Schwartz N S, Clutter W E, Shah S D, Cryer P E
J Clin Invest. 1987 Mar;79(3):777-81. doi: 10.1172/JCI112884.
To define glycemic thresholds for activation of glucose counterregulatory systems and for symptoms of hypoglycemia, we measured these during stepped reductions in the plasma glucose concentration (in six 10-mg/dl hourly steps) from 90 to 40 mg/dl under hyperinsulinemic clamp conditions, and compared these with the same measurements during euglycemia (90 mg/dl) under the same conditions over 6 h in 10 normal humans. Arterialized venous plasma glucose concentrations were used to calculate glycemic thresholds of 69 +/- 2 mg/dl for epinephrine secretion, 68 +/- 2 mg/dl for glucagon secretion, 66 +/- 2 mg/dl for growth hormone secretion, and 58 +/- 3 mg/dl for cortisol secretion. In contrast, the glycemic threshold for symptoms was 53 +/- 2 mg/dl, significantly lower than the thresholds for epinephrine (P less than 0.001), glucagon (P less than 0.001), and growth hormone (P less than 0.01) secretion. Thus, the glycemic thresholds for activation of glucose counterregulatory systems during decrements in plasma glucose lie within or just below the physiologic plasma glucose concentration range, and are substantially higher than the threshold for hypoglycemic symptoms in normal humans. These findings provide further support for the concept that glucose counterregulatory systems are involved in the prevention, as well as the correction, of hypoglycemia.
为了明确激活葡萄糖反向调节系统及出现低血糖症状时的血糖阈值，我们在高胰岛素钳夹条件下，将血浆葡萄糖浓度从90mg/dl逐步降至40mg/dl（每小时降低10mg/dl，共六个步骤）的过程中进行了测量，并将这些测量结果与10名正常人在相同条件下6小时血糖正常（90mg/dl）时的相同测量结果进行比较。采用动脉化静脉血浆葡萄糖浓度来计算肾上腺素分泌的血糖阈值为69±2mg/dl，胰高血糖素分泌的血糖阈值为68±2mg/dl，生长激素分泌的血糖阈值为66±2mg/dl，皮质醇分泌的血糖阈值为58±3mg/dl。相比之下，出现症状时的血糖阈值为53±2mg/dl，显著低于肾上腺素（P<0.001）、胰高血糖素（P<0.001）和生长激素（P<0.01）分泌的阈值。因此，在血浆葡萄糖浓度下降过程中激活葡萄糖反向调节系统的血糖阈值处于或略低于生理血浆葡萄糖浓度范围，且显著高于正常人出现低血糖症状的阈值。这些发现进一步支持了葡萄糖反向调节系统参与预防以及纠正低血糖这一概念。
