¹·1.73 m⁻²，p均<0.01）。糖尿病患者心肌对酮体的摄取显著高于对照受试者（37.0±6.3 μmol·min⁻¹·1.73 m⁻²）（10.1±3.4 μmol·min⁻¹·1.73 m⁻²，p<0.01）。糖尿病患者非酯化脂肪酸（NEFA）的摄取显著高于对照受试者（44.1±7.0）对24.1±5.1 μmol·min⁻¹·1.73 m⁻²，p<0.01）。心肌中葡萄糖、乳酸和丙酮酸的净平衡与NEFA和酮体的净平衡呈显著负相关（p<0.01）。冠状动脉血管造影正常的1型糖尿病患者心肌碳水化合物摄取明显受损。酮体和NEFA是糖尿病心肌的主要燃料。因此，在糖尿病中，心肌乳酸代谢可能会独立于冠状动脉疾病而发生深刻改变。
