Hypoglycemia

1. See Also
   1. Hypoglycemia Management
   2. Postprandial Hypoglycemia (Reactive Hypoglycemia)
   3. Fasting Hypoglycemia
2. Definitions
   1. Hypoglycemia
      1. Plasma Glucose <54 mg/dl (3.0 mmol/L)
   2. Severe Hypoglycemia
      1. Hypoglycemia event in which patient requires another person's assistance for management
3. Causes: Adults
   1. Subtypes
      1. Postprandial Hypoglycemia (Reactive Hypoglycemia)
      2. Fasting Hypoglycemia
   2. Endocrine disorders
      1. Diabetes Mellitus on Insulin or Insulin Secretagogue
      2. Adrenal Insufficiency
      3. Pheochromocytoma
      4. Hyperthyroidism
   3. Substance Abuse or Overdose
      1. Alcoholism with Alcohol Intoxication
      2. Cocaine
      3. Salicylate Toxicity
      4. Beta Blocker Overdose
   4. Nutritional
      1. Nutritional Deficiency
      2. Eating Disorder
      3. Liver disease (e.g. Cirrhosis)
   5. Medications
      1. See Sulfonylurea Drug Interactions Causing Hypoglycemia
      2. Insulin
      3. Insulin Secretagogue
      4. Quinolones (esp. Gatifloxacin and esp. with Sulfonylureas)
      5. Methadone
      6. Tramadol
      7. Pentamidine
      8. Quinine
   6. Miscellaneous
      1. Sepsis
4. Causes: Children
   1. Sepsis
   2. Inborn Errors of Metabolism
   3. Poor oral intake or decreased absorption (e.g. Diarrhea)
   4. Hypothyroidism
   5. Hypopituitarism
   6. Large malignancy (e.g. Wilms Tumor)
   7. Toxin Ingestion
      1. Beta Blocker Overdose
      2. Alcohol Toxicity
      3. Salicylate Toxicity
      4. Sulfonylurea Overdose
5. Findings
   1. Sensitivity to hypoglycemic episodes decreases with recurrent hypoglycemic episodes
      1. Higher risk for severe Hypoglycemia
   2. Sympathetic response
      1. Sweating
      2. Tremor
      3. Tachycardia
      4. Anxiety
      5. Hunger
   3. Neurologic symptoms
      1. Dizziness
      2. Visual disturbance
      3. Confusion or Delirium
      4. Loss of consciousness
      5. Seizures
      6. Syncope
6. Diagnosis: Whipple's Triad
   1. Low Plasma Glucose
      1. Men < 2.8 mmol/L (50 mg/dl)
      2. Women < 2.2 mmol/L (40 mg/dl)
   2. Hypoglycemic Symptoms
      1. May be masked by certain conditions or medications
         1. Autonomic Neuropathy
         2. Beta Blockers
   3. Symptoms improve with plasma Glucose correction
7. Management
   1. See Hypoglycemia Management
   2. Manage underlying cause
      1. See Insulin Shock
      2. See Adrenal Insufficiency
      3. See Salicylate Toxicity
      4. See Beta Blocker Overdose
      5. See Sulfonylurea Toxicity
      6. See Inborn Errors of Metabolism
      7. See Sepsis
8. Prevention
   1. See Diabetes Mellitus Glucose Management
   2. See Diabetes Sick Day Management
   3. General Dietary Measures
      1. Avoid Fasting
      2. Small, frequent meals
   4. Prepare Emergency Kit that is always available
      1. Medical alert bracelet
      2. Glucagon
      3. Emergency Glucose Replacement
      4. Glucometer
   5. Prepare for a hypoglycemic event (and teach family and friends)
      1. Recognize signs of Hypoglycemia (e.g. Altered Level of Consciousness or confusion, sweating, Dizziness)
      2. Test Blood Glucose for Hypoglycemia symptoms (but do not delay replacement)
      3. Treat Hypoglycemia if Blood Glucose <70 mg/dl (or <80-90mg/dl in elderly)
         1. See Hypoglycemia Management
         2. Deliver Glucagon in an unconscious or altered patient
            1. Temporize briefly until Glucose can be absorbed
         3. Deliver Emergency Glucose Replacement (15-20 grams carbohydrate)
      4. Glucose monitoring
         1. Monitor Blood Glucose every 15 minutes until >100 mg/dl
         2. Redose Glucose replacement per above every 15 min as needed
      5. Eat a small meal once Blood Glucose has returned to a normal level
   6. Adjust diabetes Blood Sugar goals
      1. Indicated in those with multiple comorbid conditions, elderly or other risks of severe Hypoglycemia
      2. Allow Hemoglobin A1C to rise to around 8%
   7. Adjust diabetes medications to lower risk of Hypoglycemia
      1. Avoid Glyburide (use other Sulfonylureas such as Glipizide or Glimepiride instead)
      2. Consider replacing Sulfonylurea with alternative
         1. Gliptin (e.g. Januvia)
         2. GLP-1-agonist (e.g. Byetta)
         3. Pioglitazone (Actos)
      3. Avoid Sulfonylurea with Insulin (especially with short-acting or Bolus Insulin such as Lispro/Humalog, Novolog)
         1. Sulfonylureas may be used with long-acting or basal Insulin (e.g. Lantus, Levemir) in patients at lower risk of Hypoglycemia
      4. Convert older Insulin preparations to newer agents with better predictable onset and duration
         1. Convert NPH Insulin to newer long-acting or basal Insulin (e.g. Lantus, Levemir)
         2. Convert Regular Insulin to newer short-acting or Bolus Insulin (e.g. Lispro/Humalog, Novolog)
9. References
   1. Inzucchi (2012) Diabetes Care 35(6):1364-79 [PubMed]