Hypoglycaemia

Question 1

Define Whipple’s Triad.

Answer 1

Whipple’s Triad

• Symptoms of hypoglycaemia
• Low plasma glucose
• Relief of symptoms with correction of hypoglycaemia

Question 2

What are the counter regulatory hormones to hypoglycaemia?

Answer 2

Counter regulatory response to hypoglycaemia:

1. Decrease insulin (4.4-4.7 mmol/L)
2. Increase glucagon (3.6-3.9 mmol/L); stimulates both glycogenolysis and gluconeogenesis
3. Epinephrine (3.6-3.9 mmol/L); increases gluconeogenesis
4. GH and Cortisol; limit glucose utilization, and enhances glucose production

Question 3

What causes neurogenic symptoms of hypoglycaemia?

Answer 3

Neurogenic symptoms are due to counter regulatory hormones; in normal subjects below 3.1 mmol/L

Question 4

What causes neuroglycopenic symptoms of hypoglycaemia?

Answer 4

Neuroglycopenic symptoms are due to brain glucose deficiency; in normal subjects below 2.8 mmol/L

Question 5

What are some of the mechanisms of hypoglycaemia unawareness?

Answer 5

Hypoglycaemia unaware:

• Older patients
• Patients with frequent hypoglycaemic episodes
• Patients with diabetic autonomic neuropathy

Question 6

What are the 4 mechanisms of hypoglycaemia?

Answer 6

1. Excessive insulin
2. Defective glucose production: gluconeogenesis or glycogenolysis
3. Reduced availability of alternate fuels
4. Defective counter-regulatory hormone

Question 7

Given these 72 hour fasting results, what is the likely cause of hypoglycaemia?

• Symptoms of hypoglycaemia
• Glucose is low
• Insulin is high
• C-peptide is high
• Proinsulin is high
• Ketones are low
• Sulfonylurea in plasma is negative

Answer 7

Insulinoma; excessive insulin

Question 8

Given these 72 hour fasting results, what is the likely cause of hypoglycaemia?

• Symptoms of hypoglycaemia
• Glucose is low
• Insulin is high
• C-peptide is low
• Pro-insulin is low
• Ketones are low
• Sulfonylurea in plasma is negative

Answer 8

Factitious hypoglycaemia from insulin

Question 9

Given these 72 hour fasting results, what is the likely cause of hypoglycaemia?

• Symptoms of hypoglycaemia
• Glucose is low
• Insulin is high
• C-peptide is high
• Proinsulin is high
• Ketones are low
• Sulfonylurea in plasma is positive

Answer 9

Sulfonylurea-induced hypoglycaemia