W22 - Hypoglycaemia

Question 1

Acute hypoglycaemia management in someone who is:

1. Alert and oriented:
2. Drowsy/confused but swallow intact:
3. Unconscious or concerned about swallow:

Answer 1

Acute hypoglycaemia management in someone who is:

1. Alert and oriented: oral carbs (rapid acting juice, longer acting sandwich)
2. Drowsy/confused but swallow intact: buccal glucose (glucogel), potential IV access or long acting sandwich
3. Unconscious or concerned about swallow: IV access, 20% glucose IV, if eteriorting consider IM 1mg glucagon

Question 2

When considering giving glucagon injection to a hypoglycaemic patient, what 2 things do you need to consider?

Answer 2

1. Are there glycogen stores to mobilise?
2. Takes 15-20 minutes to work

Question 3

What level of glucose defines hypoglycaemia?

Answer 3

typically less than 3.5 mmol/L

Question 4

What are adrenergic symptoms (4) of hypoglycaemia?

Answer 4

1. Tremors
2. Palpitations
3. Sweating
4. Hunger

Question 5

What are neuroglycopaenic symptoms arising from hypoglycaemia?

Answer 5

1. Somnolence
2. Confusion
3. incoordination
4. Seizures
5. Coma

Question 6

In which cohort of patients could you see little to no symptoms arising from hypoglycaemia

Answer 6

Diabetics = if they have spent a lot of time in hypos, the adrenergic symptoms get “switched off”, and they develop tolerance to symptoms.

Question 7

In hypoglycaemia, what happens to levels of insulin and glucagon? What is the net effect (4 things)?

Answer 7

Insulin low

Glucagon high

1. Reduced peripheral uptake of glucose
2. Increased glycogenolysis
3. Increased gluconeogenesis
4. Increased lipolysis

Question 8

In hypoglycaemia, with reduced insulin and increased glucagon, the body attempts to increase glucose and FFA (due to lipolysis). What happens to the FFA?

Answer 8

1. FFA could be burnt by b-oxidation in the mitochondria, producing ATP
2. FFA could also be used in ketosis = ketone body production

Question 9

In a hypoglycaemia state, what is the outcome of low neruonal glucose sensed in the hypothalamus?

Answer 9

1. Sympathetic activation - catecholamines
2. ACTH, cortisol, and GH production

Question 10

What occurs first in response to hypoglycaemia?

1. Suppression of insulin
2. Release of glucagon
3. Release of adrenaline
4. Release of cortisol

Answer 10

1. Suppression of insulin

followed by 2, then 3 + 4

Question 11

Describe the pros and cons of blood glucose meter

Answer 11

Pros => point of care device, instant result

Cons => poor precision at low glucose levels

Question 12

Which 2 diabetic medications have the highest risk of causing hypos?

Answer 12

1. Insulin
2. Sulphonylureas

Question 13

C peptide is…

1. is the cleavage product of insulin
2. is secreted in equimolar amounts to insulin
3. has a half-life of 2 hours
4. interferes with insulin measurement

Answer 13

2. is secreted in equimolar amounts to insulin

cleavage product of pro-insulin

half life of 30 mins

Question 14

Hypoglycaemia due to excess injected insulin would result in…

1. A low C-peptide
2. A high C-peptide

Answer 14

1. A low C peptide = if you switch off insulin production from your pancreas, you would not have a high c peptide. An injection insulin doesn’t have c peptide

Question 15

20 year old female, BMI 17 kg/m2

• Lanugo hair noted
• Finger prick glucose – 3.8mmol/L
• Routine bloods taken
• Doctor rung by lab 1 hr later as plasma glucose 2.6 mmol/L

What is the most likely cause of her low blood sugar?

1. Undertakes strenuous exercise regularly
2. Insulinoma
3. Anorexic with poor liver glycogen stores
4. Laxative abuse

Answer 15

3. Anorexic with poor liver glycogen stores

NB: they’re not eating very much but that shouldn’t be an issue because if she had had normal glycogen stores, she would not be so hypoglycaemic

Question 16

What would the insulin and C-peptide result be in a hypoglycaemic, anorexic person?

