Chempath: Diabetes CPC + Hypoglycaemia

Question 1

What are the diagnositic tests for DM?

Answer 1

FPG ≥ 7.0mmol/L
2hr OGTT ≥ 11.1mmol/L
HbA1c ≥ 48mmol/mol (past 3m hence preferred)

Question 2

What are the test levels for pre-diabetes?

Answer 2

HbA1c: 42-47mmol/mol

Impaired Fasting Glucose
FPG: 6.1-6.9mmol/L

Impaired Glucose Tolerance
FPG: < 7.0mmol/L and
2hr OGTT: ≥ 7.8 - < 11.1mmol/

Question 3

What is the equation for anion gap?

Answer 3

Anion Gap= Na + K – Cl – HCO3

Normal: 14-18mmol/L

Question 4

Difference between DKA & HHS (Hyperosmolar Hyperglycaemic State) / KONKC (Hyperglycaemic hyperosmolar non-ketotic coma)

Answer 4

DKA = mainly in T1DM acidosis due to no insulin hence makes ketones:

• pH <7.3
• BM >11mmol
• Blood ketones >3mmol (++ urine?)
• Raised anion gap (due to ketones)
• Rapid presentation (N+V, abdo pain etc)

HHS / HONKC = Body has insulin so no ketones are made:

• pH >7.3 - not usually acidotic
• BM >30mmol (not aloways tho)
• NO KETONES
• V. high osmolality (>320mm)
• Occurs over a few days

Question 5

Mx of DKA?

Answer 5

IV Fluids (0.9% saline)
Insulin (once drops below 14)
K+ started later (only if low) - to replace insulin caused hypokalaemia

Question 6

Mx of HHS / KONC?

Answer 6

IV Fluids (0.9% saline)
K+
Insulin if needed

Question 7

When is DKA considered to be resolved?

Answer 7

Resolution = ketones < 0.6, pH > 7.3

Question 8

What pathologies explain the following changes in glucose and ketones:

Glucose High Ketones High
Glucose High Ketones Low
Glucose Low Ketones High
Glucose Low Ketones Low

Answer 8

Glucose High Ketones High = DKA - Metabolic acidosis (raised anion gap - often in T1DM but can happen in T2DM)

Glucose High Ketones Low = HHS / HONKC - often v dehydrated, typically in T2DM but can happen in T1DM

Glucose Low Ketones High = Starvation - causes normal ketosis

Glucose Low Ketones Low = Fatty acid oxidation defects (eg. MCADD)

Question 9

What are the causes of raised anion gap metabolic acidosis?

Answer 9

KULT

Ketoacidosis- DKA, starvation, alcoholic
Uraemia- renal failure
Lactic acidosis - Metformin
Toxins (ethylene glycol (IMPERIAL LOVE THIS), methanol, salicylate)

Question 10

What can excess metformin cause?

Answer 10

Metformin excess can cause a lactic acidosis as it inhibits conversion of lactic acid to glucose (Cori cycle)

Question 11

What is the definition of hypoglycaemia?

Answer 11

Multiple definitions of Hypo but generally glucose <4.0mmol/L

Question 12

What is the mx of hypoglycaemia?

Answer 12

Alert & Orientated= PO Carbohydrates (Rapid acting: juice/ sweets, Longer acting: sandwiches)

Drowsy/ confused but swallow intact = Buccal glucose (e.g. glucogel)

Unconscious or concerned about swallow = IV 100mL 20% dextrose

Insulin induced/ Refractory/ Deteriorating/ Difficult IV access = IM/ SC 1mg Glucagon*

Question 13

Why might IM / SC glucagon not work in some patients?

Answer 13

• Patient must have adequate glycogen stores in order for this to be effective. E.g., not effective if:
• Starving
• Liver failure
• Anorexia nervosa

Important to stay by these pts and check if its worked in 10-20 mins

Question 14

How to check for rebound hypoglycaemia?

Answer 14

Check levels throughouts the day after the mx

Question 15

Ix for hypoglycaemia?

Answer 15

Insulin, C-peptide, ketones

Question 16

What can cause high insulin and low c-peptide?

Answer 16

C-peptide is produced when insulin is cleaved hence should be 1:1 ration

This suggests exogenous insulin -> factitious insulin

Question 17

What can cause high insulin and high c-peptide?

Answer 17

This suggests endogenous insulin secretion of which causes include:

Insulinoma
Islet cell hyperplasia
Sulphonureas (gliclazide) - IMPORTANT

Question 18

What can be the causes of low c-peptide and low insulin

Answer 18

If high FFA and ketones - this is appropriate response hence seen in:
- Starvation (MAIN), anorexia, organ failure, hypopituitarism and adrenal failure

High FFAs + low ketones:
- B-oxidation defect eg MCADD (niche)

low FFAs + low ketones:
- paraneoplastic ‘BIG-IGF2’ (niche)

Question 19

SBA 1: A woman presents worried because she had a low glucose reading when testing her blood glucose using daughter’s meter (her daughter has T1DM). She denies taking any drugs. She also has a BMI of 35kg/m2. The investigations show the following:
Glucose: 3.5mmol/L
Insulin: raised
C-peptide: low

What is the cause?:

1. Factitious insulin
2. Surreptitious gliclazide
3. T1DM
4. Anorexia nervosa
5. Insulinoma

Answer 19

1. Factitious insulin

Question 20

SBA 2: Which one of the following values is most likely indicative of impaired glucose tolerance 2 hours after an oral glucose tolerance test?

1. 2.8
2. 3.0
3. 304
4. 11.5
5. 10.0

Answer 20

5. 10.0

Impaired Glucose Tolerance
FPG: < 7.0mmol/L and
2hr OGTT: ≥ 7.8 - < 11.1mmol/L

Question 21

Ddx in no ketones present, very very high osmolality (‘blood is like treacle’)?

Answer 21

HHS /HONKC

Question 22

no ketones present, very very high osmolality (‘blood is like treacle’) suggests what dx?

Answer 22

DKA

Question 23

What to do in hypoglycaemia if no access?

Answer 23

IM Glucagon