Chempath 21: Diabetes CPC

Question 1

A Fasting plasma glucose of >……. defines diabetes

Answer 1

> 7mmol/L

Question 2

A 2 hour plasma glucose in a GTT > …….. defines diabetes

Answer 2

> 11.1mmol/L

Question 3

A HbA1c > ……. defines diabetes

Answer 3

> 48mmol/mol (6.5%)

Question 4

Why is respiratory compensation for metabolic alkalosis limited ?

Answer 4

If you want to increase CO2 by restricted breathing it will be limited because you require a sufficient amount of ventilation to maintain oxygen levels

Question 5

DKA is a metabolic acidosis with a ……….. anion gap

Answer 5

High

Anion gap = Na + k - Cl - HCO3

Normal is about 12 (8-16)

If >12 suggests other anions such as ketones

Question 6

How does the dialysis regime differ in treatment of ATN and diabetic glomerular kidney disease ?

Answer 6

In ATN 3 weeks of dialysis should allow recovery of renal function

In diabetic glomerular kidney disease the patient will require lifelong dialysis of transplant.

Question 7

Which of the following diseases is most likely to be associated with AA amyloidosis ?

A) Alzheimer’s disease 
B) Diabetes Mellitus 
C) Plasmacytoma
D) Rheumatoid Arthritis 
E) Thyroid carcinoma

Answer 7

D) Rheumatoid Arthritis

Rheumatoid arthritis is an inflammatory condition which contribute to serum amyloid associated (AA) protein production.

Alzheimer’s causes localised amyloid deposition know as amyloid angiopathy

Diabetes mellitus type 2 causes localised Islet cell amyloid deposition

Plasmacytoma (multiple myeloma) causes Light chain (AL) amyloid production

Medullary thyroid carcinomas cause local amyloid production in their stroma

Question 8

Phaeochromocytoma shows increased levels of ……… in the urine. Whereas a congenital Neuroblastoma of the adrenal gland would more likely show …….. in the Urine

Answer 8

They both show catecholamines in the Urine but:

Phaeochromocytoma shows more : VMA
Neuroblastoma shows more: HMA

HMA is a more mature metabolite of epinephrine (adrenaline) than VMA is and has a better prognosis.

Question 9

What are 3 causes of metabolic alkalosis

Answer 9

H+ loss (eg vomiting)
Hypokalaemia
Ingestion of bicarbonate

Question 10

List causes of hypokalaemic alkalosis

Answer 10

Intestinal loss 
- diarrhoea
- vomiting
- fistula
Renal loss
- mineralocorticoid excess
- diuretics
- renal tubular disease
Redistribution
- Insulin (drives potassium into cells)
- Alkalosis 
- Beta agonists

Question 11

What is the link between hypokalaemia and alkalosis

Answer 11

low K+
shifts H+ ions into cells
causing extracellular alkalosis

Hypokalaemia causes alkalosis
And alkalosis causes hypokalemia

Question 12

Why can ectopic ACTH cause hypokalaemia

Answer 12

Causes such high levels of cortisol that they start binding aldosterone receptors