Laboratory Tests in DM

Question 1

What is the purpose of laboratory tests in DM?

Answer 1

Diagnosis
Monitoring
Prognosis
Screening

Question 2

What is the diagnostic test for DM?

Answer 2

Random venous plasma glucose >11.1mmol/L
Fasting plasma glucose
HbA1-c > 48mmol/mol

Question 3

What does HbA1-c measure?

Answer 3

Glycosylated haemoglobin

Question 4

What to be tested in acute DM?

Answer 4

Urine testing
glyosuria
Ketonuria
Glucose meter

Question 5

13 year old female with known type 1 diabetes mellitus admitted to A&E because of drowsiness and vomiting.

POCT Testing - A Point of Care finger prick test in A&E showed blood glucose of 20 mmol/L.
The FY2 was going to give her some more insulin but decided to confirm the result by sending a blood sample to the lab.
¬ The Lab result was returned at 1.8 mmol/L.
¬ Why are the results different?

A) Laboratory error
B) Contamination when checking POC glucose
C) Blood sample mislabelled
D) POC glucose meter malfunction

Answer 5

Contamination when checking POC

Question 6

¬ 21 year old student - thirst, polyuria and weight loss over the last two months; became unwell with flu-like symptoms and began vomiting.
¬ Urinalysis-
Glucose ++++
Ketones ++
¬ Dehydrated, tachypnoeic and generalised abdominal tenderness, admitted to the surgical ward on 40% O2
What is the most likely diagnosis?

A) Acute pancreatitis
B) Diabetic ketoacidosis
C) Hyperosmolar hyperglycaemic state
D) Addison’s Disease

Answer 6

Diabetic ketoacidosis

Question 7

What cleaves of proinsulin to created the active form of insulin?

Answer 7

C-peptide

Question 8

What is elevated C-peptide levels indicative of?

Answer 8

Insulinoma

Insulin secreting tumour

Question 9

What is HbA1c an indication of?

Answer 9

Glycaemic control

Question 10

• 64 year old lady with Type 2 DM
• HbA1c 30mmol/mol (37mmol/mol five months previously).
- Quite low remember diagnosis is 48 mmol/mol
• Home blood glucose monitoring – glucose results consistently 17-18mmol/L
• LFTs:

          ALT           		65 IU/L    (<45)
          BILIRUBIN          	45umol/L  (<22)
          ALK PHOS  	72 IU/L    (25-110)

Most Likely Explanation?

A) Glucose meter malfunction
B) Haemolytic anaemia
C) Laboratory error
D) Poor glucose meter technique

Answer 10

Haemolytic anaemia

Excess red blood cells have created an increase in bilirubin which is a breakdown product of haem

Question 11

Why do lipid need to be screened in chronic diabetes?

Answer 11

Due to macrovascular risk factors