Jörneskog G, Lins P E, Adamson U, Fagrell B
Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
Int J Microcirc Clin Exp. 1994 Sep-Oct;14(5):262-8. doi: 10.1159/000178838.
Disturbed hemodynamic reactions to insulin-induced hypoglycemia have been documented in diabetic patients and considered related to hyperinsulinemia and impairment of autonomic nervous functions. In the present study we investigated the effect on skin microcirculation of insulin-induced hypoglycemia obtained during moderate hyperinsulinemia, in 7 men with type 1 diabetes and in 8 healthy age- and sex-matched controls. The patients had all normal cardiovascular reflexes as assessed by respiratory sinus arrhythmia and Valsalva ratio. The skin microcirculation of the left fourth finger nailfold was investigated by laser Doppler fluxmetry, and the skin temperature within the same area was measured by a thermistor. Hypoglycemia was induced by a constant insulin infusion of Actrapid Human, 0.034 U kg-1 h-1 during 120 min. Plasma adrenaline, noradrenaline and pancreatic polypeptide increased significantly in both groups during hypoglycemia and the insulin levels never exceeded 50 mUl-1. A close to identical arterial hypoglycemia was obtained in the two groups 60 min after onset of insulin infusion. During hypoglycemia the control subjects revealed a significant decrease in laser Doppler flux (p < 0.025), while it was unchanged in the diabetic patients. Simultaneously, the skin temperature decreased (p < 0.05) in the controls, but was unchanged in the diabetic patients. The present study indicates that type 1 diabetic patients with normal cardiovascular reflexes have an abolished vasoconstrictor response in skin microcirculation of fingers during insulin-induced hypoglycemia, despite the fact that neurogenic and neuroglucopenic symptoms developed in these patients during hypoglycemia.
糖尿病患者中已记录到对胰岛素诱导的低血糖的血流动力学反应紊乱，且认为这与高胰岛素血症和自主神经功能损害有关。在本研究中，我们调查了中度高胰岛素血症期间胰岛素诱导的低血糖对7名1型糖尿病男性患者和8名年龄及性别匹配的健康对照者皮肤微循环的影响。通过呼吸性窦性心律失常和瓦尔萨尔瓦比率评估，患者的所有心血管反射均正常。用激光多普勒血流仪研究左手无名指甲襞的皮肤微循环，并用热敏电阻测量同一区域的皮肤温度。通过持续输注诺和灵（Actrapid Human）诱导低血糖，剂量为0.034 U·kg⁻¹·h⁻¹，持续120分钟。低血糖期间两组的血浆肾上腺素、去甲肾上腺素和胰多肽均显著增加，且胰岛素水平从未超过50 mU·L⁻¹。胰岛素输注开始60分钟后，两组的动脉低血糖情况几乎相同。低血糖期间，健康对照者的激光多普勒血流显著降低（p < 0.025），而糖尿病患者则无变化。同时，健康对照者的皮肤温度下降（p < 0.05），而糖尿病患者的皮肤温度无变化。本研究表明，尽管这些1型糖尿病患者在低血糖期间出现了神经源性和低血糖性症状，但具有正常心血管反射的患者在胰岛素诱导的低血糖期间手指皮肤微循环中的血管收缩反应消失。
