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CDE Diabetes

Study Guide: Hypoglycemia in Adults (Chapter 14)

1. Chapter Overview

Hypoglycemia is the major barrier to achieving glycemic targets. For the CDE exam, you must distinguish between the “levels” of hypoglycemia (a change in terminology from mild/moderate/severe) and know the specific treatment protocols for conscious versus unconscious individuals. The 2023 update places a heavy emphasis on prevention using technology (CGM) and the use of nasal glucagon.

2. Definition and Classification

Hypoglycemia is defined not strictly by glucose levels alone but by the severity of symptoms and the risk of adverse outcomes.

  • Alert Value: A glucose level of should alert the individual and clinician to potential hypoglycemia in those treated with insulin or insulin secretagogues.
Level 1 ( but
  • Autonomic symptoms present.
  • No neuroglycopenic symptoms.
  • Self-treatable
Level 2 (
  • Neuroglycopenic symptoms appear.
  • Usually self-treatable (does not require assistance).

Level 3 (Severe) (No specific glucose threshold)

  • Characterized by altered mental/physical status.
  • Requires external assistance for recovery (cannot self-treat).

3. Clinical Presentation

Symptoms typically progress from adrenergic (autonomic) to neuroglycopenic.

  • Adrenergic (Early/Warning): Trembling, palpitations, sweating, anxiety, hunger, nausea, tingling.
  • Neuroglycopenic (Brain Glucose Deprivation): Difficulty concentrating, confusion, weakness, vision changes, slurred speech, dizziness, headache.
    • Note: Individuals with Impaired Awareness of Hypoglycemia (IAH) may experience neuroglycopenic symptoms without prior adrenergic warning signs

4. Risk Factors

Identifying “high-risk” patients is a core competency for the CDE exam.

Key Risk Factors for Severe Hypoglycemia:

  • History: Prior episode of severe hypoglycemia.

  • Demographics: Advancing age, long duration of diabetes, low health literacy, food insecurity.
     
  • Physiological: Impaired Awareness of Hypoglycemia (IAH), autonomic neuropathy, chronic kidney disease (CKD), cognitive impairment.
  • Treatment: Use of insulin or insulin secretagogues (sulfonylureas/meglitinides), strict glycemic targets (low A1C).

Impaired Awareness of Hypoglycemia (IAH):

  • Occurs when the threshold for autonomic warning symptoms drops lower than the threshold for neuroglycopenia.
  • Screening: All individuals with type 1 diabetes and those with type 2 diabetes on insulin/secretagogues should be screened for IAH.
  • Reversibility: Strict avoidance of hypoglycemia for 2 days to 3 months can restore awareness.

5. Prevention Strategies

Prevention is preferred over treatment

Pharmacotherapy Adjustments:

  • Insulin: Switch from NPH to long-acting basal analogues (glargine U-300, degludec) to reduce nocturnal hypoglycemia.

    • CDE Gem: Degludec and glargine U-300 are “second-generation” analogues with lower hypoglycemia risk than glargine U-100 or detemir.
  • Type 2 Agents: Prioritize agents with low hypoglycemia risk (GLP-1 RA, DPP-4 inhibitors, SGLT2 inhibitors) over sulfonylureas where possible.

Technology:

  • CGM: Continuous Glucose Monitoring (rtCGM or isCGM) is recommended for those with T1D or T2D on insulin/secretagogues to reduce time in hypoglycemia.

Technology:

  • CGM: Continuous Glucose Monitoring (rtCGM or isCGM) is recommended for those with T1D or T2D on insulin/secretagogues to reduce time in hypoglycemia.

Education:

  • Counsel support persons on glucagon administration.

  • Screen for Fear of Hypoglycemia (FoH), which can lead to “defensive snacking” and maintaining high BG.

6. Treatment Protocol

A. Level 1 & 2 (Conscious & Able to Swallow):

Treat: Ingest 15 g of fast-acting carbohydrate (glucose tablets, sucrose solution).

  • Examples: 4x 4 gm glucose tablets, 150 mL (2/3 cup) juice or regular soft drink, 1 tablespoon honey

Wait: Wait 15 minutes.

Retest: Check BG. If still , treat again with another 15 g.

