Karnieli E, Cohen P, Barzilai N, Ish-Shalom Z, Armoni M, Rafaelov R, Barzilai D
Horm Metab Res. 1985 Oct;17(10):518-21. doi: 10.1055/s-2007-1013593.
Insulin resistance is well established in Cushing's syndrome, but its mechanisms are not completely understood. We performed the euglycemic insulin clamp technique on four patients with Cushing's syndrome, five obese patients and five normal volunteers, in order to determine the role of impairments in insulin responsiveness and insulin clearance in hypercorticism and obesity. Insulin was infused at 0.3, 1, 3 and 10 mU/kg/min, and steady-state glucose-infusion rates required to maintain euglycemia were determined. Glucose disposal at maximal insulin levels was 11.9 +/- 0.4 mg/kg/min in normals, with a 29% decrease in obese and a 42% decrease in Cushing's syndrome patients. Half maximally effective insulin concentrations were increased in both abnormal groups compared to normals. Maximal insulin clearance rates were 1460 +/- 200 ml/min/m2 in normals, not significantly changed in obese and 40% decreased in Cushing's syndrome patients. These results indicate that the insulin resistance in Cushing's syndrome is distinct from that occurring in obesity and is characterized by both decreased insulin responsiveness and decreased insulin clearance. These impairments could be caused by a common defect which may be at or distal to the glucose transport level.
库欣综合征中胰岛素抵抗已得到充分证实，但其机制尚未完全明确。我们对4例库欣综合征患者、5例肥胖患者和5名正常志愿者进行了正常血糖胰岛素钳夹技术，以确定胰岛素反应性和胰岛素清除受损在皮质醇增多症和肥胖中的作用。以0.3、1、3和10 mU/kg/分钟的速度输注胰岛素，并确定维持正常血糖所需的稳态葡萄糖输注率。正常情况下，最大胰岛素水平时的葡萄糖处置率为11.9±0.4 mg/kg/分钟，肥胖患者降低29%，库欣综合征患者降低42%。与正常组相比，两个异常组的半数最大有效胰岛素浓度均升高。正常情况下最大胰岛素清除率为1460±200 ml/分钟/平方米，肥胖患者无明显变化，库欣综合征患者降低40%。这些结果表明，库欣综合征中的胰岛素抵抗不同于肥胖中的胰岛素抵抗，其特征是胰岛素反应性降低和胰岛素清除减少。这些损伤可能由一个共同的缺陷引起，该缺陷可能位于葡萄糖转运水平或其远端。
