Abnormal cardiac and skeletal muscle energy metabolism in patients with type 2 diabetes
Abnormal cardiac and skeletal muscle energy metabolism in patients with type 2 diabetes
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DOI：
10.1161/01.cir.0000072789.89096.10
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发表时间：
2003-06-24
期刊：
影响因子：
37.8
通讯作者：
Clarke, K
中科院分区：
文献类型：
--
作者：
Scheuermann-Freestone, M;Madsen, PL;Clarke, K
背景 - 众所周知，2 型糖尿病患者患心血管疾病的风险增加，但尚不清楚他们的心脏或骨骼肌高能磷酸盐代谢是否存在潜在异常。 方法和结果 - 我们研究了 21 名经超声心动图确定没有冠状动脉疾病或心功能受损证据的 2 型糖尿病患者，以及 15 名年龄、性别和体重指数匹配的对照受试者。使用 P-31 核磁共振波谱 (MRS) 测量静息状态下的心脏高能磷酸盐代谢物。分别在运动前、运动中和运动后使用 P-31 MRS 和近红外分光光度法测量骨骼肌高能磷酸盐代谢物、细胞内 pH 值和氧合。尽管糖尿病患者的心脏形态、质量和功能似乎正常，但糖尿病患者的磷酸肌酸 (PCr)/ATP 比率为 1.50 +/- 0.11，明显低于健康志愿者的 2.30 +/- 0.12。心脏 PCr/ATP 比率与空腹血浆游离脂肪酸浓度呈负相关。尽管运动耐量较低的糖尿病患者在休息时骨骼肌能量和 pH 值正常，但运动期间 PCr 损失和 pH 值下降明显更快。运动后，糖尿病患者的 PCr 恢复较慢，并且与组织再氧合时间相关。运动时间与脱氧率和血红蛋白 (Hb)A(1c) 水平呈负相关，复氧时间与 HbA(1c) 水平呈正相关。 结论 - 心功能明显正常的 2 型糖尿病患者心肌和骨骼肌能量代谢受损，这与循环代谢底物的变化有关。
Background - It is well known that patients with type 2 diabetes have increased risk of cardiovascular disease, but it is not known whether they have underlying abnormalities in cardiac or skeletal muscle high-energy phosphate metabolism.Methods and Results - We studied 21 patients with type 2 diabetes with no evidence of coronary artery disease or impaired cardiac function, as determined by echocardiography, and 15 age-, sex-, and body mass index - matched control subjects. Cardiac high-energy phosphate metabolites were measured at rest using P-31 nuclear magnetic resonance spectroscopy (MRS). Skeletal muscle high-energy phosphate metabolites, intracellular pH, and oxygenation were measured using P-31 MRS and near infrared spectrophotometry, respectively, before, during, and after exercise. Although their cardiac morphology, mass, and function appeared to be normal, the patients with diabetes had significantly lower phosphocreatine (PCr)/ATP ratios, at 1.50 +/- 0.11, than the healthy volunteers, at 2.30 +/- 0.12. The cardiac PCr/ATP ratios correlated negatively with the fasting plasma free fatty acid concentrations. Although skeletal muscle energetics and pH were normal at rest, PCr loss and pH decrease were significantly faster during exercise in the patients with diabetes, who had lower exercise tolerance. After exercise, PCr recovery was slower in the patients with diabetes and correlated with tissue reoxygenation times. The exercise times correlated negatively with the deoxygenation rates and the hemoglobin (Hb)A(1c) levels and the reoxygenation times correlated positively with the HbA(1c) levels.Conclusions - Type 2 diabetic patients with apparently normal cardiac function have impaired myocardial and skeletal muscle energy metabolism related to changes in circulating metabolic substrates.