Hypoglycemia (Etiologies)

1.  Drugs – the most common cause overall, with diabetic medications obviously being the biggest offenders

• Insulin and Insulin secretagogues (Sulfonylureas and Meglitinides) are the most common agents.
• Note that drugs like Metformin, Glitazones, Glucoside Inhibitors, GLP-1 receptor Agonists (e.g. Januvia) should NOT cause hypoglycemia alone without insulin.
• Alcohol – inhibits hepatic gluconeogenesis.  Hypoglycemia usually follows several days of binghing with limited food ingestions.  Alcohol is a common contributor to hypoglycemia in alcoholics.

Other drugs:

• Fluoroquinolones – remember that Gatifloxacin was removed from the market due to severe dysglycemias.  Other quinolones have this effect to a lesser extent.
• Pentamidine
• Beta-blockers
• ACE inhibitors
• Quinine

2.  Sepsis – a relatively common cause, due to cytokines accelerating glucose utilization.

3.  Liver Failure - due to inability to perform gluconeogensis and glycogenolysis.  Hypoglycemia is a late and ominous finding in liver failure.

4.  Renal Failure – mainly due to decreased renal clearance of insulin, and decreased gluconeogenesis.

5.  Malnourishment – due to severe glycogen depletion, as in anorexics.

6.  Cortisol Deficiency – cortisol is part of the body’s response to hypoglycemia and increases hepatic glucose production.  In adults, however, hypoglycemia is rarely the sole presenting symptom of adrenal insufficiency.

7.  Insulinomas        

 
8.  Other malignancies (Non-Islet Cell Tumors) – uncommon but serious complication of certain malignancies, characteristically mesenchymal tumors, fibromas, carcinoid, lymphoma, hepatocellular carcinoma, and sometimes colorectal cancer.  Due to tumor cell production of IGF-II which stimulates insulin receptors.

(Chanu Rhee MD, 5/23/11)