Maintain: Once BG is safe ():
  • Eat usual meal if due within 1 hour.
  • If meal is hour away, eat a snack (15 g carb + protein source).

B. Level 3 (Conscious but requires help):

  • Oral: 20 g carbohydrate if able to swallow.
  • Glucagon: If unable to swallow, administer Glucagon (3 mg Intranasal OR 1 mg SC/IM).

C. Level 3 (Unconscious):

  • No IV Access: Glucagon 1 mg SC/IM or 3 mg Intranasal. Call emergency services.
    IV Access (Hospital): 10–25 g glucose IV (D50W) over 1–3 minutes.

Important Notes on Glucagon:

  • Intranasal (IN) Glucagon: Effective for both T1D and T2D; easier and faster to administer than injectable.

  • Alcohol: Glucagon effectiveness is reduced if the patient has consumed standard drinks recently.
  • Sulfonylureas: Glucagon is less useful for hypoglycemia caused by secretagogues as it may stimulate further insulin release.

7. Special Considerations

  • Driving: Review safe driving guidelines at every visit.
  • Exercise: To prevent exercise-induced lows, reduce insulin or increase carbs 60-90 minutes pre-exercise.

7. Diabetes Canada Clinical Practice Guidelines Recommendations

Key takeaways from the “Recommendations” section of the Guidelines (Pages 552-554).

Counseling & Screening

  • Universal Counselling: All individuals on insulin or insulin secretagogues (and their support persons) must be counselled on risk, prevention, recognition, and treatment of hypoglycemia.

  • Every Visit Review: At every clinical encounter, review the recent history of hypoglycemia, including frequency, causes, and driving safety.
  • Screen for IAH: Screen for Impaired Awareness of Hypoglycemia (IAH) using a careful history or validated questionnaires.
  • Screen for Fear: Screen for Fear of Hypoglycemia (FoH) and refer to mental health professionals if persistent.

Prevention Strategies (High-Risk Individuals)

  • Technology: Use Continuous Glucose Monitoring (CGM) or increased capillary monitoring to identify unrecognized hypoglycemia.
    • Note: Real-time CGM (rtCGM) is Grade A evidence for Type 1 Diabetes.
  • Insulin Choice:
    • Basal vs. NPH: Long-acting analogues (glargine, detemir, degludec) are preferred over NPH insulin to reduce risk.
    • 2nd Gen vs. 1st Gen: Second-generation basal analogues (glargine U-300, degludec) are preferred over first-generation (glargine U-100, detemir) to reduce nocturnal hypoglycemia.
  • Education: Structured diabetes education and psychobehavioural interventions (e.g., Blood Glucose Awareness Training) should be utilized.

Management of Recurrent/Severe Hypoglycemia

  • Strict Avoidance: For those with IAH or recurrent severe episodes, aim for strict avoidance of hypoglycemia and potentially relax glycemic targets for up to 3 months to restore awareness.
  • Pumps & Sensors: Consider CSII (pumps), CGM, or sensor-augmented pumps for Type 1 Diabetes.
  • Transplantation: Islet cell or pancreas transplantation may be considered for T1D with recurrent severe hypoglycemia.

Treatment Recommendations (The Protocols)

  • Level 1 & 2: Ingest 15 g carbohydrate (glucose/sucrose preferred). Retest in 15 mins. Retreat if BG .
  • Level 3 (Conscious):
    • If able to swallow: 20 g carbohydrate.
    • Or: Glucagon 3 mg Intranasal or 1 mg SC/IM.
  • Level 3 (Unconscious):
    • No IV: Glucagon (3 mg IN or 1 mg SC/IM). Call emergency services.
    • With IV: 10–25 g glucose (20–50 mL of D50W) intravenously over 1–3 minutes.
  • Support Persons: Must be taught how to administer glucagon (SC, IM, or IN).
  • Post-Treatment: Eat usual meal or snack (15 g carb + protein) if meal is hour away.

Reference:  

Lega IC, Yale JF, Chadha A, et al. Hypoglycemia in Adults. Canadian Journal of Diabetes. 2023;47(7):548-559. doi:10.1016/j.jcjd.2023.08.003