Hypoglycaemia

Question 1

Define the term “hypoglycaemia”

Answer 1

Defined as low plasma glucose concentration (< 4 mmol/L)

Question 2

What is the plasma glucose concentration that defines hypogylcaemia

Answer 2

< 4 mmol/L

Question 3

Hypoglycaemia is very common among diabetic patients treated with which medication

Answer 3

Insulin or sulphonylureas

Question 4

When blood glucose concentration falls, there is activation of four counterregulatory mechanisms.

Name these

Answer 4

• Body decreases insulin secretion – immediate response
• Increase in glucagon secretion
• Increase in adrenaline secretion
• Secretion of cortisol and growth hormone – late response

Question 5

What are the two main counterregulatory mechanism to hypoglycaemia

Answer 5

Decrease in insulin secretion

Increase in glucagon secretion

Question 6

What level of hypoglycaemia stimulates the autonomic system causing the autonomic symptoms

Answer 6

< 3.1 mmol/L

Question 7

What is the most common cause of hypoglycaemia

Answer 7

Most commonly occurs in association with treatment for diabetes mellitus e.g. insulin, Sulphonylureas

Question 8

What is the most common cause of hypoglycaemia in non-diabetics

Answer 8

Insulinoma

Question 9

What is an insulinoma

Answer 9

Benign pancreatic tumour of the beta cells causing excess insulin secretion

Question 10

Naem some of the causes of hypoglycaemia

Answer 10

• Treatment for diabetes mellitus e.g. insulin, Sulphonylureas - most common in diabetics
• Insulinoma – benign pancreatic tumour of the beta cells causing excess insulin secretion - most common in non-diabetics
• Alcohol
• Sepsis
• Malnourishment
• Adrenal insufficiency
• Paraneoplastic syndrome – secretion of insulin-like growth factor

Question 11

What is the blood glucose concentrations that cause autonomic symptoms (hypoglycaemia)

Answer 11

< 3.1 mmol/L

Question 12

What is the blood glucose concentrations that cause neuroglycopenic symptoms (hypoglycaemia)

Answer 12

< 2.8 mmol/L

Question 13

What causes autonomic symptoms associated with hypoglycaemia

Answer 13

The release of glucagon and adrenaline

Question 14

What causes neuroglycopenic symptoms associated with hypoglycaemia

Answer 14

Inadequate glucose supply to the brain

Question 15

Name some of the autonomic symptoms of hypoglycaemia

Answer 15

Tremor

Palpitations

Anxiety

Sweating

Hunger

Paraesthesia

Question 16

Name some of the neuroglycopenic symptoms of hypoglycaemia

Answer 16

Dizziness

Weakness

Drowsiness

Confusion

Seizures

Coma

Question 17

Why do patients with diabetes have reduced symptoms and presentation with severe hypoglycaemia

Answer 17

This is because patients with diabetes may lose their hypoglyaemic awareness

Occur in patients with type 1 and long-standing type 2 diabetes

Question 18

The diagnosis of hypoglycaemia is based on

Answer 18

Capillary blood glucose or serum blood glucose measurements

Question 19

What is the name given to the collection of three signs that is used as a formal diagnosis of hypoglycaemia

Answer 19

Whipple’s triad

Question 20

Whipple’s triad refers to a collection of three signs that is used as a formal diagnosis of hypoglycaemia .

Name the 3 signs

Answer 20

Low blood glucose concentration

Symptoms of hypoglycaemia

Reversal of symptoms when blood glucose concentration is restored

Question 21

In what patient group is the Whipple’s triad not clinically relevant for

Answer 21

Those with diabetes as they have reduced hypoglycaemic awareness

Question 22

Name the key investigation for hypoglycaemia

Answer 22

Capillary blood glucose

OR
Serum blood glucose measurements

Question 23

Name the other investigations that may be useful to aid in the investigation of hypoglycaemia

Answer 23

Serum insulin, C-peptide and proinsulin – to distinguish the presence of exogenous and endogenous insulin

Abdominal CT/MRI – to localise an insulioma

8am cortisol and/or synacthen (synACTHen) testing – for adrenal insufficiency

Question 24

Serum insulin, C-peptide and proinsulin can be used to distinguish the presence of exogenous and endogenous insulin.

What would you expect the levels to be for an endogenous production of insulin

[High, Low, Normal]

Answer 24

High insulin

AND
High C-peptide and proinsulin

Question 25

Serum insulin, C-peptide and proinsulin can be used to distinguish the presence of exogenous and endogenous insulin.

What would you expect the levels to be for an exogenous production of insulin

[High, Low, Normal]

Answer 25

High insulin

AND

Low C-peptide and proinsulin

Question 26

How woud you manage mild/moderate hypoglycaemia

Answer 26

Oral glucose (10-20g) given in liquid, gel or tablet form

Quick acting carbohydrate e.g. GlucoGel, Dextrogel, sweets.

Followed by slow acting carbohydrates e.g. toast

Question 27

How woud you manage severe hypoglycaemia

Answer 27

ABCDE appraoch

IV load of glucose e.g. 200ml IV 10% dextrose

If not access, subcut or intramuscular injection of 1mg glucagon