Marks V, Teale J D
Royal Surrey County Hospital, Guildford, UK.
Baillieres Clin Endocrinol Metab. 1993 Jul;7(3):705-29. doi: 10.1016/s0950-351x(05)80215-0.
Hypoglycaemia is a relatively common cause for referral of patients to the accident and emergency departments of hospitals but most of it is iatrogenic. Occasionally, however, hypoglycaemia is due to any one of up to a hundred different disorders. In some, hypoglycaemia is the cause of intermittent neuroglycopenic symptoms that lead to their referral to medical outpatients for investigation. Only the most important are discussed here. Hyperinsulinism due to abnormal beta-cell function is an uncommon but important cause of spontaneous hypoglycaemia. The diagnosis is suspected from the history of episodes of altered consciousness confirmed by demonstrating raised plasma insulin, C-peptide and proinsulin levels in peripheral blood in the presence of hypoglycaemia. Differentiation of the various causes of endogenous hyperinsulinism before surgery is difficult if not impossible and the low predictive value of most of the localizing techniques that are available makes them an additional and unnecessary cost, producing little clinical benefit. Hypoglycaemia caused by non-islet cell tumours (NICTH) is seemingly rarer than hyperinsulinism from insulinoma and tends to occur in older patients. The clinical features are similar to those of hyperinsulinism but laboratory investigation reveals appropriately depressed plasma insulin, C-peptide and proinsulin levels in the presence of hypoglycaemia. The plasma IGF-II:IGF-I ratio is characteristically high and the concentration of the E-domain of proIGF-II is raised. Autoimmune hypoglycaemia is more common in some countries than others and is most often due to autoantibodies to insulin (AIS). It may also be caused by autoantibodies to the insulin receptor and possibly to autoantibodies that are stimulatory to pancreatic beta-cells. Contrary to popular belief, idiopathic reactive hypoglycaemia is rare and only one of the possible causes of the postprandial syndrome. It is characterized by a low blood glucose concentration in blood collected during a spontaneous symptomatic episode but not at other times. Its cause is unknown. Other causes of hypoglycaemia include endocrinopathies of various kinds; sepsis including malaria; congestive cardiac failure; hepatic and renal insufficiencies; diverse inborn errors of metabolism; and exogenous toxins, of which alcohol is probably the commonest.
低血糖是患者被转诊至医院急诊科的相对常见原因，但大多数低血糖是医源性的。然而，偶尔低血糖也可能由多达一百种不同疾病中的任何一种引起。在某些情况下，低血糖是间歇性神经低血糖症状的原因，导致患者被转诊至内科门诊进行检查。这里仅讨论最重要的几种。因β细胞功能异常导致的高胰岛素血症是自发性低血糖的一种罕见但重要的原因。根据意识改变发作的病史怀疑该诊断，同时在低血糖情况下外周血中血浆胰岛素、C肽和胰岛素原水平升高可证实这一诊断。术前区分内源性高胰岛素血症的各种原因即便并非不可能也很困难，而且大多数现有定位技术的预测价值较低，这使得它们成为额外且不必要的费用，几乎没有临床益处。非胰岛细胞瘤（NICTH）引起的低血糖似乎比胰岛素瘤导致的高胰岛素血症更罕见，且往往发生在老年患者中。其临床特征与高胰岛素血症相似，但实验室检查显示在低血糖情况下血浆胰岛素、C肽和胰岛素原水平相应降低。血浆IGF-II:IGF-I比值通常较高，且proIGF-II的E结构域浓度升高。自身免疫性低血糖在一些国家比其他国家更常见，最常见的原因是胰岛素自身抗体（AIS）。它也可能由胰岛素受体自身抗体以及可能刺激胰腺β细胞的自身抗体引起。与普遍看法相反，特发性反应性低血糖很少见，只是餐后综合征的可能原因之一。其特征是在自发症状发作期间采集的血液中血糖浓度低，但其他时间并非如此。其病因不明。低血糖的其他原因包括各种内分泌疾病；败血症（包括疟疾）；充血性心力衰竭；肝肾功能不全；多种先天性代谢缺陷；以及外源性毒素，其中酒精可能是最常见的。
