Hypoglycemia without Diabetes
المؤلف:
Marcello Ciaccio
المصدر:
Clinical and Laboratory Medicine Textbook 2021
الجزء والصفحة:
p417-418
2025-11-12
19
In subjects not affected by diabetes mellitus, hypoglycemia could be due to different causes. The Endocrine Society has proposed classifying the causes of hypoglycemia according to the subject’s health status. (Table1).
Table1. Classification of the hypoglycemic causes in non diabetic patients
Drugs
Drugs represent the most common cause of hypoglycemia. Numerous drugs responsible for hypoglycemia have been described, with varying degrees of evidence (Table 2). In particular, drug-induced hypoglycemia is more common in elderly patients with underlying comorbidities. Moreover, the incidence of hypoglycemia in hospitalized patients is frequent when insulin or secretagogue drugs are administered to patients in whom parenteral nutrition is suspended or when insulin sensitivity increases (as when steroid therapy is interrupted). Another common cause of hypoglycemia is alcohol intake, as it inhibits gluconeogenesis. Consequently, alcohol-induced hypoglycemia usually occurs after a few days of alcohol abuse, especially when the subject does not adequately eat.
Table2. Drugs inducing hypoglycemia (excluding alcohol and oral hypoglycemic agents)
Chronic and Acute Illnesses
Among hospitalized patients, renal and hepatic failure and sepsis are common causes of hypoglycemia. In liver failure, hypoglycemia is due to the reduced endogenous glucose synthesis; in renal failure, it is caused by reduced insulin clearance and reduced mobilization of gluconeogenesis precursors. During sepsis, the recruitment of macrophages to the infected tissues leads to the release of cytokines that induce increased glucose utilization. In inanition, on the other hand, hypoglycemia may be due to loss of adipose tissue and subsequent reduction of gluconeogenesis precursors and increased glucose utilization.
Hormonal Deficiencies
Growth hormone (GH) and cortisol deficiency are associated with reduced availability of substrates for gluconeogenesis and increased peripheral glucose utilization.
Non-insular Tumors
Fasting hypoglycemia secondary to non-insular tumors is occasionally observed in patients with large mesenchymal or epithelial tumors. It is due to hyperproduction of insulin-like growth factor 2 (IGF-2) or immature precursors resulting in hypoglycemic episodes similar to those observed in patients with insulinoma.
Endogenous Hyperinsulinism
There are many causes of endogenous hyperinsulinism. but the underlying mechanism is the failure to reduce insulin levels during hypoglycemia. Insulinoma, a rare pancreatic β-cell tumor, benign in 90% of cases, is the leading cause of endogenous hyperinsulinism. From a clinical point of view, insulinoma is characterized by periods of neuroglycopenia due to endogenous hyperinsulinemic hypoglycemia occurring mainly in the fasting and only occasionally in the post prandial period.
Hypoglycemic syndrome of pancreatic origin not secondary to insulinoma, is clinically characterized by episodes of postprandial neuroglycopenia secondary to hyperinsulinism. From a histological point of view, it is characterized by β-cell hypertrophy and hyperplasia of the β-cell nuclei.
Autoimmune hypoglycemia is a rare condition characterized by anti-insulin antibodies without pancreatic β-cell alteration. In rare cases, anti-insulin receptor antibodies may also be found.
Finally, postprandial hypoglycemia can be observed in obese patients undergoing bariatric surgery. In these patients, increased levels of the intestinal incretin GLP-1 and subsequent glucagon suppression increase insulin secretion. In addition, the increased expression of IGF-1 and IGF-2 growth factor receptors results in increased β-cell activity, thus contributing to the insulin levels increase.
Hypoglycemia Factitia
Hypoglycemia can be caused intentionally, such as during the performance of a clinical test (insulin-tolerance test); accidentally, for example, as a result of a pharmacy error; or as a result of taking insulin as a potent anabolic agent, such as in athletes. Hypoglycemia factitia should always be suspected if hypoglycemia occurs suddenly in a healthy subject. In the case of voluntary insulin administration, the decisive diagnostic criterion is related to the discrepancy between the finding of elevated plasma insulin concentrations and normal C-peptide values.
الاكثر قراءة في الغدد الصم و هرموناتها
اخر الاخبار
اخبار العتبة العباسية المقدسة
