Diagnosing diabetes

Question 1

How is blood collected for a full blood count?

Answer 1

Venipuncture

Purple-top EDTA vacutainer

Question 2

Where is the sample of blood sent?

Answer 2

Haematology laboratory

Question 3

What is a FBC commonly used for?

Answer 3

Detect anaemia

Monitor infection

Diagnose and monitor haematological conditions like malignancies

Question 4

What test can be done on FBC to diagnose diabetes?

Answer 4

Blood test for glycated haemoglobin

Question 5

When is a FBC to monitor glycated haemoglobin levels ordered?

Answer 5

If the urine test detects that glucose is present

A blood test for glycated haemoglobin can be used to confirm diagnosis

Question 6

What sample is used to diagnose diabetes?

Answer 6

1 ml venous blood collected in an EDTA container

Question 7

What is the advantage of glycated haemoglobin testing?

Answer 7

Does not require fasting or special preparation like the glucose tolerance test

Can be carried out at any time of the day

Question 8

What does the glycated haemoglobin concentration show?

Answer 8

A proportion of glucose in the blood binds to haemoglobin, to produce a form of glycated haemoglobin called Haemoglobin A1c

The amount of HbA1c formed is directly related to the average concentration of glucose in the bloodstream

Question 9

What amount of time does the HbA1c reflect the glucose concentration in HbA1c reflect?

Answer 9

Shows the average concentration of glucose over period of 2-3 months

Since RBCs circulate for 2-03 months

Question 10

What machine measures HbA1c levels?

Answer 10

Machine that automatically conducts boronate affinity high-performance liquid chromatography

HPLC separates components in a mixture such as blood allowing the identification and quantification of various components

Test is very fast - 90s per sample throughput

Question 11

Which lab conducts HbA1c level measurements?

Answer 11

Clinical biochemistry labs

Question 12

Why are HbA1c levels reflected as a percentage?

Answer 12

Identifies the proportion of glucose attaching to RBC

Question 13

Procedure of measuring HbA1c levels using an automated analyser

Answer 13

Sample is haemolysed and pumped through a column filled with an adsorbent material

The components of a solution

• have different affinities for binding the column material
• have different flow rates through it

Glycated haemoglobin binds preferentially to the material of the column

Non-glycated components pass through

Elution buffer is injected into the column to displace the bound glycated component

The concentration of glycated component is read by spectrophotometric detector

The analyser automatically calculates the concentration of HbA1c based on the spectrophotometric readings

Question 14

What are the concentration of HbA1c used for?

Answer 14

Diagnosis

Monitoring

Question 15

How can HbA1c levels be used to monitor diabetic patients?

Answer 15

Monitor how well a diabetic patient is at controlling their blood glucose levels

Question 16

How often should diabetic patients measure their HbA1c levels?

Answer 16

Diabetic patients are recommended to have their HbA1c levels checked twice a year

More frequent testing required for

• newly-diagnosed diabetics
• blood glucose levels are persistently high
• patient’s treatment plan is changed

Question 17

Why is it important to monitor blood glucose levels?

Answer 17

Poor control of blood glucose can lead to numerous complications