Veneman T, Mitrakou A, Mokan M, Cryer P, Gerich J
Department of Medicine and Physiology, University of Pittsburgh, Pennsylvania.
Diabetes. 1993 Sep;42(9):1233-7. doi: 10.2337/diab.42.9.1233.
Hypoglycemia has been incriminated as a possible factor responsible for development of the hypoglycemia unawareness phenomenon in patients with type I diabetes. Many patients with this condition, however, do not have a history of recent hypoglycemia. Because asymptomatic nocturnal hypoglycemia commonly occurs in type I diabetes, we tested the hypothesis that such episodes might be capable of inducing this phenomenon. Accordingly, autonomic and neuroglycopenic symptoms, counterregulatory hormone responses, and cognitive function were assessed during standardized insulin-induced hypoglycemia in 10 normal volunteer subjects on two occasions--once after induction of asymptomatic nocturnal hypoglycemia and once after control studies in which saline rather than insulin was infused overnight. Compared with control experiments, asymptomatic nocturnal hypoglycemia increased the threshold (required greater hypoglycemia for initiation) and reduced the magnitude of autonomic and neuroglycopenic symptoms, counterregulatory hormone responses, and cognitive dysfunction during subsequent hypoglycemia (all, P < 0.05). These results indicate that asymptomatic hypoglycemia may induce hypoglycemia unawareness and, thus, may explain why not every patient with this condition has a history of prior hypoglycemia. Our results therefore support the concept that in type I diabetes this phenomenon may be largely attributable to antecedent hypoglycemia.
低血糖被认为是导致I型糖尿病患者出现低血糖无意识现象的一个可能因素。然而，许多患有这种病症的患者并没有近期低血糖发作史。由于无症状性夜间低血糖在I型糖尿病中普遍存在，我们检验了这样一个假设，即此类发作可能会引发这种现象。因此，我们对10名正常志愿者进行了标准化胰岛素诱导低血糖试验，分两次评估自主神经和低血糖性症状、反调节激素反应以及认知功能——一次是在诱导无症状性夜间低血糖之后，另一次是在对照研究之后，对照研究中整夜输注的是生理盐水而非胰岛素。与对照实验相比，无症状性夜间低血糖提高了阈值（引发低血糖需要更低的血糖水平），并降低了随后低血糖期间自主神经和低血糖性症状、反调节激素反应以及认知功能障碍的程度（所有指标，P < 0.05）。这些结果表明，无症状性低血糖可能会诱发低血糖无意识，从而可以解释为什么并非每个患有这种病症的患者都有先前低血糖发作史。因此，我们的结果支持这样一种观点，即在I型糖尿病中，这种现象可能主要归因于先前的低血糖。