1. Low insulin, low C-peptide
2. Low insulin, high C-peptide
3. High Insulin, lowC-peptide
4. High insulin, high C-peptide

Answer 16

1. Low insulin, low C-peptide

Question 17

Hypoglycaemia => measure insulin and c-peptide (and ketones):

• high insulin, low c-peptide = what does this mean?

Answer 17

Exogenous insulin = the person hs taken too much insulin facticiously

Question 18

Hypoglycaemia => measure insulin and c-peptide (and ketones):

• low insulin, low c-peptide = what does this mean?

Answer 18

hypoinsulinaemic hypoglycaemia = proper response to hypo

Question 19

Hypoglycaemia => measure insulin and c-peptide (and ketones):

• high insulin, high c-peptide = what does this mean?

Answer 19

hyperinsulinaemic hypoglycaemia = produing too much endogenous insulin

Question 20

1 day old neonate - jittery, not-feeding

• Premature – 34 weeks gestation
• Lab glucose 1.9 mmol/L
• Glucose improved on feeding, but low blood glucose 4 hours after feed.
• 3-hydroxybutyrate measured at time of hypo and was negative.

What does the absence of ketones signify (glucose 1.9, ketones negative)?

Answer 20

FFA oxidation defect

Question 21

What is 3-hydroxybutyrate?

1. End product of insulin metabolism
2. A free fatty acid
3. A triglyceride
4. A ketone body
5. A component of artificial nutrition

Answer 21

4.A ketone body

Question 22

Name the 3 ketone bodies normally produced in humans

Answer 22

1. Acetoacetate
2. 3-beta-hydroxybutyrate
3. Acetone (rare)

Question 23

Name causes (4) for inappropriately elevated insulin levels (i.e. glucose is low, insulin is high)

Answer 23

1. Insulinoma (islet cell tumours)
2. Drugs (insulin, sulphonylurea)
3. Islet cell hyperplasia
4. Rare genetic causes

Question 24

45 year old lady admitted fitting. Recurrently seen GP in previous months due to weight gain and increased appetite

Husband reports personality change in last few months.

• Glucose 1.9 mmol/L
• Insulin 35 mu/L (high)
• C-peptide 1000 pmol/L (high)

What would you order next?

Answer 24

Low glucose, high insulin, high C-peptide => endogenous insulin production

1. Sulphonylurea drug screen (urine or serum) => you need a negative sulphonylurea screen before diagnosing insulinoma

Question 25

Insulinomas:

• incidence?
• malignant?
• associated diseases?
• treatment?

Answer 25

Insulinomas:

• incidence = 1-2/mill/year
• malignant = 10% malignant, usually small solitary adenoma
• associated diseases = 8% associated with MEN1
• treatment = resection

Question 26

9 year old boy brought in fitting.

• Glucose 1.9 mmol/L
• Insulin 205 mu/L; C-peptide <33 pmol/L

What is the most likely cause of the low blood glucose?

1. Glucose consumption during epileptic fit
2. Stress response
3. Factitious insulin
4. Need more information

Answer 26

3. Factitious insulin = most likely someone has given this boy an insulin injection so insulin is high but c peptide is low

Question 27

60 year old cachectic man found unconscious

• Smoker
• Glucose 1.9 mmol/L
• Hypoglycaemia persists – glucose infusion
• Insulin and C-peptide undetectable
• Free fatty acids – undetectable
• Ketones negative

The following diagnosis is likely:

1. Benign insulinoma
2. Non-islet cell tumour hypoglycaemia
3. Malignant insulinoma
4. Addison’s disease
5. Panhypopituitarism

Answer 27

2. Non-islet cell tumour hypoglycaemia

tumours which produce IGF-2

Question 28

What is non-islet cell tumour hypoglycaemia?

Answer 28

Tumours that cause a paraneoplastic syndrome, secreting big IGF-2 which binds to IGF-1 receptor and insulin receptor = looks as though there is insulin acting but when you measure, there is no insulin

Question 29

What is Insulin Autoimmune Syndrome?

Answer 29

ab against insulin => sudden dissocition may precipitate hypoglycaemia

Question 30

Causes (4) of reactive/post-prandial hypoglycaemia?

Answer 30

1. Post-gastric bypass (most common)
2. Hereditary fructose intolerance
3. Early diabetes
4. in insulin sensitive individuals are exercise or large meal