Fritsche A, Stumvoll M, Häring H U, Gerich J E
Department IV Internal Medicine, Endocrinology, and Pathobiochemistry, University of Tubingen, Germany.
J Clin Endocrinol Metab. 2000 Feb;85(2):523-5. doi: 10.1210/jcem.85.2.6353.
The purpose of this study was to assess the effect of strict avoidance of hypoglycemia on beta-adrenergic sensitivity in a type 1 diabetic patient with hypoglycemia unawareness and a diabetes duration of 55 yr. beta-Adrenergic sensitivity was determined by an isoproterenol test and was expressed as the lowest dose of isoproterenol that increases the heart rate by 25 beats/min (IC25). Plasma epinephrine and symptom responses to hypoglycemia were determined during a 3-h hypoglycemic (3 mmol/L) clamp. Initially, the patient had a near-normal counterregulatory plasma epinephrine response to hypoglycemia but reduced beta-adrenergic sensitivity (IC25, 2 microg) compared to 10 hypoglycemia aware, type 1 diabetic patients (0.65 +/- 0.14 microg) and 10 normal control subjects (1.13 +/- 0.21 microg). After 1 yr of strict avoidance of blood glucose levels below 4 mmol/L, the IC25 decreased to 0.25 microg, reflecting improved beta-adrenergic sensitivity. In conclusion, the reduced beta-adrenergic sensitivity in this patient was probably the reason for hypoglycemia unawareness and was reversed by strict avoidance of hypoglycemia.
本研究的目的是评估在一名低血糖无意识且糖尿病病程为55年的1型糖尿病患者中，严格避免低血糖对β-肾上腺素能敏感性的影响。通过异丙肾上腺素试验测定β-肾上腺素能敏感性，并将其表示为使心率增加25次/分钟的最低异丙肾上腺素剂量（IC25）。在3小时低血糖（3 mmol/L）钳夹期间测定血浆肾上腺素和对低血糖的症状反应。最初，该患者对低血糖的反调节血浆肾上腺素反应接近正常，但与10名有低血糖意识的1型糖尿病患者（0.65±0.14微克）和10名正常对照受试者（1.13±0.21微克）相比，β-肾上腺素能敏感性降低（IC25，2微克）。在严格避免血糖水平低于4 mmol/L 1年后，IC25降至0.25微克，反映出β-肾上腺素能敏感性提高。总之，该患者β-肾上腺素能敏感性降低可能是低血糖无意识的原因，严格避免低血糖可使其逆转。
