Sprangers F, Wijburg F A, Romijn J A, Ackermans M T, Hoekstra J H, Heymans H S, Sauerwein H P
Emma kinderziekenhuis AMC, Amsterdam, The Netherlands.
Eur J Pediatr. 2001 Mar;160(3):185-8. doi: 10.1007/s004319900362.
The plasma glucose concentration response to a glucagon bolus is considered an important diagnostic tool in hypoglycemia of unknown origin. The response of plasma glucose concentration to glucagon can however also be misleading in the differential diagnosis. In a 3-week-old male infant suffering recurrent severe preprandial hypoglycemia and dependent on continuous i.v. glucose infusion, extensive diagnostic screening including a liver biopsy did not lead to a diagnosis. Based on an insufficient glycemic response (twice) to a glucagon bolus, a disorder of glycogenolysis was suspected. Glucose production and gluconeogenesis were measured (glycogenolysis calculated) during diminishing i.v. glucose infusion and after a glucagon bolus. Reducing glucose infusion resulted in a steep increase in glycogenolysis and gluconeogenesis, maintaining total glucose turnover (production plus infusion) constant at +/-9 mg x kg(-1) x min(-1) (+/-60% gluconeogenesis, +/-40% glycogenolysis). Plasma glucose concentration however decreased from 4.9 mmol/l to 3.4 mmol/l. Glucagon increased glucose production by 50% but resulted in only a minor increase in glucose concentration. Conclusion. As glucose concentration depends on the balance between glucose production and utilization (uptake), facilitated glucose uptake rather than impaired glycogenolysis explains the hypoglycemic episodes in this patient. A subnormal response of plasma glucose to glucagon therefore does not necessarily imply a disturbance in glycogenolysis. In cases of hypoglycemia of unknown origin, measurement of glucose kinetics with stable isotopes is indicated.
胰高血糖素推注后血浆葡萄糖浓度反应被认为是不明原因低血糖症的一项重要诊断工具。然而，胰高血糖素推注后血浆葡萄糖浓度反应在鉴别诊断中也可能产生误导。一名3周大的男婴反复出现严重的餐前低血糖症，依赖持续静脉输注葡萄糖，包括肝活检在内的广泛诊断性筛查未得出诊断结果。基于对胰高血糖素推注的血糖反应不足（两次），怀疑存在糖原分解障碍。在静脉输注葡萄糖逐渐减少期间以及胰高血糖素推注后，测量了葡萄糖生成和糖异生（计算糖原分解）。减少葡萄糖输注导致糖原分解和糖异生急剧增加，使总葡萄糖周转率（生成加输注）保持在±9 mg·kg⁻¹·min⁻¹恒定水平（糖异生±60%，糖原分解±40%）。然而，血浆葡萄糖浓度从4.9 mmol/L降至3.4 mmol/L。胰高血糖素使葡萄糖生成增加50%，但仅导致葡萄糖浓度轻微升高。结论。由于葡萄糖浓度取决于葡萄糖生成与利用（摄取）之间的平衡，葡萄糖摄取增加而非糖原分解受损解释了该患者的低血糖发作。因此，血浆葡萄糖对胰高血糖素的反应异常不一定意味着糖原分解存在紊乱。对于不明原因的低血糖症病例，建议使用稳定同位素测量葡萄糖动力学。
